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Benthic Assemblages in South American Intertidal Rocky Shores: Biodiversity, Services, and Threats

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Marine Benthos: Biology, Ecosystem Functions and Environmental Impact is a book dedicated to show a series of case studies about how benthic habitats are organized and how they function as a tool for any environmental impact studies. The present book documents how the natural condition of these communities is and aims to expand our present knowledge about their organization. The human population growth is driving a very strong pressure over coastal areas, and now more than ever we urgently need elements to evaluate environmental impacts. One of the most striking situations is the loss of biodiversity and the increase of invasive species who modify the trophic networks as well as the community structure. Many endangered species and species related to fisheries depend on the benthic habitat for their basic life cycle stages (reproduction, recruitment, nursery and feeding grounds) who might be impacted by natural and human induced causes. Ranging from species richness studies to population and community structure chapters, this book will bring the reader many options on how to measure environmental impacts. In particular, an analysis of how these environmental studies are made in Mexico provided a good example of how the present report base model is overdue and expresses the need for another approach. Keep in mind the present model does not take into account any statistical approach and is not mandatory in terms of the synergic and accumulative impacts; the lack of this consistency makes evaluation impossible to tell if the impacts are really happening.
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BENTHIC ASSEMBLAGES IN SOUTH AMERICAN
INTERTIDAL ROCKY SHORES:
BIODIVERSITY, SERVICES, AND THREATS
Patricia Miloslavich
1,2
, Juan José Cruz-Motta,
1,3
,
Alejandra Hernández
1,4
, César Herrera
1
,
Eduardo Klein
1
, Francisco Barros
5
,
Gregorio Bigatti
6
, Maritza Cárdenas
7
,
Alvar Carranza
8
, Augusto Flores
9
,
Patricia Gil
10
, Judith Gobin
11
,
Jorge Gutiérrez
12
, Marcos Krull
5
,
Juan F. Lazarus
13
, Edgardo Londoño
13
,
Tito Lotufo
9
, Erasmo Macaya
14
,
Elba Mora
15
, Sergio Navarrete
16
,
Gabriela Palomo
17
, Mirtala Parragué
16
,
Franciane Pellizzari
18
, Rosana Rocha
19
,
Leonardo Romero
20
, Roberto Retamales
21
,
Roger Sepúlveda
22
, Michelle C. Silva
18
and Sabrina Soria
17
1
Universidad Simón Bolívar, Caracas, Venezuela
2
Australian Institute of Marine Science, Townsville, Australia
3
University of Puerto Rico, Mayaguez, Puerto Rico
4
James Cook University, Queensland, Australia
5
Universidade Federal da Bahia, Salvador, Brazil
6
Centro Nacional Patagónico, Chubut, Argentina
7
Bioelite and Universidad de Especialidades Espíritu Santo,
Samborondón, Ecuador
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
2
8
Museo Nacional de Historia Natural de Uruguay,
Centro Universitario Regional Este, Uruguay
9
Universidad de Sao Paulo, Sao Paulo, Brazil
10
Universidad Nacional Agraria La Molina, Lima, Peru
11
University of the West Indies, Trinidad and Tobago
12
Universidad Nacional de Mar del Plata,
Buenos Aires, Argentina
13
Universidad del Valle, Cali, Colombia
14
Universidad de Concepción, Chile
15
Universidad de Guayaquil, Guayaquil, Ecuador
16
Pontifica Universidad Católica de Chile, Santiago, Chile
17
Museo Argentino de Ciencias Naturales Bernardo Rivadavia,
Buenos Aires, Argentina
18
Universidade Estadual do Paraná, Paranavaí, Brazil
19
Universidade Federal do Paraná, Curitiba, Brazil
20
Universidad Nacional Mayor de San Marcos, Lima, Peru
21
Universidad Técnica de Manabí, Portoviejo, Ecuador
22
Universidad Austral de Chile, Valdivia, Chile
ABSTRACT
Rocky shores are areas of high diversity and productivity providing goods and services.
Since humans are altering nature at an unprecedented rate, producing shifts in important
parameters for life such as temperature, habitat availability, water quality, among others, it is
expected that species will respond by changing their natural distributions and/or abundances. To
understand how species will respond to such changes, it is necessary to learn the processes that
determine these patterns. The South American Research Group on Coastal Ecosystems was
established to assess marine diversity and biomass along both coasts of South America through an
international collaboration. The main goals of SARCE are to: (1) Test hypotheses about latitudinal
gradients and patterns of local and regional biodiversity, (2) Identify the relationship between
biodiversity and ecosystem functioning, (3) Assess the effect of environmental gradients and
anthropogenic stressors, (4) Carry out capacity building and training activities aimed to solve
environmental problems for the benefit of society. The SARCE network has sampled the coasts of
nine countries around South America with a standardized protocol in more than 150 sites (2010-
2014), ranging from 11º North to 55º South. This chapter provides a description of the biodiversity
of the sites sampled by SARCE, along with a review of the uses and services that these
ecosystems provide to human populations and the main threats and impacts these uses have
caused.
INTRODUCTION
Biodiversity has been a subject of interest for many decades by scientists and
conservationists. More recently, other groups such as managers, government agencies and
industries have also been involved in establishing its ecological and economical value, as well
as the consequences of its loss. Up to date, an important number of papers have attempted to
identify the importance of biodiversity for ecosystem functioning (Loreau et al. 2001,
Pachepsky et al. 2001, Cardinale et al. 2002, Pfisterer & Schmidt 2002, Gessner et al. 2004)
Benthic Assemblages in South American Intertidal Rocky Shores
3
and the processes by which any diversity loss will be negatively reflected in the number and
quality of services that a particular system might provide (Balvanera et al, 2006; Cardinal et
al, 2006, O´Connor et al., 2006).
Coastal marine ecosystems have a very high biodiversity (Ray 1996). Within these, the
macroalgal habitats rank among the highest along with coral reefs and seagrass communities,
due to the fact that they are dominated by bio-engineering organisms that build three-
dimensional structures, providing substrate, food and habitat complexity, which ultimately
increases species richness (van Oppen et al. 1996, Phillips 1997, Walker & Kendrick 1998,
Wysor et al. 2000, Duarte 2000, Engelhardt & Ritchie 2001, Duffy et al. 2001, Sommerfield
et al. 2002, Bulleri et al. 2002). On the other hand, due to their particular location (i.e. land-
sea interface) these coastal areas are also severely impacted by human activities such as
fisheries overexploitation, alteration of the physical environment, pollution, introduction of
alien or invasive species and recreational activities, all of which have inevitably impoverished
marine biodiversity (Beatley 1991, Norse 1993, Gray et al., 1997, Walker & Kendrick 1998,
Cury 1999, Bax et al. 2001, Tilman & Lehman 2001, Piazzi et al. 2001, Barnes 2002).
In this sense, the study of biodiversity is crucial for the sustainable use of coastal
resources (Gray 1997), especially in Marine Protected Areas (Ray 1985, Olsen 1999, Ward et
al. 1999). Biodiversity has been measured at many different levels and scales and by different
methods (France & Rigg 1998). This has made comparisons difficult, so a unified approach to
study biodiversity at a global scale was much needed (Rabb & Sullivan 1995, Valero et al.
1998, Mikkelsen & Cracraft 2001). As a response to this need, the NaGISA project (Natural
Geography in Shore Areas: www.nagisa.coml.org) of the Census of Marine Life program
(CoML: www.coml.org) provided the necessary framework to study biodiversity in rocky
shores at a global scale. The NaGISA project was a collaborative effort aimed at inventorying
and monitoring habitat specific biodiversity with a standard protocol in coastal marine areas
at a global scale (Konar et al. 2010). Thanks to NaGISA (2003-2010), the first global baseline
of nearshore biodiversity was initiated [see: Diversity in the Nearshore: The NaGISA
Collection (2010) PLoS Collections: http://dx.doi.org/10.1371/issue.pcol.v01.i06], and in
South America, it has continued through the South American Research Group on Coastal
Ecosystems network (SARCE). This network was established to assess marine diversity and
biomass along the Pacific and Atlantic (including the Caribbean) coasts of South America
through an international collaboration. The main goals of SARCE are to: (1) Test hypotheses
about latitudinal gradients and patterns of local and regional biodiversity, (2) Identify the
relationship between biodiversity and ecosystem functioning, (3) Assess the effect of
environmental gradients and anthropogenic stressors, (4) Carry out capacity building and
training activities aimed to solve environmental problems for societal benefit. The SARCE
network includes more than 30 researchers from 9 South American coastal countries and has
sampled with a standardized protocol in more than 150 sites around the continent (Figure 1).
In this chapter we provide a description of the biodiversity of the sites sampled with the
SARCE protocol (http://sarce.cbm.usb.ve/for-scientists/), along with a review of the uses and
services that these ecosystems provide to human populations and the main threats and impacts
these uses have caused.
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
4
Figure 1. Map of South America showing the localities sampled by the SARCE network
(South American Research Group in Coastal Ecosystems) in the Caribbean Sea, and in the
Atlantic and Pacific oceans.
The intertidal rocky shores in South
America: main features and associated biodiversity
THE CARIBBEAN
COLOMBIA
The Caribbean coastline of Colombia has an extension of 1760 km, of which 25%
are rocky shores (Posada & Henao 2008), mainly composed by unstable shores highly
affected by wave action and coastal erosion. Most of these shores have steep slopes and in the
areas where the platform occurs can harbor rich and abundant macro-algal communities
(Garcia & Diaz-Pulido 2006). The tide range is 0.5 m due to this is common to find in small
areas a mixture of organisms that belongs to different intertidal levels (high, mid and low
tide), factors as wave action, substrate type and slope, determine the community composition
(Lopez-Victoria et al. 2004). Due to the small tidal range only high and low tide levels can be
easily differentiated. According to Lopez-Victoria et al. (2004) the rocky shore can be divided
into two types of rocks, cohesive or non-cohesive, each having a particular associated
community (algae and macroinvertebrates). The first type of rocks is stable, hard and with
low erosion rates, with a high rate of colonization and a well developed community with
advanced succession stages. The second type of rocks is unstable, the shores are highly
affected by wave action, and therefore, species diversity and richness is lower, and the
community cannot reach advanced succession stages. The climate presents two main periods:
dry and rainy seasons with a transition season in between. The sea surface temperature and
Benthic Assemblages in South American Intertidal Rocky Shores
5
salinity during the dry and rainy seasons vary between 25.5-27.5ºC / 35.6-37 ppt and 27-
29.5ºC / 34.5-36.5 ppt respectively. The waves are higher during the dry season (1.5 to 2.5 m)
in relation to the rainy season (0.5 to 1.4 m) (Posada & Henao 2008). An upwelling system is
present from December to March in the north coast and the sea surface temperature can drop
below 20ºC.
In the Colombian Caribbean, the SARCE project sampled in 15 sites within two
localities: Santa Marta and Darien. In Santa Marta (Figure 2A), the rocky shore is dominated
by cliffs (metamorphic schist rocks), with different size boulders at the base that gives
complexity to the shore and offers a variety of habitats that can be exploited by intertidal
organisms. The cliffs are part of the Sierra Nevada de Santa Marta system that branches down
to the sea. Due to the upwelling, there is a major change in algae composition, species of
Sargassum can reach a meter in length and other algae species grow and cover most of the
rocky substrate. Along the different sites of the Santa Marta bay, the geology varies from
cliffs that continue as rocky shores with boulders in the north (Punta Verde) which are highly
exposed to wave action, to rocky platforms between 5 to 10 m wide in the south (Playaca).
The most abundant invertebrate species in the high intertidal in the north are Nerita versicolor
and Littorina sp, while the low intertidal is dominated by coralline algae, by Palisada
perforata, Zoanthus pulchellus and Hypnea musciformis, and the invertebrates Echinometra
lucunter and Isognomon bicolor. In the south, the high intertidal is mostly rock; with some
areas with filamentous algae. The most abundant macroinvertebrate species are Plicopurpura
patula, I. bicolor and Dendropoma sp. In the low intertidal, dominant species are coralline
and filamentous algae along with Laurencia obtuse, E. lucunter, I. bicolor, Spirobranchus
giganteus and Balanus sp. The low intertidal is also covered by the canopy of large
Sargassum. The east side of the bay (Playa Grande) is characterized by a rocky platform
covered by a thin layer of vermetids. Here, the high intertidal is mostly rock with some areas
covered by filamentous algae, the dominant macroinvertebrate species being N. tesellata and
Brachidontes domingensis. In the low intertidal, dominant species are the macroalgae
Acanthophora spicifera, Dictyopteris deliculata and Neoralfsia expansa and the invertebrates
Dendropoma sp. and I. bicolor. Other localities sampled in the Santa Marta region were Inka
Inka, Puerto Luz, and Aeropuerto. The first two were rocky platforms, while the third was an
exposed sandy beach with flat rocks that may be periodically covered by sand due to wave
action. In these, the high intertidal was dominated by N. tesellata, P. patula, Echinolittorina
ziczac (Inka Inka); E. ziczac, E. angustior and P. patula (Puerto Luz); and E. interrupta, E.
angustior and Chthamalus sp. (Aeropuerto). The low intertidal was dominated by coralline
algae, vermetids, filamentous algae, E. lucunter, I. bicolor, Mitrella ocellata, Sargassum
(Inka Inka), A. spicifera, L. obtuse, filamentous algae, Dendropoma sp., E. lucunter, I. bicolor
(Puerto Luz), and A. spicifera, Lyngbya sp., coralline algae, Centroceras sp., B. domingensis,
Fissurella nimbosa, Stramonita haemastoma (Aeropuerto).
The locality of Darien is located west of the Uraba Gulf, where mangroves and soft
bottoms dominate the landscape; the sediments and nutrients are brought by the Atrato River,
one of the largest rivers in the Atlantic basin of Colombia. Tropical rainy forest is the most
common type of vegetation; however, grasses for cattle growth have replaced large
extensions of this forest. In this region, the volcanic rock shore is located north of the delta of
River Atrato, followed by large sandy beaches and abrasion platforms of coralline origin
towards the Panama border. This area has little urban development and human settlements are
small, there are no roads and the main way of transportation is by boats and most of the
settlements are located on the coast. The Darien was sampled in the Trigana area which is
located north to the Atrato River delta, with a rocky shore of volcanic origin, interrupted by
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
6
sandy beaches, and with several small islands in front of the coast. The intertidal in this area
is affected by freshwater runoff. The sites ampled were Isla Napú, an islet with a narrow
rocky platform that falls to the sea reaching a maximum of 2 m depth in the surrounding
areas; Trigana, a platform 10 m wide; Titumate, an islet with a soft slope and shallow sandy
bottom (< 1 m) and sea grasses; Capurgana, located in the northwest part of the Uraba Gulf
with a rocky shore composed by abrasion platforms of coralline origin; Sapzurro, a bay close
to the Panama border, with a soft slope shore and an abrasion platform of coralline origin; and
Isla Narza, an islet of volcanic origin in front of Capurgana village, the shore consisting of a
cliff in the exposed side and boulders in the sheltered side. In these sites, the high intertidal
was dominated by E. angustior, E. ziczac and E. interrupta (Napu), E. angustior and S.
rustica (Trigana), E. angustior, B. domingensis and N. tesellata (Titumate), and E. angustior
(Sapzurro and Isla Narza). The low intertidal is dominated by L. obtusa, Pterocladiella
capillacea, Lyngbia sp., Gracilaria domingensis, Centroceras sp., the barnacles Chthamalus
sp. and Balanus sp. which form a complex with vermetids (Napu); filamentous and coralline
algae, S. serratum, Centroceras sp., L. obtuse, G. domingensis, Chthamalus sp., S. rustica
(Trigana); S. serratum, L. obtuse, Centroceras sp., Chthamalus sp., S. rustica (Titumate); L.
obtuse, coralline algae, E. lucunter, Cittarium pica (Sapzurro), and coralline and filamentous
algae, E. lucunter, Ceratozona squalida, and Chiton squamosus (Isla Narza).
VENEZUELA
Rocky shores along the 3964 km of the Venezuelan coastline are very heterogeneous in
terms of their geological composition and structure (Miloslavich et al., 2005). Due to small
tidal ranges in the southern Caribbean (20-30 centimeters) (Torres and Tsimplis, 2012)
Venezuelan rocky shores have been described considering only two levels or strata: high
intertidal and low intertidal. The low intertidal is constantly under wave action whereas, the
high intertidal is washed rarely by waves, only recei
Venezuelan rocky shores, gaps openings and/or depressions in the substrate of only few
centimeters of depth can generate zones that remain submerged most of the year. These
habitats, henceforth called substrates depressions, are located between the high and the low
intertidal on platform rocky shores and their species composition is completely different to
            
o rock pools or tide pools.
Characteristics of rocky shores are very heterogeneous and respond to the
geomorphology of the different regions of the Venezuelan coast. In the Western coast, from
the Paraguana Peninsula to Patanemo, rocky shores are emerging platforms and are composed
of limestone rocks (Figure 2B). The Central coast, from Ocumare to Chirimena (Figure 2C),
is characterized by narrow rocky stripes formed by sandstones and conglomerates. Sites
sampled on the mainland of the Eastern coast, from Santa Fe to La Pared (Figure 2D), had a
very steep slope, whereas those sampled in the insular region were emerging horizontal rocky
platforms. Nevertheless, 
the platforms are narrow (3-10 meters), except for San Juan de los Cayos platforms that are
between 60 to 120 meters wide. The length of platforms is highly variable. In the western
region, they can reach few kilometers, whereas in the central coasts they do not surpass
hundreds or tens of meters (Kennedy et al., 2014; Ellenberg, 2010).
Benthic Assemblages in South American Intertidal Rocky Shores
7
Figure 2. Sampling sites in the Caribbean. A. Colombia Taganaga, Santa Marta. B.
Venezuela - Cabo San Román, West Coast. C. Venezuela Chuspa, Central Coast. D.
Venezuela Mochima, East Coast.
Estimates of rugosity were moderately high for both strata: 0.809 ± 0.002 and 0.745 ±
0.003 for low and high intertidal, respectively. The rock's irregularities form microhabitats
that are used by some organisms like whelks, crabs, limpets and snails that protect them from
desiccation and high temperatures during low tides, which in turns contribute to the high
diversity reported for the Southern Caribbean. Crevices, scars and holes over the rocky
substrate are due to erosion of wind and wave, as well as to the activity of some organism
such as the sea urchin Echinometra sp. (Bak, 1994).
Despite a small tidal amplitude (Torres and Tsimplis, 2012), desiccation levels can vary
significantly due to the effect of wind. Northern Trade winds blow on Venezuelan coasts
intensively between December and June, increasing intensity and height wave, and
consequently decreasing exposition levels. Besides, trade winds are responsible of annual
upwelling, between January and May, in different zones of Venezuelan coast (Castellanos et
al., 2002; Muller-Karger, 2004); which has been reported to enhance algae growth and
increase the production of herbivores in rocky shores (Wieters, 2005; Bosman et al., 1987).
This has not been tested for the Venezuelan Coast, however, the only study done (western
region, Peninsula de Paraguna) found no correlation between Sea Surface temperature
Changes generated by upwelling and changes in the structure of assemblages associated with
rocky shores (Herrera unpublished data).
Like many rocky shores in the continent and the world, assemblages living in Venezuelan
rocky shores are mainly composed of seaweeds and small mollusks. The most common
seaweeds belong to phylum Rhodophyta, being genera such as Laurencia and Polysiphonia
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
8
the most abundant. Also, algae of phylum Chlorophyta (mainly Ulva spp.) and Ochrophyta
(mainly Sargassum spp) can be widely found. The species complex made of crustose
coralline algae (commonly named CCA) was present in almost all sampled sites. It is very
likely that the species composition of these complexes change among zones, sites, regions
and strata; but identification of species of crustose coralline algae in the field is not possible.
This complex was present as primary cover usually below corticated, articulated and foliose
algae, as well as secondary cover on top of sessile and mobile animals. The most common
mollusks living in Venezuelan rocky shores were snails, limpets, whelks, key-hole limpets
and chitons.
The dominant functional groups in Venezuela were primary producers (macroalgae),
small herbivores (gastropods and chitons), large herbivores (sea urchins and crabs), filter
feeders (bivalves and barnacles) and predators (mainly the gastropods Plicopurpura patula,
Stramonita and Vasula species; and octopuses). In the southern Caribbean, unlike other rocky
shores, the dominant echinoderm was not a sea star but the sea urchin Echinometra lucunter.
It has been proposed (but not tested) that E. lucunter plays a key role in structuring these
assemblages due to its high densities, high herbivory rates and bio-erosive activity. Another
peculiarity of Venezuelan rocky shores is the low density of barnacles in the intertidal. In
Venezuela, they are only present in the central and western coast, usually associated to rock-
walls, cliffs and artificial structures.
Continuous monitoring of assemblages associated with rocky shores in Venezuela has
shown that they vary importantly at different temporal and spatial scales, and between strata.
For example, during the rainy season, conspicuous changes occur due to massive algae cover
decrease, and the composition is dominated by opportunistic species such as Ulva, Dictyota,
Padina and Chaetomorpha. Also, from a spatial point of view and despite large variation at
small spatial scales (10s to 100s meters), important differences can be detected among regions
(e.g. presence of barnacles only in central and western coast).
Intertidal rocky shores of Venezuela are part of the highly diverse coastal ecosystems of

sampled, detecting a total of 217 species in total: 85 marine algae (40 Rodophyta, 20
Chlorophyta, 18 Ochrophyta, 5 Cyanobacteria, 2 seaweeds not identified), 89 molluscs (66
Gastropoda, 17 Bivalvia, 6 Polyplacophora), 21 cnidarians (17 Anthozoa, 4 Hydrozoa), 8
arthropods (5 Malacostraca, 3 Maxillopoda), 5 echinoderms (2 Echinoidea, 2 Ophiuroidea, 1
Holothuroidea), 5 marine sponges (Demospongie), 3 ascidia (Ascidiacea) and 1 seagrass
(Tracheophyta).
In the high intertidal of Venezuelan rocky shores, algae presence was uncommon; and
when they were, these usually were crustose calcified algae CCA and
Pseudolithoderma extensum, or filamentous algae such as Lyngbya spp. and Bostrychia
tenella. Mobile species were represented mostly by small herbivores mollusks such as Nerita
versicolor, Nerita peloronta, Nerita tessellata, Echinolittorina ziczac, Echinolittorina
interrupta, Acanthopleura granulata, Echinolittorina angustior, Cechritis muricatus,
Tectarius antonii and Acmaea and Siphonaria species. Carnivorous mollusks (i.e.
Plicopurpura patula) were also present but were not as abundant as herbivores species.
Assemblages in the high intertidal were highly dominated by few species, especially by
Littorinids that commonly had abundances between thousands and tens of thousands of
individuals per square meter. Neritidae species were not as abundant, but densities could
reach hundreds per square meter. In crevices and gaps, bivalves belonging to genus
Brachidontes and Isognomon, were found in low densities. Sessile mollusks of the family
Vermetidae were also occasionally found in very dense patches with abundances ranging
between the tens and hundreds of individuals per square meter.
Benthic Assemblages in South American Intertidal Rocky Shores
9
Assemblages in depressions or mid platforms shallow lagoons were dominated by
corticated foliose algae such as Dictyota and Padina, articulated calcareous algae such as
Halimeda opuntia, foliose calcareous algae such as Udotea sp and Penicillus sp, and the
foliose algae Ulva spp. Because these environments are constantly covered by water,
cnidarians belonging to genus Zoanthus and Palythoa were commonly found. Principal
mobile organisms in these microhabitats were small fishes belonging to Gobiidae family and
hermits crabs. These two groups, however, were not considered in this study. These habitats
are constantly submerged by water that is constantly being replaced, but due to their shallow
characteristics, temperature is usually few degrees above normal Sea Surface temperature.
Consequently, substrate tends to be dominated by one or two of the species mentioned above.
The low intertidal of Venezuelan rocky shores was dominated by macroalgae, mollusks
and sea urchins; whereas some cnidarians and other echinoderms (sea cucumbers and brittle
stars) were found occasionally. The most abundant and commonly found algae in all sampled
sites, were the crustose calcified algae comples CCA and P. extensum, the corticated
corticated algae Laurencia obtusa, Laurencia papillosa and Gelidiella acerosa, the
filamentous algae Polysiphonia atlantica, the leathery macrophyte Sargassum spp, and
filamentous microalgae Lyngbya spp. Few species, as the opportunistic green foliose algae
Ulva spp, the green filamentous algae Chaetomorpha spp, and cnidarians Palythoa and
Zoanthus were not commonly seen in all sites; but when they were present, they occupied an
important proportion of the primary and secondary substrata. The most abundant mobile
species in the low intertidal were herbivores E. lucunter, Chiton squamosus and Fissurella
spp, as well as carnivores Stramonita rustica, P. patula and Vasula deltoidea. The carnivore
gastropod P. patula has its highest densities in the high intertidal (very close to the transition
between the high and the mid), however it is present in the low intertidal as well. The sea
urchin E. lucunter was commonly found in almost all the sites sampled, reaching densities of
up to 72 ind/m
2
. It is likely that E. lucunter plays a key role as the principal herbivorous on
Venzuelan rocky shores, but this conceptual model has not yet been tested. Other large
herbivores such as the gastropods Cittarium pica and Astraea spp, are found in low densities
and small sizes, very likely due to the pressure of artisanal fishermen.
TRINIDAD & TOBAGO
Trinidad and Tobago is a twin-island state located on the continental shelf of north
eastern South America. Trinidad is approximately 12 kilometers from the mainland while
Tobago is 30 kilometers North East of Trinidad. Trinidad is the most southerly of the
Caribbean islands. The continental origin of the islands is reflected in the similarity of
terrestrial fauna and flora. The coastal areas of Trinidad and Tobago are largely comprised of
sedimentary rocks. The north coast however is comprised of non-sedimentary rock with low
grade metamorphic and small areas of volcanic rock (Georges, 1983). The geomorphology is
generally of gently sloping beaches and cliffs. Current flow around Trinidad and Tobago is
driven by the South Equatorial current coming north from South America. The current splits
with movement to the west entering the Gulf of Paria and to the east moving and merging
with the Atlantic Ocean.
Prior to the NAGISA project (2005), the intertidal rocky shores of Trinidad and
Tobago had not been studied in any detail. The sites sampled with the SARCE project are on
the north-east coast (Saybia, Toco) and the north coast (Maracas Bay). In the north-east coast
location (Saybia, Toco there is a fringing reef which offers some protection although there is
a strong westerly longshore current. In the north coast (Maracas Bay) area there are generally
strong offshore winds and a strong longshore current, although some protection is offered by
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
10
the headlands. The mean tidal range in Trinidad and Tobago is around 1.2m and is semi-
diurnal with a high and low every 12hrs.
The biodiversity associated with the intertidal sites typically included the common
groups: macroalgae (green, red, and brown), bivalves (Isognomon sp. the most common but
only found at Salybia and Toco Bay), gastropods (Littorina sp. the most common),
polyplacophorans, crustaceans (barnacles found at all sites except Las Cuevas), and tunicates.
The red algae, mostly Heterosiphonia were the most dominant species, while brown algae
were least dominant, and Chaetomorpha sp. was the most common green algae (found at
Maracas and Blanchisseuse). Coralline algae were well represented at all sites except for
Salybia. There were greater numbers of species of soft corals (22) as opposed to soft corals
(2), all of which were found in Salybia and Toco Bay, sites nearby to coral reef systems.
THE ATLANTIC
BRAZIL
The Northeast: Ceara
The Ceará state coastline is dominated by long sand beaches, interrupted
occasionally by beachrock reefs (Aquasis, 2003). The beachrocks have a more recent origin,
and are composed by sand, shell fragments and pebbles cemented by calcium carbonate and
iron oxide (Smith and Morais, 1984). These reefs are generally tabular, of variable extension
and sloping gently towards the sea. The coastline is more E-W oriented, along typically
equatorial latitudes. The climate is typically semi-arid, ruled by the intertropical convergence
zone, with 2 seasons characterized by the pluviometry: a rainy season from January to June,
and a dry season from July to December (IPECE, 2013). The coast is washed by the North
Brazil current, running from E to W, following the strong trade winds that are characteristic
for the region (Aquasis, 2003). The North Brazil current water mass is considered
oligotrophic, with temperatures varying little around 26ºC and salinity around 36 (NOAA,
2014). The constant trade wind regime blowing from E-SE with 6.4 m.s-1 on average,
reaching more than 10 m.s-1 during the dry season (Jimenez et al., 1999). Wind waves are
permanently splashing over the reefs, sometimes combined with swell waves, ranging from
1.8 to 3.6 m in height (Aquasis, 2003). The tidal regime is typically semidiurnal, with a mean
spring tidal range of 3.3 m, and mean neap tidal range of 1.2 m.
The beachrock reefs of Ceara host a very diverse community which is still poorly
studied. The rocky intertidal shows a typical biodiversity zonation from the supralittoral to the
subtidal zones. The supralittoral fringe is barely colonized, and the dominant species is
Echinolittorina lineolata, a small mobile gastropod that fits into minute crevices avoiding
extreme desiccation. The same species is also abundant in the high intertidal, but the space is
occupied now by barnacles, especially Chthamalus proteus and patches of the green algae
Ulva fasciata. The association of these two species characterizes the whole upper littoral
zone, which is considerably poor in terms of species richness. The mid littoral zone is more
diverse and the dominant species may vary at different locations. In Caucaia (Figure 3A),
near urban capital Fortaleza, there is a belt of the bivalve Brachidontes exustus at the higher
portion of the upper littoral zone, and a continuum of large colonies of the polychaete
Phragmatopoma caudate is also present. The dominant algae species are Chondracanthus
acicularis, Gelidiella acerosa, and Hypnea musciformis. Other dominant species are C.
Benthic Assemblages in South American Intertidal Rocky Shores
11
proteus and U. fasciata, which are still abundant in the lower littoral zone. In Trairi, there is
not a conspicuous band of B. exustus, and the mid littoral zone is then dominated by U.
fasciata, Pterocladiella caerulescens and Laurencia papillosa. Large colonies of P. caudata
are present, and the zoanthid Palythoa grandiflora also covers large areas of this zone. The
mobile fauna present in the mid littoral zone is mainly composed of crabs, especially
Pachygrapsus transversus, hermit crabs, such as Clibanarius antillensis and Calcinus tibicen
(Herbst, 1791). The lower littoral zone is the most diverse, and fully dominated by algae. The
most abundant species vary by location and site. In Caucaia, the most common species are
Centroceras clavulatum, C. acicularis, and U. fasciata, while in Trairi the dominant species
are P. caerulescens, Gracillaria spp., Amansia multifida, and crustose coralline algae. The
mobile fauna at the lower littoral zone is also more diverse and includes the species
mentioned for the mid littoral zone plus the gastropods Stramonita haemastoma and Tegula
viridula (Gmelin, 1791). Recent surveys of the whole littoral zone detected a total of 110
species for Caucaia and 103 for Trairi. Most species are shared by the two locations, but
Trairi is considerably more diverse in terms of sessile organisms (both animals and algae),
while Caucaia has more motile animals. In terms of composition, the most specious taxa, in
decreasing order, were: Rodophyta (45 spp.), Chlorophyta (18 spp.), Mollusca (18 spp.),
Ochrophyta (11 spp.), Crustacea (8 spp.), Porifera (7 spp.), Ascidiacea (7 spp.), Cnidaria (5
spp.), Polychaeta (3 spp.) and Echinodermata (2 spp.).
The data collected using the SARCE protocol for large and conspicuous organisms in
the intertidal shows that there is a considerable biodiversity along the beachrock reefs in
Ceará. There are about 130 species in total, the vast majority of them of algae, especially red
and green algae. There is also a tenable difference among locations and sites along this stretch
of coast, which highlights also a degree of beta diversity. It is worth mentioning that the
protocol favored the algae component of the intertidal community by accounting only for

out with different numbers. For instance, results form the PROBIO initiative in Ceará
indicated for the same area 109 species of algae, 53 species of Crustacea, 44 species of
Mollusca, 28 species of Ascidiacea, 24 species of Polychaeta, 22 species of Cnidaria, and 9
species of Echinodermata (Matthews-Cascon and Lotufo, 2006). Even these numbers are
underestimating the total diversity, because the effort was still punctual.
TheNortheast: Sergipe
Sergipe is the smallest Brazilian State, and the third shortest coast in extension (160
km). Located in the northeastern, it limits with the State of Alagoas in the north, and the State

two harbor complexes. Sergipe has no real rocky shores, but rather beaches with boulders and
rocky outcrops, and few areas with biolithic substrates (Pragmatopoma caudata). Beaches are
composed by fine sand, and the linear coast is fringed by esturies and mangroves, associated
with the rivers Real, Vaza-Barris, Sergipe and São Francisco.
The State has 47.3% of its territory 
secas (FAO). The climate is tropical, with the highest humidity by the coast and in semi-arid
backlands. The highest rainfall occurs between January and March.
In Sergipe, the SARCE project sampled, from south to north in three beaches: Praia
do Saco, Coroa do Meio, and Praia do Jatobá. A total of 106 taxa were found represented by
34 species of invertebrates, 66 of macroalgae, and 6 species of filamentous cyanobacteria.
The supralittoral zone is characterized mostly by bare bolders, which may be colonized by
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
12
periwinkle gastropods of the complex Echinolittorina ziczac, and filamentous cyanobacterias.
The high/medium intertidal, not always well zonated, contains a belt of the barnacle
Chthamalus bisinuatus and the mussel Brachidontes solisianus, usually fouled by the red
algae Bostrychia spp. and other filamentous red and green macroalgae. The low intertidal was
the most diverse characterized mainly by barnacles (Tetraclita stelifera), oysters (Crassostrea
rhizophorae), crab (Aratus pisonii), Lottia (Collisela) subrugosa, and mussels (Perna perna).
Regarding macroalgal assemblages, the biomass was dominated in general by filamentous,
leathery and terete functional groups. A total of 66 taxa were found: 41 Rhodophyta, 16
Chlorophyta and 9 Phaeophyceae, dominated by Rhodomelaceae (9 species), Ceramiaceae (5
species.), Corallinaceae, Cystocloniaceae, Cladophoraceae and Ulvaceae (4 species). The
most conspicuous species were Gayralia brasiliensis, Rhizoclonium riparium, Ulva flexuosa,
Sargassum platycarpum, Centroceras clavulatum, Gracilaria cervicornis, Jania adhaerens,
Hypnea valentiae, Solieria filiformis and Pterocladiella capillacea.
The Northeast: Bahia
In Bahia, rocky substrates are mainly biogenic and sandstone, but some granitic substrate
is also found. The SARCE project sampled five locations: Itacaré (Arruda, Corais, Figure 3B,
3C, 3D), Ilhéus (Backdoor, Praia do Sul), Itaparica (Penha, Mar Grande), Salvador (Stella
Maris), and Litoral Norte (Guarajuba, Itacimirim), Litoral Norte and Itacaré located within a
State marine protected area. Among these, Corais, Penha and Stella Maris are the only
sampling sites that are characterized by granitic substrate.
The total number of species found at these sites varied between 29 (Mar Grande) and 58
(Arruda). Macroalgal diversity at all sites was very high and dominated the assemblage. The
total number of macroalgal species varied between 18 (Mar Grande) to 46 (Arruda), with red
algae being the most speciose group, followed by green and brown algae. In the high
intertidal, the most abundant species were Brachidontes, Chthamalus, Lyngbya and Ulva
flexuosa. The mid intertidal was dominated by Ulva lactuca, Palisada perforata and
Gelidiela acerosa, but in general, P. perforata and G. acerosa were also abundant species in
this zone. The low intertidal was dominated by Sargassum, but Bryothamnion triquetrum and
Amphiroa anastomosans were also dominant species at Penha and Praia do Sul respectively.
The Southeast: Espírito Santo
Espirito Santo State is bordered by Minas Gerais, Bahia and Rio de Janeiro. Climate
is coastal humid tropical. Rainfall is highest during summer (1.000 mm and 1.500 mm/year),
and mean air temperatures are around 22°C and 24°C. The south coast is rocky, with
sandstone cliffs, and in the central coast, biolithic and granite formations can be found. The
south-central coast is very indented with coves and bays sheltered by rocky outcrops. The
coast is more indented in the center-south, and open sea to the north. The State comprises the
higher seaweed diversity and biomass in Brazil, been influenced by the South Atlantic Central
Water upwelling. The SARCE project sampled sites at the localities of Paraty, Ubu (Figure
3E), and Manguinhos.
A total of 183 taxa were found comprised by 48 invertebrate species and 131
macroalgae conspicuos taxa. The supralittoral zone is mostly bare but periwinkle gastropods
of the complex Echinolittorina ziczac, and the green filamentous algae Rhizoclonium may be
found. The high/mid intertidal, not always well zonated, contains a belt of the barnacle
Chthamalus sp., oysters (Crassostrea rhizophorae), the mussel Brachidontes solisianus, and a
Benthic Assemblages in South American Intertidal Rocky Shores
13
complex of the red algae Bostrychietum. The low intertidal was more diverse and
characterized by the barnacles Tetraclita stelifera, and Lottia (Collisela) subrugosa, muricid
gastropods, and Palithoa caribeorum. Regarding macroalgal assemblages, the biomass was
dominated in general by foliose, terete and calcareous (crustose and articulated) functional
groups. A total of 131 taxa were found: 69 Rhodophyta, 37 Chlorophyta and 25
Phaeophyceae. The most conspicuous species were Anadyomene stellata, Caulerpa spp.
(maily C. racemosa and C. cupressoides), Codium (mainly C. intertextum and C.
isthmocladum), Valonia aegragopila, Canistrocarpus cervicornis, Colpomenia sinuosa,
Dictyopteris delicatula, Dictyota menstrualis, Neoralfsia expansa, Padina
gymnospora, Sargassum cymosum, Arthrocardia flabellata, Dichotomaria marginata,
Gelidium spp., Hypnea spinella, H. valentiae, Jania adhaerens, Lithotamnium/Lithophylum
complex, Ochtodes secundiramea, and Palisada flagellifera.
The Southeast: São Paulo
Nine rocky shores were sampled along 150 km of the coast of São Paulo State,
Brazil, within three localities: Baixada Santista (Guaiúba/Guarujá, Ilha Porchat/São Vicente,
Itaquitanduva/Praia Grande), São Sebastião (Baleeiro/São Sebastião, Feiticeira/São Sebastião,
Itassucê/São Sebastião), and Ubatuba (Enseada/Ubatuba, Itaguá/Ubatuba, Praia
Grande/Ubatuba). This coastline faces south - southeast, with variable complexity, from long
linear stretches in Bertioga (Figure 3F) and southern São Sebastião, where long sandy
beaches prevail, to very intricate coasts in Ubatuba, where small sandy beaches (tens to a few
hundred meters) and mangrove forests are interspersed along a general rocky shoreline,
forming several small bays and coves (Tessler et al. 2006). This general feature is an outcome
of major tectonic dynamics leading to a gradual emergence towards the southwest, leading to
the formation of coastal plains and long sandy shorelines, and to submersion towards the
northeast, where a sinking mountain range, part of the Serra do Mar system, makes up most
of a remarkably convoluted shoreline and coastal islands (Martin & Suguio 1975, Almeida
1976). The rocky intertidal is usually steep, never forming large platforms, and often broken
into very large boulders. As in most of the Serra do Mar, rocks are mostly constituted by
gneiss and granite (Almeida & Carneiro 1998). The climate regime varies from tropical do
humid subtropical (Sant'Anna Neto 1990) within this area. In Ubatuba, where historical
climate data are available and have been extensively modeled (e.g. Valentim et al. 2013),
temperature is maximum during February [27.8
o
C air temperature (AT), 28.6
o
C sea surface
temperature (SST)] and minimum during July (21.1
o
C AT, 21.9
o
C SST). Continuous
measurements during the austral summer of 2011, taken at Baleeiro, São Sebastião, showed
that temperature at the rock surface in the mid intertidal averaged 28.8
o
C and occasionally
exceeded 40
o
C (Kasten & Flores 2013).
The sampled shores varied from sheltered (Enseada, Itaguá), moderately exposed
(Guaiuba, Ilha Porchat, Itaquitanduva, Baleeiro, Feiticeira, Itassucê) and exposed (Praia
Grande), within an area where wave height frequencies from 0.5 to 2.0 m sum up 90%, with a
wave height interval between 1.0 to 1.5 m making up half the observations (Bomtempo
1991). Wave exposure is apparently related to the midshore height (MH), from the upper limit
of the coralline algal turf to the upper limit of the chthamalid barnacle cover. Roughly, the
MH is lower than 0.5 m at sheltered shores, betwen 0.5 and 1.0 m at moderately exposed
shores, and higher than 1.0 m at exposed shores. In this area, coastal primary production is
comparatively low when compared to temperate areas prone to intensive seasonal upwelling
(Gianesella et al. 2008). Estimates of nitrate concentration based on SST time series taken in
the São Sebastião Channel indicated variation from only 0.2 to 0.7 M (Flores unpublished
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
14
data). Local upwelling of South-Atlantic Central Waters (SACW) may take place
sporadically, during summer months, but more frequent inputs to the coastal zone take place
via remote forcing, mostly during the passage of cold fronts during winter (Ciotti et al. 2010).
The tidal regime at this coastline is a semidiurnal one, with the tidal range at spring tides
ranging from 1.1 to 1.5 m. There is often a clear intertidal zonation, with the barnacle
Chthamalus bisinuatus dominating the upper midlittoral (level 1), the mussel Brachidontes
solisianus, and the volcano barnacle Tetraclita stalactifera prevailing in the lower midlittoral
zone (level 2), and a coralline algal turf, associated to a very diverse assemblage of other
macroalgae, making the most of the infralittoral fringe (level 3). These three levels were the
targets of sampling protocols attempting a complete report of species presence and
abundance.
Intertidal biological assemblages at the study sites - The upper levels sampled in this
survey (levels 1 and 2) showed little variation among localities, but species turnover was very
high in the lowest level (level 3), rendering almost shore-specific assemblages. At this lowest
level, diversity was very high due to the presence of a large number of small macroalgal
species. The most common species at all sites in level 1 in terms of cover were Chthamalus
bisinuatus and Brachidontes solisianus, while Collisella subrugosa was one of the most
abundant reaching densities of more than 70 ind/m
2
. Level 2 was dominated by
Phragmatopoma caudate, Brachidontes solisianus, Tetraclita stalactifera, and Chthamalus
bisinuatus. Level 3 showed differences in among the different sites, with Collisella
subrugosa, Fissurella clenchi, Phragmatopoma caudate, Ulva lactuca, Stramonita
haemastoma, and Caulerpa fastigiata as some of the most abundant and conspicuous species.
The South: Paraná and Santa Catarina
The rocky coasts along south Brazil are formed by granitic or basaltic rock, resulting
from the erosion of the border of the Serra do Mar mountain chain, which lies parallel to the
coastline. Biolithic formations are also observed as an important coastal substrate, mainly at
Paraná and Santa Catarina States. It is not a continuous ecosystem, but forms more or less
extended outcroppings between sandy beaches and around numerous coastal islands. In some
beaches there is a large rocky wall with different inclinations, where the intertidal zone is 5
6 m wide, but in most cases boulders of different sizes accumulate in front of these walls and
the intertidal community covers a band of just 1.5 2 m high in each boulder . Usually the
tide ranges from -0.2 to 1.8 m and water temperatures range from 17 23 ºC but surface
water temperatures can reach peaks of 26 28ºC. 

extension in the South and the second shortest in Brazil (98 Km). The area is between two
Estuarine Complexes (Paranaguá and Guaratuba Bays), resulting in low transparency and
high concentration of dissolved organic matter.
The monitoring of rocky coasts in the Brazilian southern region covered the
following beaches from north to south: Morro do Farol (Figure 3G) and Praia Grande (Mel
Island), Farol Island (Matinhos), Ferry Boat and Morro do Cristo (Guaratuba), in state of
Paraná; First outcrop and Third outcrop (Itapema do Norte, Itapoá), Papagaio Point and Praia
de Cima (Palhoça), in state of Santa Catarina; and Praia da Cal and Guarita Park (Torres) in
state of Rio Grande do Sul. The northern seven sites listed are close to large estuarine systems
(Paranaguá Bay, Guaratuba Bay, Babitonga Bay) and consequently exposed to low salinities
(33-34) and high loads of sediment (turbid waters) and high concentration of dissolved
organic matter.
Benthic Assemblages in South American Intertidal Rocky Shores
15
A total of 160 species were found, around 60 invertebrates and 100 conspicuous
macroalgae distributed along the three states, but known species richness in the southern
Brazilian coast can reach 220 taxa at Santa Catarina (ca.), 131 taxa in Paraná (Pellizzari et al.
2014) and 85 taxa in Rio Grande do Sul (ca.). Rhodophytes dominated over Chlorophytes and
Phaeophycean. The supralittoral zone mostly comprises bare space used by the periwinkle
gastropods Echinolittorina lineolata (d'Orbigny, 1840), which are the most common and
characteristic organisms at the lower part of this zone. Abundances can be as high as 150
individuals per 100 cm2. The high intertidal contains a dense belt of the barnacle Chthamalus
bisinuatus Pilsbry, 1916, where many Echilittorina are still present. The mid intertidal is
dominated by the mussel Brachidontes solisianus, usually fouled by the algae Pyropia
(formerly known as Porphyra) suborbiculata, Bostrychia spp., and Gelidium pusillum during
the winter time. In this zone sand accumulates among the bivalves, sometimes almost
covering all the shells, in which a community of vagile invertebrates such as polychaetes and
nematodes is found. The community of the low intertidal is more variable among sites. In
some beaches, barnacles (Tetraclita stalactifera) are very common (Morro do Farol, Morro
do Cristo, Ponta do Papagaio), while in others, the mussel Perna perna is the dominating
species (Ferryboat, Praia de Cima, Praia da Cal, Guarita Park). Below the barnacle and
mussels zone, high densities of the sabelariid polychaete Phragmatopoma caudata are found
forming sand reefs that can extend 50-70 cm away from the substrate. Not all rocks are
covered by the sand reefs and macroalgae are also very abundant in this zone. Regarding
seaweed assemblages, filamentous, foliose and terete functional groups dominated the
biomass. Species with higher coverage in the low intertidal were Acantophora spicifera,
Centroceras clavulatum, Gelidium spp., Gymnogongrus griffthsiae, Hydropuntia caudata,
Hypnea musciformis, Pyropia acantophora, Laurencia spp., Bryopsis pennata, Cladophora
spp., Codium taylorii, Gayralia brasiliensis, Ulva lactuca, U. flexuosa, Bachelotia
antillarum, Colpomenia sinuosa, Dictyota sp., Padina gymnospora and Sargassum spp. The
most important herbivores in the area are sea-urchins and turtles. In some beaches, hydroids
are also common in the low intertidal such as Obelia dichotoma, Orthopyxis sargassicola,
and Acharadria crocea. The sea anemone Bunodosoma caissarum as well as the sponge
Hymeniacidon heliophila were also frequent. When the tide is very low and the sublittoral
fringe gets exposed, a few ascidian species can be found (Polysyncraton aff. amethysteum,
Didemnum galacteum, Botryllus planus, and the introduced Eudistoma carolinense). Among
the grazers, there were five mollusk species and one sea-urchin, while among the predators,
Stramonita braziliensis was the only ubiquitous and abundant invertebrate species. No sea-
stars were found, however, 20 years ago, Asterina stellifera was common in the intertidal
zone of this region.
Along the Brazilian coast in general, macrofauna does not show significant
differences in composition, however seaweed assemblages are strongly marked by latitudinal
differences on their composition and biomass. The highest diversity of macroalgae is found
between the coasts of Espírito Santo and Bahia States, while the highest biomass is found in
the Brazilian Northeastern and also Santa Catarina, in the South, associated probably to the
influence of the South Atlantic Central Water (ACAS), distance to large estuaries (affect
water transparency), and finally to the availability of hard substrates.
URUGUAY
The Uruguayan marine and estuarine coastlines (ca. 500 km, between 34º and 35ºS)
include sandy beaches interrupted by streams and coastal lagoons and rocky (mainly
metamorphic and igneous) outcrops forming capes or peninsulae. Since the Uruguayan coast
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
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16
is under the influence of the the Río de la Plata estuary, one of the largest estuaries of South
America, a salinity gradient roughly oriented eastwest can be identified. Based on salinity,
three main regions can be identified: a west region influenced by freshwater (<1ppt), a central
region that is influenced by water of variable salinity (130 ppt) and an east region open to
ocean waters (>30 ppt) (Brazeiro, Borthagaray, and Giménez, 2006; Defeo et al., 2009;
Giménez et al., 2010). Diluted waters (i. e. salinity <33.2) dominate shallow coastal area (i.e.
depths <50m) and can reach the offshore producing a buoyant fresh water layer during
extreme continental discharge that determine variations in coastal water input (Ortega and
Martínez, 2007). Upper waters temperature could exceed 20ºC (e.g. Tropical Water)
(Thomsen, 1962) at surface. In the boundary between the estuarine and oceanic zone (Punta
del Este), water temperature can fluctuate between 10.7ºC in winter and 24.6ºC in summer,
(Burone and Bayseé, 1985; Milstein and Juanicó, 1985). The coast experiences a semidiurnal
tide (range < 0.5 m) with the water level influenced mainly by wind conditions (direction and
speed). Winds blow south-west during winter and north-east during summer. The rocky
platforms have variable slopes and are exposed to different degrees of wave action according
to their orientation. SARCE sampling sites are located in the east region (Figure 3H).
Across the Uruguayan coast, intertidal species richness of both macroalgae and
invertebrates, increased from west to east; this was most notable for sessile fauna and
macroalgae (Giménez et al., 2010). In the east region, two to three zones can be identified,
following classical zonation schemes: a high intertidal zone dominated by a cyanobacterial
film, a middle intertidal zone dominated by barnacles and a low intertidal and shallow
subtidal zone characterized by a dense cover of mussels and/or macroalgae. Intertidal mussel
beds are thus a conspicuous feature of Uruguayan rocky shores, providing important
economic and ecological services (Borthagaray and Carranza, 2007; Riestra and Defeo, 1994;
Riestra and Defeo, 2000). Along this gradient, the intertidal mussel beds changes in species
composition and structure. Currently, the western region is characterized by the invasive
mussel Limnoperna fortunei. Brachidontes darwinianus and Mytella charruana occupy
consolidated substrata along the central region (Maytía (Maytia and Scarabino, 1979;
Neirotti, 1981; Scarabino et al., 2006), overlapping with Brachidontes rodriguezii from the
eastern half of the central region and being replaced by this species in the eastern region (e. g.
Amaro (Amaro, 1965; Maytia and Scarabino, 1979; Scarabino et al., 2006). Mytilus edulis, in
turn, is distributed from the eastern half of the central region, being the dominant mussel
species in this zone. Brachidontes rodriguezii and Mytilus edulis originate dense banks in the
more saline part of the Río de la Plata, the first being characteristic of the intertidal (also
occurring in the Atlantic shores), the second mostly subtidally although some intertidal
exposed zones have been observed to be dominated by this species (Borthagaray and
Carranza, 2007). The brown mussel Perna perna originates large banks in the subtidal of the
eastern coast (Rocha) but its presence (in very low abundances) reaches Punta del Este. The
Uruguayan coast was massively colonized by this species in the late ´50ths. Since this first
colonization, P. perna almost disappeared in the late 70s to 1997, when a new process of
colonization occurred in the area (Carranza and Borthagaray, 2008; Orensanz et al., 2002).
The annotated list of macroalgal species of the Uruguayan coast given by Coll and Oliveira
(1999) reported the presence of 69 species sampled from 27 sites located along the central
and east sectors of the Uruguayan coast. Conversely, a single site (Cerro Verde) can yield
more than 40 invertebrate taxa, including the small mobile (e.g. amphipods, polychaetes), and
encrusting (e.g. briozoa, hydrozoa) fauna. Under the SARCE sampling protocol, two sites
located in the eastern region showed a combined richness of 20 species, including 9
metazoans (4 Gastropoda, 2 Bivalvia, 2 Cnidaria Anthozoa and 1 Cirripedia), 4 Chlorophyta
and 7 Rhodophyta.
Benthic Assemblages in South American Intertidal Rocky Shores
17
Figure 3. Sampling sites in the Brazilian and Uruguayan Atlantic. A. Northeast
Brazil Caucaia. B. Northeast Brazil Bahia/Itacaré. C. Northeast Brazil
Bahia/Arruda, octopus fishing. D. Northeast Brazil Bahia/Itacaré. E. Southeast
Brazil Costao de Ubu/Espirito Santo. F. Southeast Brazil Sao Lourenco. G.
South Brazil Morro de Farol/Parana. H. Uruguay Punta del Este.
ARGENTINA
The Argentinean marine coast extends along more than 4700 km and twenty degrees
of latitude. It comprises the Argentinean and Magellanic biogeographical provinces, which
are delimited by the Valdés Peninsula. The Argentinean Biogeographic Province extends
from 36 to 43º S, including the provinces of Buenos Aires and Río Negro, and the north of
Chubut province. The Magellanic Biogeographic Province, extends from 43ºS to 56ºS along
southern Chubut province as well as Santa Cruz and Tierra del Fuego provinces (the latter
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
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includes the Malvinas/Falklands and South Atlantic Islands) (López Gappa et al., 2006,
Balech and Ehrlich, 2008). Intertidal rocky platforms in Argentina increase in frequency and
extend from North to South. In the northernmost coastal province (Buenos Aires), rocky
coastal stretches are markedly discontinuous. They rarely exceed 1 km length and are
frequently associated to urban areas. Most intertidal platforms in this province are formed by
consolidated sediments (e.g., limestones, sandstones, calcretes) that support both epilithic and
endolitic biota (Bagur et al. 2013, 2014). The only exceptions are a handful of metamorphic
rock (ortoquartzite) platforms adjoining the city of Mar del Plata (38° S).
SARCE sampled two sites were sampled in the province of Buenos Aires: Playa
Chica, an orthoquartzite platform located in the urban zone of Mar del Plata (Figure 4A) and
at a calcrete platform located immediately north of the port of Quequén. Both localities are
exposed to waves and face the open sea. The tidal regime at these sites is semidiurnal and
microtidal (mean and maximum amplitude are 0.83 and 1.65 m respectively). Water
temperature varies from a media of C in winter to a media of 18 º C in summer (Servicio
Meteorologico Nacional-Argentina, http://www.smn.gov.ar). The next province to the south,
Rio Negro, presents intertidal platforms of varying substrate, including sedimentary (e.g.,
sandstones, limestones) and igneous rock types (e.g., granite, ignimbrites) (Kokot et al. 2004).
Tidal regimes are semidiurnal and macrotidal through the whole coastal range. The sampling
sites in this province were: El Espigón, La Lobería (Figure 4B), Playa Los Suecos, and Punta
Colorada. El Espigón and La Lobería face the open ocean and are characterized by
sedimentary rock substrates and maximal tidal amplitude of 4.32 m. Playa Los Suecos and
Punta Colorada are located within the San Matías Gulf and show igneous rock substrates and
maximal tidal amplitude of 8.72 m (Kokot et al. 2004). Southwards, the rocky shores of
Chubut province are exposed to unusually harsh physical conditions, particularly with regard
to desiccation (see Bertness et al. 2006). The region is characterized by persistent and intense
winds (up to 90 km/h, annual average 16.6 km/h) and low precipitation (mean 235.9 mm/yr
(Paruelo et al., 1998, Labraga & De Davies, updated 2013). The tidal regime is semidiurnal
and macrotidal. Consolidated sediments are the dominant substrate type across these rocky
shores. Sampling sites in Chubut were Puerto Lobos, Punta Este (Figure 4C), and Camarones.
Puerto Lobos is located by the Southern end of the San Matías Gulf and its maximal tidal
amplitude is about 6 m. Punta Este is located within the Nuevo Gulf, 8 km south from the city
of Puerto Madryn. Mean tidal amplitude at this site is 3.8 m (Maximal: 5.7 m). The town of
Camarones is located within the homonymous bay. This site is characterized by monthly-
averaged wind speeds ranging from 13 to 31 km/h and an average tidal amplitude of 4 m,
platforms are characterized by sedimentary rocks although some igneous rock are present.
The southernmost continental sampling site was Puerto Deseado (Figure 4D) in Santa Cruz
Province. This site is located in the Deseado Massif geological province, and characterized by
igneous rock substrates (rhyolites; see Pankhurst and Rapela, 1995; Pankhurst et al., 1998).
Climate is also dry and windy with a mean annual precipitation around 200 mm and an
average annual air temperature of 8.2 °C (Servicio Meteorologico Nacional-Argentina,
http://www.smn.gov.ar). The tidal regime is mesomacrotidal (Isla and Bujalesky, 2008), with
amplitudes ranging between 2.5 and 5.5 m. Two additional sites were sampled in Tierra del
Fuego Island: Estancia Viamonte (Figure 4E) and Playa Larga (Figure 4F). Estancia
Viamonte is located 40 km south of the city of Río Grande and characterized by an extensive
limestone abrasion platform (the low tide level is ca. 2 km distant from the high tide line) that
faces the open ocean. The tidal regime is macrotidal, with amplitudes ranging between 2.2
and 8.4 m (Bujalevsky 1997, 2007). The area shows a dry and windy climate (340 mm/yr
precipitation) with the mean annual temperatures of 5-6 °C and low between-month
variations (Bujalevsky 1997, 2007). Playa Larga is located 3.5 km east of the city of Ushuaia
Benthic Assemblages in South American Intertidal Rocky Shores
19
in the Beagle Channel. The rocky shore at this site is characterized by methamorphic rocks
and a sharp slope. The tidal regime is microtidal (1.1 m mean amplitude). Mean annual
temperature and precipitation are 6°C and 500 mm, respectively. This shore faces the
dominant SW-W winds and, thus, is exposed to considerable wave splash. The subtidal all
along the Beagle channel is characterized by dense forests of Macrocystis pyrifera (Figure

(Figure 4H).
Figure 4. Sampling sites in Argentina. A. Mar del Plata. B. La Lobería. C. Punta Este. D.
Puerto Deseado. E. Río Grande. F. Playa Grande. G. Estancia Moat Macrocystis pyrifera.
H. Estancia Moat.
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
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The main feature of this extensive coast is the low biodiversity of its rocky intertidal
shores, which at the same time involve low biomass (Wieters et al. 2012). From North to
South, the two localities in Buenos Aires Province have different geological substrates, and
are 120 km apart. Even if both assemblages have the same species composition; the structure
and relative abundance of species between localities were different. In Mar del Plata, the
locality with quarzitic substrate, the bivalve Brachidontes rodriguezii, the limpet Siphonaria
lessoni and the introduced barnacle Balanus glandula are the more abundant species of the
high intertidal. In the mid intertidal level, several algae species were added to the
assemblages, being Hildenbrandtia sp. Polysiphonia fucoides, Ulva sp. and two non-
indigenous red algae Anfeltiopsis devoniensis and Schyzimenia dubyi the most abundant. In
the low intertidal level, the most representative species are Polysiphonia fucoides and
Siphonaria lessoni in Mar del Plata and Corallina officinalis and Balanus glandula in
Quequén. The presence of non-indigenous algae species is limited to Schyzimenia dubyi, and
in very low coverage.
The Rio Negro Province comprises two localities and also an area of ecotone among
two biogeographic regions, the Argentinean and Magellanian provinces. The differences
among localities involve not only changes in the species composition but abundance of the
ones that are present in both regions. In El Espigón and Loberia, a great variability was found
between sites, the high intertidal is inhabited mainly by Mytilus platensis in one site and by
Ralfsia expansa and Enteromorpha linza in the other. The mid intertidal level could have up
to 98 % coverage of Brachidontes rodriguezii in one site and 0 % in the other. Siphonaria
lessoni is the second more abundant species in this level. In the low intertidal the areas are
patchly covered by E. linza and Corallina officinalis in one site or almost exclusively covered
by C. officinalis in the other. In Playas Doradas, the most abundant species that inhabits the
high intertidal are Siphonaria lessoni and Brachidontes rodriguezii, but in a very low
percentage cover (approximately 12 %). In the mid intertidal, Brachidontes pupuratus
replaces B. rodriguezii and it is the most abundant species followed by Ralfsia expansa and S.
lessoni. For the low intertidal, C. officinalis is the most abundant followed by a complex of
Aulacomya actra and Mytilus platensis forming mussel beds. The Chubut Province is
characterized by sites with no human settlements. In the north of the province, the
biodiversity pattern is similar to the localities in the province of Rio Negro, with B.
purpuratus being the most abundant species in the high and mid intertidal and C. officinalis in
the low intertidal. In Puerto Madryn, a site with a local population of 80,000 residents, the
pattern is similar but with a greater proportion of the green algae Ulva sp. in the mid
intertidal, depending on the season. High and mid intertidal are dominated by the mytilid
complex of Brachidontes rodriguezii and Brachidontes purpuratus that produce an
heteregenous habitat that facilitates settlement for several species. Also the non-indigenous
barnacle Balanus glandula is present in high and mid intertidal levels, while the gastropod
Trophon geversianus is a carnivore specialized on mytilid bivalves. The low intertidal is
dominated by the alga Corallina officinalis and the herbivore gastropod Tegula patagonica.
In Camarones, the zonation is similar to Puerto Madryn, presenting zones with 100% of
coverage of Brachidontes purpuratus dominating the mid intertidal, and the invasive species
Balanus glandula in the mid and high intertidals. The low interidal is dominated by the
calcareous algae Corallina officinalis, while Aulacomya atra and Siphonaria lessoni are
abundant in some localities. The gastopod Trophon geversianus is less common in this zone,
probably due to the harsh physical stress.
Santa Cruz is the last province of the continent and the one with less population, with
nearly 10,000 residents on the coast, but with an important port in the sampling locality
Benthic Assemblages in South American Intertidal Rocky Shores
21
Puerto Deseado. Here, even if biodiversity increased slightly, patterns of the most abundant
species were kept. The high and mid intertidal were dominated by Brachidontes purpuratus
and the algae Bostrichia, while the in the low tide Corallina officinalis and Chondria were
the most abundant. In the low intertidal level the presence of the non-indigenous red algae
Anotrichium furcellatum was detected as one of the most abundant. In Tierra del Fuego
Island, assemblages are different according to their degree of exposure (open ocean vs Beagle
channel). In the open ocean locality, Estancia Viamonte, near Ushuaia (56,000 residents),
mussel beds are composed mainly by Mytilus edulis platensis and covered from 50 to 87% of
the mid and high intertidal. In the low intertidal, the incrusting algae Corallina sp. is the more
abundant sessile species. The biodiversity of mollusks increased in this site, being Nacella
magellanica, Kerguelenella lateralis and Trophon geversianus the most abundant. In the
locality in the Beagle Channel, Playa Larga, macroalgal biodiversity increased, being the
most conspicuous group in the low and mid intertidal along with M. edulis platensis. The
limpet Notochthamalus scabrosus is the more abundant species in the high intertidal. As
observed in the open ocean site, the biodiversity of mobile mollusks increased with S. lessoni,
K. lateralis, N. magellanica and T. gerversianus the most abundant species in the three
intertidal levels.
THE PACIFIC
COLOMBIA
In general terms, two main regions/features can be recognized on the littoral of the
Pacific coast of Colombia: mangrove swamps and muddy flats to the south and rocky shores
to the north; with a hybrid zone almost in the middle of the coast: Málaga and Buenaventura
Bays. The shoreline is very broken, interrupted by numerous small rivers and creeks
characteristic of one of the rainiest and most bio-diverse areas in the World: The Tumbes-
Chocó-Magdalena region. Despite this condition or perhaps due to it, most of the coast is
unpopulated, with only two relatively large cities: Buenaventura (the most important
commercial port in Colombia), located almost in the middle of the coast and Tumaco, a
smaller city located at the south, near the border with Ecuador. Although these two are the
main cities, there are numerous small towns, such as Guapi and Bahía Solano, among others.
The transportation system in the region is precarious. The underdeveloped roads
infrastructure is limited to Buenaventura and Tumaco, and all other settlements can only be
reached by boat or in few cases by plane, a fact that makes it difficult and expensive to
undertake research projects in the Pacific coast of Colombia.
The Pacific coastline has an extension of nearly 1544 km, of which 636 km are
exposed rocky shores (Londoño-Cruz et al., 2008, Londoño-Cruz et al., 2014). Despite this
exposure, wave action is moderate most of the year round, reaching, on average, wave heights
of up to 1 m in most locations (INVEMAR, 2003). Tidal range is relatively large (ca. 4.5
5.0) and has a semidiurnal frequency (ca. 6:15 hrs. between high and low tide). Currents, on
the other hand, respond to prevalent winds and to the movement of the Intertropical
Convergence Zone (ITZC). The most important surface currents are the North Equatorial
Current, the North Equatorial Counter-current, the Panama Gulf Current, and the Colombia
Current. Although there are hypothesis regarding the existence of upwellings in the Pacific
coast of Colombia, these have not been unambiguously confirmed; if they do occur, they
happen during the first months of the year and at the northernmost of the Colombian Pacific
(Vides and Sierra-Correa 2003). Rocks forming the large extension of rocky shores on the
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
22
Colombian Pacific are composed by volcanic rocks from the Secondary or Tertiary periods
and by sedimentary rocks from the Quaternary. The volcanic rock characterizes the rocky
shores of the northern regions and the Gorgona and Malpelo Islands, while the sedimentary
rocks characterize the rocky shores of central (Málaga Bay, Pichidó Isthmus, and Tortuga
Gulf) and southern (Gallo Island) regions (INVEMAR, 2004). Due to the relatively large tidal
range, the rocky intertidal can be easily divided into three levels, which vary in dimension
depending on the slope of the shore. It is very common to find cliffs along the coast, with
scattered abrasion platforms and rocky/boulder beaches. Zonation in the intertidal zone is
very typical, with periwinkles and Nerita spp. occupying the upper intertidal; barnacles,
limpets, other snails and bivalves in the middle and a richer arrange of species in the lower. In
these rocky shores, the algal coverage is very low as compared to shores in higher latitudes or
the Colombian Caribbean; so although species richness in general is high, species abundances
are relatively low. It is also important to note that space seems not to be a limiting factor,
since there is plenty of free space in almost every rocky shore along the coast. One might
hypothesize that the reason for this low abundance is low algal coverage and long exposure
periods during low tide, which may bring very high temperatures or very low salinities
(during high rainfall).
The localities sampled by SARCE (from North to South) include El Choco (Punta
Ardita, Cabo Marzo) (Figure 5A), Málaga Bay (Los Negritos, Isla Palma), and Gorgona
Island (La Ventana, La Camaronera, Piedra Redonda) (Figure 5B). Punta Ardita at El Choco
is the northernmost locality, near to the border with Panamá, practically undisturbed by
human presence. The volcanic rocky shores in this locality are edged by large sandy beaches.
The high intertidal is mostly bare rock with Cladophoropsis sp., Nerita scabricosta,
Echinolittorina conspera, Chthamalus panamensis, Lottia mesoleuca, and Acanthina
brevidentata. The mid intertidal is dominated by Cladophoropsis sp., Acanthina brevidentata,
Fissurella microtrema, Phragmatopoma sp., Fissurella microtrema, and Lottia mesoleuca.
The most common species in the low intertidal are Cladophoropsis sp., Echinometra
vanbrunti, Telmatactis sp., bryozoa, and Balanus sp. Cabo Marzo is an isolated locality with
no human settlements nearby and practically undisturbed. Rocks, as in the previous locality,
are volcanic. There is some coralline formation in this place, waters are very transparent.
Wave conditions are relatively rough. Dominant species of Cabo Marzo are Chthamalus
panamensis, Echinolittorina conspera, and Nerita scabricosta in the high intertidal,
Corallinales, Fissurella virescens, and Siphonaria maura in the mid intertidal, and
Corallinales, Chiton stokesii, Siphonaria maura, Nucella melones, and Chama frondosa in the
low intertidal.
At Málaga Bay the rocks are sedimentary. This bay is part of a National Natural Park
and there is a relatively large human settlement (Juanchaco) at the mouth of the bay, as well
as a Navy Base along with several other scattered minor settlements. Seasonal tourism is,
perhaps, the main economic income for the inhabitants. The first site, Isla Palma, is an island
(uninhabited), while the second site, Los Negritos, is an intertidal rocky reef with both
volcanic and sedimentary rocks. Dominant species at Isla Palma were Chthamalus
panamensis, Balanus sp., Lottia mesoleuca, Echinolittorina paytensis, Echinolittorina
dubiosa, and Echinolittorina apicina in the high intertidal; Verrucaria sp., Lithophyllum sp.,
Nerita funiculata, Lottia mesoleuca, and Balanus sp. in the mid intertidal; and
Cladophoropsis sp., Bostrychia sp., Lithophyllum sp., Echinometra vanbrunti, Nucella
melones, and Brachidontes sp. in the low intertidal.
Benthic Assemblages in South American Intertidal Rocky Shores
23

and cliffy. Rocks are volcanic with few exceptions. Basically all sort of rocky shore types can
be found in the island. This locality is perhaps, the most sampled area in the entire Pacific
coast of Colombia. The main rocky ecosystems sampled (La Ventana, La Camaronera, and
Piedra Redonda) are located at the south and western sides of the Island. At La Ventana, the
dominant species were Nerita scabricosta, Cladophoropsis sp., Echinolittorina conspera, and
Siphonaria gigas in the high intertidal, Nerita funiculate and Cladophoropsis sp. in the mid
intertidal, and Nucella melones and Nerita funiculata in the low intertidal. At La Camaronera,
high intertidal is dominated by Echinolittorina conspera and Nerita scabricosta, the mid
intertidal by Nerita funiculata, and the low intertidal by Cladophoropsis sp., Nerita
funiculata, and Tegula pellisserpentis. At Piedra Redonda, the high intertidal is dominated by
Nerita scabricosta, the mid intertidal by Cladophoropsis sp., Nerita funiculata, and Fissurella
virescens, and the low intertidal by Cladophoropsis sp. and Nucella melons.
ECUADOR
The coast of Ecuador extends for 4,403 km from north to south and includes several
isles, islets and estuaries. The continental platform exceeds 100 km in amplitude mainly at the
Gulf of Guayaquil (Sonnenholzner et al, 2013) and a depth of 200 m from the coastline (Mora
et al, 2010). About a third of the coast is covered by mangroves, mostly in the north and in the
south. The central and part of the north coasts are characterized by large sandy beaches
interrupted by a few rocky areas, cliffs, lagoons and rocky reefs (Sonnenholzner et al, 2013;
Miloslavich et al, 2011). The rocky shore intertidal has mid to steep slopes formed by
stratified rocks within cliffs entering the sea and forming platforms within the sandy beaches.
At the base of some of the cliffs, an eroded narrow terrace can be observed, or the beach may
be narrow with boulders. Despite the importance of rocky shores, they have been poorly
studied in Ecuador, and knowledge on its biodiversity is limited to some taxonomic studies on
specific groups such as molluscs (Bonilla 1967; Cruz 1977, 1983, 1992a, b, 1996, 2007 y
2009; Mora and Reinoso 1981; Mora 1989, 1990; Arias 2012), poliychaetes (Villamar 1983,
1986, 1989), echinoderms (Avilés 1984, Sonnenholzner et al. 2013), and macroinvertebrates
(Massay et al. 1993; Arroyo and Calderón 2000; Mair et al. 2002; Cruz et al. 2003; Ayala
2010; Mora et al. 2010).
SARCE sampled at two localities at the central and south-west of the coast of
Ecuador: Caráquez Bay (Punta Bellaca and Punta Gorda) and at the Santa Elena Peninsula,
the localities of Puntilla de Santa Elena (Base Naval and La Lobería) (Figure 5C) and
Ballenita (El Barco and El Faro) (Figure 5D) which are located at the provinces of Santa
Elena and Manabí. The sites with more human impact were Punta Bellaca and Ballenita,
while Punta Gorda and Puntilla de Santa Elena were less impacted.
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
24
Figure 5. Sampling sites in the Colombian and Ecuadorian Pacific. A. Colombia
Ñuqui/Choco. B. Colombia La Ventana/Gorgona. C. Ecuador Puntilla de
Santa Elena. D. Ecuador Ballenita.
Punta Bellaca and Punta Gorda are characterized by almost vertical, high cliffs of up
to 100 m interrupted by deep valleys with steep slopes (Ochoa et al, 1987). These cliffs are
unstable and landslides are common. The beach is narrow and in some places, eroded rock
terraces can be found inserted within sandy beaches (Boothroyd et al, 1994). Weather in this
area is tropical dry with an average temperature of 25°C. Rainfall is not uniform due to the
complexity of the Oceanic Front, and varies between 200-800 mm (Ochoa et al, 1987). A
total of 16 species were found (10 at Punta Bellaca and 4 at Punta Gorda), mostly represented
by molluscs (50%), macroalgae (25%), and crustaceans (25%). The most diverse group was
the mollusks represented by 7 species of gastropod and one bivalve species. The most
abundant species were the gastropods Nodilittorina aspera, Nodilittorina paytensis and the
macroalgae Enteromorpha sp. and Bachelotia sp..
The high intertidal was mostly represented by bare rock and patches of sand, but
some rocks were colonized by the Brachidontes semilaevis/Balanus amphitrite complex. The
most common species in the mid intertidal were Balanus amphitrite and Enteromorpha sp.
and Bachelotia sp. in the low intertidal.
At the Santa Elena Peninsula, Ballenita is a public watering place with hotels all
along the border of the coast. The weather is tropical with a mean average temperature of
24°C. The intertidal is characterized by short, vertical, and unstable cliffs. The rocky
platforms are inserted within the sandy beaches, and have a soft slope (Ochoa et al, 1987).
Boothroyd et al. (1994) proposed that the low cliff originated from a system of barrier/littoral
plain formed by sand poorly cemented to the carbonates and clay. Wave energy is highest
during the rainy season (Brito, 2014). The rainy season occurs in January-April followed by
the dry season which extends to November-December (Ochoa et al, 1987). Precipitation
varies from 62.5 to 125 mm (Ochoa et al, 1987).
Benthic Assemblages in South American Intertidal Rocky Shores
25

            The
intertidal here is irregular, with low vertical, unstable cliffs that continue at sea, emerged, for
a few hundred meters. Between these formations, sandy beaches with coarse sand and steep
slopes are found. The base of the cliffs are continuously eroded by wave action (Boothroyd et
al, 1994; Soledispa, 2008). From the geological point of view, the most outstanding feature at
La Lobería is the Cayo Formation, represented by sandstone, chert and silicified clays
(Soledispa, 2008). Wave action is stronger than in the previous site and also highest during
the rainy season (Brito, 2014). At the Navy Base, the Beach is characterized by medium size
rocks covering a great extension that goes into the sea. According to Soledispa (2008), these
lay directly on top of the Cayo Formation where deposits from the quaternary are found and
composed by calcarean sandstone and conglomerates with abundant fossils. When the tide is
low, numerous intertidal pools can be observed among the sand. Weather in this area is arid,
with a mean annual temperature of 24°C, and precipitation, determined by the Humboldt
Current, varies between 62.5 and 125 mm (Ochoa et al, 1987).
At these localities, a total of 66 species were found. These were mostly represented
by molluscs (39%), macroalgae (24%), crustaceans (14%), cnidarians (9%), bryozoans (5%),
echinoderms (5%), sponges (3%), and tunicates (1%). Ballenita had a higher number of
species (30 species) in comparison to Puntilla de Santa Elena (19 species). The most diverse
group were the mollusks (29 gastropod species plus 2 bivalve species) followed by
macroalgae (9 species of rodophytes, 3 of chlorophytes, 3 of phaeophytes plus an unidentified
species), and barnacles. The most abundant species were Balanus amphitrite, Brachidontes
semilaevis, Nodilittorina aspera, Nodilittorina paytensis and one bryozoan. The dominant
species in the high intertidal were Nodilittorina aspera, Nodilittorina paytensis, and the
complex Balanus amphitrite/Brachidontes semilaevis, while the mid intertidal was dominated
by Pachygrapsus transversus, Echninometra vanbrunt, and Nerita funiculate; and the low
intertidal by Nodilittorina aspera, Thais brevidentata, Padina sp., and a bryozoan species.
The vertical zonation was more evident in the high and mid intertidal which are dominated by
littorrinid gastropods, barnacles and mussels (Nodilittorina aspera, Nodilittorina paytensis
and the complex Balanus Amphitrite/Brachidontes semilaevis) as observed by Cruz (2009)
and Brito (2014) at the Santa Elena peninsula. This pattern is dependant on the tide and time
of exposure to air (Sibaja-Cordero and Vargas-Zamora, 2006).
PERU
The coastline of Peru extends for 2414 km along the Peruvian Biogeographic
Province and is greatly under the influence of the Humboldt Current System, one of the major
upwelling systems of the world (Miloslavich et al., 2011). SARCE sampled at seven
localities, from north to south: Paita, Huarmey (Figure 6A), Ancón, Paracas (Figure 6B, 6C),
Marcona, La Meca, and Punta Colorada (Figure 6D). The geological and physical conditions
of these localities are very variable according to their origin and latitude, which ranges from a
tropical warm province in the north, to a cold, sub-Antarctic province in the south. These
changes are reflected in the composition of the intertidal flora and fauna.
In the north, Paita, located near the border with Ecuador, at the Panamic Province of
the Tropical West Pacific is one of the most intense upwelling zones in the coast of Peru and
characterized by high productivity (Fahrbach 1981, Huyer 1987, Grados 2002, Graco 2007).
It is considered suptropical with very dry weather. Coastal diversity is high at these warm
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
26
conditions (Ramírez et al., 2003), however, it is temporally affected by ENSO events
(Paredes et al. 1998, Paredes et al. 2004), that produce the migration of some vertebrate
species and the arrival of larvae or propagules of more tropical species. Sampled areas are
relatively small beaches (~100 m in extension), exposed to wave action and located south of
the bay of Paita. In this bay, 5 to 9 km from the sampling sites, functions the second largest
port of Peru, dedicated mainly to fishing activities and transportation of agriculture products.
The coast is characterized by black metamorphic rocks, over which Cretacic rocks can be
found, mainly from the quaternary forming sandstones and cliffs of up to 50 m (Palacios
Moncayo 1994). Tides are semidiurnal that may reach 1.73 m (HIDRONAV, 2012), and SST
varies between 15-29°C (INEI, 2014), with the highest values in summer (February-March)
and the lowest in spring (September-October). Paita is also under the influence of of the
Peruvian Coastal Current which is characterized by cold Waters but also of tropical ecuatorial
surface warm waters (Zuta & Guillen 1970, Cabrera et al. 2005). Very little is known about
the biodiversity of these coasts. An abundant species is the barnacle Pollicipes elegans which
is commercially exploited for exportation (Villena 1995, Oliva 1995, Pinilla 1996).
Population density of this barnacle is very high during ENSO events, but after the event,
population decreases significantly and is replaced by other invertebrates such as Semimytilus
algosus, Austromegabalanus psittacus and Balanus spp (Kameya and Zeballos 1998). As for
macroalgae, a total of 35 species were identified in the intertidal zone, of which 22% are
considered to be endemic. This diversity is seasonal, decreasing during the winter or during
other cold events such as La Niña (Benavente 1994).
In central Peru, the sites sampled at the Bay of Huarmey are exposed to wave action
and located at 6.5-11.7 km north of the Port of Huarmey, important for mineral transportation
and fishing activities. The rocky shores are part of the Casma Formation, from the late
Cretacic, mainly volcanic spills of weathered andesite and inserted sediments. The weather is
considered dry, subtropical desert, and tidal amplitude reaches 1.16 m (HIDRONAV, 2012).
SST varies between 18-22 °C (Puerto de Chimbote, INEI 2014). Upwelling events are not
frequent, but when they occur, SST may decrease to 15 °C (Berru Paz et al 2007). The most
common species found in the rocky shores are Fissurella spp, Polyplacophora, Pyropia spp.,
Chondrocanthus chamissoi, which are also commercial species and monitored by IMARPE
as artisanal fishing resources (Tam et al. 2007). The sites sampled at Ancón are within the
area known as Volcánico de Ancón, which is characterized by pyroclastic rocks and volcanic
andesites, typically metamorphic with plagioclases. Also a desert area, it was declared a
natural protected area in 2011 along with the islands in front of the coast. The main port of
Peru, El Callao, is located 33 km south of Ancón. Sampled sites are protected from wave
exposure, tides reach 1.16 m, and SST varies between 14-22°C (Tarazona, unpublished).
Upwelling events are frequent and generate hypoxia and even anoxia by the effect of
bubbling from the bottom of sulphur compounds and other gases (Tarazona 1984, Tarazona et
al. 1988, Tarazona et al. 1996). Biodiversity studies have been carried out since the 1970s
(Paredes, 1974), and report 127 invertebrate species. The high intertidal is characterized by
barnacles (Jehlius cirratus and Notochthamalus scabrosus) and littorinid gastropods
(Nodilitorina peruviana and Austrolittorina araucana), the mid intertidal by a zone of
mytilids in two bands, the upper band of Perumytilus purpuratus and the lower band of
Semimytilus algosus, among macroalgae, and the low intertidal is characterized by
Austromegabalus psittacus (Paredes & Tarazona 1980). Other spcies found in the intertidal
are Fissurella spp., Polyplacophora, Chondracanthus chamisoii, and Patallus mollis. The
locality of Paracas is located within the protected area known as Reserva Nacional de
Paracas, the first marine reserve in Peru. The landscape is a coastal cordillera that reaches the
sea forming cliffs of 50 to 400 m in height (Palacios et al. 1995). One of the sampling sites is
Benthic Assemblages in South American Intertidal Rocky Shores
27
located in the Ambo Formation from the Carboniferous, and the rocks are characterized by
carbon sheets, which were formerly exploited. The other site is located on the Paracas
Formation from the early Tertiary, characterized by phosphate sandstone and bentonites
(Fernandez Dávila 1993). Both sampling sites are protected from wave exposure, tidal range
is 1.12 m (HIDRONAV, 2012), and SST varies between 13 a 17 °C, however, at spatial
scales of 1 to 2 kilometros, increases of up to 7°C may be observed due to water circulation
and wave exposure in the bay (Romero 2000; Quispe et al. 2010, Moron et al. 1998).
Intertidal fauna is represented by Concholepas concholepas, Fissurella spp., Pyropia spp.,
Polyplacophora, Lessonia nigrecens, among other species.
In the south of Peru, Marcona is an important area of mineral extraction, but also an
area for the conservation of sea lions and pinguins (Punta Marcona). Rocky shores of the
sampling sites are characterized by granitic formations from the Coastal Basal Complex, on
which sedimentary rocks of the San Juan and Pisco formations have deposited sandstone of
calcareous origin (Caldas Vidal 1978). These shores are exposed to wave action, however this
is mitigated by a surrounding rocky reef. Tidal amplitude reaches 1.23 m (HIDRONAV,
2012) and SST varies between 12-24°C, with a marked seasonal pattern (Apaza & Figari
1999), and predominance of cold coastal waters. Upwelling events are common in this area
(Rojas de Mendiola 1981). The most common species in these shores are the macroalgae
Lessonia spp., Macrocystis pyrifera and Pyropia spp., and the invertebrates Loxoechinus
albus and Concholepas concholepas (Galindo et al 1999). La Meca is located near the
Wetlands of Ite, which were once heavily polluted by heavy metals from mining. Sampled
sites are continuos rocky shores of sedimentary origin with sandstone and some volcanic
outcrops from the Chocolate Formation of the coastal cordillera (Acosta Pereira et al. 2012).
The sites are exposed to wave action but this is mitigated by rocky reefstidal range reaches
1.38 m (HIDRONAV, 2012) and SST is around 14 °C. This area is visited by artisanal
fiherman extracting crabs (Leptograpsus variegatus), Concholepas concholepas, and
macroalgae. The most southern locality is Punta Colorada, also characterized by outcrops of
the coastal cordillera and some volcanic Rocks. The shore is exponed but some rocky reefs
are also present. Between thes two localities, there are several artisanal fishing ports (Estrella
Arellano et al. 1998).
CHILE
The coastline of continental Chile extends over 4200 km (from ca. 18°S to 56°S)
encompassing from subtropical to sub-Antarctic waters (Santelices, 2001). The regular and

gulfs, islands, channels and fjords. The rocky shores in northern and central Chile are mostly
exposed to strong wave action (Thiel et al., 2007). Substratum is composed of rock of
volcanic, granitic or sedimentary origin. Most of the coastal range consists of Jurassic and
Cretaceous volcanic rocks (Fariña et al., 2008). Most of the coastline is influenced by the
flowing Humboldt Current System, coastal upwelling and periodic occurrence of El Niño-
Southern Oscillation (ENSO) (Thiel et al., 2007).
Northern Chile: Iquique, Antofagasta and Copiapó
This area represents one of the driest regions of the world, annual precipitation is
extreme low (1 mm to 80 mm) with occasional rainfall episodes during austral summer, but
no large differences between winter and summer exist (Schulz et al. 2011) (Figure 6E, 6F).
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
28
Species richness at Iquique, Antofagasta and Copiapó intertidal rocky sites was 41,
37 and 52 respectively. The high intertidal communities are dominated by the chthamalid
barnacle Jehlius cirratus and the periwinkle Echinolittorina peruviana, occasionally small
limpets Siphonaria lessoni and Scurria variabilis can be also found. Few macroalgae are
present, mostly Porphyra sp. and Pyropia sp. The middle intertidal is dominated by the
anemones Phymactis papillosa and Anemonia alicemartinae, the purple mussel Perumytilus
purpuratus and macroalgae such as the ephemeral green alga Ulva spp. and the fleshy
crustose brown Ralfsia sp., particularly in Antofagasta sites the middle and low intertidal are
dominated by a dense turf of the red alga Caulacanthus ustulatus but in Antofagasta Bay
extensive aggregations of the barrel-shaped tunicate Pyura preaputialis dominated the middle
and low intertidal fringe, this is a non-indigenous species that affect the presence of native
organisms (Caro et al. 2011). The low intertidal is dominated by a conspicuous belt of the
kelp Lessonia berteroana, this brown alga is an ecosystem bioengineers and its holdfast
provides habitat for high variety of small invertebrates (Vásquez & Santelices 1984), patches
of the red algae C. ustulatus and Corallina officinalis var. chilensis are also present. At
several sites the calcareous crusts of Mesophyllum sp. and Lithophyllum sp. dominates the
substrata, over the crusts several individuals of the snail Tegula atra, the black sea urchin
Tetrapygus niger, the edible barnacle Austromegabalanus psittacus and the large mollusc
Enoplochiton niger can be found. At shadow protected places, the sea cucumber Patallus
mollis and the anemone Phymactis papillosa (mostly the blue morph) are quite abundant.
Several filamentous algae can be also found at middle and low intertidal, such as Centroceras
clavulatum, Polysiphonia sp. and Ceramium spp. In some places the brown algae Colpomenia
sinuosa, C. tuberculosa forms patches of several individuals.
Central-Northern Chile: Coquimbo, Los Vilos and San Antonio
In central Chile, Mediterranean climate is predominant characterized by a winter
rainy season and a dry period in summer. The ocean proximity moderates temperatures,
averages between 10°C in winter and 17°C in summer can be found. Presence of snow and
frost are rare, day-night oscillation is also lower. Species richness at Coquimbo, Los Vilos
and San Antonio intertidal rocky sites was 58, 69 and 70, respectively. The chthamaloid
barnacle Jehlius cirratus dominates the sessile communities at high intertidal. The mobile
communities are dominated for Echinolittorina peruviana and the small limpet Siphonaria
lessoni. Mostly fleshy crustose macroalgae are present, such as Hildenbrandia lecanellieri,
Ralfsia spp. and patches of the lichen Thelidium chilensis. The middle intertidal is dominated
mostly by beds of the purple mussel Perumytilus purpuratus, and red algae Mazzaella
laminarioides, Hildenbrandia lecanellieri and the turf-forming alga Gelidium chilensis. The
mobile organisms in the middle zone are dominated by small limpets such as Scurria
araucana, Scurria variabilis and the pulmonate gastropod Siphonaria lessoni. The low
intertidal zone is dominated in rocky exposed shores mainly by crustose algae such as
Lithothamnium spp., Hildenbrandia lecanellieri and the articulate calcareous coralline
Corallina officinalis var. chilensis. In lower proportion the mussel Semimytilus algosus can
be found and a conspicuous belt of the Lessonia spicata. The most common mobile
organisms in the low intertidal zone were Scurria araucana, S. scurria and the key hole-
limpets Fissurella crassa and F. costata. Several species such as Perumytilus purpuratus,
Gelidium chilense and Corallina officinallis var. chilensis are considered ecosystem
bioengineers and it loss can have significant changes in the community structure (Kelaher et
al. 2007). On the other hand, is important to mention that in Central Chile a meso-scale eddy
activity has been described (around 30ºS) (Hormazábal et al. 2004). Therefore expected
Benthic Assemblages in South American Intertidal Rocky Shores
29
differences in the structure of populations across this region can be found (Narváez et al.
2006).
Central-Southern Chile: Concepción and Valdivia
This area represents one of the rainiest regions in Chile, where the annual
precipitation is very high, reaching up to 1250 mm (average last 10 years = 847 mm) at
Concepción and 2400 mm (average last 10 years = 1800 mm) at Valdivia, with constant
rainfall episodes during austral winter (June-September), and also occasionally rainfall during
spring, and even during austral summer (December-February) (Figure 6G).
Species richness at Concepción and Valdivia intertidal rocky sites was 48 and 52
respectively, the communities at the high intertidal are dominated principally by the
chthamalid barnacle Jehlius cirratus and the littorinid snails Austrolittorina araucana,
occasionally the small limpets Siphonaria lessoni, Scurria scurra can be also found. The
middle intertidal is dominated by dense beds of mussels Perumytilus purpuratus and
Semimytilus algosus covered by the red macroalgae Mazzaella laminarioides, and in some
sites, the red macroalgae Mastocarpus latissimus and Gelidium pseudointrincatum. Among
mobile species, the limpets Scurria scurra and S. variabilis, and the snail Tegula atra are
common inhabitant in the middle zone. The low intertidal is dominated by the red macroalgae
Ahnfeltiopsis furcellata and patches of Corallina officinallis var. chilensis. At several sites,
the foliose green macroalgae Ulva sp. is also found. Over and into primary substrate
individuals of the snails Tegula atra (in some places assorted with Prisogaster niger) and
Acanthina monodon are very abundant. At shadow protected places, the anemone Phymactis
papillosa is quite abundant. Others species as the polychaete Phragmatopoma moerchi, the
solitary ascidian Pyura chilensis, and the kelp Lessonia spicata, although less important in
density, are considered important component on these latitudes because are considered
ecosystem bioengineers, which may change significantly the surrounding community
structure (Cancino & Santelices 1984, Sepúlveda et al. 2003a, 2003b).
Southern Chile: Punta Arenas
This area represents one of the most austral regions of the world, where annual
precipitation is high, reaching up to 640 mm at Punta Arenas, with constant rainfall, snow and
hail episodes during all year (Figure 6H). Winds are frequent and often exceed 100 km/h. The
minimum temperature during winter can drop up to -2°C approximately (Butorovic 2013).
Species richness at Punta Arenas intertidal rocky sites was 48. The communities at high
intertidal are dominated by the barnacle Jehlius cirratus and the red macroalgae Porphyra
spp. and Pyropia spp., and over the primary substrate the small limpets Siphonaria lessoni
can be found in medium densities. In the middle intertidal patches of several macroalgae can
be found, such as the coarsely branched Nothogenia fastigiata, Mazzaella laminariodes, the
brown alga Adenocystis utricularis, Ulva sp. and filamentous of several Ceramiales species
(e.g. the introduced species Polysiphonia morrowii), in this zone S. lessoni, and patches of
Perumytilus purpuratus are also found. The low intertidal is dominated by the brown algae
Caepidium antarcticum and Lithophyllum rugosum, however, the most conspicuous
component are the gastropods Nacella magellanica and N. deaurata, which are found in high
densities.
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
30
Figure 6. Sampling sites in the Peruvian and Chilean Pacific. A. Peru Huarmey. B. Peru
Paracas. C. Peru Paracas. D. Peru Tacna/Punta Colorada. E. Northern Chile - Huayquique.
F. Northern Chile - Copiapo. G. Central-southern Chile Cocholgue. H. Southern Chile
Fuerte Bulnes.
Uses and threats to the intertidal rocky shores in South America
The intertidal rocky shores around South America represent a valuable resource for local
populations in many aspects. The main uses given to these shores along with the threats that
such uses produce is summarized in Table 1. In general, localities with dense human
settlements face the problems associated to urbanization and sewage discharges along with
unregulated tourism, while in less densely populated areas, the uses are basically associated to
the extraction of invertebrates and macroalgae for food. Industrialization (e.g. oil and gas
extraction, mining) is another issue affecting the services that these ecosystems may provide.
Table. I. Summary of main uses, threats and impacts at intertidal rocky shores in South
America.
Country /
locality
Uses
Threats / Impacts
CARIBBEAN
Benthic Assemblages in South American Intertidal Rocky Shores
31
Colombia
Food (snails, lobster,
crab, fish, octopus, chitons)
Urbanization, tourism
Decline in species abundance
(some under threat categories by
IUCN)
Pollution, sedimentation
Venezuela
Food (snails, bivalves, sea
urchins
Tourism, urbanization
Decline in species densities
Freshwater runoff,
sedimentation, pollution (sewage),
oil spills, solid waste
Trinidad &
Tobago
Food (fish), tourism,
urbanization
Pollution, freshwater runoff,
overfishing
ATLANTIC
Northeast Brazil
Food (artisanal and tramp
fisheries of shrimp, crab),
tourism, urbanization
Pollution (sewage,
petrochemical), freshwater (urban,
agriculture) runoff, solid waste,
erosion
Southeast Brazil
Tourism, food,
urbanization, marinas
Pollution (ore mining,
petrochemical, heavy metals,
sewage), maritime traffic,
sedimentation (dredging navigation
channels)
South Brazil
Food (octopus, crabs,
oyster, mussel), tourism,
urbanization
Pollution (sewage), invasive
species, destruction of sand dunes,
freshwater runoff, port activities
Uruguay
Food (macroalgae,
mussels), tourism,
Invasive species (Rapana)
Argentina
Urbanization, food,
tourism
Invasive species, pollution
(sewage)
PACIFIC
Colombia
Food (lobsters, fish,
snails, shrimp)
Rock removal
Ecuador
Tourism, urbanization,
food
Pollution (sewage),
sedimentation, gasoline spills
Peru
Food (crabs, snails,
macroalgae, chitons, sea
urchins)
Mining
Pollution (heavy metals from
mining)
Chile
Food (macroalgae, snails)
Pollution (sewage), decline in
macroalgal density
THE CARIBBEAN
In the Colombian Caribbean, besides populated human settlements, the main
economic activity is tourism, so the marine environment is under pressure constantly due to
these related activities and waste disposal. Exploitation of some reources also occurs, for
example the snail locally known as Burgao or Cigua (Cittarium pica), lobsters (Panulirus
spp.), the Caribbean king crab (Damithrax spinosissimus), various fishes (snappers,
groupers), octopuses and chitons (Lopez-Victoria et al. 2003). Due to the exploitation, some
times exceeding sustainable population limits, several of these species have been allocated in
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
32
different risk categories of red lists (Ardila et al. 2002, Mejia et al. 2002). In less densely
populated areas such as Taganaga, next to the Tayrona Natural National Park, small
fishermen villages (ca. 4000 people) have precarious sanitary services polluting the coast with
untreated sewage.
In Venezuela, s         
related to freshwater runoff, sedimentation, pollution, tourist pressure, oil spills and
urbanization (Miloslavich et al., 2003; Paz-Villaraga et al., 2015). In particular, two of the
most important sources of freshwater on the Venezuelan coast are the Tocuyo River, and the
Tuy-Carenero Rivers system. The Tocuyo River discharges near Morrocoy National Park
(Bastidas et al., 1999), and the sediment plume of Tuy-Carenero system can be large enough
to affect the rocky shores of Cabo Codera and Chirimena (Cedeño, 2009). Both rivers are
highly polluted, they receive untreated water from a wide array of agricultural and industrial
sources, and the discharge from drain sewage from urbanization and rural areas; including
untreated waters from Caracas, the capital city of Venezuela. However, no correlations were
found between the structure of assemblages associated with rocky shore and their relative
distances to these rivers. It is very likely that other factors such as the selective collection, for
human consumption, of gastropods, bivalves, and urchins could be affecting these
communities. Some populations of invertebrates have shown an alarming decrease of their
densities, which might be related to fishermen activities. Some of the gastropods in this
situation are Cittarium pica and Astraea tecta, whose juveniles can be found on the low
intertidal (Díaz-Ferguson et al., 2010). C. pica is the second gastropod most heavily fished in
the Caribbean (Gómez-Gaspar, 1999; Miloslavich and Huck, 2009; Schmidt et al., 2002);
however, there are no statistics available for this fishery (Robertson 2003) in the Venezuelan
coast. When C. pica was present (7 of 31 sites), the diameter sizes ranged between 25mm and
40mm, which represented a clear diminution when compared to values reported in the
Archipelago Los Roques National Park on 1987, where maximum size was 115 mm (Castell,
1987; Osorno et al., 2009). Also, this size is classified as small for C. pica in the Colombian
Caribbean coast, Virgin Island and Puerto Rico (Schmidt et al., 2002; Robertson, 2003;
Osorno et al., 2009). Minimum and maximum densities of C. pica were 0.4 ind/m
2
and 1.2
ind/m
2
, respectively; which is lower than densities reported by Castell in 1987 (5.6 ind/m
2
).
Finally, despite intertidal rocky shores in Venezuela are not the principal touristic attraction
on the coast, some of them (e.g. Peninsula of Paraguaná, Morrocoy and Mochima Nationals
Parks, Patanemo, La Sabana and Chirimena) are visited by an important number of tourists,
where random collection of shells and invertebrates is a common practice.
In Trinidad & Tobago, the rocky shore areas are very important for shoreline
protection and they provide habitats for various species of fish, crustaceans, molluscs and
macroalgae. Some rocky areas are very popular for recreational fishing and ecotourism. The
main threats to biodiversity and the marine ecosystem in T&T is from land-based activities.
These include expanding industrialization and urbanization (eg. land clearing for housing
etc), and accompanying pollution and contamination (solid, liquid and gaseous wastes). As
with the rest of the region, overfishing and unmanaged coastal development and agricultural
practices also exacerbate these problems. More recently, extreme weather conditions reflected
in increased rainfall during the wet season and extremely dry seasons (attributed to climate
change) continue to result in increased flooding, freshwater runoff and sedimentation.
Trinidad and Tobago is a highly industrialized country with 2 very large industrial estates
involved in a range of activities dominated by the petrochemical sector. As the largest oil and
n
natural gas processing facilities in the Western Hemisphere. With 11 ammonia plants and
Benthic Assemblages in South American Intertidal Rocky Shores
33
 ammonia and
the second largest exporter of methanol, according to IHS Global Insight (2013). Trinidad and
          
habitats- coral reefs, sea grass beds, estuaries, mangrove forests and coastal swamps, beaches
and bays. These coastal areas account for approximately 90% of annual fish production.
Fishing occurs throughout the marine environment around both islands, in estuaries,
nearshore coastal waters and deep oceans. Today, the local fishing industry is largely
artisanal, based on resources occurring in the coastal and territorial waters, and is
characterized by multi-species, multi-gear and multi-fleet operations (Fisheries Division,
2002). In 2005, the marine fisheries sector contributed $63 million to the Gross Domestic
Product (GDP). Other coastal and marine resources include crustaceans (shrimps, lobsters,
crabs), cephalopods (squid), cetaceans (marine mammals including whales, dolphins, and
porpoises) and sea turtles. Historically, T&T has not been a recognized tourist destination and
              
estimated that on an annual basis approximately 33% of visitors to Trinidad and Tobago use
the coastal resources (Tourism Development Company, 2010). Several beaches in Trinidad
and Tobago (Pigeon Point, Maracas, Mayaro etc.) are very popular for recreation and tourism
but it is the Buccoo Reef in Tobago which generates the greater tourism income (both local
and foreign). The reefs provide livelihoods for a large portion of the local population through
both fisheries and tourism (Burke, 2008). In 2006, the value of the reefs to recreation and
tourism was estimated to be between US$100 and $130 million, or approximately 45% of
               
approximately 0.8 to 1 million USD. The coral reef shoreline protection value was calculated
at between US$18 and US$33 million in 2006 (WRI 2008). These ecosystem services (coral
reef and rocky shores) are important to the island, at the same time they are most vulnerable
to erosion and storm damage.
THE ATLANTIC
In the region of Ceará in Brazil, the intertidal reefs are vital for many human
populations established along the shore. Most of the small villages depend on the artisanal
fisheries and tourism for subsistence, but the aquaculture has also gained importance in the
last decades. The reefs play an essential role as nursery habitat for many fish species and also
for the spiny lobster, the most important economic resource of the region (Igarashi 2010;
Godinho and Lotufo 2010; Cunha et al. 2008). Tourism is a relevant source of income for the
long the whole coast. In the last three
decades, the development of tourism has followed what happened throughout the world, with
an increasing number of tourists visiting especially the coastal zone, attracted by the warm
water and constantly sunny days of the region (SETUR 2009; Aquasis 2003). The beachrock
reefs in Ceará have been strongly impacted by human activities along the shore. The reefs
closer to large urban areas, such as Caucaia, receive a large amount of pollutants carried by
the rivers that run through farmlands, industrial districts and densely populated cities (Nilin et
al. 2007). Locations outside the influence of urban areas are also under stress, because of the
exploitation of algae for industrial use, mainly Gracillaria birdiae (Plastino and Oliveira
2002). Although not properly evaluated, the impact of algae exploitation is easily noticed
when the areas are visited. As an alternative, the cultivation of the algae has been stimulated
in different coastal communities, with variable degrees of success. Also, fishermen looking
for young lobsters, crabs and especially octopuses, constantly visit these reefs. The strategy
used by fishermen for capturing octopus is dislodging the animal with the use of chlorine or
large amounts of salt thrown directly on the burrows or tide pools. Aquasis (2003) has
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
34

the conflicts and problems with the management (or absence of management) at both local
and regional scales. The main problem is that rocky shores are one of the least studied areas
of the Brazilian coast, and the northeast region as a whole is going through an accelerated
process of development and increasing pressure over these coastal ecosystems.
At Sergipe, the coastal zone is a contrasting area, in which there are many activities,
interests and conflicts, in a scenario that consists of urbanized areas, agricultural (sugar cane,
orange and coconut), extractive, industrial and port activities, besides tourism and sale of
properties. Moreover, this area is permeated by low density of occupation and occurrence of
ecosystems of high environmental significance, but which have been subject of accelerated
occupation, a tourism subproduct. This issue generates environmental degradation that hinder
the practice of many activities, including tourism. Regarding the disorderly occupation, it
             
areas of mangroves associated with estuaries. However, mangroves have been the target of
multiple human impacts, mainly shrimp farming and crab catching. In addition, mangroves
and dunes are turning into garbage dumps, without any legal or environmental criteria in the
area. Petroleum, natural gas, limestone and potassium (largest mine in the Southern
Hemisphere) are the main products from mineral extraction, Sergipe is the 6th Brazilian state
in oil production, following Rio de Janeiro, Rio Grande do Norte, Amazonas, Bahia and
Espirito Santo. Pirambu is a new port area in the State comprising a large off-shore terminal
operating primarily with petro and chlorochemical, besides being a vector to expand the
economy and the tourism, it is also a potential environmental problem. The most important
stressing factors on Sergipe rocky shores are the harbor presence, the trampling effects of
tourists and shrimp and crab catching. Other stressing factors are the influence of the petro
and chlorochemical industries, sewage pollution, and coastal erosion.
In Bahia, the main use observed at the rocky shores is trampling, especially for
fisheries of octopus, sea urchin and fish. However, there is no sign of overfishing in these
areas, as there were low numbers of fishermen and most was subsistence fishing by local
communities. Even though all sampling sites are considered important touristic areas, there is
no evidence of strong pressure in most sampling sites. Itaparica and Litoral Norte are the
closest locations to Bahia state capital, Salvador, and thus a popular touristic destination.
Tourism in Litoral Norte increased during the past 15 years with the construction of luxurious
hotel complexes and the improvement of a state highway. During the holiday season it is
common to see people walking on the rock shores. However, considering the number of
visitors in that area, it is likely that the rocky shores are affected by trampling and fishing, but
this needs further experimental tests. This is especially important in Litoral Norte as it
provides feeding and resting habitats for adult and sub-adult green turtles (Jardim et al.,
2014). Natural sedimentation is also common in Litoral Norte. Mar Grande (Itaparica
location) and Praia do Sul (Ilhéus) are the most threatened sampling sites regarding pollution.
Both are located close to urban areas and are subjected to urban runoff, solid waste and
domestic sewage discharge. Even though Stella Maris is located in Salvador, it is not a high
populated area when compared to the other parts of Salvador and not highly exposed to urban
runoff and pollution. Ilhéus is the second largest city, among all sampling sites, with around
220 thousand inhabitants. Itacaré sites are inside an ecological touristic area with a relative
low number of visitors. Thus, touristic pressure and water pollution and solid wastes, here, are
not a threat.
Espirito Santo, in contrast to the Paraná State where ca. 68% of the territory is
preserved by specially protected areas (APA), has only 2% of APA. Furthermore the coastal
Benthic Assemblages in South American Intertidal Rocky Shores
35
area of Espirito santo is out of the Conservation Units (UC). The most important stressing
factors on Espírito Santo rocky shores, directly or indirectly, are tourism, sewage pollution,
industrial complex presence (trading coffee, chocolate, edible oils, citric juices and cellulose),
and a harbour complex that handles petrochemical (mainly oil and natural gas, being the
second petroleum province in the country). Espirito Santo also encompasses the second
largest ore mining dock in the world managed by Vale do Rio Doce Company.
In Sao Paulo, coastal land use and human impacts - The Baixada Santista, at the
Southern end of the sampled coastline, is a major economic zone within São Paulo State and
heavily urbanized area, which includes the cities of Praia Grande, São Vicente, Santos and
Guarujá. Together, these cities sum up 1.6 million habitants, imposing severe impacts on the
coastal environment. Particularly problematic is the Santos Harbour, the largest in South-
America. Apart from a very intense traffic, the channel needs to be frequently dredged to
allow the passage of large cargo vessels, further impacting the seafloor and the water column
due to excessive siltation and suspended materials, including heavy metals and other major
pollutants. Further north, socio-economical activities are leaded by tourism, although there is
increasing pressure for the expansion of the São Sebastião Harbour. At the northernmost
locality, Ubatuba, the coastal impact is relatively small, although the population has been
gradually increasing. Today, the population in Ubatuba is around 85.000 habitants, and
domestic sewage is already a major pollution source.
In Parana, the most important stresses on rocky shores communities are the trampling
effects of tourists and fisherman, the selective collecting for food, oyster and crabs catching,
and mussel seeds for cultures, sewage pollution and bio-invasions. All the sites studied
receive a large amount of tourists every summer (from the end of December to the beginning
of February) and weekends. Coastal environmental problems in the South also include
unplanned occupation nearby the shoreline. Besides the destruction of the frontal dunes, the
occupation invades the beach altering the balance of the whole coastal system. Trampling
effects on the community have been studied only in one rocky coast at the southeastern region
and a negative effect on Chthamalus bisinuatus was observed suggesting that the cumulative
effect over years is significant (Ferreira & Rosso, 2009). Furthermore, the small towns at the
coast double or triple their population during summer months and domestic sewage pollution
and consequent eutrophication of coastal areas is certainly occurring, but the consequences to
rocky shore communities are not known. The brown mussel (Perna perna) is the main item
harvested both to be used directly for food, for commercialization or as seeds for cultures.
The Brazilian government started a regulation since 2006 forbidding the extraction of this
species from natural stocks from September to December each year and also regulating its
extraction during the rest of the year. Although the brown mussel was supposedly introduced
in Brazil from Africa (Sousa et al. 2004), it is well established in the intertidal community
along the southeast and south Brazilian coasts. More recently the brown mussel belt has been
invaded by another mussel, Isognomon bicolor (Adams, 1845), which forms dense
aggregations in some sites in southeastern Brazil displacing P. perna, but that have not been
so abundant in the Paraná and Santa Catarina coasts. We only found I. bicolor in one beach
(Praia de Cima) during 2010 surveys and none in 2013 surveys. Also in the south of Brazil,
the Paranaguá Harbor is the largest cereal port in Latin America, exporting mainly soybean,
and the 3rd largest port of containers from Brazil, following Itajaí, a strategic zone to monitor
alien or invasive species. The port area also presents serious problems of waste disposal. The
presence of large ports along the south coast (Paranaguá, São Francisco, Itajaí and Imbituba)
in addition to the extensive area of bivalve culture in Santa Catarina poses a constant threat of
species invasion in this region. During the surveys we found introduced barnacles at most
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
36
sites visited, being Megabalanus coccopoma (Darwin, 1854) the most frequent, but also
Amphibalanus amphitrite (Darwin, 1854) and A. reticulatus (Utinomi, 1967) (Kloh et al.
2013). In the Paranaguá Bay, Ulva australis (formerly known as U. pertusa) was detected as a
free floating thallus. Monitoring is being carried out to confirm the alien species in the area.
In Uruguay, human uses of rocky shores are mainly recreational, although some
species e.g. mussels) may be harvested by tourists or by a subsistence, small scale hand-
gathering fishery and/or to be sold in local markets (Carranza et al., 2009; Scarabino, 2004).
Extraction of the algae Ulva spp. may also occur associated to uses in local gastronomy,
especially during the summer. Sport fishing (generally unregulated) are frequently observed
in these sites, although some rocky shores are included in the National Protected Area System
(SNAP). Commercial fisheries are restricted to subtidal mussel beds located at Isla Gorriti
(34º57'S 54º58'W) and Isla de Lobos (35º0'S 54º53'W), targeting the blue mussel Mytilus
edulis (Defeo, 1991; Niggenmayer and Masello, 1992; Riestra and Defeo, 1994). To date,
threats to rocky shores biodiversity have not been evaluated at a national level. However,
although not occurring in the intertidal, the invasive rapa whelk Rapana venosa is a matter of
concern since this species preys mainly over mussels in the estuarine-oceanic interphase
(Carranza et al., 2010; Carranza, Delgado, and Martinez, 2013). Other exotic species such as
Isognomon bicolor (Breves et al., 2014) has been detected, but does not seem to have
established so far.
In Argentina, the Buenos Aires province coastline is highly urbanized and harbors
important ports. Playa Chica is located ca. 1.2 km of Mar del Plata Harbour (the most
important fishing port in Argentina) and Quequén is located ca. 2 km m from Quequén
Harbour. Both sites are subject to intense recreational use by summer visitors and pollutants
associated to maritime traffic and urban runoff, such as policyclic aromatic hydrocarbons
(PAHs), trace metals, and Tributyltin (TBT), all of which have been detected in their nearby
ports (Marcovecchio et al. 1998, Bigatti et al. 2009, Albano et al. 2013). The Quequén site
may also be impacted by a nearby (ca. 5 km) sewage effluent (López-Gappa et al. 1990). Río
Negro is not very populated (El Espigón, Punta Colorada) and human settlements are mostly
limited to small summer vacationing villages (La Lobería, Playa Los Suecos). Yet, the
shipping of iron pellets from a loading dock in Punta Colorada might have contributed with
pollutants to this area in spite that the dock in question was intermittently operational over the
past two decades. In Chubut Province, Puerto Lobos is an artisanal fishermen place, with no
evident contamination, and no ports are present. In Puerto Madryn, the local population is
about 80,000 residents but in the summer season this number may duplicate due to the
tourism. In this city, the 2nd port in importance regarding fisheries landings in Argentina is
settled, as well as different industries in nearby the port. Pollutants such as (PAHs),
organochlorinated compounds, trace metals and TBT are present in areas with intense
maritime activity in Golfo Nuevo coasts (Commendatore et al., 2000; Esteves et al., 2006; Gil
et al., 2006; Commendatore and Esteves, 2007; Massara Paletto et al., 2008; Bigatti et al.,
2009; Commendatore et al., 2012). Imposex (masculinization of female gastropods) has been
detected in the port zone but at a low frequency in the sampling sites. These are used mainly
for tourism at Punta Este during the summer season. In Camarones, the population is around
1300 habitants and the port is used by fishing boats. Near the port, imposex and TBT
contamination were detected (Bigatti et al., 2009), while the sampling sites far from this place
are imposex free. The sampling site "Algueros" is a place of algae collection for industrial
purposes, and the other places are used by tourist for recreation and sport fishing. At Puerto
Deseado, near the port, where the maritime traffic is high, TBT contamination has been
detected (Bigatti et al., 2009), however, TBT was not detected in the sampling sites.
Benthic Assemblages in South American Intertidal Rocky Shores
37
Recollection of the limpet Nacella magellanica is common within the local people. At Tierra
del Fuego Island, Playa Larga is likely the most impacted by human activities due to its
proximity to Ushuaia. This city is situated in the coast of the Beagle Channel and hosts the
southern port of South America, characterized by intense maritime traffic. Contamination by
TBT (Bigatti et al., 2009), PAHs (Esteves et al., 2006), metals (Giarratano et al., 2010) and
sewage were detected at this area, and up to 100% incidence of imposex was observed in
female gastropods.
THE PACIFIC
In the rocky shores of the Colombian Pacific, the main resources exploited are lobsters
(Panulirus gracilis) and fishes (snappers, groupers), however, some other species such as
oysters (families Ostreidae and Pteriidae), and snails (families Littorinidae and Muricidae) are
locally exploited. Another source of perturbation is the removal of rocks in the search for
shrimps (Upogebia spp.) that are used as bait in fishing activities (Lopez-Victoria et al. 2003).
The population density on the Pacific coast is very low in comparison to the Caribbean, with
most of the shore basically uninhabited. In this way, human disturbance is localized and/or of
low impact.
The rocky shores of Ecuador are used for urbanization, fishing, tourism, recreation, and
marinas. Punta Gorda is relatively far away from human settlements and therefore, less
impacted, but Punta Bellaca, more accessible was once a fishing ground for the lobster
Panulirus gracilis and it is used sporadically at present by tourism. The main threats detected
in the coast of Ecuador are sedimentation, pollution with sewage waters, diesel spills at the
marinas, development of vacational complexes and unplanned human settlements.
In Peru, fisheries are a key component of the countries economy. Such fisheries are mostly
pelagic resources, however, several species of the coastal zone are also fishing targets. At
Paita, the barnacle Pollicipes elegans is commercially exploited and exported (Villena 1995,
Oliva 1995, Pinilla 1996). Along the coast, there are several benthic species subject to
artisanal fisheries in the intertidal including invertebrates and macroalgae: Fissurella spp,
Polyplacophora, Pyropia spp., Chondrocanthus chamissoi, Patallus mollis, Concholepas
concholepas, Lessonia nigrecens, Lessonia spp., Macrocystis pyrifera, Pyropia spp., and
Loxoechinus albus among others (INRENA, 2002). At Paracas, subtidal artisanal fisheries
also occurs (Mendo & Wolff 2003). Mining has been very intensive in Peru and some areas
show pollution associated to mineral exploitation including heavy metals (Jacinto et al. 2001,
Jacinto et al. 2003, Jacinto et al. 2008).
In Chile, the impact of human activities on the rocky intertidal has been studied extensively
(see Fernández et al. 2000 and references therein). Several types of human impacts clearly
affecting nearshore ecosystems can be identified along the coast of Chile, although the
intensity, extent, and persistence of these sources vary geographically (Fernández et al. 2000).
One of the most important human impacts along the Chilean coast, in terms geographical
extent and persistence, are sewage discharges and the harvesting of invertebrates and algae in
rocky shores (Gross & Hayek 1998). The removal of several important ecologically species
during low tides have a dramatic effect on the structure of the intertidal communities.
Historically, intertidal populations were exploited as a food resource but in modern times,
flora and fauna are also collected for fish bait, for research, as souvenirs, and for home
aquaria uses. A keystone muricid gastropod Concholepas concholepas, locally known as
         ioning of food webs at
Patricia Miloslavich, Juan José Cruz-Motta, Alejandra Hernández
et al.
38
intertidal rocky shores (Castilla, 1999). The increasing international demand for brown large
macroalgae and local requirement as food for abalone aquaculture has caused deterioration of
natural kelp populations along the rocky shore in Chile, especially between 18° and 42°S
(Vega et al. 2014). Impact of non-indigenous species have been poorly documented, some
species have displayed an expansion of their geographical range and increasing of their
abundance, such as the anemone Anemonia alicemartinae (Hausermann & Forsterra 2001)
and the red alga Mastocarpus sp. (Macaya et al. 2013). Together with exploitation of marine
species, sewage discharges are important in geographical extension and persistence having an
impact along the Chilean coast (Fernández et al. 2000).
Gaps in our knowledge and future prospects
Knowledge of the intertidal rocky shore ecosystem is very variable among the
different South American countries, and also between different areas within each of the
countries. While some countries seem to have a long tradition of research in these ecosystems
(e.g. Chile), other are just beginning to study them (e.g. Venezuela). In the Southern
Caribbean, rocky shores remain virtually unexplored, despite the high diversity that these
ecosystems support (Miloslavich et al., 2010). For example, in Venezuela, most of the
research articles on these ecosystems are non-published descriptions or informal inventories
about the fauna and algae that inhabit them. Few studies have considered quantitative
description of patterns of temporal and across different scales, which would allow proposing
underlying mechanisms that drive assemblages associated with intertidal rocky shores (Cruz-
Motta, 2007). Furthermore, the total number of scientific publications for this ecosystem is
the lowest for coastal and marine ecosystems of Venezuela (Miloslavich et al., 2003).
Consequently, describing patterns and determining processes affecting assemblages
associated with Caribbean intertidal rocky shores is still a prevailing necessity. Caribbean
rocky shores harbor an important biodiversity, however