Olive Ridley Nesting in Peru: The Southernmost Records in the Eastern Pacific

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Marine Turtle Newsletter No. 126, 2009 - Page 1
Issue Number 126 October 2009
ISSN 0839-7708
Editorials:
Kemp’s Ridley Annual Reproductive Data Should be Posted on Government Agency Web Sites................CW Caillouet, Jr.
The IUCN’S New Clothes: An Update on the Dhamra – Turtle Saga..................................................................J Lenin et al.
Articles:
Olive Ridley Nesting in Peru: The Southernmost Records in the Eastern Pacic..........................................S Kelez et al.
Habitat Choices Made by Hatchling and Juvenile Green Turtles and Loggerheads.....................MM Smith & M Salmon
Leatherback Nesting in Tomatal, Oaxaca, Mexico in 2007/2008.....................................L Vannini & PA Rosales Jaillet
Genetic Characterization of Loggerhead Turtles from Bycatch and Uncommon Nesting Sites...........................EC Reis et al.
IUCN-MTSG Quarterly Report
Letter to the Editor
Obituary
Announcements
Recent Publications
Juvenile green turtle resting within (top) and a juvenile loggerhead resting upon (below) a
mat of Sargassum. Both pictures were taken within minutes after each turtle was released
in the ocean near a mat of oating algae - see pp 9-13 (photos by A. Cornett).
Marine Turtle Newsletter

Marine Turtle Newsletter No. 126, 2009 - Page 1
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Nicolas J. Pilcher
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Editors:

Marine Turtle Newsletter No. 126, 2009 - Page 5
Olive Ridley Lepidochelys olivacea Nesting in Peru:
The Southernmost Records in the Eastern Pacic
Shaleyla Kelez1, Ximena Velez-Zuazo2, Fernando Angulo3 & Camelia Manrique4
1ecOceanica, Peru & Duke University, 135 Duke Marine Lab Rd, Beaufort NC 28516, USA (E-mail: shaleyla.kelez@duke.edu);
2ecOceanica, Peru & Universidad de Puerto Rico,USA (E-mail: xvelezuazo@gmail.com); 3CORBIDI, Peru (E-mail: fangulo@
corbidi.org); 4Grupo de Tortugas Marinas, Peru (E-mail: camelia.manrique@web.de)
Epilogue
Recently obtained documents from the offices of the Forest
Department of Orissa show that the land on which the Dhamra port
project is being built is a Protected Forest. The project does not have
the mandatory clearance from the Government of India’s Ministry
of Environment and Forests for usage of such land and has therefore
violated the Indian Forest Conservation Act, 1980. An application
has been led in the Supreme Court by conservationists Bittu Sahgal,
Romulus Whitaker and Shekar Dattatri seeking punitive action,
and on October 9, 2009, the court issued notices to the Ministry
of Environment and Forests and the state government of Orissa.
FRAZIER, J.G. 2005. Biosphere reserves and the Yucatan Syndrome:
Another look at the role of NGOs. In: R. Smardon and B. Faust (Eds.)
Biosphere Reserve Management in the Yucatan Peninsula - Special
Edition. Landscape and Urban Planning 74: 313-333.
FRAZIER, J. 2008. Why do they do that? Ruminations on the Dhamra
drama. Marine Turtle Newsletter. 121: 28-33.
IGOE, J. & S. SULLIVAN. 2009. Problematising Neoliberal Biodiversity
Conservation: Displaced and Disobedient Knowledge Executive
summary of a workshop held at Washington D.C., American University,
Department of Anthropology, May 16-19, 2008. Available at www.iied.
org/pubs/pdfs/G02526.pdf
MATHEW, S. 2004. Socio-economic aspects of management measures
aimed at controlling sea turtle mortality: a case study of Orissa, India.
Paper presented at the Expert Consultation on Interactions between
Sea Turtles and Fisheries within an Ecosystem Context, Rome, 9-12
March2004. FAO Fisheries Report No. 738, Suppl. Rome, Food and
Agriculture Organization of the United Nations (FAO), 2004. 238p.
PRUSTY, B.G. & S. DASH. 2006. The effect of rookery geomorphology
on olive ridley nesting in Gahirmatha, Orissa. In: K. Shanker &
B.C. Choudhury (Eds.). Marine Turtles of the Indian Subcontinent.
Universities Press, Hyderabad, India. pp. 384-392.
SHANKER, K. B.C. CHOUDHURY, A. FERNANDES, S. GOPAL, A.
HAMID, C. KAR, S. KUMAR, J. LENIN, B. MOHANTY, B. PANDAV,
S. RODRIGUEZ, A. SRIDHAR, W. SUNDERRAJ, B. TRIPATHY, R.
WHITAKER, S. WORAH & B. WRIGHT. 2009. A little learning …the
price of ignoring politics and history. Marine Turtle Newsletter 124: 3-5.
SHANKER, K., B. PANDAV & B.C. CHOUDHURY. 2004. An assessment
of the olive ridley turtles (Lepidochelys olivacea) nesting population in
Orissa, India. Biological Conservation 115: 149 – 160.
SHANKER, K. & R. KUTTY. 2005. Sailing the agship fantastic: myth and
reality of sea turtle conservation in India. Maritime Studies 3-4: 213-240.
SHANKER, K. & B.C. CHOUDHURY. 2006. Marine turtles in the Indian
subcontinent: a brief history. In: In: K. Shanker & B.C. Choudhury
(Eds.). Marine Turtles of the Indian Subcontinent. Universities Press,
Hyderabad, India. pp. 3-16.
SRIDHAR, A. 2005. Sea turtle conservation and sheries in Orissa,
India. Samudra Monograph. International Collective in Support of
Fishworkers, Chennai, India.
WRIGHT, B. & B. MOHANTY. 2006. Operation Kachhapa: an NGO
initiative for sea turtle conservation in Orissa. In: In: K. Shanker &
B.C. Choudhury (Eds.). Marine Turtles of the Indian Subcontinent.
Universities Press, Hyderabad, India. pp. 290-303.
The olive ridley sea turtle, Lepidochelys olivacea, is widely
distributed in all oceans except the Mediterranean Sea, and is
currently listed as Vulnerable by IUCN due to declining numbers
in the past several decades (www.redlist.org). Some populations of
olive ridleys, along with Kemp’s ridleys, exhibit a particular nesting
strategy called arribadas, which consist of the simultaneous nesting
of hundreds and even thousands females on a relatively small portion
of beach (Hughes & Richard 1974). Ridleys also exhibit solitary
nesting, the common reproductive behavior of other chelonians.
The occurrence of these two contrasting nesting strategies, unique
for ridley sea turtles, may demonstrate a capacity to maximize
offspring survival in a complex ecological environment (Bernardo
& Plotkin 2007).
In the Eastern Pacic (EP), the olive ridley is the most abundant
sea turtle species and ranges from US to central Chile; however,
it is most commonly observed in waters off Mexico and Central
America (Eguchi et al. 2007; Olson et al. 2001a, 2001b). Currently,
arribada beaches occur in Panama, Costa Rica, Nicaragua and
Mexico (Abreu-Grobois & Plotkin 2007; NMFS & USFWS 1998).
Non-arribada (i.e. solitary) beaches are located mainly in Mexico
but nesting is reported from Mexico to Colombia and rarely from
Ecuador and Peru (Hays-Brown & Brown 1982; NMFS & USFWS
1998). All the females that nest in the different rookeries in the EP
are believed to belong to the same subpopulation (Abreu-Grobois
& Plotkin 2007); however, it seems that some demographic
independence does exist among beaches (Abreu-Grobois & Plotkin

Marine Turtle Newsletter No. 126, 2009 - Page 6
Figure 1. Locations of recorded nests (circles) and sites where
interviewees observed nesting activity (stars) in the northern
Peruvian Coast. Nest references at Punta Malpelo and Nueva
Esperanza from Hays-Brown & Brown 1982 and Vera et al.
2008, respectively.
2007; Lopez-Castro & Rocha-Olivares 2005).
Diet analysis, feeding observations and turtle migrations have
shown that coastal Peru (nearshore and offshore) is a signicant
foraging area for sea turtles (Hays-Brown & Brown 1982; Paredes
1969; Shillinger et al. 2008) but is not considered an important area
for nesting, although nesting does occur in Peru. Hays-Brown &
Brown (1982) reported an olive ridley nest laid in 1979 in Punta
Malpelo, Tumbes (Fig. 1) with 79 undeveloped eggs and 1 egg with
an embryo. Turtle crawls were also observed in beaches south to
Punta Malpelo, suggesting nesting activity. In the subsequent two
decades, no other evidence of nesting has been reported. However,
in recent years, nesting activity has been observed.
New ndings: In July 2000, a nest in Caleta Grau, Tumbes (Fig.
1) was observed by shermen who informed personnel from the
Tumbes Laboratory of the Instituto del Mar del Peru (IMARPE)
and from Fondo de Desarrollo Pesquero (FONDEPES). When the
nest emerged in September, the hatchlings were raised in captivity
in the facilities of the FONDEPES Aquaculture Center La Tuna
Carranza at Puerto Pizarro, Tumbes (Perez et al. 2001). Nine
months later, in June 2001, we were able to evaluate the olive ridley
surviving hatchlings. The mean hatchling length was 18.7 ± 1.5 SD
cm (range: 15-22.1, n=35) for curved carapace length from notch
to tip (CCL) while their mean weight was 988 ± 229 SD g. (range:
630-1530, n=35). Turtles weighing more than 1.1 kg (n=9) were
tagged with inconel tags in both rear ippers and all turtles were
released 1 hour offshore.
During 2001 and 2002, we conducted a sea turtle survey along
the Peruvian coast (3080 km), covering a total of 57 localities,
including ports, shing villages, beaches, and guano islands and
guano points. In 47 of these sites, we informally questioned a total
of 85 inhabitants, particularly shermen, to learn about sea turtles in
the area. Our questions covered a wide range of subjects including
the presence of different sea turtle species and habitats, abundance,
food items, human interactions, exploitation, commercialization,
uses, strandings, and nesting activity. We specically asked if they
knew how sea turtles reproduce and if they have seen reproductive
events. Of the 47 sites where we conducted interviews, we obtained
information about nesting activity, including direct observations of
nesting females, eggs and/or hatchlings in only ve locations: Punta
Capones, El Bendito, Playa Hermosa and Caleta Grau in Tumbes,
and Negritos in Piura (Fig. 1). All these areas are located in the two
northernmost coastal departments of Peru.
Five years elapsed until we obtained new evidence of sea turtles
nesting in Peru. In August 2007, several open nest chambers and
one nest were observed by a house guard on a beach north of El
Ñuro, Piura (Fig. 1). The nest was located about 50 m from the
high tide mark and the guard estimated it had around 300 eggs, but
eggs were not counted. Subsequently, within a week, the guard and
a local sherman removed all the eggs to eat them, either cooked
or raw as accompaniments while drinking pisco (Peruvian liquor
distilled from grapes).
Three eggs, were observed, photographed and measured by F.
A. (Fig. 2), who was also allowed to keep one for genetic analysis.
This egg was analyzed using molecular techniques to determine
the sea turtle species. A 740 base-pairs fragment of the control
region of the mitochondrial DNA was amplied and sequenced
using primers LTEi9 and H950 (Abreu-Grobois et al. 2006), and
subsequently compared with available sequences for Pacic sea
turtles on Genbank (http://www.ncbi.nlm.nih.gov/) and SWFSC
Marine Turtle Research Program (http://swfsc.noaa.gov). Results
conrmed that the sea turtle clutch from El Ñuro was deposited by
an olive ridley sea turtle with haplotype O. This haplotype has been
previously reported for East Pacic nesting populations, including
Costa Rica and Mexico (Bowen et al. 1998; Briseño-Dueñas 1998;
Lopez-Castro & Rocha-Olivares 2005), and represents the rst
genetic information from a sea turtle nesting in Peru.
The eggs had a mean diameter of 3.68 cm (range: 3.65-3.70,
n=3), which is smaller than the global average (3.93 cm) reported
for this species (Miller 1997), slightly larger than the range reported
for Playa El Valle (2.9-3.6, mean = 3.3 cm), an important nesting
beach in Colombia (Barrientos & Ramirez 2008) but is within the
size range of olive ridley eggs in EP rookeries (Hirth 1980). This
olive ridley nest is the southernmost record of a sea turtle nest in
the Eastern Pacic.
More recently, in March 2008, another nest was observed in
Nueva Esperanza, Tumbes (Fig. 1), when 36 hatchlings were
observed during hatchling emergence and positively identied as
olive ridleys (Vera et al. 2008).
Olive ridleys can be found along the entire Peruvian coast, but
they are more common in the north where sea surface temperatures
are warmer (Hays-Brown & Brown 1982). They are the third most
abundant species captured on pelagic longlines in Peru (Kelez et al.
2008) and the second most commonly captured species in gillnets in
the Pisco area (de Paz et al. 2002). Biometric data from our longline
on-board observer project and from eld surveys show that the mean
CCL of olive ridleys in Peru is 61.1 ± 7.4 SD cm (range 42-78, n=63,
unpublished data). Using the average size of nesting females as the
best estimate for minimum adult size (Miller 1997) and data from

Marine Turtle Newsletter No. 126, 2009 - Page 7
the closest signicant nesting beach Playa El Valle in Colombia
(Barrientos & Ramirez 2008), 33% of the individuals observed
in Peru can be considered adults. However, if we removed the
turtles caught by longlines and consider only the individuals found
during coastal surveys (strandings and carapaces on sale), which
seem to come from more near shore areas, the proportion of adults
changes to 57% (average CCL = 64 ± 7.2 SD cm, range 48.3-78,
n=28). Also, during longline on-board observations we were able
to observe 3 adult males showing secondary sexual characteristics
and one of them measured 63 cm CCL. These ndings indicate that
olive ridleys are a common species in Peru and that there is a large
adult component in coastal waters. This is not restricted to years
with incursions of warm water (el Niño or ENSO), but is generally
the case.
The recent observations of nests in Peru are not unique in the
Southeast Pacic. In the last ve years, nesting activity has been also
reported in Ecuador. Alava et al. (2007) reported a nest with 50 eggs
and one dead late-stage embryo in a beach near Manta in October
2004. The authors also reported a hatchling found in October 2006
in a beach in the Province of Esmeralda. More recently, increasing
evidence of nesting activities was found in several beaches in
continental Ecuador: Ayampe – Puerto Rico, Montañita, Puerto
López, Jupiter, Portete and Isla de la Plata (Baquero et al. 2008).
In Pacic Colombia, the olive ridley is the most common nesting
species. The Colombian Institute of Coastal and Marine Research
(INVEMAR) considers four beaches to have abundant olive ridley
nesting (more than 100 turtles/beach/year). These are in order of
importance Playa El Valle, Amarales, Mulatos and Vigia (Ceballos-
Fonseca et al. 2003). In addition to these four, an additional 36
other beaches are used by olive ridleys for nesting. Despite being
abundant in Colombia, the nesting aggregations there are threatened
by intensive direct capture of nesting females and egg predation for
human consumption (Barrientos & Ramirez 2008; Ceballos-Fonseca
et al. 2003). Nonetheless, current conservation efforts might be
increasing the survival of hatchlings. Some hatcheries are protecting
a large number of nests, especially at Playa El Valle, which has had
an active hatchery since 1991 (Ceballos-Fonseca et al. 2003).
Nesting at low density in higher latitudes, such as the recent
nesting events in Peru and Ecuador, may reect relaxed natal homing
in olive ridleys, which facilitates the colonization of beaches distant
from the respective natal beaches. Studies have shown that olive
ridleys do not always return to the same beach to nest. A small
proportion of ridleys have been found using both Nancite and
Ostional beaches; other adult females from Nancite and Ostional
have been observed nesting, or about to nest, in Chacocente,
Nicaragua and Escobilla in Mexico (Cornelius & Robinson-Clark
1986). More recently, a female that nested in Osa Peninsula, Costa
Rica was seen nesting in Playa El Valle, Colombia, 728 Km away
(Barrientos & Ramirez 2008). The relaxed natal homing behavior
may explain the lack of strong genetic structure observed among
EP olive ridley rookeries (Bowen & Karl 2007). Wandering gravid
females are important to the species’ continuity in the long term,
as particular nesting beaches may become unsuitable over time for
reproduction. In northern Peru, coastal inhabitants often assert that
sea turtle nesting was common “in the past,” probably around the
1960s (Hays-Brown & Brown 1982). Therefore, the new nesting
activity might be a re-colonization of beaches at the southern limit
of their reproductive distribution in the Eastern Pacic.
The recent nesting activity reported in Peru and Ecuador might
also be the result of a combination of two factors: increased research
efforts and more conservation. Even though there are no ‘baseline’
data, there has been greater activity related to sea turtles in Peru and
Ecuador in the past 10 years. Additionally, in the EP, actions such
as protection of nesting females and nests and by-catch mitigation
in coastal an oceanic waters have also increased, and likely have
had a positive impact on olive ridleys. If population numbers in
the area are increasing, nesting events could be increasing as well.
The hatcheries established in Playa El Valle, the most important
nesting beach in Pacic South America, have been protecting
nests and releasing hatchlings into the population since 1991.
Considering that time to maturity has been calculated in 13 years for
olive ridleys (Zug et al. 2006), an increase in the adult population
since 2004, with concomitant increased nesting activity, seems
like a plausible possibility. Additionally, nesters numbers in the 2
most important arribada beaches in the EP, Ostional and Escobilla,
increased considerable from the 1980s to the year 2000 (Chaloupka
et al. 2004).
However, the intense capture of olive ridleys in the EP must
not be forgotten. During the 1960s and 1970s, olive ridleys were
harvested for the leather industry. Slaughter houses dedicated
exclusively to this sea turtle species operated intensely in Mexico
and Ecuador in the 1970s until populations began to decline
(Cliffton et al. 1982; Cornelius 1982). As a consequence, many
arribada beaches collapsed and have not been able to recover to
past levels yet (Abreu-Grobois & Plotkin 2007). Currently, olive
ridleys are legally protected in all countries of the EP with some
exceptions for egg harvest in Panama, Costa Rica, Nicaragua and
Guatemala (e.g. Hope 2002); El Salvador banned this practice in
February, 2009 (http://www.mag.gob.sv). Nevertheless, in spite of
the legal protection, enforcement is sub-optimal and two principal
threats remain in the region: sheries bycatch and egg exploitation
(Cornelius et al. 2007; Frazier et al. 2007).
The findings presented here are an encouraging sign of
conservation efforts and monitoring. The need for increasing
conservation programs in the northernmost coastal departments of
Peru (Tumbes and Piura) is evident. Under these circumstances, it
is extremely important to protect each nest deposited on Peruvian
beaches and increase conservation efforts. Nests in northern Peru
will not only add to population numbers but also have the potential
Figure 2. Three eggs observed in a beach north of El Ñuro,
Piura.

Marine Turtle Newsletter No. 126, 2009 - Page 8
of contributing to a higher proportion of males due to colder
temperatures compared to rookeries north of Peru (Fiedler & Lavin
2006). We recommend the implementation of regular monitoring
of beaches and the protection of each natural nest.
Acknowledgments: We thank O. Perez and A. Lujan for giving us access to
the headstarted hatchlings and for all their efforts to release them offshore,
Dr. Llanos for all his help in Tumbes, APECO for their support, NMFS-
SEFSC for eld materials and M. Godfrey for his valuable comments. The
sequencing and genotyping facility of the University of Puerto Rico-Rio
Piedras is supported in part by the following agencies: NCRR-AABRE
grant no. P20RR16470, NIH-SCORE grant no. S06 GM08102, University
of Puerto-Rico Biology Department, NSF-CREST grant no. 0206200 and
NINDS-SNRP USA NS39405. The information reported were obtained
under the following research permits: 016-2002-INRENA-J-DGFFS-
DCB, 049-2002-INRENA-DGFFS-DCB, 014-2004-INRENA-IFFS-DCB,
017-2004-INRENA-IFFS-DCB, and 117-2008-INRENA-IFFS-DCB.
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A Comparison Between the Habitat Choices Made by Hatchling and
Juvenile Green Turtles (Chelonia mydas) and Loggerheads (Caretta caretta)
Morgan Michelle Smith1,2 & Michael Salmon1
1Department of Biological Sciences, Florida Atlantic University, 777 Glades Rd, Box 3091,
Boca Raton, Florida 33431 USA (E-mail: salmon@fau.edu);
2Pacic Whale Foundation, 300 Ma’alaea Rd, Suite 211, Wailuki, Maui, Hawaii 96793 USA (E-mail: shmorg@aol.com)
Hatchling green turtles and loggerheads emerge from underground
nests at night, crawl to the ocean, and swim offshore during a
“frenzy” period that lasts about 24 h (Wyneken & Salmon 1992).
By the end of the frenzy period, the turtles are typically in deep
oceanic waters where they remain for several years (Bjorndal et al.
2000; Reich et al. 2007).
Many hatchling and juvenile marine turtles fail to survive
(Heppell et al. 2003) because they are unable to defend themselves
against their predators (Gyuris 1994; Pilcher et al. 2000). Their
best option may be to avoid detection. In the Western Atlantic,
postfrenzy loggerheads (Caretta caretta) probably accomplish that
feat by minimizing movement in open water and by associating
with mats of Sargassum which the turtles resemble in color and
in “texture” (Musick and Limpus 1997; Witherington 2002). This
association makes them difcult at least for humans to distinguish
from an algal background although whether their natural predators
are similarly affected remains unknown.
Much less is known about how hatchling green turtles (Chelonia
mydas) avoid detection by predators except that when released in the
ocean after the frenzy period, they are not inactive like loggerheads.
Instead, young (2 – 8 week old) green turtles swim vigorously, make
frequent shallow dives and only briey return to the ocean surface
to breathe (Salmon et al. 2004), probably because at that location
they are vulnerable to avian predators (such as frigate birds; Carr
and Meylan 1980). Their counter-shaded coloration has led to the
hypothesis that both hatchlings and small juveniles prefer open water
(Musick & Limpus 1997) even though in the absence of cover many
predators take small turtles (Stancyk 1982). Nevertheless, the “open
water” hypothesis was until recently supported by the apparent
absence of juvenile green turtles from the same Sargassum mats
where juvenile loggerheads were abundant (Witherington 2002),
and by a behavioral study done in large tanks demonstrating that
young green turtles avoided oating mats (plastic “plants”) and
swam instead in the tank’s “open” areas (Mellgren et al. 2003).