Clarisse Odebrecht

Universidade Federal do Rio Grande (FURG) | FURG · Institute of Oceanography - IO

“Surf diatoms” can form high biomass in the surf zone of sandy beaches around the world, Asterionellopsis and Anaulus being the main genera of this group in Brazil. Asterionellopsis glacialis was considered a cosmopolitan species, and taxonomic studies using molecular and morphological tools showed that A. glacialis is a complex with cryptic and se...

Several automated molecular methods have emerged for distinguishing eukaryote species based on DNA sequence data. However, there are knowledge gaps around which of these single-locus methods is more accurate for the identification of microalgal species, such as the highly diverse and ecologically relevant diatoms. We applied genetic divergence, Aut...

The Taperaçu Estuary is distinct from other Amazonian estuaries due to the absence of significant fluvial discharge and consequent dominance of marine influence. The present study investigated the influence of physical-chemical variables on the composition and dynamics of the local phytoplankton and their spatiotemporal variation, with emphasis on...

Estuaries are among the most productive aquatic ecosystems and provide important ecological and economic services in coastal areas. However, estuarine systems have been threatened worldwide by natural and anthropogenic impacts acting on local, regional and global scales. Long-term ecological studies contribute to the understanding and management of...

Harmful effects of the toxic cyanobacterium Nodularia spumigena were observed in experimental marine shrimp production ponds in Brazil. Strains of this cyanobacterial species were isolated and cultured, and in the present study, we evaluated the influence of light intensity and the concentration of dissolved inorganic nitrate and phosphate on the g...

Diatoms are considered the main base of the Southern Ocean food web as they are responsible for more than 85% of its annual primary production and play a crucial role in the Antarctic trophic structure and in the bio-geochemical cycles. Within this context, an intense diatom bloom reaching > 45 mg m −3 of chlorophyll a was registered in the Norther...

Estuaries are influenced by seasonal and inter-annual variability in marine and freshwater intrusion. This variability affects the abundance and distribution of resources and consumers and may drive estuarine food web dynamics. This study tests for relationships among environmental variables and estuarine consumer δ 13 C, and assesses whether fresh...

Exchange of matter and energy between ecosystems has been an important topic in ecology. In this work, we estimated the relative assimilation and seasonality of autochthonous versus allochthonous organic matter by macrofauna and fishes of a subtropical sandy beach. Sampling of consumers and autotrophic food sources (particulate organic matter in su...

Harmful blooms of the cyanobacterium Nodularia spumigena occur in several parts of the world, and this species is notorious for its ability to produce cyanotoxins, such as nodularin. This species is also able to perform akinete differentiation, thus favoring the success of their populations under adverse conditions. In southern Brazil, N. spumigena...

Estuaries are highly influenced by environmental changes, especially the effects of marine and freshwater intrusions on salinity profiles. Such environmental fluctuations affect abundance and distribution patterns of consumers and food sources and may lead to temporal changes in trophic networks sustaining estuarine fishes. In this work, we investi...

Attempts to provide general patterns of phytoplankton and their regulating factors benefit from ecosystem comparisons, but these are strongly biased toward high-latitude environments of the northern hemisphere (> 20°N). In the present study, we compare the phytoplankton biomass and composition variability in two coastal environments in the southern...

The Patos Lagoon (10,000 km ² ) is the dominant feature in the coastal plain of Southern Brazil. The estuary of the Patos Lagoon (32° 05' S, 52° 10'W) and adjacent coast were chosen as a SITE (1,500 km ² ) for the Brazilian Long Term Ecological Research (LTER). This region presents high biological productivity and at the same time is host of import...

The continental shelf in Southern Brazil is characterized by high biological productivity associated with horizontal and vertical density gradients due to the mixing of distinct water masses. Phytoplankton biomass and composition were evaluated in summer 2013 along an on-offshore transect off the mouth of the Patos Lagoon (Lat. 32⁰12S). Photosynthe...

Blooms of the toxic cyanobacterium Nodularia spumigena occur in various locations worldwide, but have not been observed in Brazil until recently. Three Nodularia strains were isolated from summer blooms in experimental shrimp production ponds of Penaeus vannamei in Rio Grande, in southern Brazil; these strains were characterized by morphology, phyl...

The composition and distribution of phytoplankton assemblages were studied monthly at two sites in the Patos Lagoon estuary and at one site on the adjacent coast over three years (May 2012–April 2015). Samples were collected for microscopic examination and high-performance-liquid-chromatography pigment analysis. The pigment data were analysed using...

Three sampling stations located in the inner Patos Lagoon estuary, the lagoon’s mouth and the adjacent coastal beach were visited monthly from the end of 1992 until 2014. The stations are in close proximity, but are distributed along saline and hydrological gradients and had never previously been analysed together. Our main questions were: (1) Are...

We report here the draft genome assembly of the brackish cyanobacterium Nodularia spumigena strain CENA596 isolated from a shrimp production pond in Rio Grande do Sul, Brazil. The draft genome consists of 291 contigs with a total size of 5,189,679 bp. Secondary metabolite annotations resulted in several predicted gene clusters, including those resp...

The diatom Asterionellopsis glacialis sensu lato forms high-density patches in the surf zone of some sandy beaches worldwide and was until recently considered a cosmopolitan species. With the recent description of four cryptic species, the identity of specimens found in these accumulations remains uncertain. In this study, diatom patches were sampl...

Surf zone diatoms thrive in the harsh conditions of exposed sandy beaches. The patch-forming Asterionellopsis glacialis sensu lato (A. glacialis s. l.) is the main producer in a rich food chain in Cassino Beach, southern Brazil. This work aimed to verify the influence of sediment particles on the quantity and composition of carbohydrates produced i...

Abstract An updated synthesis of cyanobacteria and algae information is presented for Brazil aiming to refine the data gathered to date and evaluate the progress of the biodiversity knowledge about these organisms in the country since the publication of the Catálogo de Plantas e Fungos do Brasil. The results of 2015 showed an increase of 1,250 spec...

The aim of this study was to evaluate the influence of salinity (S) fluctuations on the growth and carrying capacity of the dinoflagellates Akashiwo sanguinea and Prorocentrum micans, isolated from coastal water in southern Brazil, and the relationship between salinity and their distribution in the environment. The effect of salinity on these speci...

Seasonal and interannual changes (1993–2012) of water temperature and transparency, river discharge, salinity, water quality properties, chlorophyll a (chl-a) and the carbon biomass of the main taxonomical phytoplankton groups were evaluated at a shallow station (∼2 m) in the subtropical Patos Lagoon Estuary (PLE), Brazil. Large variations in salin...

Zooplankton is a vital element in pelagic trophic links in marine ecosystems. Despite its importance in controlling phytoplankton production and in modeling pelagic ecosystems, several aspects of zooplankton ecology are still not fully understood, especially regarding its biomass and trophic interactions. The present study assessed the distribution...

This study aimed to evaluate the contribution of three diatom species on the lipid content of bioflocs, their permanence on the bioflocs and influence on the growth performance of juvenile shrimps. Juveniles of Litopenaeus vannamei were reared (30 days; three replicates per treatment) in biofloc systems inoculated with diatoms Amphora coffeaeformis...

The accumulation of high biomass of diatoms in the surf zone is a characteristic feature of some sandy beaches where the wave energy is sufficiently high. A few species of diatoms, called surf diatoms, thrive in this harsh environment. The main processes driving the spatial and temporal distribution of surf diatoms as well as their standing biomass...

This paper provides information on the morphology and occurrence of extant diatoms of the family Asterolampraceae and Azpeitia species of the southernmost Brazilian continental shelf and slope waters in the Southwestern Atlantic Ocean (28 -34ºS), under the influence of Tropical, Subtropical, Subantarctic Waters, terrestrial discharges from La Plata...

Aquaculture generates a large load of effluents rich in organic matter and nutrients that may be introduced into the environment. This study aimed to assess in a microcosm experiment, the effect of shrimp pond water mixed with Patos Lagoon estuary water on phytoplankton chlorophyll a and primary production, simulating two salinities. Chlorophyll a,...

To understand the mechanisms that trigger changes in chlorophyll a and species composition in the phytoplankton of the surf-zone at Cassino Beach (RS), we performed two short nutrient-enrichment experiments (4–5 days each) during the summer and winter of 2010. Seawater was incubated under controlled conditions of temperature (summer 25 ± 3 °C, wint...

Bio-floc shrimp culture systems have been investigated in an attempt to optimize water use and prevent the discharge of effluent into the environment. The importance of microalgae in maintaining water quality and nutrition of the shrimp is well known in conventional systems; however, its maintenance amid bio-flocs and its role in the shrimp perform...

This study aimed at identifying morpho-species of microplankton dinoflagellates (> 20 μm) of the order Peridiniales and Prorocentrales off Santa Marta Grande Cape, CSMG (SC, 28º 40' S) and Albardão-Chui, AC (rS, 34º 40' S) during oceanographic cruises conducted in winter 2005 and summer 2007. Plankton samples were obtained by vertical net (mesh siz...

This study aimed at identifying morpho-species of microplankton dinoflagellates (> 20 pm) of the order Peridiniales and Prorocentrales off Santa Marta Grande Cape, CSMG (SC, 28 degrees 40' S) and Albardao-Chui, AC (RS, 34 degrees 40' S) during oceanographic cruises conducted in winter 2005 and summer 2007. Plankton samples were obtained by vertical...

water quality, phytoplankton and zooplankton were evaluated in a shrimp pond (Litopenaeus vannamei) and the adjacent Patos Lagoon estuary in summer from November/2007 to February/2008. Every two weeks, temperature, salinity, dissolved inorganic nutrients, total chlorophyll a and size fractions (>20μm; 1-20μm; <1μm) and phytoplankton and zooplankton...

Here we compare cell physiology and domoic acid (DA) production for two strains of the diatom Pseudo-nitzschia multiseries originating from two opposite latitudes: Canada (CA) and Brazil (BR). The algae were grown as chemostat cultures at 0.2, 0.3 and 0.4 day−1 under nitrogen (N)- and phosphorus (P)-deficient conditions. The level of deficiency sig...

The dinoflagellates of the Dinophysiales order are a morphologically diverse and ecologically heterogeneous group that includes autotrophic, mixotrophic and heterotrophic species and others containing endosymbionts or phycotoxin producers. In this research Dinophysis, Ornithocercus, Histioneis and Amphisolenia species have been identified in both c...

Os dinoflagelados da ordem Dinophysiales representam um grupo morfologicamente diverso e ecologicamente heterogêneo, incluindo espécies autotróficas, mixotróficas e heterotróficas, outras contendo endossimbiontes ou ainda produtoras de ficotoxinas. No presente trabalho, foram identificadas as espécies de Dinophysis, Ornithocercus, Histioneis e Amph...

In the shallow microtidal Patos Lagoon estuary, southern Brazil (32° 07′ S–52° 06′ W), chlorophyll a (Chl a) variability was studied at different time scales during the last 25years (hourly–daily sampling in 1984/1985; weekly sampling in 1986 and from 1988 to 1990; monthly sampling from 1993 to 2008). Phytoplankton biomass variation seems to be mos...

A long-term study (monthly sampling, 1992 to 2007) was conducted in the surf zone of Cassino Beach, Southern Brazil, in order to detect possible natural and/or anthropogenic disturbances. Surface water temperature (6–29°C) was the only parameter with predictable seasonal variation; salinity (14–38) was inversely related to rainfall (3.1–485.2mm mon...

The detailed description of rarely recorded Thalassiosira species in Brazil is presented with light microscope (LM) and scanning electron microscope (SEM) illustrations. A total of 78 phytoplankton net samples (20 microm) collected between the years 2000 and 2006 in coastal waters of southern Brazilian, Cassino Beach and the estuary of Lagoa dos Pa...

We examined the morphology of Skeletonema species occurring in coastal waters of southern Brazil, on the basis of LM, SEM, and TEM analyses of six isolated strains and of 13 field samples from the Patos Lagoon estuary and the adjacent Cassino Beach. We concluded that the genus Skeletonema is highly diverse in coastal waters of southern Brazil, with...

O trabalho apresenta uma chave dicotômica e uma tabela comparativa com as dimensões e características diagnósticas para a identificação de dezessete espécies de Thalassiosira (diatomáceas), comumente observadas no estuário da Lagoa dos Patos e na área costeira adjacente à sua desembocadura (~32° S e 52° W). Para todas as espécies estudadas são forn...

The paper presents a dichotomous key and a comparative table summarizing dimension data and diagnostic characteristics of seventeen Thalassiosira species (diatoms) commonly found in Lagoa dos Patos estuary and the coastal adjacent area (~32° S and 52° W). For all studied species, optic microscope illustrations and comments on significant morphologi...

The biodiversity of marine heterotrophic protists is poorly known in the South Atlantic coastal zone (~32 °S) especially regarding the nanoflagellates. The presence of loricate choanoflagellates was reported for the first time in the Patos Lagoon estuary and the adjacent coastal zone. Seventeen species of eleven genera of loricate choanoflagellates...

The diatom Palmerina hardmaniana (Greville) Hasle presents a wide geographical distribution in neritic tropical and subtropical regions. In the present work we analyzed plankton samples collected monthly between 1995 and 2007 at the surf zone of Cassino Beach, RS (32° 12' S and 52° 10' W), and in winter 2005 and summer 2007 at the continental shelf...

A taxonomic survey of nanoflagellates in the extreme southern Brazilian coastal waters of the Patos Lagoon estuary and adjacent coastal shelf was undertaken using transmission electron microscopy. A total of 44 species was recorded including 42 nanoflagellates, one scale-bearing amoeba and two species incertae sedis. Scale-bearing haptophytes predo...

The contribution of biofilm and artificial feeds for the growth of the pink shrimp Farfantepenaeus paulensis reared in tanks and net cages were evaluated by using stable isotope (δ13C and δ15N) analysis. In the net cage experiment, mass balance and mixing equations showed that the biofilm contribution to shrimp growth was over 49% of carbon and 70%...

Broodstock of the Brazilian flounder Paralichthys orbignyanus (Valenciennes, 1839) kept in the laboratory suffered recurrent heavy infestations by the ectoparasitic dinoflagellate Antyloodinium cf. ocellatum. Between 10 January and 26 February 2003 we monitored A. cf. ocellatum dinospore (infectious motile stage) abundance in a maturation system in...

Short-term variability of chlorophyll a concentration, abundance and composition of phytoplankton and ciliates and of abiotic parameters were analyzed at the Patos Lagoon estuary during two seasons, in the austral spring (October/November 2004) and summer (January/February 2005). Sampling was carried out at a fixed station every 2h30min for chlorop...

RESUMO O objetivo deste trabalho foi o de determinar a taxa de absorção de CO2 das espécies de microalgas, Nannochloropsis oculata, Chaetoceros affinis, Chaetoceros muelleri, Phaeodactylum tricornutum, Skeletonema costatum, Thalassiosira weissflogii, Thalassiosira pseudonana, Tetraselmis chuii, Tetraselmis tetrathele e Isochrysis galbana, normalmen...

Stable isotopes ratios (δ13C and δ15N) were measured in primary producers and consumers of two bays with contrasting eutrophic conditions in the Patos Lagoon estuary, southern Brazil: the Justino bay, a more pristine ecosystem, and the Mangueira bay, a heavily polluted region that receives the Rio Grande city sewage and effluencts of several indust...

The effect of a 7-mo drought (La Niña 1988) was evaluated on pelagic properties in the large Patos Lagoon (30°12′–32°12′S, 50°40′–52°15′W). From December 1987 to December 1988, surface water was sampled along the longitudinal axis of the lagoon for temperature (10–29°C), salinity (0–31.4), dissolved inorganic phosphate (0.02–4.73 μM), nitrate (0.05...

The phytoplankton composition and abundance in the large, subtropical coastal Merin Lagoon (Brazil-Uruguay) were analyzed seasonally between 1998 and 1999, based on plankton net and bottle samples in 38 stations. The lagoon is connected to the choked Patos Lagoon forming a complex ecosystem with a drainage basin of 201626 km2. Temperature and condu...

The surf-zone diatom Asterionellopsis glacialis (Castracane) Round attains extremely high abundances (up to 109 cells l–1) and chl a concentrations (up to 1.5 mg chl a l–1), forming darkbrown patches in Cassino Beach, southern Brazil. Several lines of evidence from this study indicate a decoupling between A. glacialis and heterotrophic bacteria. Fo...

Impact of microzooplankton granzing on the phytoplankton in the Patos Lagoon estuary We considered the hypothesis that phytoplankton biomass in summer is controlled by herbivory in the Patos Lagoon estuary. The impact of herbivorous grazing on phytoplankton growth and biomass was quantified in February 1999 using laboratory bioassays (dilution tech...

The Atlantic subtropical anticyclone and the antarctic circumpolar current drive the upper oceanographic circulation in the Southwest Atlantic. The large-scale flow field comprises the south and northward flowing western boundary currents, the Brazil and Malvinas (=Falkland) currents, respectively. The Brazil Current transports warm tropical water...

Adotamos um conceito amplo de microorganismos marinhos (bacterias, microalgas, protozoarios, fungos e virus), e apresentamos suas caracteristicas gerais, o seu papel como produtores primarios, remineralizadores e consumidores, e os seus principais fatores controladores. Aspectos metodologicos do plano amostral, coleta e conservacao de amostras, con...

The coastal dunes of southern Brazil are remarkably similar because Holocene sea-level changes have influenced their genesis (Pfadenhauer 1980; Schwarzbold and Schafer 1984), resulting in the sequential formation of depressions and dune ridges parallel to the shore. The most recent transgression-regression events moulded the 300–1000 m wide foredun...

The South Atlantic between Africa and South America is under the domain of the high pressure centre of the Atlantic anticyclone which controls the climate and determines the large-scale oceanographic circulation. The northward flowing eastern boundary Benguela Current, the South Equatorial Current, and the western boundary currents, represented by...

Subtropical convergence regions in the southwestern Atlantic have a high biological productivity, and are important as nursery and feeding areas and as reproduction grounds for fishery stocks of subtropical and antarctic origin. This book represents the first multidisciplinary treatise of this large and complex marine ecosystem. It analyses how sub...