Southeastern Brazilian Coast Research Articles

A new species of Pisionidens (Aiyar & Alikunhi, 1943) (Annelida: Sigalionidae) from Southeastern Brazil

Herein we describe specimens found along the southeastern coast of Brazil which belong to a new species, P. caissara sp. nov. This species differs from the other species of the genus by the glabrous antennae and palps, proboscis extending up to the sixth segment, jaws with smooth cutting edge and a pair of lateral wing-like sheaths, two pairs of seriate male copulatory organs, first pair of testes on segment 19 and ovaries from segment 26 onward. Reproductive characters commonly used for characterizing species are also discussed.

Mercury, selenium and stable isotopes in four small cetaceans from the Southeastern Brazilian coast: Influence of feeding strategy

Dolphins are good bioindicators of the contamination status of marine ecosystems, since their dietary and habitat plasticity in both coastal and offshore ecotypes provide information on the trace elements levels originated from natural and anthropogenic sources. In this context, this study aimed to investigate provides mercury (Hg), selenium (Se) levels, trophic ecology and feeding environments of four small cetaceans (Tursiops truncatus, Steno bredanensis, Sotalia guianensis and Pontoporia blainvillei) inhabiting the central-northern coast of Rio de Janeiro State, southeastern Brazil. For the latter, δ15N and δ13C stable isotopes were used as indicators in this regard. Stable isotope values indicate that the four studied species have distinctive foraging habitats, coastal and least coastal, and occupy different trophic positions. The significant relationship found between muscle Hg and δ15N suggests that individual foraging preference remains relatively constant for the studied dolphin species over extended periods. The individual prey size and species are probably responsible for the differences found in Hg and Se concentrations in muscle tissue among all dolphin species. The vulnerable small coastal cetacean, P. blainvillei, which feeds on small teleost fish and squid, presented the lowest muscular Hg concentrations (less than 3.5 μg g−1 dry wt.). Meanwhile, S. bredanensis is more likely to uptake large amounts of trace elements among the four dolphin species, due to its feeding habits mainly being large offshore fish that accumulate high amounts of trace elements in organs and tissues. Differences found between Hg concentrations in fetus-mother pairs were much higher in S. guianensis than in P. blainvillei, suggesting that maternal contribution of Hg via placenta was more significant for the former.

A new species of Falcidens (Mollusca, Aplacophora, Caudofoveata) from the southeastern Brazilian coast: external anatomy, distribution, and comparison with Falcidens caudatus (Heath, 1918) from the USA

Falcidens australocaudatus sp. nov. is described from the southeastern Brazilian coast, based on characters of external anatomy, including size, shape, and ornamentation of the sclerites, and on the structure of the radula. It bears a tail characteristically distinct from the trunk, a U-shaped oral shield, and the sclerites of the trunk and shank are slender, without an obvious separation between a blade and base; it differs from all other tailed species of Falcidens, which have sclerites that are flared at the base. Externally, it is very similar to F. caudatus, recorded from the northeastern coast of the USA; the sclerites of this species are illustrated here and are characterized as being larger, slightly flared, and with a different ornamentation as compared to those of the new Brazilian species. Based on the examination of a large collection, the new species can be characterized as very abundant at the southeastern Brazilian coast, with a wide bathymetric distribution, but mainly occurring in the upper continental slope.

Geochemistry of river suspended sediments in tropical watersheds: anthropogenic and granite-gneiss sources, SE Brazil

ABSTRACTMineralogy and geochemistry of the total suspended sediment (TSS) from a granite-gneiss watershed in southeast Brazil brought light to geogenic and anthropogenic sources. TSS was sampled in 15 points along the Piabanha watershed in summer (February 2013) and winter (August 2013). The Piabanha watershed (2 × 103 km2) is located in the mountainous region of Rio de Janeiro, and it is an affluent of the Paraiba do Sul River, the most important river from the Brazilian southeastern coast. TSS mineralogical analyses were performed with X-ray powder diffraction. Geochemical analysis was done with energy dispersive X-ray fluorescence. Quartz, kaolinite and gibbsite were dominant in the TSS mineralogy, followed by feldspar and mica. Granite and gneiss rocks contribution in the TSS have a common mineralogical and geochemical source. But the alluvial deposits from river banks might have been responsible for the differences between summer and winter samples. The major features in TSS from geogenic sources were SiO2, Al2O3, MgO, Ga2O3, Nb2O5, Rb2O, K2O, SrO, ZrO2 and TiO2. The good correlation on the Si:Al molar ratio suggested that the source area is intensely weathered. Pollution features (sewage source) were given by significant TSS concentration of Fe2O3, MnO, ZnO, CuO, As2O3, CaO, Na2O, P2O5 and SO3.

A comprehensive analysis of trends in extreme precipitation over southeastern coast of Brazil

ABSTRACTSoutheast Brazil (SE Brazil) is the most densely populated region in Brazil. Previous studies have shown evidence of positive trends in average precipitation and extreme events in a few locations, suggesting the increase in rainfall‐related hazards with potential impacts to urbanized areas of SE Brazil. This study provides a comprehensive analysis of the spatial variability of trends in extreme precipitation over SE Brazil focusing on regional and local scales. We examine two daily rainfall datasets with more than 70 years of data: individual stations and gridded observed precipitation data. Our results indicate that the frequency of both rainy days and extreme daily precipitation events have increased in Sao Paulo state. Conversely, precipitation has become more concentrated in fewer events in Rio de Janeiro and Espirito Santo states where both data sets indicate positive trends in the intensity of extreme daily rainfall. The increases in frequency and intensity of extreme events have both contributed to positive trends in total seasonal and average daily precipitation over Sao Paulo. Additionally, the individual stations indicate negative trends in the number of light rainy days over large urbanized areas in the state of Sao Paulo. The spatial patterns of trends indicate that they are influenced by the proximity of large urban centres and topographic features, and also suggest variations and changes in the major climatic systems affecting precipitation regimes over SE.

A CONSTRUÇÃO SOCIAL DO FANDANGO COMO EXPRESSÃO CULTURAL POPULAR E TEMA DE ESTUDOS DE FOLCLORE

Resumo O artigo propõe um olhar antropológico sobre a profunda participação dos estudos de folclore e de categorias usadas por estes estudiosos nas construções de sentido e dinâmicas do fandango, expressão popular comum no litoral sul e sudeste brasileiro, especialmente nos estados do Paraná e de São Paulo. Revisitando obras e processos de pesquisa empreendidos por Mário de Andrade, Renato Almeida, Fernando Corrêa de Azevedo, Inami Custódio Pinto, Alceu Maynard Araújo, Rossini Tavares de Lima, entre outros, procuro elucidar, a partir do fandango, suas diferentes concepções e projetos no tratamento dado a questões, estratégias e práticas caras ao folclorismo, como patrimonialização, regionalismo, risco, rumor e resgate. Proponho ainda pensar sobre como tais autores articularam, cada um em seu tempo e a seu modo, os estudos de folclore com os campos das artes e das ciências sociais.

Phylogenetic analysis of the genus Lensia (Cnidaria, Hydrozoa, Siphonophora), based on the species morphology.

Siphonophores are poorly studied despite their abundance and ecological importance in marine ecosystems. The genus Lensia Totton, 1932 contains the highest number of species within Siphonophora, but systematic studies of these organisms are scarce in the literature. This study presents a phylogenetic analysis for fifteen species of Lensia based on morphological data. The material for this study was obtained during two oceanographic campaigns made along the southeastern Brazilian coast. A total of twenty two characters of the anterior nectophore morphology were scored. The shortest trees were searched using parsimony (under different weighting regimes). All analyses provided the same topology: (M. kochi (D. dispar + D. bojani) (L. leloupi (L. havock (L. conoidea (L. subtilis; L. meteori; L. hardy; L. fowleri; (L. subtiloides (L. hotspur; L. cossack; L. campanella)); (L. multicristata (L. hunter (L. lelouveteau + L. grimaldii))). The monophyly of the genus Lensia is supported by the hydroecium measuring up to 1/4 the height of the nectosac.

Social monogamy and egg production in the snapping shrimpAlpheus brasileiro(Caridea: Alpheidae) from the south-eastern coast of Brazil

This study tested for social monogamy inAlpheus brasileiroAnker, 2012. We also analysed egg production in this species. Sampling was conducted bimonthly from March 2013 to January 2014, and specimens were collected manually in the intertidal estuarine zone of Cananéia, São Paulo, Brazil. A total of 186 specimens (92 males and 94 females) were captured, and ~46% of them were found living in heterosexual pairs. The carapace length (CL mm) of paired males and females was positively correlated. We analysed 35 females carrying eggs underneath the abdomen: 28 of these females had eggs in stage I of development, four had eggs in stage II, and three had eggs in stage III. The average (±SD) mean fecundity for females carrying early (stage I) eggs was 149 (±93) eggs. Egg volume differed significantly among developmental stages, with a 35.4% increase in egg volume between stages I and III. The egg volume and size (CL) of females correlated positively. A positive correlation between the number of eggs and carapace length was found, with a proportional increase in the number of eggs according to the size of females. Our results suggest that the studied population ofA. brasileirois socially monogamous and provide the first insights into egg production in this species.

The Path towards Endangered Species: Prehistoric Fisheries in Southeastern Brazil.

Brazilian shellmounds are archaeological sites with a high concentration of marine faunal remains. There are more than 2000 sites along the coast of Brazil that range in age from 8,720 to 985 cal BP. Here, we studied the ichthyoarchaeological remains (i.e., cranial/postcranial bones, otoliths, and teeth, among others) at 13 shellmounds on the southern coast of the state of Rio de Janeiro, which are located in coastal landscapes, including a sandy plain with coastal lagoons, rocky islands, islets and rocky bays. We identified patterns of similarity between shellmounds based on fish diversity, the ages of the assemblages, littoral geomorphology and prehistoric fisheries. Our new radiocarbon dating, based on otolith samples, was used for fishery characterization over time. A taxonomical study of the ichthyoarchaeological remains includes a diversity of 97 marine species, representing 37% of all modern species (i.e., 265 spp.) that have been documented along the coast of Rio de Janeiro state. This high fish diversity recovered from the shellmounds is clear evidence of well-developed prehistoric fishery activity that targeted sharks, rays and finfishes in a productive area influenced by coastal marine upwelling. The presence of adult and neonate shark, especially oceanic species, is here interpreted as evidence of prehistoric fisheries capacity for exploitation and possibly overexploitation in nursery areas. Various tools and strategies were used to capture finfish in seasonal fisheries, over rocky reef bottoms and in sandy littoral environments. Massive catches of whitemouth croaker, main target dermersal species of South Atlantic coast, show evidence of a reduction in body size of approximately 28% compared with modern fisheries. Fishery activity involving vulnerable species, especially in nursery areas, could mark the beginning of fish depletion along the southeastern Brazilian coast and the collapse of natural fish populations.

Studying exotics in their native range: Can introduced fouling amphipods expand beyond artificial habitats?

Knowledge of the habitat use patterns of introduced species in their native or naturalized range can provide unique insights into processes of secondary dispersal and colonization of natural habitats. Caprellid amphipods are small mobile marine epibionts with limited natural dispersal. The global distribution of some caprellid species is mostly the result of anthropogenic transport; however, their subsequent spread beyond artificial habitats is poorly understood. A biogeographic approach, mainly focused on the native-range ecology of introduced and common fouling caprellid amphipods of southern Europe, was used to understand the implications of habitat use patterns for predicting their spread in the introduced regions. Specifically, abundance and composition of caprellid populations were compared among different primary habitats including artificial (floating pontoons), sheltered and wave-exposed rocky shores along the southern and southeastern coasts of Brazil. The findings indicated that artificial habitats act as reservoirs for globally distributed species in both their native and introduced ranges, while endemic species are more scarcely represented. Environmental conditions provided by primary habitats appear important in structuring caprellid assemblages on secondary substrata (basibiont species). Most wide-ranging caprellids were negatively correlated with the level of wave exposure, being more abundant in sheltered (artificial or natural) than in exposed habitats. In this context, Caprella scaura and Paracaprella pusilla, the two introduced caprellids recorded in the Mediterranean, where they are virtually restricted to artificial habitats, may become established in sheltered and even highly polluted natural habitats but hardly colonize wave-exposed rocky shores.

Fishers’ knowledge indicates short-term temporal changes in the amount and composition of catches in the southwestern Atlantic

The scarcity of data on fish catches difficult management of small-scale fisheries in developing countries. This study applies fishers’ knowledge to investigate temporal changes in the amount (biomass) and composition (major ecological categories) of fishing resources exploited by small-scale coastal fisheries in the southeastern Brazilian coast. Four hypotheses were investigated: (1) The amount of fish caught reported by fishers would decrease over time. (2) Older fishers would report higher fish catches than younger fishers. (3) Recent interviews would mention large-sized predators less often. (4) Recent interviews would mention less high valued fishing resources. Interviews with 421 fishers in 36 communities in the southeastern Brazilian coast were analyzed, covering a time span of 14 years, from 1995 to 2009. The hypothesis 1 was confirmed, 3 was partially confirmed, while 2 and 4 were not confirmed. Fishers’ age was unrelated to all variables. The results from fishers’ interviews indicated the temporal trends of: (1) a decrease in the biomass of fish caught; (2) an increase in the occurrence of smaller fish and invertebrates in the catch; (3) an increase of high value fishing resources; and (4) maintenance of large predators. The first two indicators suggest excessive fishing, but the later indicators (3 and 4) suggest that the socioecological system of the southeastern Brazilian coast had not yet undergone major ecological shifts.

The Usiminas shellmound on the Cabo Frio Island: Marine reservoir effect in an upwelling region on the coast of Brazil

Abstract The mixture of different water masses can strongly influence the marine reservoir effect (MRE) in localities under the effect of coastal marine upwelling. The Cabo Frio region, on the southeastern Brazilian coast, is well known for its seasonal marine upwelling and for its rich landscape of Holocene shellmounds. In this kind of archaeological settlement, common on the southern and southeastern Brazilian coasts, marine mollusk shells are frequently used for radiocarbon dating and can represent a valuable tool in the study of MRE. On the other hand, terrestrial mollusks have proven to be an important alternative to represent the atmospheric carbon isotopic concentration. In this work we analysed the most frequent terrestrial and marine mollusk shells from the Usiminas shellmound, on Cabo Frio Island. The radiocarbon signal of marine shells from Pinctada imbricata (Roding, 1798), Ostreidae (Rafinesque, 1815), Cymathium parthenopeum (Von Salis, 1793), Leucozonia nassa (Gmelin, 1791), Lithopoma olfersii (Philippi, 1846), and that of terrestrial shells from Thaumastus achilles (Pfeiffer, 1852) and Megalobulimus terrestris (Spix, 1827), collected from the archaeological layers in the sequence, were measured and a value of 67 ± 33 14C yr was obtained for the local offset from the average global marine reservoir age. The effect of upwelling in this region and in its surrounding area is discussed.

Tracking the southern Brazilian schools of Mugil liza during reproductive migration using VMS of purse seiners

Brazilian mullet Mugil liza is a schooling fish that migrates in fall and winter, leaving estuaries and coastal lagoons to spawn in ocean waters. In order to understand the reproductive migration pattern of southern stock along Brazil’s coast, we analyzed data collected through the Brazilian Satellite Vessel Tracking Program (Programa Nacional de Rastreamento das Embarcacoes Pesqueiras por Satelite-PREPS) from 2008 to 2012. The migration period overlaps with the fishing season (May-July) when the licensed purse seine fleet fishes along the southern and southeastern coast of Brazil, motivated to capture mullet by the high value of the roe. During the five fishing seasons the average effort was of 51 active vessels. The average time per season that each vessel navigated in the Speed Compatible with Fishing Operation (SCFO) was 349.3 h, which represented an average of 17% of the total time at sea. From May to July the highest frequency (54%) of SCFO transmissions occurred in June ( P 0.05).

First records of the Gull-billed Tern, Gelochelidon nilotica (Gmelin, 1789) (Aves: Sternidae), from Rio de Janeiro state, Brazil

Here we report the first documented records of the Gull-billed Tern, Gelochelidon nilotica (Gmelin, 1789), from Rio de Janeiro state, on the coast of southeastern Brazil. The species was recorded in Sepetiba Bay, in Rio de Janeiro municipality, in August and September 2014 and September 2015. In all cases, the birds had full nuptial plumage, which suggests breeding in the austral spring and summer. This is inconsistent with the possibility of a migrant from the Northern Hemisphere. The regular monitoring of the coastal environments of this region should provide more conclusive insights into seasonal patterns and the migration routes of this species.

Spatial database modeling for mangrove forests mapping; example of two estuarine systems in Brazil

This work considers mangrove cover changes in two subtropical estuaries in the southeastern coast of Brazil: Cananeia-Iguape Coastal System and Santos Estuarine System. A sequence of Landsat images from 1985 to 2014 from both areas was segmented, classified and analyzed in order to develop a systematic GIS approach for identifying and characterizing mangrove fragments in such estuaries and how they change over time. The main goal of our work is to propose a unified hierarchical spatial database model in a GIS framework developed to incorporate different types of spatial information such as spectral (e.g. vegetation indices), spatial (e.g. fragmentation indices) and temporal (e.g. change detection) at different scales. The examples analyzed showed that changes and fluctuations in mangrove habitats could be identified and characterized revealing potential tools for handling and analyzing data focused on environmental monitoring and the coastal resource protection and conservation.

Mercury species, selenium, metallothioneins and glutathione in two dolphins from the southeastern Brazilian coast: Mercury detoxification and physiological differences in diving capacity

In the present study, the concentration of trace elements, total mercury (Hg) and selenium (Se) and mercury forms (MeHg, Hginorg and HgSe) in the vulnerable coastal dolphins Pontoporia blainvillei and Sotalia guianensis were appraised and compared, using metallothioneins (MT) and glutathione (GSH) as biomarkers for trace element exposure. The trace element concentrations varied between muscle and liver tissues, with liver of all dolphin specimens showing higher Hg and Se concentrations than those found in muscle. Hg, MeHg and Hginorg molar concentrations showed a clear increase with Se molar concentrations in the liver of both dolphins, and Se concentrations were higher than those of Hg on a molar basis. Se plays a relevant role in the detoxification of MeHg in the hepatic tissue of both dolphins, forming Hg-Se amorphous crystals in liver. In contrast, MT were involved in the detoxification process of Hginorg in liver. GSH levels in P. blainvillei and S. guianensis muscle tissue suggest that these dolphins have different diving capacities. Muscle Hg concentrations were associated to this tripeptide, which protects dolphin cells against Hg stress.

Geochemical records in sediments of a tropical estuary (Southeastern coast of Brazil)

The Piraquê-Açú and Piraquê-Mirim estuarine system (PAPMES) is considered to be a hydrologically unaltered estuary; however, several human activities including introduction of pollutants may have contributed to changes in this system. We have studied hydrocarbons, major elements (Al, Mg, Fe and Mn), trace elements (As, Ba, Cd, Co, Cr, Cu, Li, Ni, Pb, V and Zn), Corg./Ntotal ratio, and δ13C and δ15N stable isotopic composition of organic matter to assess the natural and anthropogenic depositional record in three sediment cores dated by 210Pb geochronology. The sediments showed a strong terrestrial C3 plant contribution to organic matter input in the rivers (−29.2≤δ13C≤−25.1‰; 2.1≤δ15N≤5.3‰; 23.3≤Corg./Ntotal≤53.9), with a higher phytoplankton influence downstream (−29.3≤δ13C≤−20.7‰; 0.4≤δ15N≤6.6‰, and 15.4≤Corg./Ntotal≤34.4). Greater n-alkane concentrations typical of higher plants (nC27, nC29, nC31) confirmed the terrestrial inputs. There was no indication of contamination by petrogenic sources, but relatively high amounts of 17β(H), 21β(H) and 17β(H), 21α(H) terpanes, indicate a possible association with biogenic activities (bacteria). The distributions of major and trace elements were associated with a high lithogenic input and iron and manganese oxides/hydroxides. Although there is little evidence of enrichment by direct human activity, the downstream sediments may be influenced by deforestation for charcoal production which occurred between the 1950s and 70s, exposing soils to weathering and erosion.

Morphometric and gonad maturity of the spider crabLibinia ferreiraeBrito Capello, 1871 (Decapoda: Majoidea: Epialtidae) on the south-eastern Brazilian coast

Sexual maturity of the spider crabLibinia ferreiraewas assessed for each sex, based on body dimensions and observations of gonad condition. A total of 346 crabs were analysed, of which 68% were females. Immature and adult individuals were recognized based on their allometric growth and gonad development. Abdomen width (AW)vscarapace width (CW) and propodus length (PL)vsCW were the relationships that best separated allometric groups of females and males, respectively. For females, gonad and allometric morphological maturity were, respectively, 38.77 and 39.43 mm of CW, which is close to the carapace size of the smallest ovigerous female (38.08 mm). For males, gonad maturity was 34.86 mm of CW and three allometric phases were observed: immature (IM♂), adolescent (AD♂) and adult morphometrically mature (MM♂). The IM♂ phase showed lower values of CW and PL than the AD♂ phase, without spermatophores inside the vas deferens; the AD♂ phase exhibited higher CW values than IM♂, but lower CW and PL values than the MM♂ phase, and the presence of spermatophores in the vas deferens; the MM♂ phase had higher values of CW and PL than the AD♂ phase and spermatophores in the vas deferens. Therefore, females showed synchronic morphometric, gonadal and functional maturity, while in males, gonadal maturity was attained before morphometric maturity, which probably could be a reproductive strategy for this species.

Decapod crustacean associations with scyphozoan jellyfish (Rhizostomeae: Pelagiidae) in the Southeastern Brazilian coast

In southeastern Brazil, decapod crustaceans were found living in association with the scyphozoan jellyfish. In total, 2002 specimens of the Scyphozoa Lychnorhiza lucerna were collected of which 511 were associated decapods that were identified as three species of the crab Libinia ferreirae, Libinia spinosa, and one Grapsoidea sp. and two species of caridean shrimps Periclimenes paivai and Leander paulensis. This is the first record of an association between the caridean shrimp L. paulensis and a scyphozoan and the first report of symbioses involving the crabs L. spinosa and Grapsoidea sp. on the Brazilian coast.

Growth and reproduction of the shrimp Rimapenaeus constrictus (Decapoda: Penaeidae) from the southeastern coast of Brazil

Few studies have been performed on the shrimp Rimapenaeus constrictus, despite its wide geographic distribution in the western Atlantic Ocean. The population dynamics of R. constrictus were evaluated, focusing on sex ratios, growth, longevity, and reproduction, in the Cananeia region, along the southern coast of São Paulo state, Brazil. Monthly trawls were conducted from July 2012 through May 2014 using a shrimp boat outfitted with double-rig nets. The shrimp were identified according to their sex and reproductive condition, and carapace length (CL) was measured. A total of 1702 individuals were collected, and females were found to reach sexual maturity at a greater CL (9 mm) than males (7 mm). Based on the estimated growth curve parameters, males exhibit shorter longevity (0.73 years) than females (1.14 years). In terms of the sex ratio, there was a statistically significant bias toward females observed over the months, beginning at a CL of 9 mm (binomial test, p<0.05). The seasonal reproductive pattern recorded during the spring and summer coincided with higher temperatures and chlorophyll concentrations (plankton production), which suggests that food availability for protozoeal and mysis larvae may be an important selective factor in the reproductive success of R. constrictus.