Niche-Relationships Within and Among Intertidal Reef Fish Species

Niche-related processes (e.g., density or niche-breadth compensation and competition) are fundamental to a broad understanding of community ecology and ecosystem functioning. Most evidences of competition are from controlled indoor trials with few species, and it remains a challenge to estimate competition among multiple species in the field. Here, we analyze stable isotopes and distributional data from 51 fish taxa in six locations in the southwestern Atlantic to predict intraspecific trophic pressure (ITP) and the potential competitive strength among species in a trophic-based framework. We used two proxies built upon 2-dimensional isotopic space (δ13C vs. δ15N), its predicted overlap, and fish density to calculate winner and loser taxa in potential paired interspecific competitive interactions. The intraspecific proxy indicated that cryptobenthic fishes are under high among-individual trophic pressure (high densities and small niche sizes). Also, cryptobenthic behavior together with feeding specialization and extremely small-sizes were the most important traits related to low success in interspecific simulations. Although cryptobenthic fishes face strong competitive pressures, there are some known inherent trade-offs to cryptobenthic life such as trophic and habitat use specializations. These seem to compensate and ensure coexistence among cryptobenthic fishes and non-cryptobenthic species. Habitat loss/degradation via urbanization, invasive species and climate-change-driven sea-level rise can reduce the suitability of habitat and increase competition on cryptobenthic species, especially in shallow reefs and intertidal shores

Intertidal Biogeographic Subprovinces: Local and Regional Factors Shaping Fish Assemblages

Intertidal zones shelter a wealth of species and natural resources, provide important ecological services, and sustain several economic activities in coastal communities. However, the tidepool fish species that inhabit the intertidal zone are subject to a wide array of impacts due to the human presence and their accessibility, creating a challenge for the mitigation of habitat loss, in particular in tropical regions where the ecology and distribution of species are poorly known. In this study, we investigated tidepool fish species distribution patterns systematically across ca. 4,900 km of tropical Brazilian coastline (00–21° latitude) in order to verify the latitudinal trends and environmental variables influencing tidepool communities. A total of 5,113 fish specimens belonging to 67 taxa were collected at the 19 sites, revealing four distinct biogeographic subprovinces: Amazon Estuary (AE), Northern Mangrove (NM), Northeastern Semiarid (NS), and Tropical Warm (TW). Distance-based linear modeling evidenced in sequence water salinity, tidal range, shape of rocky shore formation, algae cover, distance to subtidal zone, latitude and rainfall as the most important environmental variables to shape biogeographic subprovinces. Fish species such as Bathygobius soporator, Bathygobiusgeminatus, Labrisomus nuchipinnis, and Scartella cristata presented wide distribution, occupying more than one subprovince. The trophic structure of the tidepool fishes also varied among subprovinces, with carnivores being associated with the AE subprovince, omnivores with the NM, and herbivores dominating the NS and TW. These findings reinforce the determining role of local and regional factors in the geographic distribution of fish and, in particular, highlight a new arrangement for the intertidal subprovinces of the tropical Brazilian shoreline, which may provide a valuable tool for the more effective management and conservation of this vulnerable ecosystem at the land-ocean interface

The influence of additives on the fate of plastics in the marine environment, exemplified with barium sulphate

With an inherent density marginally below that of seawater, polyolefins (polyethylene-polypropylene) are predicted to float or undergo beaching in the marine environment. Polyolefins commonly observed on the seabed, therefore, require additional considerations that are usually based around increasing density through fouling or packaging into sinking faecal matter. Here, however, we propose that the presence of additives is of least equal significance to the behaviour of such plastics in marine systems. We compared barium, present largely as the filler, BaSO₄ (density = 4.5 g cm⁻³), in consumer and beached plastics and established that the metal was more abundant and occurred at higher concentrations in the former samples, consistent with the environmental fractionation of plastics based on additive content. Significantly, the Ba content of polyolefins required to confer a density above seawater is about 13,000 mg kg⁻¹, a value that was exceeded in many consumer plastics but never observed in beached samples

Maternal and embryonic trace element concentrations and stable isotope fractionation in the smalleye smooth-hound (Mustelus higmani)

Universidade Federal do Pará. Núcleo de Ecologia Aquática e Pesca da Amazônia. Belém, PA, Brazil.Universidade Federal do Pará. Núcleo de Ecologia Aquática e Pesca da Amazônia. Belém, PA, Brazil / Universidade Federal do Espírito Santo. Departamento de Oceanografia e Ecologia. Laboratório de Ictiologia. Vitória, ES, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Toxicologia. Ananindeua, PA, Brasil.University of Windsor. Integrative Biology. Windsor, Ontário, Canada.Here, we evaluate maternal offloading of 16 trace elements (Essential: Co, Cr, Cu, Fe, Mn, Ni, Se and Zn; Nonessential: Al, As, Ba, Cd, Hg, Pb, Tl and U) and determine mother-offspring isotopic fractionation of δ13C and δ15N in muscle and liver tissue of four pregnant Mustelus higmani and 18 associated embryos sampled from the Amazon Coast of Brazil. Embryo muscle tissue had significantly higher concentrations of most trace elements when compared to mothers, with the exception of Hg. Embryo liver accumulated more nonessential elements than muscle (n = 7 vs. 0, respectively), while the Se:Hg molar ratio was >1 in liver and muscle of both mothers and embryos. Livers of embryos were moderately enriched in δ13C and δ15N when compared to that of their mother. Negative correlations were observed between embryo body length and δ13C and trace elements concentrations. We conclude that mothers offload a large portion of all essential elements and Al, As and Pb to their young and that the isotopic fractionation of embryos reflects maternal diet and habitat occupied, with δ13C diluted with embryonic growth. We also show that muscle and liver accumulate trace elements at different rates relative to the body length of embryos. The Se:Hg molar ratio suggests that Se could play a protective role against Hg toxicity during early stages of M. higmani embryonic development

Before the dam: a fish-mercury contamination baseline survey at the Xingu river, Amazon basin before the Belo Monte dam

National Council for Scientific and Technological Development (CNPq # 311078/2019-2) and Norte Energia S.A. (P&D-02-2020); Fundacão de Amparo e Desenvolvimento da Pesquisa (FADESP).Parque de Ciência e Tecnologia Guamá. Espaço Inovação. Grupo Ecologia Aquatica. Belém, PA, Brazil.Parque de Ciência e Tecnologia Guamá. Espaço Inovação. Grupo Ecologia Aquatica. Belém, PA, Brazil / Universidade Federal do Espírito Santo. Departamento de Oceanografia e Ecologia. Laboratório de Ictiologia. Vitoria, ES, Brazil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Avaliacao & Promoção da Saude Ambiental. Rio de Janeiro, RJ, BrazilMinistério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Parque de Ciência e Tecnologia Guamá. Espaço Inovação. Grupo Ecologia Aquatica. Belém, PA, Brazil / Universidade Federal do Ceará. Instituto de Ciências do Mar. Fortaleza, CE, Brazil.In the last decades, mega-diverse rivers worldwide (e.g., the Amazon and their tributaries) have experienced several human-driven transformations, although impact assessments oftentimes lack baseline data or reference values to better estimate observed disturbances. Herein, we assessed THg and δ15N in fish muscle tissue to determine biomagnification processes, also including seasonal assessments, concerning Hg in fish from the Belo Monte reservoir, located on the Xingu River, prior to its impoundment. A total of 312 samples from 19 fish species belonging to distinct feeding guilds were sampled. None presented THg concentrations above the threshold levels of 0.5 μg g−1 established by the World Health Organization. However, biomagnification was observed (R = 0.8; p < 0.001), also confirmed by a trophic magnification factor of 1.76 for the entire food web. The THg content in the water was less than 0.001 mg L−1 and only Hemiodus unimaculatus presented seasonal variations for THg. Therefore, at the time of this study, the Xingu River presented low Hg contamination levels in both water and target fish

The influence of allochthonous macroalgae on the fish communities of tropical sandy beaches

This study evaluates the hypothesis that detached macroalgae (drift algae) influence the structure of fish communities in the surf-zones of two tropical sandy beaches from the central coast of Brazil. Surf-zone seine hauls were conducted weekly during three consecutive 6-week periods according to the occurrence of drift algae in pre-drift, drift and post-drift periods. Drift algae comprised 33 macroalgae species and likely came from offshore rhodolith beds. Fish biomass, density and species richness increased from pre-drift to drift periods, and species composition differed significantly between periods, particularly in the more sheltered of the sampled beaches. the density of young-of-the-year (YOY) fishes also increased significantly from the pre-drift to drift periods, suggesting the importance of drift algae to early fish stages. the gut contents of the two most abundant species during the drift algae period, Trachinotus falcatus and Trachinotus goodei, demonstrated the importance of macrophyte-associated amphipods in their diets, suggesting that the drift algae may be used as feeding habitats for these species. Our results showed that the influx of allochthonous drift algae may structure fish communities of tropical sandy beaches and that it may also represent an important alternative resource for YOY fish by providing shelter and food during autumn and winter. (C) 2014 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Espirito Santo (FAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ Fed Espirito Santo, Dept Oceanog & Ecol, BR-29075910 Vitoria, ES, BrazilInst Fed Educ Ciencia & Tecnol Espirito Santo, BR-29285000 Piuma, ES, BrazilUniversidade Federal de São Paulo, Inst Mar, BR-11030400 Santos, SP, BrazilUniv Fed Pernambuco, Museu Oceanog, BR-50740550 Recife, PE, BrazilUniversidade Federal de São Paulo, Inst Mar, BR-11030400 Santos, SP, BrazilFAPES: 002/2009CAPES-PNPD: 02907/09-7Web of Scienc

GLOVE: The Global Plastic Ingestion Initiative for a cleaner world

Plastics are one of the most used materials in the world. Their indiscriminate use and inappropriate disposal have led to inevitable impacts, for instance ingestion, on the environment arousing the attention of the global com-munity. In addition, plastic ingestion studies are often written in scientific jargon or hidden behind paywalls, which makes these studies inaccessible. GLOVE is an online and open-access dashboard database available at gloveinitiative.shinyapps.io/Glove/ to support scientists, decision-makers, and society with information collected from plastic ingestion studies. The platform was created in the R environment, with a web interface developed through Shiny. It already comprises 530 studies, including all biological groups, with 245,366 indi-vidual records of 1458 species found in marine, freshwater, and terrestrial environments. The main goal of the GLOVE dashboard database is to improve data accessibility by being a scientifically useful grounded tool for designing effective and innovative actions in the current scenario of upcoming global and local agreements and actions on plastic pollution