Functional reorganization of North American wintering avifauna.

Wintering birds serve as vital climate sentinels, yet they are often overlooked in studies of avian diversity change. Here, we provide a continental-scale characterization of change in multifaceted wintering avifauna and examine the effects of climate change on these dynamics. We reveal a strong functional reorganization of wintering bird communities marked by a north-south gradient in functional diversity change, along with a superimposed mild east-west gradient in trait composition change. Assemblages in the northern United States saw contractions of the functional space and increases in functional evenness and originality, while the southern United States saw smaller contractions of the functional space and stasis in evenness and originality. Shifts in functional diversity were underlined by significant reshuffling in trait composition, particularly pronounced in the western and northern United States. Finally, we find strong contributions of climate change to this functional reorganization, underscoring the importance of wintering birds in tracking climate change impacts on biodiversity.

Plastic pollution on the world's coral reefs.

Coral reefs are losing the capacity to sustain their biological functions1. In addition to other well-known stressors, such as climatic change and overfishing1, plastic pollution is an emerging threat to coral reefs, spreading throughout reef food webs2, and increasing disease transmission and structural damage to reef organisms3. Although recognized as a global concern4, the distribution and quantity of plastics trapped in the world's coral reefs remains uncertain3. Here we survey 84 shallow and deep coral ecosystems at 25 locations across the Pacific, Atlantic and Indian ocean basins for anthropogenic macrodebris (pollution by human-generated objects larger than 5 centimetres, including plastics), performing 1,231 transects. Our results show anthropogenic debris in 77 out of the 84 reefs surveyed, including in some of Earth's most remote and near-pristine reefs, such as in uninhabited central Pacific atolls. Macroplastics represent 88% of the anthropogenic debris, and, like other debris types, peak in deeper reefs (mesophotic zones at 30-150 metres depth), with fishing activities as the main source of plastics in most areas. These findings contrast with the global pattern observed in other nearshore marine ecosystems, where macroplastic densities decrease with depth and are dominated by consumer items5. As the world moves towards a global treaty to tackle plastic pollution6, understanding its distribution and drivers provides key information to help to design the strategies needed to address this ubiquitous threat.

TimeFISH: Long-term assessment of reef fish assemblages in a transition zone in the Southwestern Atlantic.

The TimeFISH database provides the first public time-series dataset on reef fish assemblages in the southwestern Atlantic (SWA), comprising 15 years of data (2007-2022) based on standardized Underwater Visual Censuses (UVCs). The rocky reefs covered by our dataset are influenced by pronounced seasonal cycles of ocean temperatures with warm tropical waters from the Brazil Current in the summer (~27°C) and colder waters from the La Plata River Plume discharge and upwelling from the South Atlantic Central Water in the winter (~18°C). These oceanographic conditions characterize this area as the southernmost tropical-subtropical climatic transition zone in the Atlantic Ocean. As a result, reef fish assemblages are comprised of both tropical and subtropical species. All records included in TimeFISH were collected using UVCs, a nondestructive method that allows the estimation of fish species richness, abundance, and body size distributions. UVCs were performed through 40 m2 belt transects by scuba diving in nine locations along the southern Brazilian coast (25-29°S). Four of these locations lie within the boundaries of the no-entry Arvoredo Marine Biological Reserve, where fishing and recreational activities are forbidden, and the remaining locations are unprotected from these activities. During each belt transect, a diver swam at a constant depth above and parallel to the reef, identifying fish species, counting the number of individuals, and estimating the total body length (Lt in cm) of all detected individuals. All fish individuals in the water column (up to 2 m above the substratum) and at the bottom were targeted. In total, 202,965 individuals belonging to 163 reef fish species and 53 families were recorded across 1857 UVCs. All survey campaigns were funded by either public or mixed capital (private-public) sources, including seven grants from the Brazilian federal and Santa Catarina state governments. Part of the data has already been used in multiple MS.c. and Ph.D. theses and scientific articles. TimeFISH represents an important contribution for future studies aiming to examine temporal and spatial variations of reef fish assemblages in transition zones. No copyright restrictions apply to the use of this data set, other than citing this publication.

Long-term monitoring projects of Brazilian marine and coastal ecosystems.

Biodiversity assessment is a mandatory task for sustainable and adaptive management for the next decade, and long-term ecological monitoring programs are a cornerstone for understanding changes in ecosystems. The Brazilian Long-Term Ecological Research Program (PELD) is an integrated effort model supported by public funds that finance ecological studies at 34 locations. By interviewing and compiling data from project coordinators, we assessed monitoring efforts, targeting biological groups and scientific production from nine PELD projects encompassing coastal lagoons to mesophotic reefs and oceanic islands. Reef environments and fish groups were the most often studied within the long-term projects. PELD projects covered priority areas for conservation but missed sensitive areas close to large cities, as well as underrepresenting ecosystems on the North and Northeast Brazilian coast. Long-term monitoring projects in marine and coastal environments in Brazil are recent (<5 years), not yet integrated as a network, but scientifically productive with considerable relevance for academic and human resources training. Scientific production increased exponentially with project age, despite interruption and shortage of funding during their history. From our diagnosis, we recommend some actions to fill in observed gaps, such as: enhancing projects' collaboration and integration; focusing on priority regions for new projects; broadening the scope of monitored variables; and, maintenance of funding for existing projects.

Low functional vulnerability of fish assemblages to coral loss in Southwestern Atlantic marginal reefs.

Marginal reefs sustain coral assemblages under conditions considered suboptimal for most corals, resulting in low coral abundance. These reefs are inhabited by numerous fishes with a generally unknown degree of association with corals that might lead to the assumption that corals play minor roles in determining fish occurrence, when corals could be actually sustaining diverse and resilient assemblages. Using site-occupancy models fitted to data of 113 reef fish species of different life stages (adults and juveniles) from 36 reefs distributed across the Southwestern Atlantic (0.87-27.6°S) we first assessed fish assemblage's response to coral and turf algal cover, and identified coral-associated fish. Then, we simulated the loss of coral-associated fishes and contrasted it with random losses, providing inferences on the resilience of fish assemblage's functional trait space to species loss. The entire fish assemblage responded more positively to coral than to turf algae, with 42 (37%) species being identified as coral-associated fish. The simulated loss of coral-associated fish reduced up to 5% the functional trait space and was not different from the random loss. These results reveal that marginal reefs of Southwestern Atlantic reefs host resilient fish assemblages that might preserve fundamental ecological functions and ecosystem services even with coral declines.

The COVID-19 pandemic has altered illegal fishing activities inside and outside a marine protected area.

The global COVID-19 pandemic has presented a unique opportunity to explore the consequences of illegal exploitation on wildlife communities, as it continues to have wide-reaching impacts on multiple sectors, including local and national economies, international trade, and conservation enforcement1. The ongoing reductions in monitoring and enforcement during the pandemic have allowed increased opportunities for illegal, unreported, and unregulated activities, particularly for small-scale fisheries2. Even before the pandemic, policymakers and fisheries managers intent on controlling illegal fishing activities established marine protected areas (MPAs) that restrict or prohibit fishing3. Unfortunately, non-compliance with MPAs is often the rule rather than the exception, and less than 10% of the world's MPAs have managed to effectively reduce infringement4. The COVID-19 pandemic has exacerbated these management challenges: a recent review of MPAs worldwide has revealed a general decline in tourism revenue to operate park services during the pandemic, especially revenue needed for supporting personnel to monitor, patrol, and enforce restrictions2. Here, we compile infraction records of illegal fishing activities by both professional (commercial) and amateur (recreational) boats inside and outside of the Tupinambás Ecological Station and the Alcatrazes Wildlife Refuge (Figure 1A), notable for its high reef-fish biomass and diversity in the Southwestern Atlantic5. We show that illegal exploitation has shifted since the onset of the pandemic, targeting larger, higher-value species that contribute disproportionately to the structure and function of reef-fish communities in the region.

Severe coral bleaching of Siderastrea stellata at the only atoll in the South Atlantic driven by sequential Marine Heatwaves / Branqueamento severo de Siderastrea stellata no único atol do Atlântico Sul impulsionado por ondas de calor marinhas sequenciais

Abstract: Threatened by global warming and extreme climatic events, such as El Niño Southern Oscillation (ENSO) and Marine Heatwaves (MHW), coral reefs worldwide faced the worst bleaching and mortality event between 2014 and 2017, induced by the 2015/2016 ENSO. We evaluated the impacts of ENSO and MHW episodes on bleaching and mortality frequencies of Siderastrea stellata at Rocas Atoll, Southwestern Atlantic, using visual censuses conducted in 2016, 2017 and 2019. Bleaching rate varied significantly along the sampling period (11.71% in 2016, 1.52% in 2017, and 88% in 2019), but mortality was always less than 4%. Bleaching events in Atlantic reefs have been constantly associated with ENSO, until these recent events of the last two years. We suggest that MHW were probably the primary driver of the observed bleaching, especially in 2019, when much higher bleaching rates were observed than in ENSO periods. Although Southwestern Atlantic massive corals are considered more resistant to thermal stress than reefs corals worldwide, the strong events registered since 2019 highlight the need for continuous monitoring to better understand coral bleaching dynamics and improve predictions on the effects of global change in the region.

Resumo: Ameaçados pelo aquecimento global e eventos climáticos extremos, como El Niño Oscilação Sul (ENSO) e Ondas de Calor Marinhas (MHW), os recifes de coral em todo o mundo enfrentaram o pior evento de branqueamento e mortalidade entre 2014 e 2017, induzido pelo ENSO 2015/2016. Nesse estudo, avaliamos os impactos dos episódios de ENSO e MHW nas frequências de branqueamento e mortalidade de Siderastrea stellata no Atol de Rocas, Atlântico Sudoeste, a partir de censos visuais realizados em 2016, 2017 e 2019. O branqueamento variou significativamente ao longo do período de amostragem (11,71% em 2016, 1,52% em 2017, e 88% em 2019), mas a mortalidade não, sendo sempre inferior a 4%. Eventos de branqueamento em recifes do Atlântico têm sido constantemente associados ao ENSO, até os eventos recentes dos últimos dois anos. Nós sugerimos que as MHW foram provavelmente o principal impulsionador do branqueamento observado, especialmente em 2019, quando as taxas de branqueamento observadas foram maiores do que nos períodos de ENSO. Embora os corais massivos do Atlântico Sudoeste sejam considerados mais resistentes ao estresse térmico quando comparados com corais recifais de outros oceanos, os fortes eventos registrados desde 2019 destacam a necessidade de monitoramento contínuo para entender melhor a dinâmica do branqueamento de corais e melhorar as previsões sobre os efeitos das mudanças globais na região.

Historical distribution and current drivers of guppy occurrence in Brazil.

Humans introduce non-native species by means such as the deliberate release of fish into fresh waters and through commercial trade. The guppy Poecilia reticulata Peters, 1859, is commonly kept in aquaria and controls disease vectors, and now it occurs in many areas outside its natural distribution. Its initial habitat in Brazil was identified, and a study was performed to determine whether the density of guppies can be explained by the density of human population, per-capita gross domestic product, level of human impact on the areas where guppies have been found and fish-sampling effort. A total of 1402 guppy records were found; the southeastern region had the oldest records; and the southeastern, northeastern and central-western regions had the maximum records. Low tolerance to the colder climate may be the reason for the lack of guppy records in the southernmost states. It was also observed that the occurrence of this fish is positively, yet weakly, related to the density of human population, indicating that improved regulations regarding its use in controlling disease vectors, the aquarium trade and education of aquarium hobbyists could help prevent the spread of this species and its potential impacts in Brazil.

Contrasting feeding and agonistic behaviour of two blenny species on a small and remote island in the equatorial Atlantic Ocean.

We investigated the feeding rates, agonistic behaviour and diet of two blenny species, Entomacrodus vomerinus and Ophioblennius trinitatis, by direct observation and gut content analysis. Both species coexist in small and shallow tide pools in the St Peter and St Paul's Archipelago, equatorial North Atlantic Ocean. The feeding rate of O. trinitatis was c. 55% higher than E. vomerinus. On the other hand, agonistic rate of O. trinitatis was negatively related to body size, whereas in E. vomerinus was positively related. Both species showed a high diet overlap, in which detritus was the most important food item (86% in O. trinitatis and 80% in E. vomerinus). Feeding activity was more intense during the morning for O. trinitatis but afternoon for E. vomerinus. These behavioural observations support the importance of temporal feeding partitioning as the main strategy allowing species co-existence in tide pools.

Systematic relationships of sympatric pipefishes (Syngnathus spp.): A mismatch between morphological and molecular variation.

Analyses of mitochondrial DNA and morphological variation were performed on specimens of all five currently recognised Syngnathus pipefish species from the eastern Pacific Ocean with type localities currently considered to lie within the Californian marine biogeographic province: kelp pipefish Syngnathus californiensis, bay pipefish S. leptorhynchus, barred pipefish S. auliscus, barcheek pipefish S. exilis and chocolate pipefish S. euchrous. Results consistently differentiate S. auliscus from the other species and fail to distinguish all other specimens as distinct species, as indicated by extensive morphological overlap as well as incomplete lineage sorting and considerably low genetic divergence for 16s and coI genes(<1%). This study presents a taxonomic revision of eastern Pacific Syngnathus spp. and proposes the synonymy of S. leptorhynchus, S. euchrous and S. exilis, under the senior synonym, S. californiensis. There is still a need to study populations of Syngnathus spp. from north and south of the Californian province to assess whether these too are synonyms of the two-species recognised here.

The omnivorous triggerfish Melichthys niger is a functional herbivore on an isolated Atlantic oceanic island.

This study evaluated the functional role of the highly generalist omnivore Melichthys niger in the remote St. Peter and St Paul's Archipelago (SPSPA), Brazil, where grazing herbivorous fishes are very scarce. We analysed patterns of distribution from zero to 30 m deep during three time intervals during the day and sampled different aspects of their feeding behaviour, including diel feeding rate, feeding substrate and diet. The density of M. niger increased with depth (26-30 m) and decreased by the end of the day. Although M. niger did not present a typical herbivore diel feeding pattern, they targeted the epilithic algal matrix as their primary feeding substrate, ingesting predominantly algae and detritus. The characteristic Caulerpa racemosa var. peltata from SPSPA was ingested only as detached fronds. We suggest that in the isolated SPSPA, the single species M. niger may perform a unique role as a link between benthic primary production and higher levels. Further studies on the trophic ecology of omnivorous species are necessary to better understand their roles in a reef system, especially in impoverished areas where they are likely to play a crucial role.

Large-scale patterns of benthic marine communities in the Brazilian Province.

As marine ecosystems are influenced by global and regional processes, standardized information on community structure has become crucial for assessing broad-scale responses to natural and anthropogenic disturbances. Extensive biogeographic provinces, such as the Brazilian Province in the southwest Atlantic, present numerous theoretical and methodological challenges for understanding community patterns on a macroecological scale. In particular, the Brazilian Province is composed of a complex system of heterogeneous reefs and a few offshore islands, with contrasting histories and geophysical-chemical environments. Despite the large extent of the Brazilian Province (almost 8,000 kilometers), most studies of shallow benthic communities are qualitative surveys and/or have been geographically restricted. We quantified community structure of shallow reef habitats from 0° to 27°S latitude using a standard photographic quadrat technique. Percent cover data indicated that benthic communities of Brazilian reefs were dominated by algal turfs and frondose macroalgae, with low percent cover of reef-building corals. Community composition differed significantly among localities, mostly because of their macroalgal abundance, despite reef type or geographic region, with no evident latitudinal pattern. Benthic diversity was lower in the tropics, contrary to the general latitudinal diversity gradient pattern. Richness peaked at mid-latitudes, between 20°S to 23°S, where it was ~3.5-fold higher than localities with the lowest richness. This study provides the first large-scale description of benthic communities along the southwestern Atlantic, providing a baseline for macroecological comparisons and evaluation of future impacts. Moreover, the new understanding of richness distribution along Brazilian reefs will contribute to conservation planning efforts, such as management strategies and the spatial prioritization for the creation of new marine protected areas.

Estimating population parameters of longsnout seahorses, Hippocampus reidi (Teleostei: Syngnathidae) through mark-recapture

Estimating population parameters is essential for understanding the ecology of species, which ultimately helps to assess their conservation status. The seahorse Hippocampus reidi is directly exposed to anthropogenic threats along the Brazilian coast, but the species still figures as Data Deficient (DD) at IUCN's Red List. To provide better information on the ecology of this species, we studied how population parameters vary over time in a natural subtropical environment. By combing mark-recapture models for open and closed populations, we estimated abundance, survival rate, emigration probability, and capture probability. We marked 111 individuals, which showed a 1:1 sex ratio, and an average size of 10.5 cm. The population showed high survival rate, low temporary emigration probability and variable capture probability and abundance. Our models considering relevant biological criteria illuminate the relatively poorly known population ecology and life history of seahorses. It is our hope that this study inspires the use of mark-recapture methods in other populations of H. reidi in a collective effort to properly assess their conservation status.(AU)

Parâmetros populacionais são essenciais para compreender a ecologia das espécies, além de auxiliar a avalição do seu status de conservação. Dentre as espécies de cavalo-marinho que ocorrem no Brasil, Hippocampus reidi é a mais abundante, o que expõe suas populações a frequentes ameaças antropogênicas. Entretanto, esta espécie ainda consta como Deficiente em Dados (DD) na lista vermelha da IUCN. Considerando esta falta de informações sobre populações de H. reidi, utilizamos métodos de marcação e recaptura para avaliar como parâmetros de uma população de ambiente subtropical variam ao longo do tempo. Baseado em históricos de captura individuais, combinamos modelos de populações abertas e fechadas para estimar abundância, taxa de sobrevivência, probabilidade de emigração e probabilidade de captura. Ao todo, marcamos 111 indivíduos, em proporção sexual de 1:1, e tamanho médio de 10,5 cm. Esta população relativamente pequena apresentou alta taxa de sobrevivência, baixa probabilidade de emigração temporária e probabilidade de captura e abundância variáveis. A partir dos nossos modelos que consideraram critérios biológicos relevantes, fornecemos estimativas de parâmetros chave que auxiliarão a compreensão da ecologia e da história de vida de cavalos-marinhos. Nossa expectativa é que este método passe a ser amplamente utilizado em outras populações, em um esforço coletivo para avaliar o estado de conservação desta espécie.(AU)