Environmental factors have stronger effects than biotic processes in patterns of intertidal populations along the southeast coast of Brazil.

Rocky shore communities are shaped by complex interactions among environmental drivers and a range of biological processes. Here, we investigated the importance of abiotic and biotic drivers on the population structure of key rocky intertidal species at 62 sites, spanning ∼50% of the Brazilian rocky shoreline (i.e., ∼500 km). Large-scale population patterns were generally explained by differences in ocean temperature and wave exposure. For the gastropod species Lottia subrugosa, differences at smaller scales (i.e., 0.1-1 km) were better explained by other abiotic influences such as freshwater discharge and substrate roughness. Based on the general population patterns of intertidal species identified, three main oceanographic groups were observed: a cold-oligotrophic grouping at northern sites (Lakes sub-region), a eutrophic group associated with large estuaries and urban zones (Santos and Guanabara bays); and a transitional warm-water group found between the two more productive areas. Larger individuals of Stramonita brasiliensis, L. subrugosa and Echinolittorina lineolata were generally found in the cold-oligotrophic system (i.e., upwelling region), while small suspension feeders dominate the warm-eutrophic systems. Evidence of bottom-up regulation was not observed, and top-down regulation effects were only observed between the whelk S. brasiliensis and its mussel prey Pernaperna. Environmental drivers as compared to biotic interactions, therefore, play a key role determining the population structure of multiple intertidal species, across a range of spatial scales along the SW Atlantic shores.

Macroecology of rocky intertidal benthic communities along the southwestern Atlantic: Patterns of spatial variation and associations with natural and anthropogenic variables.

Assessing spatial variability in biodiversity and its relationships with potential drivers is necessary for understanding and predicting changes in ecosystems. Here, we evaluated spatial patterns in sessile macrobenthic communities in rocky intertidal habitats along the southwestern Atlantic (SE Brazil), spanning over 500 km of coastline. We applied a rapid-survey approach focusing on the main space occupiers and habitat-forming taxa. We partitioned community variance into spatial scales ranging from metres to hundreds of kilometres and assessed whether community patterns were associated with variation in shore topography, nearshore ocean, and human influence. The communities from the mid-midlittoral level exhibited equivalent variation (31-35%) at the scales of quadrats (metres), sites (kilometres), and sub-regions (tens of kilometres). For the communities from the low-midlittoral and infralittoral fringe levels, most variability occurred at the scales of quadrats and sites (30-42%), followed by sub-regions (22%). Wave fetch, sea surface temperature (SST), and shore inclination were the variables that best explained community structure at the mid-midlittoral. At the low-midlittoral and infralittoral fringe, the most influential variables were related to oceanic forcing (SST, total suspended solids, particulate organic carbon, chlorophyll-a concentration) and human influence. Univariate analyses also revealed strong associations between the abundance of the main components of the communities and the predictor variables evaluated. Our results suggest that urbanised estuarine bays and coastal upwelling regimes have a strong influence on adjacent benthic communities, driving macroecological patterns in the study area. This study advances the knowledge in macroecology and biogeography of rocky shores in an understudied coastline and globally and provides valuable insights for future assessments of ecological changes resulting from unfolding human impacts.

The increase in intensity and frequency of surface air temperature extremes throughout the western South Atlantic coast.

The climate is changing. At this stage, it is important to specify an 'extreme' climate and identify patterns that indicate its potential harm worldwide, including the coastal zones. Herein, we considered extremes based on the "Peaks Over Threshold" method from the "Extreme Value Theory". We looked after geographical patterns of surface air temperature (SAT) extremes (e.g., Tmax, Tmin, daily temperature range (DTR), and inter-daily temperature range) over the last 40 years throughout the Brazilian coast. Overall, we found a trend increase in intensity and frequency, but the duration was barely affected. The latitudinal pattern of extremes and the temperatures considered extremes followed the settled perception that areas in higher latitudes will be more affected by the extent of warming. Additionally, the seasonal pattern of DTR demonstrated to be a good approach to make inferences about air mass changes, but joint analyses on extremes with other atmospheric variables are desirable. Given the potential effects of extreme climates on society and natural systems over the world, our study highlights the urge for action to mitigate the effects of the increase in SAT in coastal zones.

Local and large-scale spatial variation in a marine predator-prey interaction in the southwestern Atlantic.

Predator-prey interactions are a key ecological process which can be modified by environmental conditions over a range of spatial scales. Through two complementary short-term experiments, we assessed how local and large-scale environmental conditions affect a subtropical intertidal predator-prey interaction. At a local scale, we evaluated the effects of the degree of exposure to wave action and prey density on consumption rate and interaction strength using a whelk-barnacle system. Consumption rate decreased with wave exposure at experimentally reduced prey density but did not change at ambient density. Such an interactive effect occurred due to shifts in the whelk's feeding behaviour, likely linked to encounter rate and stress amelioration underpinned by prey density. Per capita interaction strength of the whelk on the barnacle weakened along the wave exposure gradient, but to a greater degree at reduced compared to ambient prey density. This confirms that environmental harshness can decrease the importance of predators, but the magnitude of change may be modified by density-dependent effects. A large-scale experiment did not reveal spatial patterns in the whelk-barnacle interaction, nor relationships to chlorophyll-a concentration or the minor change in sea temperature across the study area. Patterns in the size of consumed barnacles along the chlorophyll-a gradient suggest changes in food choice related to prey quality and size. We conclude that disentangling the effects of wave exposure and prey density revealed important potential mechanisms driving species locally. Large-scale variation in the whelk-barnacle interaction appeared to be linked to species' traits shaped by the environmental context.

When One Health Meets the United Nations Ocean Decade: Global Agendas as a Pathway to Promote Collaborative Interdisciplinary Research on Human-Nature Relationships.

Strong evidence shows that exposure and engagement with the natural world not only improve human wellbeing but can also help promote environmentally friendly behaviors. Human-nature relationships are at the heart of global agendas promoted by international organizations including the World Health Organization's (WHO) "One Health" and the United Nations (UN) "Ocean Decade." These agendas demand collaborative multisector interdisciplinary efforts at local, national, and global levels. However, while global agendas highlight global goals for a sustainable world, developing science that directly addresses these agendas from design through to delivery and outputs does not come without its challenges. In this article, we present the outcomes of international meetings between researchers, stakeholders, and policymakers from the United Kingdom and Brazil. We propose a model for interdisciplinary work under such global agendas, particularly the interface between One Health and the UN Ocean Decade and identify three priority research areas closely linked to each other: human-nature connection, conservation-human behavior, and implementation strategies (bringing stakeholders together). We also discuss a number of recommendations for moving forward.

Reviewing the effects of contamination on the biota of Brazilian coastal ecosystems: Scientific challenges for a developing country in a changing world.

Pollution is a major worldwide problem that is increasing with urban growth, mainly along coastal areas. Pollution is often worse, governance is poorer and managerial strategies to improve environmental quality are less advanced in developing than developed countries. Here, we present an overview of the current scientific knowledge of the impacts of contamination on the biota of coastal ecosystems of Brazil and evaluate the scientific challenges to provide baseline information for local managerial purposes. We compiled data from 323 peer-reviewed published papers from the extensive Brazilian coast. We critically evaluated the produced knowledge (target contaminants, sources, ecosystems, taxa, response variables) and the science behind it (rigour and setting) within its socioenvironmental context (land occupation, use of the coast, sanitation status, contamination history). Research was driven largely by environmental outcomes of industrial development with a focus on the single effects of metals on the biota. The current knowledge derives mainly from laboratory manipulative experiments or from correlative field studies of changes in the biota with varying levels of contamination. Of these, 70% had problems in their experimental design. Environmental impacts have mainly been assessed using standard indicators of populations, mostly in ecotoxicological studies. Benthic assemblages have mostly been studied using structural indicators in field studies. Future assessments of impacts should expand research to more taxonomic groups and ecosystem compartments, adding combined functional and structural responses. Furthermore, further investigations need to consider the interactive effects of contaminants and other environmental stressors. By doing so, researchers would deliver more robust and effective results to solve problems of pollution.

Influence of environmental variables over multiple spatial scales on the population structure of a key marine invertebrate.

Quantifying scale-dependent patterns and linking ecological to environmental variation is required to understand mechanisms regulating biodiversity. We conducted a large-scale survey in rocky shores along the SE Brazilian coast to examine spatial variability in body size and density of an intertidal barnacle (Chthamalus bisinuatus) and its relationships with benthic and oceanographic predictors. Both the size and density of barnacles showed most variation at the smallest spatial scales. On average, barnacle body size was larger on shores located in areas characterised by higher chlorophyll levels, colder waters, low wave action and low influence of freshwater. Barnacles were more abundant at wave-exposed shores. We identified critical scales of spatial variation of an important species and linked population patterns to essential environmental predictors. Our results show that populations of this barnacle are coupled to scale-dependent oceanographic variation. This study offers insights into the mechanisms regulating coastal populations along a little studied coastline.

Aichi Target 18 beyond 2020: mainstreaming Traditional Biodiversity Knowledge in the conservation and sustainable use of marine and coastal ecosystems.

Indigenous Peoples and Local Communities (IPLCs) have inhabited coastal areas, the seas, and remote islands for millennia, and developed place-based traditional ancestral knowledge and diversified livelihoods associated with the biocultural use of marine and coastal ecosystems. Through their cultural traditions, customary wise practices, and holistic approaches to observe, monitor, understand, and appreciate the Natural World, IPLCs have been preserving, managing, and sustainably using seascapes and coastal landscapes, which has been essential for biodiversity conservation. The international community has more than ever recognized the central role of IPLCs in the conservation of biodiversity-rich ecosystems, in particular, for the achievement of the Global Biodiversity Targets determined by the Parties to the United Nations Convention on Biological Diversity to tackle biodiversity loss. However, much remains to be done to fully recognize and protect at national levels IPLCs' Traditional Biodiversity Knowledge (TBK), ways of life, and their internationally recognized rights to inhabit, own, manage and govern traditional lands, territories, and waters, which are increasingly threatened. At the 2018 4th World Conference on Marine Biodiversity held in Montréal, Canada, eight themed working groups critically discussed progress to date and barriers that have prevented the achievement of the Aichi Biodiversity Targets agreed for the period 2011-2020, and priority actions for the Post-2020 Global Biodiversity Framework. Discussions in the "Application of Biodiversity Knowledge" working group focused on Targets 11 and 18 and the equal valuation of diverse Biodiversity Knowledge Systems (BKS). This Perspective Paper summarizes the 10 Priority Actions identified for a holistic biodiversity conservation, gender equality and human rights-based approach that strengthens the role of IPLCs as biodiversity conservation decision-makers and managers at national and international levels. Furthermore, the Perspective proposes a measurable Target 18 post-2020 and discusses actions to advance the recognition of community-based alternative conservation schemes and TBK to ensure the long-lasting conservation, customary biocultural use, and sustainable multi-functional management of nature around the globe.

Impacts of copper contamination on a rocky intertidal predator-prey interaction.

Metal contamination can change ecological interactions with potential effects on community dynamics. However, understanding real effects of metals on biota relies on studies undertaken in natural conditions. Through a field experiment, we investigated the effects of copper contamination on the responses of a barnacle prey and its predator, the dogwhelk, and explicitly their interaction. Contamination increased barnacle mortality and reduced predation with no effects on interaction strength. This was because the higher mortality of the prey compensated for the lower consumption of the predator. Despite not affecting the interaction strength, these results suggest a decrease in energy flow in the trophic chain that may lead to important changes in community structure and ecosystem functioning. This study shows the importance of manipulative experiments designed to provide mechanistic insights into ecological interactions to better clarify the effect of stressors on the structure and dynamic of communities.

Functional responses of filter feeders increase with elevated metal contamination: Are these good or bad signs of environmental health?

Fast urbanization in coastal areas has increased the load of contaminants entering estuaries worldwide, threatening the diversity and provision of services by these important systems. Contamination causes structural changes in ecosystems, but the consequences for their functioning are still overlooked. Here we investigated filtration and biodeposition rates of the mussel Mytilaster solisianus across different concentrations of metals, nutrients and suspended material, and levels of urbanization. As expected, filtration rates increased with the number of particles in the water column. However, in areas with low particle concentration, filtering increased in mussels with higher metal concentrations (Cu/Zn/Ni), which were, in turn, related to high urbanization. Similarly, biodeposition rates were positively related to metal concentration in mussels. The increased functional responses observed here is likely a symptom of stress, caused by potential compensatory mechanisms to the energetic costs of cell maintenance and body detoxification of mussels, rather than an indication of healthy systems/organisms. CAPSULE: Increased functional responses of mussels can be a sign of environmental stress.

Coastal upwelling affects filter-feeder stable isotope composition across three continents.

Large-scale nutrient fertilisation by coastal upwelling promotes benthic productivity through energy subsidies from enhanced phytoplankton production, and predictions of alterations to upwelling under climate change have implications for benthic ecosystem functioning. We investigated the stable isotope compositions of two bioengineers of global significance, the mussels Perna perna and Mytilus galloprovincialis, from upwelling and non-upwelling sites in five upwelling systems. Samples from Brazil, South Africa and Oman exhibited lower δ13C values at upwelling sites than at non-upwelling sites, with clearer effects where upwelling is more intense and frequent. North West Africa showed variability, probably linked to Saharan dust input. We highlight the importance of upwelling to sustaining benthic primary consumers and the sensitivity of consumer diet to the intensity and frequency of upwelling within each region. These results have implications in relation to climate change scenario effects on upwelling events, with potential cascading effects on higher trophic levels and ecosystem functioning.

Abundance of biofilm on intertidal rocky shores: can trampling by humans be a negative influence?

Trampling by human visitors to rocky shores is a known stressor on macroorganisms. However, the effects of trampling on rocky intertidal biofilm, a complex association of microorganisms of ecological importance in coastal communities, have not been quantified. We evaluated the impact of trampling frequency and intensity on total biomass of epilithic microalgae on intertidal rocky shores in the southeast of Brazil. There was a trend of increase in the variability of biomass of biofilm in function of intensity of trampling, but no significant effects emerged among trampling treatments. The low influence of trampling on biofilm might be a result of the small dimensions of the organisms coupled with their natural resilience and roughness of the substrate; the former preventing the removal of biofilm layers by shoes and facilitating their quick recovery. Our results provide insights for management and conservation of coastal ecosystems revealing a weaker impact of trampling on biofilm than that reported on macroorganisms.