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.

Portuguese Consensus on Acute Porphyrias: Diagnosis, Treatment, Monitoring and Patient Referral.

Acute porphyrias are a group of rare genetic metabolic disorders, caused by a defect in one of the enzymes involved in the heme biosynthesis, which results in an abnormally high accumulation of toxic intermediates. Acute porphyrias are characterized by potentially life-threatening attacks and, for some patients, by chronic manifestations that negatively impact daily functioning and quality of life. Clinical manifestations include a nonspecific set of gastrointestinal, neuropsychiatric, and/or cutaneous symptoms. Effective diagnostic methods are widely available, but due to their clinical heterogeneity and non-specificity, many years often elapse from symptom onset to diagnosis of acute porphyrias, delaying the treatment and increasing morbidity. Therefore, increased awareness of acute porphyrias among healthcare professionals is paramount to reducing disease burden. Treatment of acute porphyrias is centered on eliminating the potential precipitants, symptomatic treatment, and suppressing the hepatic heme pathway, through the administration of hemin or givosiran. Moreover, properly monitoring patients with acute porphyrias and their relatives is fundamental to preventing acute attacks, hospitalization, and long-term complications. Considering this, a multidisciplinary panel elaborated a consensus paper, aiming to provide guidance for an efficient and timely diagnosis of acute porphyrias, and evidence-based recommendations for treating and monitoring patients and their families in Portugal. To this end, all authors exhaustively reviewed and discussed the current scientific evidence on acute porphyrias available in the literature, between November 2022 and May 2023.

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.

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.

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.

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.