Ocean currents, driven by gravity, wind, and water density, disperse marine biota worldwide, often leading species to shorelines alive or as carcasses. These carcasses provide vital information about species' health conditions and threats within their habitats. Marine animal strandings thus offer crucial insights into the ecological implications of population mortality. This research is instrumental for conservation efforts and identifying trends and threats. Scientists use human and animal forensics approaches to trace the origins of beached bodies. The capability to backtrack carcass drift and estimate death sites helps evaluate anthropogenic impacts. This information also forms the basis for legal applications and gives ecological indicators for marine megafauna conservation. Using backtracking in forensic ecology for conservation research presents expansive investigative opportunities. This paper offers a comprehensive review of: 1) Physical and environmental processes; 2) Drift applications; 3) Marine megafauna examples; 4) Forensic principles; 5) Postmortem intervals; 6) Marine megafauna backtracking. We further discuss these findings' potential conservation applications for endangered species. Our review aims to enhance understanding of coastal animal distribution, estimate mortality rates from strandings, explore seasonal variations for beach monitoring programs, and investigate anthropogenic impacts.

Brachyuran crabs are the most conspicuous macrobenthic fauna in Brazilian mangrove forests and salt marshes. This chapter presents basic information about the habitat, spatial distribution, and most remarkable biological features of 36 species from these ecosystems in Brazil. A brief overview of the crabs' ecological role is given, and, for exploited species, their socioeconomic roles are described, as well as the techniques with which they are fished and the status of their current fisheries management and conservation.

The exploited mangrove crab Ucides cordatus, an important ecosystem engineer in South American mangroves, has a biphasic lifecycle with pelagic larvae developing offshore. Megalopae return to the mangrove forest to settle, i.e., metamorphose into benthic juveniles but its environmental drivers remain poorly understood. We postulate that conspecific crabs facilitate recruitment. In the field, we investigated whether the number of recruits is higher near conspecific burrows than in areas without conspecific bioturbation. Recruit sampling was conducted monthly from April 2008 to May 2009 along an environmental gradient. First, U. cordatus recruits of that year emerged from March to July. Intraspecific facilitation was indicated by significantly higher recruit numbers in bioturbated than in non-bioturbated substrates. Recruits were most abundant in zones with intermediate conditions of inundation, leaf litter standing stock, sediment consistency, luminosity, temperature, salinity, and pH. Avoidance of more inundated zones likely reduces predation by fishes and of less inundated zones helps individuals escape more stressful, drier environmental conditions. The observed habitat-specific recruitment pattern must be considered when designing field assessments of the population structure of U. cordatus (which should include sampling recruits) and enhancing stocks by releasing laboratory-cultivated larvae and first juveniles into the wild.

Ucides cordatus is a relevant economic resource for the traditional communities of the Brazilian coast and stands out for its ecological importance for the mangrove ecosystem. Damages on land and in the ocean (sewage, dam failure, and oil spills) can affect these populations in long term. Crab collectors lose their source of income and food after these impacts, either by contamination or by the prohibition of capture. We monitored the crab’s population in seven estuaries and one coastal area of mangrove between October 2018 and September 2019. We plan to monitor these resources as preliminary assessment to measure long-term damage after the Fundão dam failure. In the areas considered potentially affected, fixed plots were established. The data collected were population density, carapace width, salinity, granulometry, calcium carbonate, and organic matter in the sediment. The density varied spatially among the estuaries as a reflection of the oceanographic and geomorphological conditions. A population may respond differently to impacts on the environment since mangroves have distinct forest composition and structure, as well as sedimentary characteristics. Except in Caravelas, the sampled areas showed predominance juvenile crabs. The maintenance of fishery stock is of concern considering that the environmental impacts that have occurred in the region and, when they become chronic, can harm the adaptation capacity of the population. The results presented show the vulnerability of populations in terms of size and density average, putting at risk the sustainability of the traditional communities that depend on the capture of U. cordatus and the health of the environment.

Concerns about protecting coastal wetlands in Brazil date back to the eighteenth century, and in the 1960s, mangroves and salt marshes were declared "Permanent Preservation Areas." Environmental legislation currently includes a system of protected areas (PAs) within many different management categories. In addition to reviewing the history of those PAs in Brazil, this chapter discusses three issues: (i) the importance of PAs for guaranteeing mangrove and salt marsh ecosystems, (ii) the undermining of PAs resulting from the lack of resources and by recent changes in Brazilian legislation, and (iii) the increase in the numbers of officially designated areas that allow the sustainable use of natural resources – at the expense of areas requiring full protection (i.e., no-take areas). The chapter ends by discussing future mangrove conservation challenges as well as ideological and political explanations for the difficulties faced by the Brazilian system of PAs.

This essay is a conceptual framework for testing the causal mechanisms of system degradation by metals in the mangrove ecosystem. The Fundão Dam collapse caused massive damage to the marine environment on the Southern Atlantic and Brazilian coast, reaching various kilometers from its origin, becoming a source of contamination. Along this Brazilian coast are vast mangrove areas with high biodiversity, different geomorphology, and distinct ecological functioning. These mangroves support fisheries' productivity in the Tropical South Atlantic, in connection with Abrolhos Reef. Brazil does not have a protocol to monitor environmental damage in this ecosystem, and we proposed to develop a way to identify the impact and quantify it. Along the estuaries, to assess the damage, the plots were demarked in three regions: the upper, middle, and lower estuary, and in both types of forest: fridge and basin. Samples of sediment and leaves were collected bi-monthly to evaluate metal concentrations, especially iron and manganese, the most abundant metals in Fundão Dam. The monitoring also evaluated the forest structure, dynamics of the crabs' population, and flora productivity. First-year monitoring identifies a high concentration of iron or manganese in the sediment above the NOAAs' recommendation in all the estuaries. The concentration of Fe and Mn in sediment varies seasonally in magnitude, concentration, and types of metals between estuaries, sectors, and forests. The behavior of biological indicators in the presence of metals (type and concentration) differed between fauna and flora species. The monitoring recognized that the tailings mining from Fundão Dam impacted all estuaries by different magnitudes and persistence. These differences are due to geomorphology diversity, climate, and oceanographic influences.

Background The mangrove crab Ucides cordatus is considered a key species for the ecological balance of mangrove forests and a major source of employment and income for traditional crab collectors in Brazil. Several studies evidenced weak genetic variation among populations due to an efficient larval transport. However, gene flow patterns of the species is poorly understood, with no information about migration rates. The influence of the two main Brazilian currents in larval dispersion is also not clear. In order to provide baseline information for conservation, planning and management of this important fishery resource, the present study aimed to estimate and evaluate spatial distribution of genetic diversity, migration rates and gene flow directivity among populations of U. cordatus in Brazil. Methods Nine microsatellites were used to resolve population structure of 319 crabs collected from six sites located along the Brazilian coast. The degree of geographical differentiation included estimates of genetic diversity, population structure and gene flow models, with spatial analysis of shared alleles (SAShA), isolation by distance tests, AMOVA, discriminant analysis of principal components (DAPC) and Bayesian clustering. We estimated the amount of ongoing gene flow between clusters using the coalescent-based method implemented in Migrate-N. Results Loci were highly polymorphic (average of 12.4 alleles per locus) evidencing high genetic variability. There was significant differentiation among localities, despite of the low value of FST (= 0.019; P < 0.001). FST and Jost’s D indexes were also estimated in pairwise comparisons and showed significant differences between most of the surveyed site pairs (P < 0.05). Structure evidenced a single genetic group among samples, however SAShA pointed to a non-panmictic condition (P = 0.011). AMOVA detected four statistical significant clusters with low level of differentiation (FCT = 0.037; P = 0.023). The gene flow model that best described the population connectivity was the island model, with ∼24 crabs being exchanged among localities per generation. Discussion The high migration rates found among localities seem to be the main force acting to sustain the distribution of the genetic diversity of U. cordatus. Despite the high gene flow and the weak population structure among samples, the significant genetic differences found suggest that gene flow alone does not bypass the effects of genetic drift, natural selection and/or human exploitation. These findings are vital for the establishment of a database to be used in the development of conservation programs.

This synthesis is framed within the scope of the Brazilian Benthic Coastal Habitat Monitoring Network (ReBentos WG 4: Mangroves and Salt Marshes), focusing on papers that examine biodiversity-climate interactions as well as human-induced factors including those that decrease systemic resilience. The goal is to assess difficulties related to the detection of climate and early warning signals from monitoring data. We also explored ways to circumvent some of the obstacles identified. Exposure and sensitivity of mangrove and salt marsh species and ecosystems make them extremely vulnerable to environmental impacts and potential indicators of sea level and climate-driven environmental change. However, the interpretation of shifts in mangroves and salt marsh species and systemic attributes must be scrutinized considering local and setting-level energy signature changes; including disturbance regime and local stressors, since these vary widely on a regional scale. The potential for adaptation and survival in response to climate change depends, in addition to the inherent properties of species, on contextual processes at the local, landscape, and regional levels that support resilience. Regardless of stressor type, because of the convergence of social and ecological processes, coastal zones should be targeted for anticipatory action to reduce risks and to integrate these ecosystems into adaptation strategies. Management must be grounded on proactive mitigation and collaborative action based on long-term ecosystem-based studies and well-designed monitoring programs that can 1) provide real-time early warning and 2) close the gap between simple correlations that provide weak inferences and process-based approaches that can yield increasingly reliable attribution and improved levels of anticipation.

The large mangrove crab Ucides cordatus (“caranguejo-uçá”) is a key fisheries resource in Brazil, critical for the sustenance of livelihoods of thousands of people in coastal rural areas. Today's crab populations suffer from habitat degradation, disease, and increasing fishing pressure. Crabs are sold alive on local and regional markets, or traded as processed meat and the market chains typically involve intermediaries (i.e. traders). The present study examined the relationship between crab harvesters and the intermediaries, and the socio-ecological implications thereof. The research was performed between September 2013 and October 2014 in the Mamanguape River estuary, northeastern Brazil. Socioeconomic information and data regarding the catch (sex and carapace width of the crabs), the processing of U. cordatus meat and the commercial relationship between harvesters and intermediaries were obtained through structured (questionnaires) and semi-structured interviews and direct observations. The crab harvesters exist under precarious socioeconomic conditions that place them at the edge of society and therefore often seek loans offered by the intermediaries, generating loyalty and dependence that guarantees the intermediaries a stable supply of crabs needed to supply an avid market. Within this relationship, the intermediaries create pressure on natural crab populations by stimulating non-selective captures, as they buy specimens below the legal size limit (6cm wide carapace) for meat processing. During crab meat processing, the intermediaries themselves report that the meat is often mixed with cooked and shredded of other marine vertebrates, such as spotted eagle ray (Aetobatus narinari) and nurse shark (Ginglymostoma cirratum), to increase the weight of the final product. As with the crab harvesters, the women involved in processing the crabmeat often accept loans, resulting in the same type of dependence and loyalty to the intermediaries. The intermediaries, with their strong influence on the crab harvesting, are directly linked to the commercial, social and ecological implications of these harvesting activities, together with the crab harvesters themselves. Hence, to ensure sustainability of the U. cordatus fishery and maintain (better improve) dependant livelihoods, all actors involved in the production chain of U. cordatus must be considered when developing management strategies, rather than the current approach of considering the crab harvesters only. We advise the development and implementation of fisheries associations to give the crab harvesters (and regulating bodies) greater control over and capital gains from their catches.

O presente artigo traz um diagnóstico que integra o processo de planejamento do "Programa de Monitoramento da Biodiversidade de Manguezais de UCs Federais (MoMa)", do ICMBio. O objetivo foi levantar e avaliar as pesquisas sobre a biodiversidade de manguezais com potencial de contribuição ao monitoramento deste ecossistema. A metodologia envolveu consultas ao Cadastro Nacional de Unidades de Conservação (CNUC), acessos ao Sistema de Autorização e Informação em Biodiversidade (SISBIO), e uma pesquisa junto a representantes de UCs, que responderam a questionários estruturados. Foram levantadas 50 UCs com manguezal, sendo 32% do grupo de proteção integral e 68% do grupo de uso sustentável. Das 48 UCs cujos gestores responderam aos questionários, 56% ainda não possuíam dados de medição de área de cobertura de manguezal. Segundo os gestores, em 48% das UCs não eram executadas pesquisas científicas sobre biodiversidade de manguezal. Adicionalmente, as 162 pesquisas registradas com potencial de contribuição para monitoramento estavam mal distribuídas geograficamente, com uma maior concentração nos estados do Pará e Paraíba, o que dificulta a formação de redes nacionais de monitoramento. Observou-se uma concentração das pesquisas em algumas espécies, notadamente ameaçadas de sobrexplotação (p. ex., caranguejo-uçá, Ucides cordatus) ou ameaçadas de extinção (p. ex., peixe-boi, Trichechus manatus). Esta concentração de pesquisas poderá facilitar a formação das redes de monitoramento destas espécies. Por outro lado, é preocupante a carência de pesquisas sobre espécies importantes para a conservação, como as aves congregatórias (p. ex., guará-vermelho, Eudocymus ruber). O fato de 60% das pesquisas existentes à época serem executadas por universidades indica que estas instituições são potenciais parceiras das UCs na condução desses monitoramentos. No entanto, foi observada uma curta duração (média de dois anos), provavelmente devido ao tempo limitado para a finalização de teses e dissertações e/ou à limitação de recursos financeiros, cerceando os monitoramentos de longo prazo. Assim, o grande desafio para elaborar e implementar um programa de monitoramento da biodiversidade de manguezais não é apenas o de estabelecer métodos padronizados e viáveis, mas também permitir o encadeamento e a continuidade dos estudos realizados por sucessivas gerações de pesquisadores no interior das UCs. Para tanto, a captação de recursos através da vinculação de monitoramentos a condicionantes de licenciamento ambiental de empresas privadas e o investimento em monitoramentos participativos são duas estratégias promissoras, e podem viabilizar a execução do Programa de Monitoramento.

The harvested mangrove crab Ucides cordatus exhibits conspicuous cycles of searching for mates en masse. This phenomenon, called andada, always occurs at the syzygies, but the particular moon phase, full, new or rarely both, varies for unknown reasons. The presence and absence of andada activities of a Northeast Brazilian crab population was assessed by boat between 2006 and 2011. In 2008 crabs were additionally collected in sampling plots to determine the duration and intensity of andada events and in 2010 the timing of andada with respect to the light: dark cycle and tidal cycle was studied by observations from platforms. We found that andada occurred during the day and night and that the rhythm of mate searching was linked to the syzygy tide inequality cycle (STIC). Andada shifted between new and full moon, depending upon which moon phase had the higher amplitude tides. The ultimate cause of andada is likely to be increased larval survival after synchronous release at highest amplitude spring tides 1 month later. Such anticipatory behaviour is probably under endogenous control. The results of this study can help to improve temporal placements of capture bans for this harvested species and reduce current conflicts between fishers and regulatory agencies. (C) 2012 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Relationship between burrow opening and cephalothoraxes length of the caranguejo-uçá, Ucides cordatus (Linnaeus, 1763) (Crustacea: Decapoda: Brachyura) In the mangroves of Caravelas and Canavieiras, South of Bahia state, monthly stratified samplings were performed from October 2003 to October 2004, in a Laguncularia racemosa (white mangrove) zone, a Rhizophora mangle (red mangrove) zone and a mangrove to dry land (apicum) transition zone. Within 25 m2 sampled quadrats, all burrow openings of the mangrove crab Ucides cordatus were measured with an adapted vernier caliper, and the corresponding crabs were removed, whenever possible, for biometry with a standard caliper. Equations of simple linear regression were estimated for diameter of burrow openings in function of cephalotorax length, as well as, for cephalotorax width in function of cephalotorax length (and viceversa). A relatively strong correlation was observed between the smallest burrow opening diameter and the length of inhabiting crab, which can be described by a linear model with the following equation: BA = 0.36 + 1.04 * CL (r2 = 0.721; n=1873). It was determined that minimum U. cordatus size permitted for commercial capture – 6.0 cm cephalotorax width – corresponds to a 4.6 cm cephalotorax length and a 5.1 cm burrow opening diameter. The work shows that burrow opening measurement is an efficient method to estimate the individual length of Ucides cordatus.

Recruits of the mangrove crab Ucides cordatus (Linnaeus, 1763), rarely encountered in the field were found co-inhabiting burrows of larger male and female conspecifics in the mangrove forest. They were located in the sediment of the inner walls and burrow plugs. Average carapace width (CW) of the hosting and co-inhabiting crabs was 3.8 +/- 0.20 and 0.9 +/- 0.03, respectively. As shown by the size-frequency distribution, while most recruits leave the conspecific burrows after reaching 1.0 cm CW, some stay until they reach a size of 2.5 cm CW. The results of this study contribute to a better understanding of recruitment patterns in this ecologically and economically important mangrove crab species. Follow-up studies are however needed to fully determine the role of conspecific burrows for juvenile habitat choice and survivorship in U. cordatus.

The size, structure, and density of a population of Lytechinus variegatus were recorded from a shallow seagrass bed (Halodule wrightii) at 40-day intervals from April 1994 to April 1995. A local mass mortality was observed in May 1994. The density declined from 0.57+/-0.10 to 0.06+/-0.05 ind.m(-2), mean size declined from 37.6+/-0.49 to 16.2+/-2.14 mm and maximum size from 75 to 40 mm. Ten months after mortality, the maximum and mean sizes had returned to initial values, but density had not (0.10+/-0.03 ind.m(-2)). A second, smaller mass mortality occurred in April 1995. High values of gonad index were recorded before mortality (9.40+/-5.97) and after population recovery (11.96+/-5.74). Recruitment was continuous throughout the year, but reached a peak from August to October. This can be related to the patterns of upwelling in the region. Mass mortality is probably an annual event in this population that can be correlated with the occurrence of low tides during daytime in the fall. The population can recover during the summer when low tides occur during the night. The massive input of recruits prevents extinction of the population during the season of high mortality. Population recovery depends on the magnitude of recruitment.

Experimental testing of a latent heat store with direct contact reflux boiling heat exchanging