Search

The population of wandering albatrosses Diomedea exulans at South Georgia is decreasing because of bycatch in longline fisheries. Until at least the early 1990s, the survival rate of females was lower than males, consistent with the adult female-biased bycatch reported for fisheries operating around the Brazil-Falklands Confluence (BFC). Here we use extensive tracking data (1990–2012) from breeding birds at South Georgia to investigate overlap with longline fishing effort reported to the International Commission for the Conservation of Atlantic Tunas (ICCAT). Using data from multiple years, we conclude that breeding females are at higher risk than males from all the main pelagic longline fleets in the south-west Atlantic. Our overlap index (based on fishing effort and bird distributions) correlated positively with numbers of ringed birds reported dead on longliners, indicating that the metric was a good proxy of bycatch risk. The consistent sex bias in overlap across years, and the likely resulting sex-biased mortality, could account for lower adult female survival rate at the colony. The risk from fisheries changed seasonally; both sexes overlapped with pelagic longline effort during incubation (January–March), and particularly during post-brood chick-rearing (May–December), whereas overlap was negligible during brooding (April). The highest percentage of overlap was with the Taiwanese fleet, then vessels flagged to Brazil, Uruguay, Spain, Japan and Portugal. Females were consistently at greatest risk in the BFC region, whereas males showed lower and more variable levels of overlap with fisheries from 35 to 45°S. Our results have important implications for management of ICCAT longline fisheries and conservation of this highly threatened albatross population.

El análisis de largo plazo de las pesquerías costeras de Uruguay sugiere que el estado de los principales recursos es preocupante. Esto puede deberse a múltiples causas (sobrepesca, polución, causas naturales), a lo cual se suman fallas en el diseño (e.g. información de base insuficiente) o en la implementación de las normativas vigentes (e.g. fiscalización), así como a la ausencia de un enfoque integrado. Este libro plantea estrategias para el desarrollo e implementación del Manejo Ecosistémico de Pesquerías (MEP) costeras de Uruguay. En este contexto, se hace especial énfasis en la identificación de Áreas Marinas Protegidas (AMPs) como herramientas de manejo pesquero y conservación de la biodiversidad de la costa uruguaya. Se recabó información de los últimos 30 años, referida a descriptores ecológicos (número de especies, abundancia, biomasa, áreas de crías y desove, tipos de hábitats), pesqueros (captura, esfuerzo de pesca), socio-económicos (urbanización, turismo) y legales, la cual fue integrada y analizada en un Sistema de Información Geográfica (SIG). Se identificaron tres ecorregiones en la zona costera entre San José y Rocha, con diferencias en sus características ambientales y ecológicas, así como en cuanto a la naturaleza e intensidad de los usos humanos. En éstas, se identificaron y categorizaron 10 sitios como potenciales AMPs, cuya implementación sería de utilidad como herramienta para el MEP en la costa uruguaya. Dada la heterogénea distribución espacio-temporal de los recursos, así como de varios procesos pesqueros y ecosistémicos, se sugiere además la definición de ventanas espacio-temporales de manejo. Esto permitiría maximizar el uso de los recursos económicos y humanos para el manejo de una red de AMPs, optimizando los esfuerzos de monitoreo y/o fiscalización en áreas o períodos críticos. Se propone asimismo el empleo de indicadores de desempeño, puntos de referencia y reglas de decisión a efectos de evaluar la eficiencia de las AMPs. Se destaca también la necesidad de reconocer la heterogeneidad espacial y dinámica de las comunidades faunísticas, de sus componentes y procesos claves, así como del proceso pesquero en su conjunto, a efectos de desarrollar un MEP en Uruguay. Finalmente, se propone la implementación de procesos participativos de co-manejo pesquero que se adapten a las condiciones de cada sitio, de manera de proveer incentivos a los usuarios que permitan aumentar las probabilidades de éxito de los planes de manejo. La implementación de un sistema participativo de gobernanza de estas características, nuevo para el sector pesquero uruguayo, implicará focalizarse en procesos socio-ecológicos que no solamente consideren medidas de manejo tradicionales (e.g. captura máxima sostenible, control del esfuerzo pesquero y del poder de pesca), sino que reconozcan la legitimidad de la participación de los usuarios en este proceso. Esto potenciará sinergias entre los esfuerzos de manejo y conservación, reconociendo a la integridad de los ecosistemas como base para la sostenibilidad de los recursos y el crecimiento socio-económico. Solo la consideración simultánea de aspectos ecológicos y sociales permitirá augurar un futuro promisorio en la conservación y el uso sostenible de lo recursos pesqueros de la zona costera uruguaya. Long-term analysis of Uruguayan coastal fisheries suggests that the status of the main stocks is worrisome. This can be due to multiple factors, including: overfishing, pollution, natural variability of stocks, failures in the design (e.g. lack of basic information) and implementation of current regulations (e.g. control) and a lack of an integrated approach to their management. This book addresses the development and implementation of strategies for an Ecosystem-Based Fishery Management (EBFM) approach for Uruguayan coastal fisheries. Special emphasis is placed on the identification of Marine Protected Areas (MPAs) as fishery management and biodiversity conservation tools. Three ecoregions were identified in the Uruguay’s coastal zone between San José and Rocha, characterized by contrasting environmental and ecological characteristics and a diversity in nature and intensity of human uses. Information from the last 30 years was gathered and analyzed covering ecological aspects (species number, abundance, biomass, nursery and spawning areas, types of habitats), fishery indicators (catch, fishing effort), socioeconomic data (urbanization, tourism) and legal issues. This information was integrated into a Geographic Information System (GIS), which allowed the identification and categorization of 10 potential MPAs sites, whose implementation would be a useful tool in applying an EBFM approach along the Uruguayan coast. The use of spatio-temporal management windows is suggested to address the heterogeneous distribution of the resources and of several fishery and ecosystem-level processes. These would maximize the efficiency of economic and human resources needed to manage an MPA network as well as optimizing monitoring and control efforts in critical areas or periods. Performance indicators, reference points and decision rules are also proposed to evaluate MPA efficiency. The development of an EBFM approach in coastal Uruguayan fisheries would need to recognize the spatial heterogeneity and dynamics of faunal communities, their components and key processes, and the fishing process. Finally, the implementation of fisheries co-management initiatives, adapted to local conditions and specific situations, is proposed in order to provide incentives to the stakeholders and increasing the probability of achieving management plan objectives. This innovative strategy for Uruguayan fisheries should focus on socio-ecological processes that consider not only traditional management measures (e.g., regulation of catch, fishing effort and fishing power), but also the legitimacy of users’ participation in the management process. This approach would boost synergies between management and conservation efforts, recognizing ecosystems integrity as a basis for the sustainable use of fishery resources and socioeconomic growth. Only the simultaneous consideration of ecological and social aspects holds any promise for the future in promoting conservation and the sustainable use of the fishing resources of the Uruguayan coastal zone. As this socio-ecological process matures it will also need to increase the inclusiveness of resource management goals to include non-use factors, such as biodiversity and other ecosystem services, which are still poorly understood and managed in artisanal fisheries. Published

The variation in density and population structure of the land crab Gecarcinus lateralis (Gecarcinidae) was studied in a tropical semi-deciduous forest on the coast of Veracruz, Mexico. Crab density changed as a function of forest type (old or young), forest cover (understorey or gap), and year (1997 and 1998). In 1997, crab density was similar between old forest (OF) and young forest (YF), gaps and understorey, and between floor topographies. However, in 1998, crab density was higher in OF as compared to YF, and understorey in relation to gaps. For both years, crab density in the understorey of valleys and peaks was higher than in gaps. The population age structure of G. lateralis (as determined by burrow size) also varied as a function of forest age, floor topography, and forest cover. For both years, bigger crabs were found in YF than in OF, in valleys and slopes relative to peaks, and in the understorey as opposed to gaps. Forest variations in soil characteristics (humidity, amount of leaf litter and compaction) are invoked as explanatory variables for the observed differences in density and population structure of G. lateralis La variación en la densidad y estructura poblacional del cangrejo Gecarcinus lateralis fue estudiada en un bosque tropical subcaducifolio en la costa de Veracruz, México. La densidad de cangrejos cambió en función del tipo de selva (joven o vieja), cobertura (sotobosque o claros) y año (1997 o 1998). En 1997 no se encontraron diferencias significativas en la densidad de cangrejos entre selvas, ni entre topografía del suelo. Sin embargo, en 1998, la densidad de cangrejos fue mayor en la selva vieja (SV) con relación a la selva joven (SJ) y en el sotobosque respecto a los claros. Para ambos años, la densidad de cangrejos fue mayor en el sotobosque de los valles y las cimas mientras que, en las laderas las diferencias no fueron significativas. La estructura poblacional de G. lateralis, basada en la talla de las madrigueras, reveló que, en ambos años, en la SJ se encuentran individuos más grandes que en la SV. De la misma manera, en los valles y laderas, los cangrejos fueron más grandes que los de las cimas. Asimismo, se encontraron tallas significativamente mayores bajo el dosel que en los claros. Se sugiere que las diferencias en las condiciones del suelo (humedad, hojarasca y compactación) entre los sitios podrían estar implicadas en las variaciones observadas en la densidad y estructura poblacional del cangrejo semi-terrestre G. lateralis A variação na densidade e estrutura populacional do caranguejo Gecarcinus lateralis foi estudada num bosque tropical sub caducifólio na costa de Veracruz, México. A densidade de caranguejos mudou em função do tipo de selva (jovem ou velha), cobertura (soto-bosque ou claros) e do ano (1997 ou 1998). Em 1997 não se encontraram diferenças significativas na densidade de caranguejos entre selvas, nem entre topografia do solo. No entanto, em 1998, a densidade de caranguejos foi maior na selva velha (SV) em relação à selva jovem (SJ) e no soto-bosque em relação aos claros. Para ambos anos, a densidade de caranguejos foi maior no soto-bosque dos vales e as cimas enquanto que, nas ladeiras as diferenças não foram significativas. A estrutura populacional de G. lateralis, baseada no tamanho das madrigueiras, revelou que, em ambos anos, na SJ encontram-se indivíduos maiores que na SV. Da mesma maneira, nos vales e ladeiras, os caranguejos foram maiores que os das cimas. Assim mesmo, encontraram-se tamanhos significativamente maiores sob o dossel que nos claros. Sugere-se que as diferenças nas condições do solo (umidade, folhada e compactação) entre os lugares poderiam estar implicadas nas variações observadas na densidade e estrutura populacional do caranguejo semiterrestre G. lateralis

As sites of floating marine material deposition, sandy beaches accumulate marine litter. While research and assessment on beach litter is increasing and involves various actors (scientists, society and NGOs), there is the need to assess current and future dominant trends, directions and priorities in that research. As such, a textural co-occurrence analysis was applied to published scientific literature. Words were considered both singly and as part of compound terms related to concepts relevant to sandy beach ecology: morphodynamic state; Littoral Active Zone; indicator fauna. Litter as a compound term was also included. The main co-occurrences were found within compounds, with scarce interaction of “morphodynamic state” with the others, indicating the need for further integration of beach ecology paradigms into beached plastics studies. Three approaches are proposed to overcome the research limits highlighted: the unequivocation of terms, the consideration of adequate scales, and the attention to dynamics rather than just patterns.

Sandy beaches are ecosystems under increasing human pressure that require efficient management and conservation strategies. Resident macroinvertebrates usually respond to disturbances by changing their behaviour and abundance, and therefore they may be used as indicator species using simple and low-cost monitoring strategies. We synthesize information from the scientific literature on the use of sandy beach macroinvertebrates as indicators of human disturbances operating at local scales. Response ratios were applied to perform a meta-analysis supported by empirical data to objectively assess the magnitude of human disturbances on beach fauna. The “compare and contrast” approach represented some 80% of the studies. Gradient assessments were performed by 16% of the studies, though without determining thresholds of disturbance. Long-term monitoring (encompassing more than two years) was the general approach used in studies about harvesting, but it was not used when assessing other type of disturbances. Causality relationships and mechanisms underlying impacts were rarely assessed. Useful indicators to specific human disturbances were: 1) ghost crabs, which indicate the negative effects of vehicle traffic and nourishment; 2) talitrids as indicators of trampling and mechanical cleaning; and 3) clams as indicators of harvesting. As beaches are affected by multiple stressors acting simultaneously, the relative importance of each one has been difficult to reveal. It remains a priority to identify how different human disturbances are affecting macroinvertebrates under a range of diffuse impacts. Such results would allow for the depiction of patterns and future studies should prioritize gradient analyses and manipulative experiments to provide thresholds of specific stressors and mechanisms of impacts.

Native oyster reefs once dominated many estuaries, ecologically and economically. Centuries of resource extraction exacerbated by coastal degradation have pushed oyster reefs to the brink of functional extinction worldwide. We examined the condition of oyster reefs across 144 bays and 44 ecoregions; our comparisons of past with present abundances indicate that more than 90% of them have been lost in bays (70%) and eco regions (63%). In many bays, more than 99% of oyster reefs have been lost and are functionally extinct. Overall, we estimate that 85% of oyster reefs have been lost globally. Most of the world's remaining wild capture of native oysters (> 75%) comes from just five ecoregions in North America, yet the condition of reefs. in these ecoregions is poor at best, except in the Gulf of Mexico. We identify many cost-effective solutions for conservation, restoration, and the management of fisheries and nonnative species that could reverse these oyster losses and restore reef ecosystem services.