OSIRIS: A model for integrating the effects of multiple stressors on marine ecosystems.

While much has been learnt about the impacts of specific stressors on individual marine organisms, considerable debate exists over the nature and impact of multiple simultaneous stressors on both individual species and marine ecosystems. We describe a modelling tool (OSIRIS) for integrating the effects of multiple simultaneous stressors. The model is relatively computationally light, and demonstrated using a coarse-grained, non-spatial and simplified representation of a temperate marine ecosystem. This version is capable of reproducing a wide range of dynamic responses. Results indicate the degree to which interactions are synergistic is crucial in determining sensitivity to forcing, particularly for the higher trophic levels, which can respond non-linearly to stronger forcing. Stronger synergistic interactions sensitize the system to variability in forcing, and combinations of stronger forcing, noise and synergies between effects are particularly potent. This work also underlines the significant potential risk incurred in treating stressors on ecosystems as individual and additive.

Practitioner insights as a means of setting a context for conservation.

A key obstacle to conservation success is the tendency of conservation professionals to tackle each challenge individually rather than collectively and in context. We sought to prioritize barriers to conservation previously described in the conservation literature. We undertook an online survey of 154 practitioners from over 70 countries to ascertain the most important barriers to conservation they faced. We used statistical analyses to identify the key impediments to conservation success and to examine whether these were affected by organizational attributes. Twenty-one barriers were identified. The importance ascribed to those was influenced by continent of operation and organization size, but not by organization age or autonomy (from larger parent organizations). We found the most important barriers to consider when undertaking conservation action were wider issues (e.g., population growth, consumerism, favoring development, and industrial-scale activity), operating environment (e.g., lack of political will, ineffective law enforcement, weak governments, corruption, safety and security), community attributes (e.g., dynamics, conflicts, and education levels), and the way conservation is undertaken (overconfidence, lack of funding, and externally set agendas). However, we advise against applying a one-size-fits-all approach. We propose that conservationists account for the complex socioecological systems they operate in if they are to achieve success.

Percepciones de los Profesionales Como Medio para Establecer un Contexto Para la Conservación Resumen Un obstáculo clave para el éxito de la conservación es la tendencia de los profesionales de la conservación a abordar cada desafío individualmente en lugar de colectivamente y en contexto. Buscamos priorizar las barreras a la conservación descritas anteriormente en la literatura de conservación. Realizamos una encuesta en línea a 154 profesionales de más de 70 países para determinar las barreras más importantes para la conservación a las que se enfrentaban. Utilizamos análisis estadísticos para identificar los principales impedimentos para el éxito de la conservación y para examinar si estos se vieron afectados por atributos organizativos. Se identificaron veintiún barreras. La importancia que se les atribuye fue influenciada por el continente donde operan y el tamaño de la organización, pero no por la edad o la autonomía de la organización (de las organizaciones más grandes). Encontramos que los obstáculos más importantes a tener en cuenta al emprender acciones de conservación eran cuestiones más amplias (e. g., crecimiento de la población, consumismo, fomento del desarrollo y actividad a escala industrial), medio ambiente (e. g., falta de voluntad política, ineficacia en la aplicación de la ley, gobiernos débiles, corrupción, seguridad y protección), atributos comunitarios (e. g., dinámicas, conflictos y niveles educativos) y la forma en que se lleva a cabo la conservación (exceso de confianza, falta de financiamiento y agendas establecidas externamente). Sin embargo, aconsejamos no aplicar un enfoque "un tamaño se ajusta a todo". Para lograr el éxito, proponemos que los conservacionistas tengan en cuenta los complejos sistemas socioecológicos en los que operan.

Body Size Versus Depth: Regional and Taxonomical Variation in Deep-Sea Meio- and Macrofaunal Organisms.

Body size (weight per individual) is an important concept in ecology. It has been studied in the deep sea where a decrease in size with increasing depth has often been found. This has been explained as an adaptation to food limitation where size reduction results in a lowered metabolic rate and a decreased energetic requirement. However, observations vary, with some studies showing an increase in size with depth, and some finding no depth correlation at all. Here, we collected data from peer-reviewed studies on macro- and meiofaunal abundance and biomass, creating two datasets allowing statistical comparison of factors expected to influence body size in meio- and macrofaunal organisms. Our analyses examined the influence of region, taxonomic group and sampling method on the body size of meiofauna and macrofauna in the deep sea with increasing depth, and the resulting models are presented. At the global scale, meio- and macrofaunal communities show a decrease in body size with increasing depth as expected with the food limitation hypothesis. However, at the regional scale there were differences in trends of body size with depth, either showing a decrease (e.g. southwest Pacific Ocean; meio- and macrofauna) or increase (e.g. Gulf of Mexico; meiofauna only) compared to a global mean. Taxonomic groups also showed differences in body size trends compared to total community average (e.g. Crustacea and Bivalvia). Care must be taken when conducting these studies, as our analyses indicated that sampling method exerts a significant influence on research results. It is possible that differences in physiology, lifestyle and life history characteristics result in different responses to an increase in depth and/or decrease in food availability. This will have implications in the future as food supply to the deep sea changes as a result of climate change (e.g. increased ocean stratification at low to mid latitudes and reduced sea ice duration at high latitudes).

The Falkland Islands marine ecosystem: A review of the seasonal dynamics and trophic interactions across the food web.

The Falkland Islands marine environment host a mix of temperate and subantarctic species. This review synthesizes baseline information regarding ontogenetic migration patterns and trophic interactions in relation to oceanographic dynamics of the Falkland Shelf, which is useful to inform ecosystem modelling. Many species are strongly influenced by regional oceanographic dynamics that bring together different water masses, resulting in high primary production which supports high biomass in the rest of the food web. Further, many species, including those of commercial interest, show complex ontogenetic migrations that separate spawning, nursing, and feeding grounds spatially and temporally, producing food web connections across space and time. The oceanographic and biological dynamics may make the ecosystem vulnerable to climatic changes in temperature and shifts in the surrounding area. The Falkland marine ecosystem has been understudied and various functional groups, deep-sea habitats and inshore-offshore connections are poorly understood and should be priorities for further research.