A Systematic Review of the Behavioural Changes and Physiological Adjustments of Elasmobranchs and Teleost’s to Ocean Acidification with a Focus on Sharks

In recent years, much attention has been focused on the impact of climate change, particularly via ocean acidification (OA), on marine organisms. Studying the impact of OA on long-living organisms, such as sharks, is especially challenging. When the ocean waters absorb anthropogenic carbon dioxide (CO2), slow-growing shark species with long generation times may be subjected to stress, leading to a decrease in functionality. Our goal was to examine the behavioral and physiological responses of sharks to OA and the possible impacts on their fitness and resilience. We conducted a systematic review in line with PRISMA-Analyses, of previously reported scientific experiments. We found that most studies used CO2 partial pressures (pCO2) that reflect representative concentration pathways for the year 2100 (e.g., pH ~7.8, pCO2 ~1000 μatm). Since there is a considerable knowledge gap on the effect of OA on sharks, we utilized existing data on bony fish to synthesize the available knowledge. Given the similarities between the behaviors and physiology of these two superclasses’ to changes in CO2 and pH levels, there is merit in including the available information on bony fish as well. Several studies indicated a decrease in shark fitness in relation to increased OA and CO2 levels. However, the decrease was species-specific and influenced by the intensity of the change in atmospheric CO2 concentration and other anthropogenic and environmental factors (e.g., fishing, temperature). Most studies involved only limited exposure to future environmental conditions and were conducted on benthic shark species studied in the laboratory rather than on apex predator species. While knowledge gaps exist, and more research is required, we conclude that anthropogenic factors are likely contributing to shark species’ vulnerability worldwide. However, the impact of OA on the long-term stability of shark populations is not unequivocal

Enhancing Small-Medium IsLands resilience by securing the sustainability of Ecosystem Services: the SMILES Cost Action

European islands are hotspots of biological and cultural diversity, which, compared to mainland, are more vulnerable to climate change, tourism development, uncontrolled land-use changes and the consequences of financial crisis. These drivers of change have increasingly resulted in severe impacts on socio-economic and environmental parameters. Projected climate, land-use and socio-economic change will impact on islands’ biodiversity, ecosystem services and, in turn, on the quality of life of island inhabitants. Even if the existing methods can adequately predict the abovementioned changes of the larger islands, this is not the case for small and medium-size islands, where there is a need for refinement. Although ecosystem services (ES) assessments have been carried out worldwide in different geographical areas, islands are still under-represented. Despite the recognised islands’ importance and vulnerability, efforts to date have focused solely on the pressures they face. Still, we know little about ES supply, flow and demand and their spatio-temporal variability, whilst integrated approaches that consider ES cross-island realms (terrestrial, marine and their interface) remain scarce. Even more under-represented are studies that explore the telecoupled relationship amongst islands and their mainland counterparts. Moreover, the current conceptual approaches guiding ES mapping and assessment need further refinement to account for the complex manifestations of nature and culture arising from peoples’ interaction with island spaces. This paper discusses the creation of a platform for coordinated interdisciplinary research on several aspects of mapping and assessment of ES in small and medium European islands in order to synthesise and strengthen the knowledge base for conservation of island realms and contribute to their sustainable development