Two degrees of global warming above the preindustrial level is widely suggested as an appropriate threshold beyond which climate change risks become unacceptably high. This “2 °C” threshold is likely to be reached between 2040 and 2050 for both Representative Concentration Pathway (RCP) 8.5 and 4.5. Resulting sea level rises will not be globally uniform, due to ocean dynamical processes and changes in gravity associated with water mass redistribution. Here we provide probabilistic sea level rise projections for the global coastline with warming above the 2 °C goal. By 2040, with a 2 °C warming under the RCP8.5 scenario, more than 90% of coastal areas will experience sea level rise exceeding the global estimate of 0.2 m, with up to 0.4 m expected along the Atlantic coast of North America and Norway. With a 5 °C rise by 2100, sea level will rise rapidly, reaching 0.9 m (median), and 80% of the coastline will exceed the global sea level rise at the 95th percentile upper limit of 1.8 m. Under RCP8.5, by 2100, New York may expect rises of 1.09 m, Guangzhou may expect rises of 0.91 m, and Lagos may expect rises of 0.90 m, with the 95th percentile upper limit of 2.24 m, 1.93 m, and 1.92 m, respectively. The coastal communities of rapidly expanding cities in the developing world, and vulnerable tropical coastal ecosystems, will have a very limited time after midcentury to adapt to sea level rises unprecedented since the dawn of the Bronze Age.
The copepod Calanus euxinus is a key prey species for fish in the Black Sea. To estimate the distribution and biomass of the late developmental stages of this species in July 2013, we analysed multi-frequency (38, 120, and 200 kHz) echo-sounder data from a fisheries survey of the Black Sea. The dependence of acoustic backscatter on frequency, i.e. the frequency response, was estimated for daytime scattering layers, which were confirmed by net catches to be dense, post-copepodite-stage (C4) aggregations of C. euxinus with prosome lengths greater than 2 mm. The high-resolution acoustic observations revealed that the nighttime, shallow distribution was bounded by the lower portion of the thermocline and that the daytime, deep distribution was bounded by oxygen. The dense and isolated aggregations were observed in seawater with a specific density, σT, of between 15.2 and 15.9 kg m−3. These results show that fisheries acoustic surveys, typically targeting only commercially exploited fish species, may also provide information on the lower trophic levels and thereby serve as an ecosystem-monitoring tool.
Social-ecological (SE) traps refer to persistent mismatches between the responses of people, or organisms, and their social and ecological conditions that are undesirable from a sustainability perspective. Until now, the occurrence of SE traps is primarily explained from a lack of adaptive capacity; not much attention is paid to other causal factors. In our article, we address this concern by theorizing the variety of human responses to SE traps and the effect of these responses on trap dynamics. Besides (adaptive) capacities, we theorize desires, abilities and opportunities as important additional drivers to explain the diversity of human responses to traps. Using these theoretical concepts, we construct a typology of human responses to SE traps, and illustrate its empirical relevance with three cases of SE traps: Swedish Baltic Sea fishery; amaXhosa rural livelihoods; and Pamir smallholder farming. We conclude with a discussion of how attention to the diversity in human response to SE traps may inform future academic research and planned interventions to prevent or dissolve SE traps.
The geographic distribution of Octopus mimus Gould, 1852 is unclear, as most records are restricted to coastal localities of Peru and Chile, and some references have mentioned its presence off Central America. It is unknown whether this octopus is found off Ecuador as two previous unpublished records have suggested. The aim of the present study is to identify genetically the main octopus captured in a marine protected area known as Reserva de Produccion Faunistica Marino-Costera Puntilla de Santa Elena (REMACOPSE) off the Santa Elena peninsula, Ecuador. Samples collected from the local fishery were used to test the presence of this species based on the sequences of three mitochondrial markers and using a Bayesian approach. The phylogenetic analysis confirms that O. mimus inhabits the REMACOPSE. The results also indicate that the octopus specimens captured in the fishery from this marine protected area, are more closely related to O. mimus specimens from Central America than those from South America. The genetic identification of two groups of O. mimus could be associated with the different marine environmental conditions of the two biogeographic provinces. The finding in this study represents an important step for posterior research on the biology and fishery of octopus in Ecuador.
Over the past decade, an increasing number of public organizations involved in marine governance in Europe have adapted their formal coordination structures for fisheries and marine environmental management. This study examines why the International Council for the Exploration of the Sea (ICES), DG FISH of the European Commission, the Norwegian Institute of Marine Research (IMR), and the Swedish Agency for Marine and Water Management (SwAM) have changed their sectoral structures into organizations with a geographical focus on marine ecosystems. The study finds that the gradual convergence of formal coordination structures for fisheries and marine environmental management is driven by coercive, normative and mimetic processes of isomorphism. The structural changes reflect an organizational adaptation to a changing institutional environment and an Ecosystem Approach to Management (EAM) focusing on regional marine areas, cross-sector integration and coordination.
Small-scale fisheries are increasingly studied around the world due to their “too big to ignore” ecological and economic impacts. Understanding their limitations and interactions with environmental dynamics is crucial for a more comprehensive management. Utilizing spring-summer gillnet fishery data from the Río de la Plata estuarine region, we addressed the influence of environmental drivers on Mustelus schmitti shark yield (individuals per 100 m net and 24 h soak time). In particular, we applied a two-stage boosted regression tree (Delta-BRT) approach to investigate relationships between environmental predictors and both smoothhound presence and relative yield. Results suggested that M. schmitti presence was most influenced by distance to coast, latitude and temperature, and the relative yield by distance to coast, month and wind. Fishery success was more likely to occur at long distances from the shore, southernmost locations, during early spring when temperature remains cool, and under environmental factors favouring the occurrence of the salinity front (28–30 range) over the fishing ground. Interannual differences in M. schmitti distribution were mainly explained by changes in salinity conditions driven by extreme anomalies in freshwater discharge. This study provides insight into considering environmental importance on resources availability for a more effective management of small-scale fisheries settled along environmental boundaries.
This study aims to estimate, model and map the spatial differences of ecosystem functioning expressed by community bioturbation potential (BPc), an indicator of benthic faunal function based on bioturbation, in the German part of the Baltic Sea. The usefulness of bioturbation potential calculations was justified by its moderate but significant correlation with estimates of bioturbation rates derived from diagenetic models fitted to the in situ measured sediment depth profiles of naturally-occurring chlorophyll-a tracer. Seasonal and interannual variations of BPc were assessed and key species contributing to bioturbation in the study area were identified. To generate the most accurate map of BPc and to investigate its predictability based on abiotic parameters, we have tested 3 different methodological approaches: i) benthic macrofauna community bioturbation potential was initially calculated per station and treated as response variable for species distribution modelling technique (RandomForest, RF) with relevant available environmental layers used as predictors, ii) 35 key species were selected as the most contributing to BPc (responsible for 90% of total BPc), their population bioturbation potential (BPp) estimates were used as response variables and RF models were fitted on each of them to predict their full coverage distributions, that were subsequently summed up to the BPc, iii) BPc values at stations were interpolated to a raster surface using a natural neighbour technique. The comparison with observed values of BPc indicated that map derived by natural neighbour interpolation was the most accurate one given the considered resolution of 1 × 1 km.
The Coastal Adaptation Strategies Handbook summarizes the current state of NPS climate adaptation and key approaches currently in practice or considered for climate change adaptation in coastal areas in order to guide adaptation planning in coastal parks. The chapters focus on policy, planning, cultural resources, natural resources, facility management, and communication/education. The handbook highlights processes, tools and examples that are applicable to many types of NPS plans and decisions. One chapter includes a case study of Hurricane Sandy response and recovery strategies including changes to infrastructure. Another chapter features practical coastal infrastructure information including cost per unit length of constructed features (including seawalls, beach nourishment, and nature-based features). The level of detail varies by topic depending on the state of research and practice in that field.
The manual is intended to help countries within the wider Caribbean Region better understand the size and contributions from recreation fishing to their economies. The methods proposed within can be applied to other countries outside this region, too. The results are meant to explain the economic impacts at the national and regional level, not to the individual. Measures of recreational fishing’s impacts upon individuals are a valid concern, and may represent a second or separate effort on the part of the countries using this document. The manual was tested in Bahamas and Martinique and the resulst of these tests are included in the circular.
The study presents a review of the status of billfish resources and fisheries in the WECAFC region. It considered over 100 pertinent documents on the subject matters. Billfish are caught as bycatch in large Atlantic tuna fisheries. They represent a mere 0.76% of the tuna landings and this characteristic represents a major hurdle to objectively collect statistical data for billfish stock assessments. The review found that billfish resources have been subjected to intense exploitation in the tuna and tuna like fisheries in the Atlantic Ocean for more than 6 decades, and as consequence billfish resources appear depleted, overfished and/or undergoing overfishing.