We present the first objective quantitative assessment of the threats to all 359 species of seabirds, identify the main challenges facing them, and outline priority actions for their conservation. We applied the standardised Threats Classification Scheme developed for the IUCN Red List to objectively assess threats to each species and analysed the data according to global IUCN threat status, taxonomic group, and primary foraging habitat (coastal or pelagic). The top three threats to seabirds in terms of number of species affected and average impact are: invasive alien species, affecting 165 species across all the most threatened groups; bycatch in fisheries, affecting fewer species (100) but with the greatest average impact; and climate change/severe weather, affecting 96 species. Overfishing, hunting/trapping and disturbance were also identified as major threats to seabirds. Reversing the top three threats alone would benefit two-thirds of all species and c. 380 million individual seabirds (c. 45% of the total global seabird population). Most seabirds (c. 70%), especially globally threatened species, face multiple threats. For albatrosses, petrels and penguins in particular (the three most threatened groups of seabirds), it is essential to tackle both terrestrial and marine threats to reverse declines. As the negative effects of climate change are harder to mitigate, it is vital to compensate by addressing other major threats that often affect the same species, such as invasive alien species, bycatch and overfishing, for which proven solutions exist.
Effective ocean management and the conservation of highly migratory species depend on resolving the overlap between animal movements and distributions, and fishing effort. However, this information is lacking at a global scale. Here we show, using a big-data approach that combines satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space-use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively), and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of fishing effort in marine areas beyond national jurisdictions (the high seas). Our results demonstrate an urgent need for conservation and management measures at high-seas hotspots of shark space use, and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real-time, dynamic management.
Scuba diving continues to be one of the most popular recreational activities in marine tourism, but its sustainability is currently threatened due to environmental, social, political, and economic risks. The East African Marine Ecoregion is renowned for its richness in marine fauna and flora, including some of the Indian Ocean's most diverse and abundant coral reef ecosystems, making it a popular destination for scuba divers. However, empirical evidence suggests that external risks (international and domestic) are impacting on dive operators in the region, creating the need to better understand these impacts. This research was therefore aimed at identifying the most significant of these external risks from the perspective of dive operators, via an explorative and descriptive study. The qualitative and quantitative primary data collected revealed that domestic and international economic and political risks have the greatest impact on dive operators in the East African Marine Ecoregion, and this trend is expected to continue. Environmental degradation of coral reefs, while not seen as a threat to dive operators at present, constitutes a key threat within the near future. In terms of the variation in perceived risk across the region, Kenya suffers most from social and political risks, Tanzania from environmental risks, Mozambique from political risks, and South Africa from economic risks. The research contributes to Africa's Blue Economy, which aims to guide African countries in sustainable use of the marine environment while harnessing its social and economic benefits. The findings create awareness of the impact of external risks on regional dive operators and their significance. Furthermore, they create an opportunity for decision makers and stakeholders in the region to craft solutions to improve the sustainability of the scuba diving industry.
Ecological risk assessment (ERA), including Productivity-Susceptibility Analysis (PSA), is becoming increasingly used to assess the relative vulnerability of data-limited non-target species to the impacts by fishing. PSA was developed for the eastern Pacific Ocean (EPO) tuna purse-seine fishery to assess the vulnerability of incidentally-caught species for three set types, “dolphin sets”, “unassociated sets” and “floating-object sets”, during 2005–2013. Because of operational differences between these set types, susceptibility values were combined for each species across the three set types to produce an overall fleet-wide susceptibility estimate. Vulnerability was highest for elasmobranchs, namely the giant manta ray, bigeye and pelagic thresher sharks, smooth and scalloped hammerhead sharks, and silky shark. Billfishes, dolphins, other rays, ocean sunfish, and yellowfin and bigeye tunas were classified as moderately vulnerable while the remaining species, all teleosts, had the lowest vulnerability scores. This purse-seine fleet-wide PSA identified potentially vulnerable species that can be compared with PSAs for other fisheries operating in the EPO, once detailed catch information becomes available for those fisheries. Such information can assist managers with prioritising fishery- and species-specific research programsand/or mitigation measures.
Ballast water managements systems (BWMS) installed on vessels may use active substances to inactivate organisms. This paper provides new insights in the global issue of noxious disinfection by-products (DBP) discharge with ballast water, and the related risk assessment for human health. The GESAMP ballast water working group plays a role in the certification process of BWMS that make use of active substances evaluating potential negative effects. We analyzed all BWMS that passed GESAMP final approval over a decade until 2017 providing an overview of chemicals in the discharged ballast water generated by BWMS. We used these data to calculate the chemical load humans may be exposed to for two different commercial ports (Koper, Slovenia and Hamburg, Germany). None of the chemicals in this study reached levels of concern that would indicate a risk for humans after exposure to chemicals present in the discharged ballast water. Nevertheless, although this exposure only adds to a lesser degree to the overall exposure to disinfection by-products, some chemicals, such as tribromomethane, have carcinogenic properties. In case studies we show which chemicals have the largest contribution to the aggregated exposure of humans. We note that tribromomethane, despite its low bio-concentration factor (BCF), may accumulate in fat, when fish are continuously exposed to DBPs during low-level chlorination. Since this figure would give a higher value for the internal dose for tribromomethane from seafood consumption than the current BCF in the GISIS database, the calculated value may underestimate the contribution of tribromomethane, and possibly also other DBPs.
We performed an environmental risk assessment for microplastics (<5 mm) in the marine environment by estimating the order of magnitude of the past, present and future concentrations based on global plastic production data. In 2100, from 9.6 to 48.8 particles m−3 are predicted to float around in the ocean, which is a 50-fold increase compared to the present-day concentrations. From a meta-analysis with effect data available in literature, we derived a safe concentration of 6650 buoyant particles m−3 below which adverse effects are not likely to occur. Our risk assessment (excluding the potential role of microplastics as chemical vectors) suggests that on average, no direct effects of free-floating microplastics in the marine environment are to be expected up to the year 2100. Yet, even today, the safe concentration can be exceeded in sites that are heavily polluted with buoyant microplastics. In the marine benthic compartment between 32 and 144 particles kg−1 dry sediment are predicted to be present in the beach deposition zone. Despite the scarcity of effect data, we expect adverse ecological effects along the coast as of the second half of the 21st century. From then ambient concentrations will start to outrange the safe concentration of sedimented microplastics (i.e. 540 particles kg−1sediment). Additional ecotoxicological research in which marine species are chronically exposed to realistic environmental microplastic concentration series are urgently needed to verify our findings.
The potential risk to the marine environment of oil release from potentially polluting wrecks (PPW) is increasingly being acknowledged, and in some instances remediation actions have been required. However, where a PPW has been identified, there remains a great deal of uncertainty around the environmental risk it may pose. Estimating the likelihood of a wreck to release oil and the threat to marine receptors remains a challenge. In addition, removing oil from wrecks is not always cost effective, so a proactive approach is recommended to identify PPW that pose the greatest risk to sensitive marine ecosystems and local economies and communities. This paper presents a desk-based assessment approach which addresses PPW, and the risk they pose to environmental and socio-economic marine receptors, using modelled scenarios and a framework and scoring system. This approach can be used to inform proactive management options for PPW and can be applied worldwide.
Marine environments are subject to a range of human disturbances. Identifying effective conservation strategies, in order to manage or mitigate the negative impacts of human activities, requires a way to first identify and evaluate the impact of activities on ecosystem components. Multicriteria decision analysis (MCDA) techniques such as the Analytic Hierarchy Process (AHP) offer a way to systematically evaluate and integrate stakeholder opinion in order to set priorities and make decisions. With a goal to synthesize current knowledge of the potential impacts of human activity on breeding and non-breeding seabirds in the western North Atlantic Ocean, we present a case study involving the use of AHP to assess sensitivity of species to such hazards as: fisheries bycatch, oiling, light pollution, vessel traffic, marine debris, and offshore wind turbines. Based on responses from ten North Atlantic seabird experts, fisheries bycatch (particularly when involving suspended gill nets) was identified as the greatest risk across a wide range of species, with an overall relative value of 0.47 ± SE 0.026. Oiling risk was the second most highly ranked (0.26 ± 0.026, of which 0.214 corresponded with surface oil, 0.044 with oil and gas platform interactions), and was considered to have the greatest potential impact on alcids (Common and Thick-billed Murre, Atlantic Puffin, Razorbill, Dovekie). Offshore wind turbines (0.097 ± 0.022), marine debris (0.08 ± 0.016), light pollution (0.058 ± 0.0077), and traffic (0.042 ± 0.0053) were considered to be less serious risks for seabirds than fisheries bycatch and oiling. In addition to demonstrating how relative risk can be quantified using a multicriteria decision analysis technique such as AHP, we summarize the sensitivities of fourteen seabirds and suggest ways in which multicriteria decision analysis can enhance conservation planning.
Fishery managers worldwide are evaluating methods for incorporating climate, habitat, ecological, social, and economic factors into current operations in order to implement Ecosystem Approaches to Fishery Management (EAFM). While this can seem overwhelming, it is possible to take practical steps toward EAFM implementation that make use of existing information and provide managers with valuable strategic advice. Here, we describe the process used by the U.S. Mid-Atlantic Fishery Management Council (Council) to develop an ecosystem-level risk assessment, the initial step proposed in their recently adopted EAFM guidance document. The Council first defined five types of Risk Elements (ecological, economic, social, food production, management) and identified which management objectives aligned with each element. Based on an existing ecosystem status report for the region and other existing sources (including expert opinion), potential ecological, social, economic, and management indicators were identified for each risk element. Finally, low, low-moderate, moderate-high, and high risk criteria were defined for each indicator, and the indicator data were used to score each risk element using the criteria. The ultimate outcome is a ranked risk assessment in order to focus on the highest risk issues for further evaluation and mitigation. The risk assessment highlights certain species and certain management issues as posing higher cumulative risks to meeting Council management objectives when considering a broad range of ecological, social, and economic factors. Tabular color coded summaries of risk assessment results will be used by the Council to prioritize further EAFM analyses as well as research plans over the coming 5 years. As ecosystem reporting and operational EAFM continue to evolve in future years, the Council foresees integrating these efforts so that ecosystem indicators are refined to meet the needs of fishery managers in identifying and managing risks to achieving ecological, social, and economic fishery objectives. Overall, ecosystem indicator-based risk assessment is a method that can be adapted to a wide range of resource management systems and available information, and therefore represents a promising way forward in the implementation of EAFM.
The coastal and marine environment is often managed according to the principles of sustainable development, which include environmental, economic, and social dimensions. While each are equally important, social sustainability receives a lower priority in both policy and research. Methodologies for assessing social sustainability are less developed than for environmental and economic sustainability, and there is a lack of data on the social aspects of sustainable development (such as social equity), which constitutes a barrier to understanding social considerations and integrating them into natural resource management. This paper explores a threat and risk assessment to the marine estate in New South Wales, Australia, which identified and categorised both the benefits that communities gain from the marine estate and the threats to those benefits. A broad range of benefits were identified including participation (e.g., socialising and sense of community), enjoyment (e.g., enjoying the biodiversity and beauty), cultural heritage and use, intrinsic and bequest values, the viability of businesses, and direct economic values. Threats to community benefits were categorised as resource use conflict, environmental, governance, public safety, critical knowledge gaps and lack of access. An integrated threat and risk assessment approach found that the priority threats to community benefits were environmental threats (e.g., water pollution), critical knowledge gaps (e.g., inadequate social and economic information), governance (e.g., lack of compliance), resource-use conflict (e.g., anti-social behaviour), and lack of access (e.g., loss of fishing access). Threat and risk assessment is an evidence-based tool that is useful for marine planning because it provides a structured approach to incorporating multiple types of knowledge and enables limited resources to be targeted to the threats identified as being most important to address.