A trait‐based framework for assessing the vulnerability of marine species to human impacts

Abstract

Marine species and ecosystems are widely affected by anthropogenic stressors, ranging from pollution and fishing to climate change. Comprehensive assessments of how species and ecosystems are impacted by anthropogenic stressors are critical for guiding conservation and management investments. Previous global risk or vulnerability assessments have focused on marine habitats, or on limited taxa or specific regions. However, information about the susceptibility of marine species across a range of taxa to different stressors everywhere is required to predict how marine biodiversity will respond to human pressures.We present a novel framework that uses life-history traits to assess species' vulnerability to a stressor, which we compare across more than 44,000 species from 12 taxonomic groups (classes). Using expert elicitation and literature review, we assessed every combination of each of 42 traits and 22 anthropogenic stressors to calculate each species' or representative species group's sensitivity and adaptive capacity to stressors, and then used these assessments to derive their overall relative vulnerability. The stressors with the greatest potential impact were related to biomass removal (e.g., fisheries), pollution, and climate change. The taxa with the highest vulnerabilities across the range of stressors were mollusks, corals, and echinoderms, while elasmobranchs had the highest vulnerability to fishing-related stressors. Traits likely to confer vulnerability to climate change stressors were related to the presence of calcium carbonate structures, and whether a species exists across the interface of marine, terrestrial, and atmospheric realms. Traits likely to confer vulnerability to pollution stressors were related to planktonic state, organism size, and respiration. Such a replicable, broadly applicable method is useful for informing ocean conservation and management decisions at a range of scales, and the framework is amenable to further testing and improvement. Our framework for assessing the vulnerability of marine species is the first critical step toward generating cumulative human impact maps based on comprehensive assessments of species, rather than habitats.

Mapping the risks of China’s global coastal development to marine socio-ecological systems

“…We used the latest data from Butt et al 50 on marine species’ vulnerability to anthropogenic stressors to identify risks to marine species (see section Calculating impact risks ). We considered the following five marine taxonomic groups whose status and distribution have been most comprehensively assessed and for which mean vulnerability scores have been estimated: elasmobranchs, bony fishes, marine mammals, marine reptiles, and sea birds (see Supplementary Table 2 for taxonomic information).…”

“…Pollution from floating plastic debris (including microplastics) is one of the most pervasive stressors in the sea, capable of spreading thousands of kilometers from the initial source 83, 84 . Plastic litter is the most probable cause of plastic pollution associated with DFI projects, including litter from roads, bridges, ports, and other facilities 2, 50, 85 . Although plastic litter can travel across entire oceans, we limit the extent of this potential risk to 100 km surrounding these DFI projects to capture the pervasive nature of plastic pollution while limiting the range at which we expect plastic density to be greatest for a single project.…”

“…Fishing vessels are associated with several stressors that are unique from shipping vessels, including biomass removal, bycatch (biomass removal of non-target species), entanglement from nets and other fishing gear, and the use of poisons or toxins (e.g. dynamite or cyanide fishing) 50 . For most of these stressors, these risks are prevalent across most types of commercial fisheries, which may increase with the creation or expansion of fishing ports.…”

“…We use data from Butt et al 50 , which estimates the average vulnerability of each of the five taxonomic groups included in this study to the following 15 stressors relevant for DFI projects: habitat loss/degradation, noise pollution, light pollution, thermal pollution, inorganic pollution, nutrient pollution, organic pollution, sedimentation, plastic pollution, invasive species, wildlife injury, biomass removal, bycatch, entanglement, and poisons/toxins (Supplementary Table 5). Vulnerability weights range from 0 to 1 and represent the expected average vulnerability for all species within the taxonomic group based upon the vulnerability of species’ biophysical, movement, reproduction, specialization, and spatial traits to different stressors estimated through extensive literature reviews, expert elicitation, and sensitivity tests.…”

“…Although important variations still exist between species in the same taxonomic group, we use this global trait-based vulnerability framework to provide a relative index of vulnerability among diverse taxonomic groups to a variety of anthropogenic stressors at a global scale. See Butt et al 50 for methodological details.…”