Need to address gaps in global fisheries observation

A global meta-analysis of gillnet bycatch of toothed whales: Mitigation measures and research gaps

Odontocetes are globally distributed and are foundational to the structure and function of marine food webs, and hence bycatch impacts from gillnet fishing need to be considered in the context of their conservation and population viability. Currently, global gillnet bycatch numbers are unknown yet are estimated to be the greatest in Asia, East Africa, and the west coasts of North and South America. Here we provide the first global meta-analyses of small- and large-scale gillnet bycatch estimates of odontocetes during 1990-2020, compiling population size, estimated gillnet bycatch, and conservation status in support of geographical and species-specific risk estimates. We estimate that annual gillnet bycatch is ∼50,000 from 1990 to 2020, and, combined with overfishing, pollution, and noise, it has been shown to be a serious threat to these long-lived and slow-reproducing species with heavy offspring investment. The global gillnet bycatch of odontocetes is a difficult challenge to address and mitigate and requires improved species and regional-based management strategies including collaborations between fishers, fisheries managers, marine mammal experts, and marine spatial planners. This has been worked on for decades, yet more attention is needed for successful management of odontocete gillnet bycatch to ensure their sustainable future in the Anthropocene Ocean, in accordance with local subsistence dynamics and the relevant United Nations (UN) sustainable development goals.

Threats of illegal, unregulated, and unreported fishing to biodiversity and food security in the Republic of the Congo

Illegal, unregulated, and unreported (IUU) fishing poses a major threat to effective management of marine resources, affecting biodiversity and communities dependent on these coastal resources. Spatiotemporal patterns of industrial fisheries in developing countries are often poorly understood, and global efforts to describe spatial patterns of fishing vessel activity are currently based on automatic identification system (AIS) data. However, AIS is often not a legal requirement on fishing vessels, likely resulting in underestimates of the scale and distribution of legal and illegal fishing activity, which could have significant ramifications for targeted enforcement efforts and the management of fisheries resources. To help address this knowledge gap, we analyzed 3 years of vessel monitoring system (VMS) data in partnership with the national fisheries department in the Republic of the Congo to describe the behavior of national and distant-water industrial fleets operating in these waters. We found that the spatial footprint of the industrial fisheries fleet encompassed over one-quarter of the Exclusive Economic Zone. On average, 73% of fishing activity took place on the continental shelf (waters shallower than 200 m). Our findings highlight that VMS is not acting as a deterrent or being effectively used as a proactive management tool. As much as 33% (13% on average) of fishing effort occurred in prohibited areas set aside to protect biodiversity, including artisanal fisheries resources, and the distant-water fleet responsible for as much as 84% of this illegal activity. Given the growth in industrial and distant-water fleets across the region, as well as low levels of management and enforcement, these findings highlight that there is an urgent need for the global community to help strengthen regional and national capacity to analyze national scale data sets if efforts to combat IUU fishing are to be effective.