Assessing fishing vessel compliance with area closures on the high seas

Abstract

High seas marine ecosystems are facing a variety of threats, including fish stock overexploitation; the destruction of deep-sea habitats by harmful fishing gears; and illegal, unreported, and unregulated fishing. To help combat these threats, regional fisheries management organizations (RFMOs) can implement area-based management tools (ABMTs)—methods of spatial regulation, such as closed areas, that address human impacts on marine spaces by restricting certain activities. While ABMTs offer benefits that can help reduce stress on high seas ecosystems, research suggests that they should be coupled with strong monitoring to best provide these benefits. In the past, insufficient technology posed an obstacle to monitoring high seas fishing effort. However, increasingly common automatic identification system (AIS) data, which are broadcast from fishing vessels and communicate vessel identity and location information, provide an ideal mechanism to assess fishing activity in international waters. To understand vessel compliance with ABMTs implemented by RFMOs, I used AIS data from Global Fishing Watch to evaluate fishing effort inside closures on the high seas from 2017 to 2019. Results revealed that 11 of the 14 ABMTs examined likely experienced some level of illegal fishing across all three years, with a total of 13,259.7 hours of fishing effort classified as illegal based on my analysis occurring in 2017, 12,664.3 hours in 2018, and 14,541.1 hours in 2019. These analyses give insight into the success of current RFMO closures and suggest future considerations in the use of ABMTs by regional fishery bodies.