Assessing Fisheries Effort in Two Dynamic Pelagic Ecosystems

• Main Author: Bering, Janet
• Other Authors: Halpin, Patrick
• Format: Master Thesis
• Language: unknown
• Published: 2022
• Subjects: Pacific; North Atlantic
• Online Access: https://hdl.handle.net/10161/24838

As human impacts on the global oceans increase, the effective protection of biodiversity and sustainable management of ocean resources has become increasingly important. Complicating these efforts is the fact that sixty-four percent of the surface area of the ocean is beyond national jurisdiction, but many pelagic ecosystems cross between national and international waters. In recent years, there have been efforts to create integrated, area-based management for these transboundary ecosystems, with the Costa Rica Thermal Dome in the Eastern Tropical Pacific Ocean and the Sargasso Sea in the North Atlantic emerging as potential candidates. This MP is a part of a larger project which will create an integrated model of ecology and human impacts, an analysis of existing policies and a set of conclusions aimed at informing and improving governance for each ecosystem. As a preliminary part of this larger analysis, this project characterized the spatial extent of commercial fisheries in each region. Fisheries are one of the largest direct impacts on pelagic ecosystems. The project relied on fishing effort data from Global Fishing Watch, which uses a machine learning algorithm to estimate fishing effort based on vessel track activity. Global Fishing Watch provides the data in an aggregated format, providing total fishing hours from each vessel in 0.1-degree cells. Global Fishing Watch also estimates fishing gear type and provides the flag for each vessel. These data were utilized to characterize fishing effort over six years, 2015–2020. Additionally, this analysis examined drivers of the spatial distribution of this effort. Two drivers were examined: jurisdiction and an environmental variable for each region. The fishing effort was categorized as either on the high seas or within national waters. In the Costa Rica Thermal Dome, water temperature at 35 meters depth was utilized as a proxy for the location of the Dome to see if fishing effort was tracking the upwelling area. In the Sargasso Sea, sea surface temperature was ...