Minimal overlap between areas of high conservation priority for endangered Galapagos pinnipeds and the conservation zone of the Galapagos Marine Reserve

Abstract

Abstract Galapagos sea lions (Zalophus wollebaeki) and fur seals (Arctocephalus galapagoensis) are endangered pinnipeds that live in a highly variable marine environment, influenced by seasonal changes in productivity and by the unpredictable occurrence of El Niño. The Galapagos marine habitat is protected through the Galapagos Marine Reserve (GMR), which has recently undergone a redefinition of its zonation. However, the effectiveness of the GMR in protecting the habitat of Galapagos pinnipeds has never been investigated, and it is unclear how well their habitat use aligns with the newly proposed conservation zone. A spatial prioritization analysis framework was applied based on the complementary use of density estimation (kernel utilization distributions, KUDs) and habitat modelling (resource selection functions, RSFs). Using tracking data collected over two years and under three environmental scenarios (cold season, warm season, and El Niño) in the western archipelago, hot spots of pinniped habitat usage were identified (through KUDs), and predictions about the location of patches of good habitat were generated (through RSFs). The output of KUDs and RSFs was used for a spatial prioritization analysis to delineate areas of high conservation priority. The overlap between these areas and the GMR zonation was then calculated. Both species were found to use largely distinct habitat types: sea lions used the waters over the continental shelf, whereas fur seals used the offshore deep waters and showed a more heterogeneous space usage over time. The spatial prioritization analysis identified three key areas of high conservation priority for both species in the Western Galapagos. These areas were all within the boundaries of the GMR but the overlap with the conservation zone was only 8%. Hence, under the current proposition, the largest proportion of key pinniped foraging habitat in the western archipelago will not be protected from licensed activities in the sustainable use zone, particularly fishing and boat traffic.