Long-range movement of humpback whales and their overlap with anthropogenic activity in the South Atlantic Ocean.
Humpback whales (Megaptera novaeangliae) are managed by the International Whaling Commission as 7 primary populations that breed in the tropics and migrate to 6 feeding areas around the Antarctic. There is little information on individual movements within breeding areas or migratory connections to feeding grounds. We sought to better understand humpback whale habitat use and movements at breeding areas off West Africa, and during the annual migration to Antarctic feeding areas. We also assessed potential overlap between whale habitat and anthropogenic activities. We used Argos satellite-monitored radio tags to collect data on 13 animals off Gabon, a primary humpback whale breeding area. We quantified habitat use for 3 cohorts of whales and used a state-space model to determine transitions in the movement behavior of individuals. We developed a spatial metric of overlap between whale habitat and models of cumulative human activities, including oil platforms, toxicants, and shipping. We detected strong heterogeneity in movement behavior over time that is consistent with previous genetic evidence of multiple populations in the region. Breeding areas for humpback whales in the eastern Atlantic were extensive and extended north of Gabon late in the breeding season. We also observed, for the first time, direct migration between West Africa and sub-Antarctic feeding areas. Potential overlap of whale habitat with human activities was the highest in exclusive economic zones close to shore, particularly in areas used by both individual whales and the hydrocarbon industry. Whales potentially overlapped with different activities during each stage of their migration, which makes it difficult to implement mitigation measures over their entire range. Our results and existing population-level data may inform delimitation of populations and actions to mitigate potential threats to whales as part of local, regional, and international management of highly migratory marine species.
Ocean Giants Program, Global Conservation Program, Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, NY 10460-1099, U.S.A.; Sackler Institute for Comparative Genomics, American Museum of Natural History, 79th Street and Central Park West, New York, NY 10024, U.S.A.; Department of Ecology, Evolution & Environmental Biology, Columbia University, 1014 Schermerhorn Ext., 1200 Amsterdam Avenue, New York, NY 10027, U.S.A.. hrosenbaum@wcs.org.
Howard C
HC
Rosenbaum
Sara M
SM
Maxwell
Francine
F
Kershaw
Bruce
B
Mate
D025041:Animal Migration; D000818:Animals; D001267:Atlantic Ocean; D003247:Conservation of Natural Resources; D005247:Feeding Behavior; D005260:Female; D005398:Fisheries; D005681:Gabon; D050640:Humpback Whale / Q000502:physiology*; D008297:Male; D058998:Remote Sensing Technology
Actividad antropogénica; Golfo de Guinea; Gulf of Guinea; anthropogenic activity; habitat use; international management; manejo internacional; migraciones; migrations; población; population; satellite telemetry; telemetría satelital; uso de hábitat