Spatial distribution and dive behavior of Gulf of Mexico Bryde's whales: potential risk of vessel strikes and fisheries interactions

TitleSpatial distribution and dive behavior of Gulf of Mexico Bryde's whales: potential risk of vessel strikes and fisheries interactions
Publication TypeJournal Article
Year of Publication2017
AuthorsSoldevilla M.S, Hildebrand JA, Frasier K.E, Dias L.A, Martinez A., Mullin K.D, Rosel P.E, Garrison L.P
JournalEndangered Species Research
Date Published2017/07
Type of ArticleArticle
ISBN Number1863-5407
Accession NumberWOS:000405721900002
KeywordsAcousonde; atlantic right whales; Balaenoptera edeni; balaenoptera-musculus; baleen; Biodiversity & Conservation; blue whales; california coast; cetaceans; Distribution; dive behavior; Fishery entanglement; gulf; killer; Kinematic tag; marine protected areas; of Mexico; satellite; ship strikes; telemetry; valdez oil-spill; Vessel collision; whales

Bryde's whales Balaenoptera edeni are the only resident baleen whale species in the Gulf of Mexico (GoM), where they are extremely rare, have a restricted distribution, and re present a unique evolutionary lineage. The reasons for the restricted distribution and small population size are unknown, but high levels of industrial activity in the GoM may be a major factor. We evaluated the geospatial overlap of GoM Bryde's whales with 2 industries known to impact baleen whale species: commercial shipping and commercial fisheries. We further evaluated the potential for impacts by examining the first dive behavior data collected from a kinematic tag attached to a GoM Bryde's whale for 3 d. Vessel traffic and fishery effort are low in GoM Bryde's whale habitat compared to the rest of the northern GoM, but several shipping lanes transit through the habitat, and the reef fish bottom longline fishery exerts considerable effort within the habitat. The tagged whale exhibited diel diving behavior with diurnal deep dives and foraging lunges at or near the sea floor, and shallow nocturnal diving, with 88% of its nighttime spent near the surface within the draught depths of most large commercial vessels. Given the location of commercial shipping traffic in GoM Bryde's whale habitat, ship strikes may pose a threat to this population if the whales commonly spend time near the surface, especially at night. Also, if bottom or near-bottom feeding is a normal feeding strategy for these whales, there is potential for entan-glement in bottom longline gear. Managing these threats may improve population recovery.

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