Cetaceans on the Upper Continental Slope in the North-Central Gulf of Mexico

• Published in: Fishery bulletin (Washington, D.C.) Vol. 92; no. 4; p. 773
• Main Authors: Mullin, Keith D, Hoggard, Wayne, Roden, Carol L, Lohoefener, Ren R, Rogers, Carolyn M, Taggart, Brian
• Format: Journal Article
• Language: English
• Published: 01.10.1994
• Subjects: Cetacea; Grampus griseus; Kogia breviceps; Kogia simus; Stenella attenuata; Stenella clymene; Stenella coeruleoalba; Stenella frontalis; Stenella longirostris; Tursiops truncatus; ASW, Mexico Gulf
• ISSN: 0090-0656

The US Marine Mammal Protection Act and the Endangered Species Act mandate that federal agencies ensure that their activities do not contribute to the depletion of marine-mammal populations. In order to assess the impact of offshore oil and gas activities in the north-central Gulf of Mexico, aerial surveys have been conducted to determine which cetaceans are present, document spatial and temporal distributions, and estimate relative abundances for each species. Results are presented from these surveys. Of the 275 identified herds, seven species or species groups were determined: Risso's dolphin; sperm whales; bottlenose dolphins; Atlantic spotted dolphins; pygmy and dwarf sperm whales; striped, spinner, and clymene dolphins; and pantropical spotted dolphins. Mean herd sizes ranged 1.9 87.8 animals. The relative abundance of several species or species groups varied seasonally, and each species sighted had a wide spatial distribution. Some individuals of all species were sited at depths less than 200 m, which conflicts with what is generally known about the water-depth distribution of each species. All relevant data are tabulated.