Spinner dolphin (Stenella longirostris)

Marine mammal diversity, abundance and habitat use data are lacking in the southwestern Pacific state of Guerrero, Mexico. Aggressive behavior from fishing and tourist boats toward marine mammals, exacerbated by the absence of monitoring and enforcement underlies the need for a better understanding of species present. Our intended five-year study aims to document presence/absence of marine mammals, to establish patterns of spatio-temporal habitat use and to identify sensitive marine mammal areas in the interest of improved ecosystem management.

Nurturant behavior toward dead conspecifics has been documented in several free-ranging marine and terrestrial mammals but still remains undocumented and poorly understood for most species. This study describes observations of adults carrying dead calves and juveniles in 7 odontocetes (toothed cetaceans) species and discusses the subject in mammals in general.

We undertook a survey of the main (windward) Hawaiian Islands during May and June 2003 to examine odontocete population structure.

Of the 18 species of odontocetes known to be present in Hawaiian waters, small resident populations of 11 species—dwarf sperm whales, Blainville’s beaked whales, Cuvier’s beaked whales, pygmy killer whales, short-finned pilot whales, melon-headed whales, false killer whales, pantropical spotted dolphins, spinner dolphins, rough-toothed dolphins, and common bottlenose dolphins—have been identified, based on two or more lines of evidence, including results from small-boat sightings and survey effort, photo-identification, genetic analyses, and satellite tagging.

An emerging theme in animal and human health-related research is that associated microbial communities or 'microbiomes' play vital and active roles in maintaining normal functioning and health. Yet, very little attention has been paid towards understanding the microbiomes of marine mammals. The skin microbiome of humpback whales was recently shown to contain a core community of two main bacterial genera that are maintained across populations and ocean environments.