Risso's dolphin (Grampus griseus)

In 2014 a study was initiated off Cape Hatteras, North Carolina, to examine the spatial use and diving behavior of a number of species of odontocetes, with particular emphasis on Cuvier’s beaked whales (Ziphius cavirostris) and short-finned pilot whales (Globicephala macrorhynchus).

Sighting and stranding data are often used to identify patterns in marine mammal occurrence. Here we evaluate the use of public sighting reports, systematic surveys (where available), and stranding data from 1995-2015 to test how well these reflect trends in nine cetacean species in Puget Sound, Washington, USA. In general we found good agreement in documenting trends in occurrence between one of the sighting sources and strandings for 7 of 9 species, though there were often some species-specific considerations.

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.

Marine mammal strandings associated with specific mid-frequency active sonar (MFAS) systems have driven much of the awareness, research, and regulatory attention to the effects of noise on these taxa. However, controlled measurements of cetacean responses to known exposures of such sounds have been unavailable.

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.

Early studies that categorized odontocete pulsed sounds had few means of discriminating signals used for biosonar-based foraging from those used for communication. This capability to identify the function of sounds is important for understanding and interpreting behavior; it is also essential for monitoring and mitigating potential disturbance from human activities. Archival tags were placed on free-ranging Grampus griseus to quantify and discriminate between pulsed sounds used for echolocation-based foraging and those used for communication.

SOCAL‐10 was a scientific research project conducted in Aug‐Sept 2010 in the Southern California Bight. The overall objective was to provide a better understanding of marine mammal behavior, while providing direct scientific data for the Navy and regulatory agencies to estimate risk and minimize adverse effects of human sounds, particularly military sonar.

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