ACS Research Committee Report

OCCURRENCE AND BEHAVIOR OF HAWAIIAN SPINNER DOLPHINS
Source: Lammers, M.O. 2004. Occurrence and behavior of Hawaiian spinner dolphins (Stenella longirostris) along Oahu's leeward and south shores. Aquatic Mammals 30(2): 237-250.

Spinner dolphins live in coastal and offshore tropical and subtropical habitats throughout the world. In this study, spinner dolphins on the southern and western shores of Oahu, Hawaii, were studied for five years. The dolphins exhibited a strong preference for specific locations along the west coast, but not along the south coast. The average pod size was also larger along the south coast. The prevalence of resting and social behaviors was dependent on the time of day, not to location. The spinner dolphins seemed to have a preference for water depth less than 60 feet. Feeding behavior began in the late afternoon along the edge of banks, where prey migrate vertically to shallower depths. Spinner dolphin reliance on the resources in shallow waters near the coast of Oahu indicates that increased human use of these areas may have a negative impact on this species.   

DECLINE IN SEA OTTER POPULATIONS IN ALASKA
Source: Burn, D.M. and Doroff, A.M. 2005. Decline in sea otter (Enhydra lutris) populations along the Alaska Peninsula, 1986-2001. Fishery Bulletin 103: 270-279.

The population estimate of sea otters along the Aleutian archipelago declined by 70% between 1992 and 2000. Aerial surveys were conducted along the Alaska Peninsula to determine the eastern extent of this decline. Since 1986, the abundance of sea otters in offshore habitats declined by 27-49% and in the Alaskan Peninsula by 93-94%. In all areas, sea otters were concentrated in bays and lagoons, whereas historically, they were often located in large rafts offshore. The decline in the Alaskan Peninsula occurred at approximately the same time as the decline in the Aleutians and it could have long term effects to the conservation of the species.   

MORPHOLOGY AND HISTOPATHOLOGY OF NORTH ATLANTIC RIGHT WHALE MORTALITIES
Source: Moore, M.J., Knowlton, A.R., Kraus, S.D., McLellan, W.A., and Bonde, R.K. 2004. Morphometry, gross morphology and available histopathology in North Atlantic right whale (Eubalaena glacialis) mortalities (1970-2002). Journal of Cetacean Research and Management 6(3): 199-214.

Between 1970 and 2002, 54 right whale mortalities were reported between Florida and the Canadian Maritimes. Thirty of these whales were examined. Of these, 18 were adults and juveniles and 12 were calves. Calves grew approximately linearly in their first year. Length and fluke width grew linearly with age, until a plateau was reached at physical maturity. Weight also increased linearly with age and exponentially with total length. Among the adults and juveniles, human interaction appeared to be the major cause of death. In 14 of 18 cases, trauma was a significant finding and in ten of those 14, the cause of the trauma was vessel collision. The remaining four cases were attributed to an entanglement in fishing gear. Trauma was also present in four of the 12 calves examined. In the majority of calves, the cause of death was unknown. Ship collisions resulted in a variety of injuries including propeller lacerations, internal bruising, and major bone fractures. Management efforts must continue to focus on mitigation of ship collisions and fishing gear entanglements for the species to avoid extinction. In addition, any carcasses that are found must be analyzed to the fullest extent to determine the rate and nature of human interactions for management efforts.