ABSTRACT
Even more than before, marine mammals in captivity should be used to obtain a set of reference data to interpret values obtained from animals expected to be affected by contaminants.
Reijnders (1988)
Most reported levels of organochlorine (OC) contamination in marine mammals are derived from deceased or moribund animals for which there is little or no relevant biological information. In the absence of data for reproductive and medical histories, parentage, and feeding habits, it is difficult to understand the dynamics and consequences of contaminant exposure (Bignert et al., 1993; Skaare, 1996). In addition, the time between death and sampling of tissues has been shown to affect analysis (Borrell and Aguilar, 1990). Stranded specimens are generally recovered after some, often extensive, degradation has taken place. Even when samples are fresh, it is difficult to ascribe the cause of the event to a disease process or toxic exposure without knowing anything about the animal’s history, the progression of clinical illness, or the mechanism leading to the mortality event. Thus, the scope of OC investigations on wild animals is limited. Logistical problems can place significant restrictions on the experimental design of longitudinal studies to monitor contaminants in wild populations over time. What is needed is a population of animals that can be readily accessed for sampling and observation and for which long-term health and reproductive histories are available. Marine mammals in the care of humans may fulfill the need.
