A review of the feeding, migratory, and breeding ecology of the eastern Pacific gray whale and related anthropogenic environmental impacts

• Main Author: Hager, Rebecca
• Format: Text
• Language: unknown
• Published: Digital Commons @ CSUMB 1999
• Subjects: Arctic; Baja; Bering Sea; Pacific; Alaska
• Online Access: https://digitalcommons.csumb.edu/caps_thes_restricted/153; https://digitalcommons.csumb.edu/cgi/viewcontent.cgi?article=1152&context=caps_thes_restricted

ecent increases in numbers of gray whale deaths between Baja and Alaska have given rise to some concern over the whales' food supply and other factors which may be influencing the population. This paper reviews available literature concerning the feeding, migratory, and breeding ecology of the gray whale and related anthropogenic factors which may be contributing to the increased mortality rates. Studies of stranded whales show a higher than average number of deaths are due to starvation. There is some suggestion that the population may be reaching carrying capacity and is putting too much strain on it's food supply. In addition, warming trends in the global climate have been linked to a decrease in ice cover in the Arctic, with the effect of reducing primary productivity, which directly affects the gray whales' benthic prey populations. Algal blooms in the Bering Sea in the past three years have also been linked to a decrease in primary productivity. Additional threats to the gray whale population include coastal development along their migration route and in the breeding lagoons, increased shipping traffic, and pollution. A proposed salt extraction plant in the last pristine breeding lagoon, Laguna San Ignacio in Baja California, Mexico, has provoked much opposition by conservationists on the grounds that it will adversely affect the whales' breeding and the survival of the calves, as well as increasing pollution, noise, and vessel traffic in and around the lagoon. Impacts of human activity on the whales' habitat which may threaten the future health and survival of the species must be balanced with local, regional and global economic concerns. In order to develop effective and sustainable environmental policies, more extensive and long-term research is required to determine the actual extent of the effect our activities are having on the ecosystem. These policies must in turn take into account not only the health of the ecosystem but the necessary development of nearby communities. One cannot be sacrificed for the other; in order for policies to be effective and lasting there must be an endurable balance between human and environmental concerns.