What are the main threats to whales these days?
Although commercial whaling currently does not present a threat to the survival of the baleen whales, loss of habitat and other human activities may make recovery more difficult. Collisions with vessels, oil spills and other changes in water quality, coastal development, and increasing noise created from the use of oceanic resources may all affect the whales.
Fisheries may affect whales in two ways. First, whales may become entangled in fishing gear. As an example, each year several humpback whales are entangled in fishing gear along the east coast of the United States and Canada. Second, fisheries may compete with whales for food, such as herring.
Increased noise or boat traffic may cause whales to alter their behavior. There is evidence that humpback whales in Hawaii may have changed their use of near-shore waters where calves are raised by their mothers because of increasing human activity. Migrating bowhead whales may move further offshore to avoid human-caused noise.
Although we do not have a full understanding of the possible impacts, pollution could also affect whales. Many contaminants are stored in a whale's blubber for long periods of time. Pollutant loads are usually lower in baleen whales than in dolphins and porpoises. Deterioration of the environment could possibly affect the whales in another way: if pollution and other factors reduce the number of fish and crustaceans, the food available to the whales could also be reduced.