Whales consume great numbers of fish and invertebrates, are themselves prey of other predators, and spread nutrients through the water.
After studying several decades of work on whales from around the world, researchers have learned that whales are the “engineers” of the sea — they have an impressive and positive influence on the function of oceans, global carbon storage and the health of commercial fisheries.
“The decline in great whale numbers, estimated to be at least 66 percent and perhaps as high as 90 percent, has likely altered the structure and function of the oceans,” University of Vermont conservation biologist Joe Roman and his colleagues posit in a study published in the journal Frontiers in Ecology and the Environment, “but recovery is possible and in many cases is already underway.”
“The continued recovery of great whales may help to buffer marine ecosystems from destabilizing stresses,” the biologists contend.
Baleen and sperm whales, known together as the “great whales,” are the ocean’s engineers: They consume great numbers of fish and invertebrates, are themselves prey of other predators, and spread nutrients through the water. There are even species that only live on “whale falls” or whale carcasses that have dropped to the seafloor.
“As humpbacks, gray whales, sperm whales and other cetaceans recover from centuries of overhunting, we are beginning to see that they also play an important role in the ocean,” Roman explained. “Among their many ecological roles, whales recycle nutrients and enhance primary productivity in areas where they feed.”
While commercial fisherman have often thought of whales as competition, the researchers argue that there is plenty of evidence that suggests that the opposite may be the case. They write that whale recovery “could lead to higher rates of productivity in locations where whales aggregate to feed and give birth,” encouraging heartier fisheries.
Now with radio tagging and other advanced technologies researchers can better understand the functional roles of whales in marine ecosystems. New research on whales will offer a clearer picture of historical population dynamics and “will improve estimates of the benefits…of an ocean repopulated by the great whales.”