Baleen and sperm whales act like ecosystem engineers in the global ocean, according to a new study from the University of Vermont. Whales help maintain the global ecological balance due, in part, to the release of vast quantities of feces.
A new study examined decades of research on the marine mammals and their role in maintaining the balance of life in oceans.
"For a long time, whales have been considered too rare to make much of a difference in the oceans," Joe Roman, conservation biologist at the University of Vermont, said.
The researcher and his team found the animals play critical roles in the food chain underwater, and greatly affect commercial fisheries. The giant mammals also alter the uptake of carbon dioxide in the world's oceans. Whales could, therefore, also be affecting levels of the atmospheric greenhouse gas.
"The decline in great whale numbers, estimated to be at least 66% and perhaps as high as 90%, has likely altered the structure and function of the oceans, but recovery is possible and in many cases is already underway," researchers wrote in an article announcing their investigation.
Many species of whales were once on the verge of extinction. Recovery of whale populations could help stabilize oceans stressed by abnormally-high levels of carbon dioxide and pollution. The marine mammals can live several decades, giving these animals the chance to moderate the ecosystem over a significant period of time.
Great whales, like the sperm and baleen varieties, consume vast quantities of fish. Baleen whales are the largest animals on the planet, yet they eat some of the smallest animals in the water. They then spread these nutrients throughout the water as they pass the digested food. When these massive creatures die, their bodies sink to the ocean floor, becoming "whale falls." Many species live exclusively within the remains of these behemoths.
Centuries of hunting for food, oil and other resources pushed down the number of great whales around the world. This likely changed the balance of life in the oceans, the researchers stated. As populations recover, the ecosystem could also recover, biologists believe, and fishermen who once looked on whales as competition should instead welcome greater numbers of the animals. Regions where the giant mammals eat and mate could be ripe with nutrients and fish, ready to be caught by commercial fishing vessels.
Study of how whales affect the world's marine ecosystem was published in the online journal Frontiers in Ecology and the Environment.
