Whales Acting as Marine Ecosystem Engineers

Study assures that Whales contribution keep environment rich of fish populations. Whal and Calf navigate.

The recovery of populations of whale has allowed new investigations to reveal their role in ocean health. The new study ­"Whales as Marine Ecosystem Engineers" published at the Ecological Society of America ESA assures that "future changes in the structure and function of the world's oceans can be expected with the restoration of great whale populations".

National Geographic reported on July 12^th that Large Whales are contributing the health of the oceans. The study lead by Joe Roman of the University of Vermont assures that whales have been underestimated. “Whales, in fact, make a huge difference — they have a powerful and positive influence on the function of oceans, global carbon storage, and the health of commercial fisheries,” the University of Vermont stated.

Roman´s paper estimated decline of great whales to be of at least 66% or perhaps as high as 90% in the past decade. This decline has altered the structure and function of oceans. Today whales under protection and in recovery programs are returning in large numbers. This allows scientists to study the environmental services which the group provides.  

Large whales considered under the study include Blue Whales, Sperm Whales, Frank Whales and Grey Whales. Joe Roman stated that the studies on large whales were “practically absent” because whales were hunted down in great numbers. Over one million sperm whales navigate the ocean waters today as well as dozens of grey whales. The Blue Whale recovery has been slower according to Roman.

Large Whales main contribution to ocean health is the capacity to create “predictability and stability of the marine ecosystems”. The paper adds that Whales could be “especially important as climate change threatens ocean ecosystems with rising temperatures and acidification”.

Large whales also contribute to the Vertical Water Column composition and cycles. When large whales emerge and descend great depths for feeding and other purposes the vertical water column is “stirred” allowing for the “breaking of thermoclines and other natural barriers” which keep nutrients waters, surface water and depths waters separated. By mixing the waters of the vertical column Large Whales contribute significantly to the ecosystem trophic chain and ocean chemistry. Vertical Water Column dynamics should not be underestimated –this type of surface and deep water relationships occur in the most hot-spot fishing zones of the world including Peruvian coast. Nutrients, micro-organisms, plankton and other elements are “stirred” in this dynamic.  Large Whales are also known to migrate large distance. The paper assures that their migrations in turn affects the Horizontal Water Dynamics.

Large Whales also contribute to the trophic system in its final recycling. Whales excrete nutrients including iron and nitrogen which are fundamental for ocean life and key for plankton booms.

Even at final resting place dead large whales continue to provide services. Dead massive whale corpse provide unique source of nourishment for a large amount of stratus and depths organisms, decomposers and others. 

“Analysis proved that ecosystems which homes large populations of whales also home large populations of fish,” Roman signaled to the fishing sector.

"For a long time, whales have been considered too rare to make much of a difference in the oceans," Roman told Tech Times. 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.

New observations of whales will provide a more accurate understanding of historical population dynamics and "are likely to provide evidence of undervalued whale ecosystem services," note the ten scientists who co-authored this new paper. "This area of research will improve estimates of the benefits—some of which, no doubt, remain to be discovered—of an ocean repopulated by the great whales," the study states.