Featured Research

from universities, journals, and other organizations

Whales as ecosystem engineers: Recovery from overhunting helping to buffer marine ecosystems from destabilizing stresses

Date:
July 3, 2014
Source:
University of Vermont
Summary:
A review of research on whales shows that they have more a powerful influence on the function of oceans, global carbon storage, and the health of commercial fisheries than has been commonly assumed. The continued recovery of great whales from centuries of overhunting may help to buffer marine ecosystems from destabilizing stresses, including climate change, reports a global team of scientists.

After feeding at depth, sperm whales off the coast of Sri Lanka return to the surface — and poop. This “whale pump” provides many nutrients, in the form of feces, to support plankton growth. It’s one of many examples of how whales maintain the health of oceans described in a new scientific paper by UVM’s Joe Roman and nine other whale biologists from around the globe.
Credit: Tony Wu

"Consider the subtleness of the sea; how its most dreaded creatures glide under water, unapparent for the most part," wrote Herman Melville in Moby Dick. Today, we no longer dread whales, but their subtlety remains. "For a long time, whales have been considered too rare to make much of a difference in the oceans," notes University of Vermont conservation biologist Joe Roman. That was a mistake.

In a new paper, Roman and a team of biologists have tallied several decades of research on whales from around the world; it shows that 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 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," Roman and his colleagues write in the July 3, 2014, online edition of Frontiers in Ecology and the Environment, " but recovery is possible and in many cases is already underway."

Whale benefits

"The continued recovery of great whales may help to buffer marine ecosystems from destabilizing stresses," the team of scientists writes. This recovered role may be especially important as climate change threatens ocean ecosystems with rising temperatures and acidification. "As long-lived species, they enhance the predictability and stability of marine ecosystems," Roman said.

Baleen and sperm whales, known collectively as the "great whales," include the largest animals to have ever lived on Earth. With huge metabolic demands -- and large populations before humans started hunting them -- great whales are the ocean's ecosystem engineers: they eat many fish and invertebrates, are themselves prey to other predators like killer whales, and distribute nutrients through the water. Even their carcasses, dropping to the seafloor, provide habitat for many species that only exist on these "whale falls." Commercial whaling dramatically reduced the biomass and abundance of great whales.

"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 said. "Among their many ecological roles, whales recycle nutrients and enhance primary productivity in areas where they feed." They do this by feeding at depth and releasing fecal plumes near the surface -- which supports plankton growth -- a remarkable process described as a "whale pump." Whales also move nutrients thousands of miles from productive feeding areas at high latitudes to calving areas at lower latitudes.

Sometimes, commercial fishermen have seen whales as competition. But this new paper summarizes a strong body of evidence that indicates the opposite can be true: whale recovery "could lead to higher rates of productivity in locations where whales aggregate to feed and give birth," supporting more robust fisheries.

As whales recover, there may be increased whale predation on aquaculture stocks and increased competition -- real or perceived -- with some commercial fisheries. But the new paper notes " a recent investigation of four coastal ecosystems has demonstrated the potential for large increases in whale abundance without major changes to existing food-web structures or substantial impacts on fishery production."

Watch whales

In death, whale carcasses store a remarkable amount of carbon in the deep sea and provide habitat and food for an amazing assortment of creatures that only live on these carcasses. "Dozens, possibly hundreds, of species depend on these whale falls in the deep sea," Roman notes.

"Our models show that the earliest human-caused extinctions in the sea may have been whale fall invertebrates, species that evolved and adapted to whale falls," Roman said, "These species would have disappeared before we had a chance to discover them."

Until recently, ocean scientists have lacked the ability to study and observe directly the functional roles of whales in marine ecosystems. Now with radio tagging and other technologies they can better understand these roles. "The focus of much marine ecological research has been on smaller organisms, such as algae and planktonic animals. These small organisms are essential to life in the sea, but they are not the whole story," Roman said.

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."


Story Source:

The above story is based on materials provided by University of Vermont. The original article was written by Joshua Brown. Note: Materials may be edited for content and length.


Journal Reference:

  1. Joe Roman, James A Estes, Lyne Morissette, Craig Smith, Daniel Costa, James McCarthy, JB Nation, Stephen Nicol, Andrew Pershing, Victor Smetacek. Whales as marine ecosystem engineers. Frontiers in Ecology and the Environment, 2014; 140703070154008 DOI: 10.1890/130220

Cite This Page:

University of Vermont. "Whales as ecosystem engineers: Recovery from overhunting helping to buffer marine ecosystems from destabilizing stresses." ScienceDaily. ScienceDaily, 3 July 2014. <www.sciencedaily.com/releases/2014/07/140703102957.htm>.
University of Vermont. (2014, July 3). Whales as ecosystem engineers: Recovery from overhunting helping to buffer marine ecosystems from destabilizing stresses. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2014/07/140703102957.htm
University of Vermont. "Whales as ecosystem engineers: Recovery from overhunting helping to buffer marine ecosystems from destabilizing stresses." ScienceDaily. www.sciencedaily.com/releases/2014/07/140703102957.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) — Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) — With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) — Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:  

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile iPhone Android Web
      Follow Facebook Twitter Google+
      Subscribe RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins