Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

New Study Reveals Whales as Marine Ecosystem Engineers

Animals

Baleen and sperm whales, known collectively as the great whales, include the largest animals in the history of life on Earth. Though large in size, whales have long been considered too rare to make much of a difference in the ocean, and the focus of much marine ecological research has been on smaller organisms, such as algae and planktonic animals. While these small organisms are essential to life in the sea, they are not the whole story. As great whales recover from centuries of overhunting, scientists are beginning to appreciate their roles as ecosystem engineers of the ocean.

Whales transfer nutrients from deep to surface water via plumes of fecal matter. Image credit: Roman et al.

A recent synthesis, published in Frontiers in Ecology and the Environment, evaluates decades of research on the ecological role of great whales. The authors, led by Joe Roman at the University of Vermont, suggest that the influence of these animals has been substantially undervalued because, until now, scientists have underestimated the degree to which the decline in whale population has altered marine ecosystems.

Commercial whaling dramatically reduced the abundance of great whales—by at least 66 percent and perhaps as high as 90 percent, according to some estimates—but recovery is possible, and potentially critical for ocean resiliency.

Among their many ecological functions, whales recycle nutrients and enhance primary productivity, locally and on a regional scale. Whales mix the water column, and after feeding at depth, release surface plumes of fecal material. This “whale pump” supplies iron and nitrogen—essentially fertilizers—to primary producers in the surface ocean. Further, the migrations of baleen whales between highly productive, high-latitude feeding and low-latitude calving grounds are among the longest annual movements of mammals. By fasting in these winter calving grounds near the equator, humpback whales, for example, release nitrogen in the form of urea into comparatively nutrient-poor areas—transporting nutrients nearly 10,000 kilometers on the “great whale conveyor belt.”

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. Photo credit: Tony Wu

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.

Whales, as one of the longer-lived species in marine systems, can ease the impact of perturbations in climate, predation and productivity. The continued recovery of great whales may help buffer marine ecosystems from destabilizing stresses and could lead to higher rates of productivity in locations where whales aggregate to feed and give birth.

And when they die, many whale carcasses sink to dark depths of the ocean—delivering massive pulses of organic material to a realm that is typically nutrient and energy impoverished. A 40-ton gray whale, for example, provides more than 2,000 times the background carbon flux that would typically rain down on the area underlying the carcass in an entire year.

“Whales appear to harbor a specialized suite of animals in the deep sea, with many species requiring whale falls to complete their life cycles and persist in the ocean,” said Craig Smith, co-author and Oceanography Professor at the University of Hawai‘i at Mānoa. “When whales were removed from the ocean by whalers, these whale-fall specialists lost their essential habitat.”

Fallen whale carcasses are home to species that rely on the unique habitat. Photo credit: C.Smith

“Our models show that the earliest human-caused extinctions in the sea may have been whale fall invertebrates, species that evolved adaptations to live on whale falls,” according to Smith. “As a result of 1,000 years of whaling by humans, many of these whale-fall species may have disappeared before we had a chance to discover them.”

Reflecting on the recent synthesis of data, Roman stated, “This warrants a shift in view from whales being positively valued as exploitable goods—or negatively valued because they compete with people for marine fish—to one what recognizes that these animals play key roles in healthy marine ecosystems, providing services to human societies.”

EcoWatch Daily Newsletter

Pexels

By Shawna Foo

Anyone who's tending a garden right now knows what extreme heat can do to plants. Heat is also a concern for an important form of underwater gardening: growing corals and "outplanting," or transplanting them to restore damaged reefs.

Read More Show Less
Malte Mueller / Getty Images

By David Korten

Our present course puts humans on track to be among the species that expire in Earth's ongoing sixth mass extinction. In my conversations with thoughtful people, I am finding increasing acceptance of this horrific premise.

Read More Show Less
Women sort potatoes in the Andes Mountains near Cusco Peru on July 7, 2014. Thomas O'Neill / NurPhoto / Getty Images

By Alejandro Argumedo

August 9 is the International Day of the World's Indigenous Peoples – a celebration of the uniqueness of the traditions of Quechua, Huli, Zapotec, and thousands of other cultures, but also of the universality of potatoes, bananas, beans, and the rest of the foods that nourish the world. These crops did not arise out of thin air. They were domesticated over thousands of years, and continue to be nurtured, by Indigenous people. On this day we give thanks to these cultures for the diversity of our food.

Read More Show Less
A sand tiger shark swims over the USS Tarpon in Monitor National Marine Sanctuary. Tane Casserley / NOAA

By John R. Platt

Here at The Revelator, we love a good shark story.

The problem is, there aren't all that many good shark stories. According to recent research, sharks and their relatives represent one of the world's most imperiled groups of species. Of the more than 1,250 known species of sharks, skates, rays and chimeras — collectively known as chondrichthyan fishes — at least a quarter are threatened with extinction.

Read More Show Less
The Anderson Community Group. Left to right, Caroline Laur, Anita Foust, the Rev. Bryon Shoffner, and Bill Compton, came together to fight for environmental justice in their community. Anderson Community Group

By Isabella Garcia

On Thanksgiving Day 2019, right after Caroline Laur had finished giving thanks for her home, a neighbor at church told her that a company had submitted permit requests to build an asphalt plant in their community. The plans indicated the plant would be 250 feet from Laur's backdoor.

Read More Show Less
Berber woman cooks traditional flatbread using an earthen oven in her mud-walled village home located near the historic village of Ait Benhaddou in Morocco, Africa on Jan. 4, 2016. Creative Touch Imaging Ltd. /NurPhoto / Getty Images

By Danielle Nierenberg and Jason Flatt

The world's Indigenous Peoples face severe and disproportionate rates of food insecurity. While Indigenous Peoples comprise 5 percent of the world's population, they account for 15 percent of the world's poor, according to the World Health Organization.

Read More Show Less

Trending

Danny Choo / CC BY-SA 2.0

By Olivia Sullivan

One of the many unfortunate outcomes of the coronavirus pandemic has been the quick and obvious increase in single-use plastic products. After COVID-19 arrived in the United States, many grocery stores prohibited customers from using reusable bags, coffee shops banned reusable mugs, and takeout food with plastic forks and knives became the new normal.

Read More Show Less