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Photo of the fluke of a sperm whale swimming away.

The return of large whales—such as sperm (pictured), blue, right, and gray—could help ocean fish populations recover.

Photograph by Stephen Frink, Corbis

Brian Clark Howard

National Geographic

Published July 10, 2014

Scientists and fisheries managers have long underestimated the valuable role large whales play in healthy ocean ecosystems, a new study suggests. And, scientists add, those commercial fishermen who complain that whales steal fish from their nets have it wrong.

An increase in the number of large whales—like blue, sperm, right, and gray—around the world could lead to a healthier ocean and more fish, a team of scientists report in a review study published this month in the journal Frontiers in Ecology and the Environment.

The underestimation occurred because "when oceanographic studies were started, large whales were largely absent from the ecosystem—because we had killed most of them," says the study's lead author, Joe Roman, a biologist at the University of Vermont in Burlington.

Large whales were heavily hunted until the 1970s. At that point an estimated 66 to 90 percent of the animals had been removed from ocean waters.

But since then, great whales have been slowly recovering. There are now more than a million sperm whales, and tens of thousands of gray whales.

Watch as a mother gray whale and her calf migrate past a pack of killer whales.

Yet blue whales—the largest animal ever known to have lived on the planet—have been slower to rebound. In fact, they remain at about one percent of their historic range in the Southern Hemisphere. Roman says scientists think their absence may have altered the ecosystem in a way that made it harder for all life to survive there. (Watch a video of blue whales.)

In recent years, as whale numbers have increased and technology has advanced—especially the ability to tag and track seafaring animals—we've begun to gain a better understanding of how important cetaceans are, says Roman. (See video of humpback whales.)

"Whale Pumps and Conveyor Belts"

The scientists report that when whales feed, often at great depths, and then return to the surface to breathe, they mix up the water column. That spreads nutrients and microorganisms through different marine zones, which can lead to feeding bonanzas for other creatures. And the materials in whale urine and excrement, especially iron and nitrogen, serve as effective fertilizers for plankton.

Many great whales migrate long distances to mate, during which time they bring those nutrients with them. When they breed in far latitudes, they make important nutrient contributions to waters that are often poor in resources. Even their placentas can be rich sources of feedstocks for other organisms, says Roman, who calls whale migration a "conveyor belt" of nutrients around the ocean.

A baby sperm whale learns to swim alone while its mother hunts deep below.

Whale deaths can be helpful too. When one of the massive mammals dies, its body sinks to the sea bottom, where it nourishes unique ecosystems of scavengers, from hagfishes to crabs to worms. Dozens of those scavenger species are found nowhere else, says Roman.

"Because [humans] took out so many whales, there were probably extinctions in the deep sea before we knew those [scavenger] species existed," says Roman, who adds that he's working on a new study to estimate how many of those scavenger species were lost.

Maddalena Bearzi, a marine biologist and president of the California-based Ocean Conservation Society who was not affiliated with the study, calls the paper "a great and interesting piece" that could help us better understand the role marine mammals play in the ocean ecosystem.

Fishers vs. Whales

For decades some commercial fishermen have complained that whales eat the fish that they're trying to catch. Japan's government has been particularly vocal, going as far as to say that whaling is necessary because "whales are threatening our fisheries." (See "Japan's Commercial Whaling Efforts Should Resume, Says Prime Minister.")

Masayuki Komatsu, one of Japan's international whaling negotiators, famously told the Australian Broadcasting Corporation in 2001 that "there are too many" minke whales, calling them "the cockroach of the ocean."

Roman disagrees.

"It's far more complicated than that," he says, referring to the whale pump and the conveyor belt. "Our new review points to several studies that show you have more fish in an ecosystem by having these large predators there."

The next step, he says, is to conduct more field studies on those processes. That could help scientists better understand exactly how plankton and other organisms respond to the presence of whales.

Follow Brian Clark Howard on Twitter and Google+.

22 comments
Eric Paul
Eric Paul

Let's not divert from the real issues here - over-fishing and pollution.  These two things will continue to destroy our oceans, lakes, and rivers.

Marian Lee
Marian Lee

Every animal in the animal kingdom, whether they live on land, in the trees, or deep in the depths of the blue oceans, has a purpose. Why did it really take this long for scientists to shed such news? 

Jang Hun Oh
Jang Hun Oh

Japan. Do not kill them ! Shame on you !


nicola red
nicola red

Scientist are always fast to make hipothesis with or without foundation, always assuming but the majority of the time forgetting. THE BIG PICTURE that everything is related to everything.-One examplee our body can function without legs but function is not 100 % of what supposed to be everything on the air on the ground or below had a purpose .-We need to learn the if we do not understand or we do not know does not mean that there is not such purpose.-Normally when scientist or specialist most of the time only exist in there mind and there pride without connection with reality and some follow this egotist believers.I am myself an old scientist that also I was in a hurry to be somebody today at the winter of my life I humble realizrd that to promote my name I was lying to myself and lige is much bigger than my mind

Roiikka-Ta P Globetrotter
Roiikka-Ta P Globetrotter

i would think more of any life in the sea would mean halthier oceans .. it doesnt take a rocket scientist to figure that out .. ..

MJ Darling
MJ Darling

Too bad the psychopathic geoengineers are spraying the oceans to keep methane frozen.  They're poisoning the entire food chain.  Our military and NASA are trying to break up methane in the atmosphere by shooting electromagnetic waves from two sides at it.  They are decimating our ozone layer....It is not hairspray use.  This lets ultraviolet B and C in at enormous levels, destroying the plankton and thus everything in the food chain.  Somebody oughta tell President Obama and other country leaders that their 'Science Advisors' are depopulation experts bamboozling our 'leaders' into allowing them to carry out the largest genocide and ecocide in human history.  God help us all, because we don't have much time to stop them and fix it.

Bailey Arthur
Bailey Arthur

Eliminating any animal completely from the oceans ecosystem would affect the food chain and how animals feed individually. Whales eating their share of krill and fish does not eliminate all the food sources for the worlds population. To say that whaling is a necessity would be ignorant. 

If plankton and other organisms respond positively to the whales presence I don't see a need to put an endangered species completely extinct. Whales are beautiful creatures that should be protected and studied, not killed off for greed. There are plenty of fish in the sea for everyone, and any animal endangerment should not be encouraged or condoned.

tamanna tasneem
tamanna tasneem

Hopefully these observations will help human being to be more understanding about the nature and abandon silly ideas!

walker paradine
walker paradine

most Politian's are so ignorant of the problem, they will screw it up so bad that we will die of hunger for one more vote or study

Russ Nash
Russ Nash

Masayuki Komatsu: "there are too many" minke whales, calling them "the cockroach of the ocean"... If there are "cockroaches" in our oceans, they will surely not be the whales. Look in the mirror.

Secret drudown
Secret drudown

Let's be intellectually honest. More "fish" and "plankton" for Whales does not in any rational sense equate to more pelagic fish, i.e., the latter are (literally) being "fished out" by unregulated commercial fishing. 


The US (or China) should be proposing a unified "policing" of the shared Pacific with Russia, Japan and a collaboration of smaller sovereigns. Like the available supply of fresh, potable water (i.e., far more valuable to drink and irrigate crops than to "frack" for energy when less onerous means- that do not THREATEN the very lifeblood of water- are READILY AVAILABLE) the oceanic resources need to be PROTECTED via REGULATION. Sorry, the SAME entities trying to BANKRUPT the US, UK and EU and DISRUPT cooperation between Russia, China and the US (that is their biggest fear strategically) cannot say "but there is no money" or "it isn't the government's duty." What a lie. See Article I, Section 8. It is Congress' LEGAL DUTY.


Res ipsa loquitur.


"Paid for" scientific conclusions (see, e.g., "Climate Change is uncertain despite EVIDENCE of record surface temperatures in last 15 years) with unfounded, unprovable conclusions aren't really subject to the Scientific Method and, as such, are not Science, e.g., more Arctic ice "disproves" Global Warming and self-evident "desertification."


Say.


Instead of "imposing sanctions" at home (see, e.g., "no new taxes, ever" and abroad (see, e.g., fining Russia for establishing order pursuant to Monroe Doctrine exercisable by Russia, EU, China, et al.)….why don't we all WIPE AWAY MAN-MADE debt and engage on the largest infrastructure initiative to date: vast DESALINATION PLANTS and VAST IRRIGATION systems to offset "decertification" and AVOID A FABRICATED "crisis" in such integral areas of our SHARED SURVIVAL, e.g., REGULATING and WHOLLY SUBSIDIZING PROPER INDUSTRIAL WASTE DISPOSAL and eliminating oceanic pollution by "restarting" arbitrary, made up obligations crated by (enter JAWS music) Foreign corruption wanting to ruin government with the Military Might. Think well on this.


"After the event, even the fool is wise." - Viscount Symonds



KENNETH LANE
KENNETH LANE

This pipeline of nutrients by whales makes sense and the fact that other species are gaining numbers makes it a win, win.  Time for some rational approaches to our planets problems--------enough of the politics and silliness.

Amjad Khalaf
Amjad Khalaf

thanks god for these information you may save world some day


Eric Paul
Eric Paul

@MJ Darling - I'm all for saving the Ozone layer as well, but take off your tinfoil hat.  There are A LOT easier ways to enact genocide on the world's population, if that was their true intentions.  But yes, the world's military powers are responsible for a large amount of environmental destruction.

Achlen Daniel-Browne
Achlen Daniel-Browne

@Russ Nash

Some of these Dolts don't even have the presence of mind to not overfish so the fish have a chance to breed & make more fish.

Achlen Daniel-Browne
Achlen Daniel-Browne

@Russ Nash

You'd be amazed how clueless some people are, so they wouldn't understand your analogy.

Actually, cockroaches are a bad comparison, as they are scavengers that clean up things, it's just that they transport diseases along the way, as do rats & mice.


A better analogy is that Many Humans are the Cancer of the Oceans & the Rest of the Planet.

Todd Brown
Todd Brown

@Secret drudown Does your mom bring breakfast down to you or do you have to leave your mom's basement in order to get something to eat?

Sorry to be snarky, but what the heck are you talking about or where did you copy and paste your diatribe from?

Ching Fong Lau
Ching Fong Lau

@Владимир Предоев Well, mosquitoes are food for some insectivorous creatures. i'm sure some organisms also feed on ticks, flukes, flatworms etc, the role might not be great (i dont know) but still, it's a role they play in the ecosystem. Anyway, I suppose you consider these species as parasites to larger animals including human. they spread diseases and kill the host species. Good thing about this is that the infection/killing eliminate the weaker individuals, it might also help to boost the immune system (think when you have stronger virus, someone will create a more powerful antivirus). Also, the weaker gene will be eliminated, which in turn help the evolution of the species.. I do think mosquitoes and ticks' bites are annoyingly itchy!!

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