(K'JIPUKTUK) Halifax - Improving ocean fertility, strengthening fish stocks and combating climate change? All in a day's work for the great whales.

A study entitled Whales as Marine Ecological Engineers was published early July of this year in the journal Frontiers in Ecology and the Environment. It challenged many age old assumptions about the great whales and puts whale conservation into an entirely new light.

“The more whales you have, the more healthy your ecosystem will be," summarized Lyne Morissette, a marine biologists who co-authored the July study. Since 1995, Morissette has been involved with the study of marine mammals, with a particular focus on great whales since 2001. Based in Quebec, she conducts much of her research in the Gulf of St Lawrence, but because the great whales are migratory creatures, she follows them south to the Caribbean Sea during winter - a good excuse for a vacation.

Great whales have long been viewed as competition for commercial fishermen, because it was assumed they ate many of the fish humans intended to catch. It was this misconception Morissette and her colleagues hoped to disprove when beginning their study in 2011. Morissette made note of the Japanese whaling industry, which has justified its hunting of endangered whale species by saying these species are damaging fish stock.

"With some ideas going around like the Japanese idea that [whales] are a threat to fisheries, we must do something to make people understand that whales are not a threat to anything and more than that, they are actually good for ecosystems," said Morissette

A major finding of their study is that whales make the ecosystems they inhabit more resilient to sudden and dramatic changes, such as overfishing and climate change. By consuming large volumes of fish not generally hunted by humans, whales keep these populations in check. Otherwise, these prey species would overpopulate and destabilize the entire ecosystem, making it less adaptable to stresses like overfishing.

But the eating habits of whales aren't their only gift to marine ecosystems. Equally important is what comes out the other end.

Whale poop is incredibly rich in iron, nitrogen and other nutrients scarce in our oceans. These nutrients are vital for the growth of phytoplankton, microorganisms which take the role of plants in the oceans, absorbing carbon dioxide and producing oxygen.

"So often we hear the Amazon is the lungs of the planet,” said Morissette, “but actually one breath out of two is taken from the ocean, from oxygen that is produced by the ocean from phytoplankton. This is where whales become important, because they feed at the bottom [of the ocean] and poop at the surface when they come back to breath. Doing that, they take all the nutrients that are at the bottom of the ocean and they put it back at the surface where the phytoplankton is. Doing that, they fertilize the ocean."

This “whale pump” as it is called, does more than move nutrients from deep water to surface water. Because whales are so migratory, they carry nutrients across oceans. Phytoplankton are the basis of countless ocean ecosystems, so by “fertilizing” the oceans and producing more phytoplankton, whales increase an ecosystem's potential for growth.

This increase in phytoplankton has an added benefit. By promoting the growth of phytoplankton, whales are increasing the ocean's capacity to absorb carbon dioxide, thus combating climate change. It isn't know exactly how much whales are combating climate change with their poop, but Morissette said their contribution is likely significant.

"If we have more whales and if we put lots of effort into conservation to make sure that whales are bouncing back to pre-harvesting abundance, we will definitely have a true and real impact on climate change."

For these reasons, Morissette said whale conservation should be viewed with renewed urgency. She said this is particularly true for the Gulf of St Lawrence, a primary feeding ground for many of the North Atlantic's whale species. Whales eat here…and thus poop here. She said 13 species of cetacean (whales and dolphins) frequent the Gulf of St Lawrence, half of whom are listed as either threatened or endangered. There are the beluga, killer, beaked, sperm, minke, humpback, right, fin and blue whales occupying our coastal waters.

Of all the obstacles to the recovery of these species, Morissette said oil and gas development in the Gulf of St Lawrence is the most pressing. She took special note of the Cacouna oil terminal in the St Lawrence Estuary and the Old Harry proposal at the heart of the Gulf.