Weather that brings stronger and more frequent hurricanes, cyclones and droughts is not the only thing that is being altered by climate change. As ocean temperatures rise the we are seeing the effects of global warming on marine migrations.

sharks and fish burt jones Global Warming on Marine Migrations


Marine Species on the Move

NEEF reports that more than 80% of marine species are migrating, changes that effect where marine life feeds and breeds. And these changes are accelerating, occurring 10 times faster for marine species than species on land. (photo – Burt Jones)

Fish depend on very consistent ocean temperatures for their food sources. As temperatures rise they must seek cooler waters elsewhere. And as they migrate, their predators are forced to follow and so on up the food chain.

Because of the effects of global warming on marine migrations we are seeing some marine species migrate up to 600 miles from where they were just several decades ago. These changes can disrupt the livelihood of fisheries around the world and stress economic relationships between neighboring countries.


As Fish Move Toward the Poles, the Tropics Suffer

A study in 2014 found that 802 species of commercially important fish, including halibut, herring, tuna and cod have migrated north. This makes fish in colder waters more abundant. But the report also, warns that as fish move toward the poles, fish stocks in the tropics suffer. And it is these fish stocks in the tropics that millions of people depend on for food.


North Atlantic Right Whales victims of rising ocean temperatures

Right Whale Deaths in Gulf of St. Lawrence Global Warming on Marine Migrations In 2017 we witnessed numerous North Atlantic Right Whales being struck and killed in collisions with shipping in the Gulf of St. Lawrence. The endangered whales numbering under 500, travel along North America’s eastern seaboard.  Arriving in Canada during the summer, where they feed off Nova Scotia.

However, now the giant, filter feeders have been migrating further north, following krill into the dangerous St. Lawrence shipping lanes.


Enormous Economic Consequences

The journal Science, recently released a report stating that by 2100 more than seventy countries will face changing patterns of marine migration. How will these countries adjust existing international agreements on managing fish? How will they protect this necessary source of protein for their people? Will they violently face off against their neighbors?

“When fish move across political boundaries, we’re not good at sharing,” said Malin Pinsky, an ecologist at Rutgers University, who led the recent study. “That causes conflict to erupt.”

This is not being overly alarmist, we are already witnessing this scenario play out.


The Scallop Wars

Just last month French scallop fishermen threw smoke bombs and rammed British fishing boats off the coast of Normandy.

Several years ago, fishing rights between Iceland and the EU erupted into an international standoff. In 2009, Iceland had intended to join the EU, but by 2015 they had withdrawn their request, in large part over who could fish mackerel and where.


Collapsing Cod on the Grand Banks

It’s cod that cooled relations between fishing communities in Eastern Canada and the U.S. Once, one of the ocean’s most plentiful species, cod on the Grand Banks was over-fished (mainly by foreign trawlers) to the brink of extinction. Twenty five years ago the collapse of cod stocks and the resulting moratorium on fishing cod caused the loss of 45,000 jobs in the Canadian fishing industry. After Canada extended its maritime limits to 200 miles, most of the Grand Banks were protected from predatory foreign fishing, it was hoped that the species would recover. And now they do seem to be coming back, increasing at about 30% a year. However, that’s just a beginning and it’s only for northern cod off the shores of Newfoundland.

Cod in waters closer to the U.S. are not recovering and new quotas on halibut and flounder that were set in agreement between the US and Canada are reducing the allowable catch for US  fishermen.

Clashes between nations over fish is nothing new. “These problems might start in fisheries, but they often spill out beyond fisheries as well,” Pinsky said. Adding that fishing rights have been a major cause of armed conflict between countries since the Second World War. Is it inevitable that clashes over fishing be the result of global warming on marine migrations?


Cod-operation Between Countries

Conflict is not inevitable, countries do share fishing rights peacefully. In the Pacific, eight nations, Kiribati, the Marshall Islands, Nauru, Palau, Papua New Guinea, the Solomon Islands, Tuvalu and the Federated States of Micronesia have come together to manage tuna. For thirty years these countries have shared the bounty in an ingenious, cap-and-trade arrangement. Each country gets a specified slice of the world’s largest tuna pie.

“There’s been a great appreciation for a long time, by these small island nations, that they need to work together to achieve their mutual ends,” said Australian fisheries scientist Johann Bell.


Cooperation Over Conflict

In the North Atlantic, Norway and Russia peacefully manage cod and are sharing an abundance of fish. Cooperation is working better than conflict.

Today sharing the management of fish is more important than ever. Fish stocks are under pressure from climate change and are further diminished from over-fishing. See more in Amy Mcdermott’s article: Climate Change Could Ignite ‘Fish Wars,’ But It Doesn’t Have To.

Humpback-whale-Eaglewing-tours whale watching victoria bc Global Warming on Marine Migrations

Whale Watching Without Whales

As important as the fishing industry is to the world’s economy, another growing industry may also suffer from the effects of global warming on marine migrations. What happens to whale watching when there are no longer whales to watch? Will the economy of the Yucatan be impacted if the annual migration of whale sharks changes? What if scuba divers no longer see schools of iconic tropical fish on coral reefs? Will the growing ecotourism industry suffer?

Certainly we are not suggesting that all fish will flee, they certainly will not. But the future of marine migrations in an age of climate change is uncertain. Unfortunately, the studies that we have now, suggest that climate change is severely stressing our oceans and the consequences of marine migrations is one more serious threat that our oceans must now adapt to.

By Robert Frerck, Blue Ocean Network

See These Related Blue Ocean Articles:

Unlocking the Mysteries of Marine Migration: Sea Turtles, Whale Sharks and More
Marine Migrations: How Can We Protect These Ocean Travelers?
Marine Migrations Magnified by Ocean Warming
A Whale of a Tale
Ban the Trade in Shark Fins
Guy Harvey Research Institute Discovers Extensive Migration of Mako Sharks
Scientists Discover Hundreds of Pregnant Whale Sharks Use Galapagos as Pit Stop
Old Fish, New Fish, All Things Fish, plus Whales, Sharks and Dugongs
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