Russell Wangersky: Sea change


Published on June 19, 2017

Twillingate harbour.

©Patrick Murphy/The Pilot file photo

We know the effects and impacts of the ocean here. We know its role in heating and cooling — look no further than the seven or eight degree (if you’re lucky) difference between days with onshore winds and no wind.

Russell Wangersky
File photo

Already this spring, I’ve driven as little as 300 metres towards the sea in Conception Bay North and watched the car thermometer sink from 14 degrees to a lowly six.

So when climate scientists point out that the most important temperatures to watch aren’t on the land, but in the sea, well, we’re already familiar.

What they’re saying is that the dense, huge oceans soak up extra heat and store it; the ocean has absorbed some 90 per cent of additional heat from climate change, and in the process, it has risen to the highest temperatures since recording began in the 1880s.

There’s a June 15th article in the journal Yale Environment 360 about the effect that temperature change is having on fish species, especially in fisheries in the northeastern United States, as far north as the Gulf of Maine. (You can read it here — http://bit.ly/2s5qyVQ)

It talks about the “general trend” of fish having a liking for particular temperatures, and when those temperatures get too high, the fish move to cooler pastures.

A lot of the article isn’t new: species like Atlantic sunfish have been popping up occasionally in Newfoundland waters for years, and the spawning temperature requirements for cash-crop species like cold water shrimp are well known. But species like lobster, herring, cod, black sea bass, butterfish and a host of others are moving north, and the simple fact is that the fish are moving faster than the fishermen.

The best example in the story centres around black sea bass: the bulk of the quota for the fish is held by fishermen in North Carolina, who used to be adjacent to the largest body of the stock. The fish are now moving into New England waters, so quota holders have to travel as much as 10 hours north to successfully catch their bass.

Why is that important here?

Well, for one small common-sense reason that’s so obvious it should poke us all in the eye — range.

What’s at risk is not only the fish species, but the ecology of the fish harvester.

What’s at risk is not only the fish species, but the ecology of the fish harvester.

Here’s why: you could call it a form of evolution, a near-textbook case of survival of the fittest. The fish harvester who is likely to be able to fish sustainably is also likely to be the one who has the broadest available number of species, and, put simply, the biggest boat. The bigger the boat, the further the vessel can roam, and the larger catch it can store when it does find fish. Smaller boat fish harvesters may be left with nowhere to go, and little to catch.

(Think about that in terms of the recent refit of the Katsheshuk II — the Ocean Choice International shrimp factory freezer has just gotten $8 million in refits to catch and process groundfish. The ship will have a far greater reach than smaller boats, all the way to the Arctic Circle, and will be able to capitalize on fish stocks others can’t effectively reach, especially vessels without the ability to freeze and store catches. You can only travel with unrefrigerated fish for so long.)

It’s the same for fishing towns: if you depend on one species, and that species likes a specific water temperature, the town’s days may be numbered.

There’s no easy escape or solution. We can’t make the fish stay.

Warmer waters may reduce the numbers of particular fish species.

They may reduce the number of particular fish harvesters, too.

 

Russell Wangersky’s column appears in 30 SaltWire newspapers and websites in Atlantic Canada. He can be reached at rwanger@thetelegram.com — Twitter: @wangersky.