Ocean im­bal­ance

The Gulf News (Port aux Basques) - - Editorial -

Even though the sci­en­tists have only just made their point, you al­most imag­ine the re­ac­tion com­ing from the fish­ing in­dus­try. Fish­eries sci­en­tists, writ­ing in the Cana­dian Jour­nal of Fish­eries and Aquatic Sciences, sug­gest that the south­ern Gulf of St. Lawrence cod stock may be ex­tinct by 2050, be­cause cod five years old and older now face an an­nual mor­tal­ity rate of 50 per cent.

The stock was al­ready hit hard by the fish­ery, and col­lapsed in the 1990s.

But it’s still not re­bound­ing, even after years of lim­ited fish­ing, and the sci­en­tists sug­gest that could be be­cause the cod con­gre­gate to spawn, and are easy tar­gets for the Gulf grey seal pop­u­la­tion, whose num­bers have grown from around 6,000 in the 1960s to 100,000 in 2014.

You can al­most hear the sug­ges­tion — time for a seal cull. Or an ex­panded seal har­vest.

Hav­ing started one prob­lem, the sim­plis­tic so­lu­tion is that we have to step in and try to ad­dress the new prob­lem.

Well, no. In its own way, that’s a lot like the chil­dren’s song that starts, “There was an old lady who swal­lowed a fly,” ex­cept in re­verse. How many dif­fer­ent pop­u­la­tions in the ocean would we end up hav­ing to ad­just be­fore we even got close to recre­at­ing the or­der that na­ture used to have all by it­self?

Hav­ing ad­justed the cod pop­u­la­tion to the point where it isn’t self-sus­tain­ing, we jump quickly to the idea of ad­just­ing the next ma­rine pop­u­la­tion to straighten out the re­sults of what we did last time.

At the same time, we fail to ad­dress is­sues like the over­har­vest­ing of species like caplin that are food for cod.

For too long, we’ve looked at ocean ecol­ogy as sim­ple equa­tions: if we do A, then B will hap­pen. In re­al­ity, the func­tion of some­thing as large as an ocean ecosys­tem is so in­cred­i­bly com­plex that we’re re­ally just pulling random levers to see what re­sults.

In spe­cific in­stances, we can make changes by stop­ping things: halt­ing fish­eries that are in trou­ble may help them re­cover, but only if the fish­ing ef­fort it­self is the sole prob­lem. Of­ten, it isn’t. Fish lar­vae sur­vival, ocean tem­per­a­ture, food species, preda­tors, al­gal blooms and sea­wa­ter acid­ity all play roles.

Jump­ing in to sim­ply try and re­move seals may seem like an at­trac­tive so­lu­tion, but it is also a sim­plis­tic one.

After all, this is not a sim­ple two-sided coin: off New­found­land and Labrador, fish­ers com­plain that strength­en­ing cod num­bers there are tak­ing a toll on more lu­cra­tive fish­eries like shrimp and snow crab.

There are many pieces of the puz­zle. Solv­ing it does not just mean tak­ing the ones we find the most straight­for­ward and jam­ming them to­gether.

That is the kind of think­ing that got us here in the first place.

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