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Come out and support us presenters on the Georges Bank Moritirium issue.
Let's broaden it to make the area a "Dragger/Trawler Free Zone."
Monday, January 11, 1999
The Halifax Herald Limited
Only benign fishery methods keep fisheries sustainable
By Ralph Surette
NEARLY TWO decades after the world began learning that tropical
forests and their biological diversity are being devastated, it is
difficult to imagine that another human disturbance of even greater
extent could occur almost unnoticed by scientists, the media and
political leaders. But there is one: fishing on the seabed with towed
gear such as trawls and dredges."
That's from a thick scientific journal entitled Conservation Biology.
In its December issue, the Massachusetts-based periodical has
assembled a mounting body of evidence from around the world on the
effects of dragged gear and declares itself "disturbed."
Here in Atlantic Canada, where the groundfish fishery is mostly kaput,
and the remainder of it off western Nova Scotia is being
bottom-trawled as before and apparently sinking fast, we should be
disturbed as well.
For what the scientists are saying is that the problem is not just
that we're wiping out the fish, but their habitat and much of their
food supply as well - a logical reason why the fish are not only not
coming back, but also why the remaining ones are smaller than they
should be and dwindling.
"Mobile fishing gear crushes, buries and exposes marine animals and
structures on and in the substratum, sharply reducing structural
diversity," the journal's lead article states. By churning up the
bottom continually on a vast scale "it also alters bio-chemical
cycles, perhaps even globally."
There are before-and-after pictures: rich bottoms of marine plants and
animals before trawling, a desert after.
The scientists compare bottom-trawling and "dredging" (not just for
groundfish, but for scallops and deep-sea clams in our waters, and
many other species in southern latitudes) with the loss of forests
worldwide and declare trawling a worse assault on living species.
The area of forest loss in the world each year equals about the size
of the Gulf of Maine and Georges Bank. The area trawled is about 150
times larger - larger than all of Canada.
Coral reefs, rock reefs, seagrass beds, kelp beds and so on - features
that are flattened by trawling - provide the "habitat complexity" that
improves the survival rate of fish, especially at the juvenile stage.
A study of cod done off Nova Scotia in 1995 is cited which showed that
survival and growth are better "in structurally more complex habitats
where the cod can avoid predators."
It's not that everything is destroyed by trawling, but that only
"opportunistic species" that require a less complex habitat can
survive.
Nor are the effects the same everywhere. Shallow sandy areas, like
some parts of Georges Bank, are already "storm tossed" and life there
is more used to disturbance. However the deeper you go the greater the
disturbance.
And the fishery has been going not only deeper but wider - the latest
development being "rock-hopper" gear allowing rougher bottom to be
trawled.
The scientists want "no trawling zones" to allow the bottom to
recover, less destructive gear, a broader section of the public
involved in fishery decision-
making, and other measures.
I would go farther.
A sustainable fishery is not now, nor ever has been, consistent with
anything but hook and line, cod traps and other benign gear that
doesn't disturb the bottom.
For the Department of Fisheries and Oceans, the message is clear:
start creating dragger exclusion zones now, and ultimately phase out
otter trawling entirely where the fishery is still open, and don't
ever let it come back in those areas now closed.
The scientists contritely admit that they're late on this - a story
that is out of view, unlike forest destruction, and with little public
pressure.
Yet people endowed with nothing more than common sense have been
warning about the destructiveness of trawling from the beginning, and
trawlers were even banned in Maritime nearshore waters for a time.
Let us merely hope that this late wisdom is not, in fact, too late.
e-mail: rj.surette@ns.sympatico.ca
[2] Back
_________________________________________________________________
Copyright © 1999 The Halifax Herald Limited
_________________________________________________________________
References
0. http://www.herald.ns.ca/cgi-bin/home/altdisplaystory?1999/01/11+113.raw+altColumnists
1. http://www.herald.ns.ca/cgi-bin/home/altsecfront?1999/01/11+altColumnists#113.raw
2. http://www.herald.ns.ca/cgi-bin/home/altsecfront?1999/01/11+altColumnists#113.raw
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