BIODIVERSITY PAGE
This page is dedicated to fighting the good fight for animals and plants that can't fight for themselves. Biodiversity has become a very dear subject to so many well-meaning people. To the snail darter detractors and those who slight the spotted owl, biodiversity has become the poster child of extremist environmentalism. To us here, it's a sad subject because man's increasing influence on this planet means less room for those animals with a more tenuous grasp on what ever tiny niche in nature from which they are slowing being wrested.
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Salmon Return Spells Hope Amid Mystery 10.18.11
Workman installing splashboards to improve fish runs
When NBN heard that Massachusetts' Merrimack River had a record run of Atlantic salmon this year, we thought we had a great story for. That’s because in 2009 the Lawrence Dam in the Merrimack River was repaired in a way design to increase the flow of anadromous fish like the Atlantic salmon past this ancient impediment. Was the record 2011 salmon run proof the repair is working? No, according to Joe McKeon, a fisheries expert with the U.S. Fish and Wildlife Service. Rather, the reason for the spike in salmon numbers counted passing through the dam’s tiny fish lift is somewhere out in the Atlantic Ocean. That’s where the fish spends the first two years of its life after hatching in the freshwater retreats of the Northeast’s rivers and streams like the Merrimack and the dozens of tributaries, streams and rivers that feed it.
The Lawrence Dam fish lift is tiny compared to the river stretching behind it.
Something changed in the Atlantic, McKeon said, that has caused salmon runs to spike from southern New England to Canada. While the record 2011 Merrimack run still just totaled 401 fish, the count in many Maine rivers jumped by several thousand salmon and Canadian Rivers are seeing even more robust runs. (Sadly, no change to report in Connecticut rivers.) There is a broad range of environmental factors in the Atlantic that can account for the increased survival of the salmon now seen in their return to these rivers. Not the least of these is ever tightening restrictions on commercial fishermen working the waters for other species and catching salmon by accident. (Atlantic salmon cannot be commercially caught.) Salmon have also been troubled by disease and an epidemic of sea lice believed to have spread from the many salmon farming operations along the coast of Maine and Canada. It’s also feared the fish from those farms, a genetically weaker strain, escape and spawn with the wild Atlantic salmon producing young less able to live in the open ocean. Lastly, all anadromous fish struggle with increased pollution from road runoff which is degrading the watershed these fish depend on for spawning grounds.
This YouTube illustrates exactly the problem hobbling salmon runs in Lawrence and at other dams: water spilling over the top diverts salmon from the lift on the left. You can see salmon in the background attempting to jump up the dam. This problem was fixed in Lawrence in time to greet a record sun of salmon.
In the face of all that, there has been a lot of talk of the Atlantic salmon going extinct. So it's resurgence this year is huge news. So much so it has NBN changing its thinking on this subject. It’s always seemed to us anadromous fish will never return to Northeast rivers as long as impediments like the Lawrence Dam are in place. The improvement of these fish runs is an oft-cited argument in what's becoming a nationwide program to remove them. Dams are coming out all over the place. Yet the growing interest in alternative energy like hydropower that these dams, even small ones, can produce is becoming increasingly attractive. For decades anadromous fish runs up and down the coast have been hobbled by dams. The number of salmon at the Lawrence dam dropped as low as 21, in past years. Yet 2011 shows the animal still bounces back. That's got us thinking maybe the Atlantic salmon could make a comeback even with the dams in place.
McKeon said the fish lift at the Lawrence dam will work en masse if there are fish there to use it. The repairs to the dam will only help as will other improvements constantly being made on behalf of anadromous fish runs in rivers across the country. Government scientists like McKeon have spent decades trying to bring these fish back to these rivers. Are they about to see their efforts rewarded?
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