How One Man Changed the Ecology of the Great Lakes With Salmon

An anonymous reader writes During the sixties the Great Lakes were facing an ecological disaster due to invasive species and over fishing. Biologist Howard Tanner's solution to the problem was to bring in another non-native species, the Pacific salmon. Fishing boomed for many years but with the recent salmon crash in Lake Huron many wonder if the salmon were a band-aid on a ecological wound that's too big to fix. From the article: "Tanner's goal wasn't to just alter the species composition of the lakes; he wanted to change the public's relationship with the lakes themselves. Beyond pier fishing for perch and smallmouth bass, fishing in the lakes primarily had been the domain of relatively few commercial fishing crews using big boats and nets to harvest lake trout, perch, whitefish and chubs for restaurants and stores. But because these commercially fished native species had been so destroyed by overfishing and the lamprey and alewife infestations, Tanner inherited something of a blank slate — almost like a freshly filled reservoir in the West. He had little interest in trying to repaint the same old picture, but wanted instead to turn the waters over to large numbers of sportsmen who fished as much for thrill as fillet."

Comments

Re:Fear the Asian carp

[Anonymous Coward]

When it does, lay the blame squarely on the City of Chicago. Electric barriers are not going to keep them out.

Wrong conclusion: not "unintended consequences"

[mveloso]

This is totally not a story about unintended consequences. If you read all three parts (which is a great read), you'll see that the cycle went like this:

Native fish taken out by alweifes
Alewifes taken out by Salmon
Salmon taken out by too few alewives (overfeeding)
Native species recover, because of no alewifes

The original guy did exactly what he set out to do: destroy alewives with salmon and build a fishing economy. That was pretty successful. After that population crashed they eventually discovered that the original fish came back, due to the lack of alewives.

The unintended consequences in this case are positive - marine biologists were able to learn something totally unexpected by doing experiments on a large scale.

The original goal was never to get the native species back; it was to make the lakes back into a commercial fishery. Is the state today "better" because the native species are back? Who knows. Just because things are status quo ante doesn't mean it's better. That population is just as vulnerable to a die off as it used to be.

That's why it's better to read the article instead of skimming it.

Re:Wrong conclusion: not "unintended consequences"

[Feral Nerd]

Meanwhile here in New England, the alewives' natural range, shad and alewives are so endangered it's illegal to take one except in a few larger rivers. The springtime herring run are largely gone, along with the massive influx of marine nutrients they brought to fresh waters.

One of the things that always mystified me growing up fishing here was the incredible uniformity of freshwater fish species across water bodies with very little geographic connection. New England is dotted with thousands of small ponds, and they all have more or less the same fish. Even tiny little ponds of a few acres with no major tributaries and only seasonal outlets will have bluegill, yellow perch, and probably a few black bass lurking somewhere and reportedly some pike or muskellenge. How did they get there? And why aren't fish like bluegill from different watersheds distinctive, the way the finches Darwin found in different Galapagos islands were different? Surely natural dispersion of these fish across the whole region would have taken thousands of years.

I was recently reading about the history of dams in the US, and got the answer. In the late 1800s inland fisheries across the country were collapsing because of dam building for powering mills, so the federal government set about restocking ponds and streams across the country. The scale must have been mind boggling, because you can find the same fish in tiny, isolated ponds that don't show up except on detailed topographical maps. Even the neighbors seem scarcely aware of these ponds, but at some point maybe a hundred years ago the federal government planted fish there.

Looked at one way it was an astonishingly successful effort. There's almost no body of water in New England larger than a persistent puddle where a competent angler will catch *nothing*. And there are ponds not ten miles from Boston I can be certain of catching a half dozen crappie in a day and one or two largemouth bass -- certainly not trophy size, but enough to put up a game fight. But I often wonder what was in these waters before we crashed and rebooted the fish populations.

That may be part of the explanation but It's not quite that simple. Canada and Scandinavia for example are dotted with isolated mountain lakes that also have various fish species living in them but in this part of the world there has never been an intentional large scale stocking effort which has long puzzled biologists. The current theory is that the eggs of the fish or the larvae are carried between lakes in in the feathers of water birds.