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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."
I wouldn't call the collapse of the salmon a failure. By introducing them, the invasive alewives were greatly reduced in number, which gave the native lake trout and walleyes a chance to recover.
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.
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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.
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?
From Michigan here, lots of unconnected lakes and ponds here too.
It was always explained to me that they get there carried on the feet of waterfowl. Ducks and such land in the shallows and weeds, feet get covered in eggs. Ducks move on. Sometimes they're stocked by property owners or the DNR.
The fish *are* genetically diverse. Big fishing tournaments rely on this fact and do genetic testing on fish to make sure they came from the correct lake.
Get off my lawn.
They already are classed as an invasive species so can likely be caught in any amount by anyone. They are a fairly fun fish to bring in and make good fertilizer for the garden so I am doing my part to try and control the problem. I probably catch 20-30 of them a year in the early spring and fall and hand them out to neighbors and family who are looking to improve the soil in their gardens. Add to it that they are pretty easy to catch, a yellow leadhead with a nigh crawler bounced off the bottom seems to work really well in pool 2 on the Mississippi, so it is a great way to introduce a kid to fishing as they can actually catch some big fish without much effort.
Time to offend someone
If the Asian Carp shares the same fate as the rest of the invasive species that have infiltrated the lakes, expect walleye to start eating them sooner rather than later. Already walleye are eating zebra mussels and brown gobies. The downside is that the walleye fishery has changed a lot, because they're no longer interested in the bait that fishermen have to offer.
Easy Online Role Playing Campaign Management
Exactly!
I proposed a fix and they said I was mad. My fix would have completely cleaned up the Asian Carp problem and not involved any silly electric barriers.
You see, Bull Sharks http://en.wikipedia.org/wiki/B... are fresh water capable. They have an organ that allows them to do salinity adjustments in their body so they can adapt to fresh water. In the early 1900s one was actually caught near Chicago.
So we start stocking the Mississippi with lots of young hungry bull sharks.
They will grow at amazing speed as they stuff themselves with the Asian Carp. With the abundant carp I think they should pass world record sizes in the first year or two. Imagine how many carp a bull shark that is bigger than Australian great white, can eat in a day.
Those carp will be gone in short order and I will have ridden my fame to another new job and completely forgotten the shark project by then.