The fish lift/ladder combination at Conowingo Dam cost a huge amount of money, both to construct and operate. And to some degree, it worked, but not very well. keep in mind that the dam was built in 1920, and the shad runs still were pretty incredible until the mid 1970s, which is about the time that the offshore intercept fishery began. If you kill them before they reach the spawning grounds, then reproduction is not even remotely possible. Same goes for blueback and branch herring, both of which have been pretty much wiped out by the same commercial fishery.
Hatcheries do work, as was first witnessed with stocking lakes and tidal rivers with largemouth bass during the early 1960s. This was a time when the North East River was clogged with various forms of aquatic grasses that supported what was deemed the best largemouth bass fishery in the nation. It was here that huge numbers of largemouth bass were netted and placed in the nearby hatchery in the town of Elkton, spawned out, and hundreds of millions of juveniles were then transported throughout the US to be stocked in thousands of locations. The project was very successful.
While the fish ladders worked in the PNW, the salmon stocks were so depleted by commercial interests that the fishery had to be supplemented with a huge stocking program, which is what resurrected that fishery.
In nearby Delaware and Pennsylvania, their American shad fishery was restored in the Delaware River's upper reaches by supplemental stocking that took place for more than a decade. That fishery had been completely wiped out by commercial fishing. And, while it is still a mere skeleton of what it was a century ago, Delaware's shad runs have become a multi-million dollar industry for the recreational catch and release fisherman.
While the striped bass moratorium of the early 1980s was heralded as the big deal in restoring the striped bass fishery throughout the East Coast, in reality, supplemental stocking played a huge role in that restoration process. Again, this fishery was essentially wiped out by commercial interests, as they frequently targeted the big spawning stocks as they migrated to the spawning grounds during the winter months. I knew one commercial netter who fished out of Tilghman Island who often bragged of 10,000 daily catches in his gill nets during January and February. He told me that 90 percent of those fish were huge, roe laden females, fish that did not have the opportunity to spawn.
The striped bass hatchery program was the result of a joint effort by recreational and commercial fishermen in Maryland and was established where the old largemouth bass hatchery in Elkton was located. At the time, Maryland DNR Fisheries biologists said the hatchery would not work and the stripers could only spawn naturally - DNR was dead wrong. Only a half-million juvenile stripers were stocked that first year, but tagging studies revealed a 75 percent survival rate, which is huge compared to less than 1 percent in the wild.
As I stated at the onset, the best remedy to this would be to stop the offshore intercept fishery for shad, and the same goes for gill netting for striped bass. Fisheries scientist James Price once said "I don't know of a single fishery in the US that has been wiped out by pollution - they have all been decimated by overfishing, mainly by commercial interests."
All the best,
Gary
careinke wrote:Well, I have some good news from the lower Puget Sound. Evidently the water temp, PH, tides, time of year, and probably a lot of other factors came together and there are now baby pacific oysters everywhere in huge abundance!
I did a quick survey (I plan on a more scientific one soon), and I estimate we easily have over a million new pacific oysters on our beach alone! I, (nor anyone else I know), remember anything like this, and we go back over 70 years.
The density rate seems to be 10-30 per square foot. Right now, they are 1"-2" across and look healthy. Besides food, the beneficial filtering should provide a huge environmental boost to the South Sound.
When I first saw them, I thought someone up the beach had seeded and the oysters drifted down to our beach (this happened once before around forty years ago). However, after one of my relatives talked with Taylor Shellfish, it turns out the phenomena was widespread.
Sometimes things do turn out OK. So far this global warming thing seems to be working out for us, beautiful weather, and now oysters! <with tongue in cheek>
Timo wrote:Sorry to burst your bubble, but those are the periodic (several decade) oysters hatching now, and only having 12 hours to mate and reproduce, and then die, leaving their offspring to hatch and spring back to life in another few decades. Here in the inland states, we call those critters cicadas. You simply have a different species in Puget Sound. Sounds to me like they're the 70 year variety. What do they sound like? In these parts, those suckers are LOUD!
careinke wrote:Timo wrote:Sorry to burst your bubble, but those are the periodic (several decade) oysters hatching now, and only having 12 hours to mate and reproduce, and then die, leaving their offspring to hatch and spring back to life in another few decades. Here in the inland states, we call those critters cicadas. You simply have a different species in Puget Sound. Sounds to me like they're the 70 year variety. What do they sound like? In these parts, those suckers are LOUD!
Interesting theory, but as far as I know oysters don't make sounds, although sometimes people eating them do. Nor do they produce in decades long cycles, otherwise the shellfish industry in the Puget Sound would not be expanding.
onlooker wrote:http://www.nature.com/news/man-made-pollutants-found-in-earth-s-deepest-ocean-trenches-1.20118
Man-made pollutants found in Earth's deepest ocean trenches
The researchers suspect that the proximity of the Mariana Trench to large plastic manufacturers in Asia, as well as to a long-term US military base on the island of Guam, may have contributed to its high PCB levels. The waters above the trench are also part of the North Pacific gyre, a system of strong swirling ocean currents that might be sucking materials on the surface down into the deep sea. Both the Mariana and Kermadec trenches are around 11 kilometres deep. “It sounds quite deep, but it’s not in terms of pollutant transport,” says Jamieson.
dohboi wrote:http://www.bloomberg.com/news/articles/2016-08-02/rising-sea-levels-could-cost-u-s-homeowners-close-to-1-trillion
Rising Sea Levels Could Cost U.S. Homeowners Close to $1 Trillion
Being underwater will soon mean exactly what it says. Especially in Florida.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
Zillow has done some number crunching on pending property losses coming up in the next few decades. As this state change takes hold as the new normal (rain bombs, insta-floods, king tide invasions), how will insurance companies react? What will happen to policies and premiums going forward?
A report released earlier this month by the real estate sales company Zillow predicted that almost 1.9 million homes, worth a combined $882 billion, would be lost to the rising sea levels — and the flooding likely to follow — that climate scientists expect to see by the year 2100.
If sea levels rise as much as climate scientists predict by the year 2100, almost 300 U.S. cities would lose at least half their homes, and 36 U.S. cities would be completely lost.
One in eight Florida homes would be underwater, accounting for nearly half of the lost housing value nationwide.
data from satellites and ocean... show a definite slowdown [in AMOC] since 2004, confirming a trend suspected before then from spottier data
dohboi wrote:A Horrifying New Study Found that the Ocean is on its Way to Suffocating by 2030
http://www.theinertia.com/environment/a ... g-by-2030/
(Thanks to Abel at rs's blog for this)
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