Post by kingseeker on Feb 10, 2014 17:40:22 GMT -5
from the 2-7-14 Michigan City News-Dispatch;
A vitamin deficiency will result in fewer coho stocked in Lake Michigan.
Its unfortunate, but it seems the only time you hear about the outstanding hatchery system around the lake, which is the life blood of a multi-million dollar salmon fishery, is when things go awry.
It appears this year's coho crop will be reduced by half. Or more.
"Its too early to tell, but we've probably had 50 percent mortality," Tom Schwartz, 35-year Indiana DNR veteran and manager of Mixsawbah Hatchery near Stillwell, said.
"It is lake wide, the others (states) are seeing similar numbers."
The target goal for coho stocking in Indiana tributaries is 240,000 one-year old fingerlings. Lake wide, annual coho releases are pegged at 2.6 million, with 1.6 produced in Michigan.
Ed Eisch, hatchery manager at the Platte River facility in Michigan, where coho eggs are collected for all of the Lake Michigan states, echoed Schwartz.
"There has been significant mortality, probably half, but it is too soon to determine how many," Eisch said. "We haven't counted them, we've just started to feed them (at the fry stage)."
Eisch pointed to a thiamine deficiency as the culprit for the extra mortaility.
"We diagnosed it early and were able to treat them a second time, which likely saved (some)," Eisch said.
The thiamine vitamin deficiency is directly related to a diet high in alewives and has been a cause for salmonid reproductive failures over the years, particularly in coho and lake trout.
"The coho (adult spawners) were bigger this year, although not as pronounced as Chinook, which likely means they ate more alewives," Eisch explained.
Fortunately, enough coho fry have survived to avoid threatening an entire year class.
"Our highest priority is stocking enough for brood collection here (Platte River) and we expect to be able to maintain that," Eisch said.
Schwartz added a silver lining to the coho cloud.
"We, here in Indiana, will be able to fill the hatchery space (voided by coho mortality) with summer-run steelhead," Schwartz said. "The total number of fish produced should be similar."
The current coho slight in the hatcheries will impact fishing in 2016.
Coho are a very important part of the fishery in southern Lake Michigan, but account for only a portion of salmonids produced in hatcheries. Annual lake wide stockings (in millions) are roughly 3.0 lake trout, 2.6 coho, 1.7 Chinook, 1.6 steelhead and 1.4 brown trout.
Additionally, millions more Chinook and lake trout are produced naturally each year.
A vitamin deficiency will result in fewer coho stocked in Lake Michigan.
Its unfortunate, but it seems the only time you hear about the outstanding hatchery system around the lake, which is the life blood of a multi-million dollar salmon fishery, is when things go awry.
It appears this year's coho crop will be reduced by half. Or more.
"Its too early to tell, but we've probably had 50 percent mortality," Tom Schwartz, 35-year Indiana DNR veteran and manager of Mixsawbah Hatchery near Stillwell, said.
"It is lake wide, the others (states) are seeing similar numbers."
The target goal for coho stocking in Indiana tributaries is 240,000 one-year old fingerlings. Lake wide, annual coho releases are pegged at 2.6 million, with 1.6 produced in Michigan.
Ed Eisch, hatchery manager at the Platte River facility in Michigan, where coho eggs are collected for all of the Lake Michigan states, echoed Schwartz.
"There has been significant mortality, probably half, but it is too soon to determine how many," Eisch said. "We haven't counted them, we've just started to feed them (at the fry stage)."
Eisch pointed to a thiamine deficiency as the culprit for the extra mortaility.
"We diagnosed it early and were able to treat them a second time, which likely saved (some)," Eisch said.
The thiamine vitamin deficiency is directly related to a diet high in alewives and has been a cause for salmonid reproductive failures over the years, particularly in coho and lake trout.
"The coho (adult spawners) were bigger this year, although not as pronounced as Chinook, which likely means they ate more alewives," Eisch explained.
Fortunately, enough coho fry have survived to avoid threatening an entire year class.
"Our highest priority is stocking enough for brood collection here (Platte River) and we expect to be able to maintain that," Eisch said.
Schwartz added a silver lining to the coho cloud.
"We, here in Indiana, will be able to fill the hatchery space (voided by coho mortality) with summer-run steelhead," Schwartz said. "The total number of fish produced should be similar."
The current coho slight in the hatcheries will impact fishing in 2016.
Coho are a very important part of the fishery in southern Lake Michigan, but account for only a portion of salmonids produced in hatcheries. Annual lake wide stockings (in millions) are roughly 3.0 lake trout, 2.6 coho, 1.7 Chinook, 1.6 steelhead and 1.4 brown trout.
Additionally, millions more Chinook and lake trout are produced naturally each year.