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About Fish – December 30, 2015

This past year has seen a big decline in the availability of locally harvested wild fish.  For the past several years we have been using Red Lake Band walleye and Lake Superior whitefish as the “seafood” staples in our menu.  The Red Lake fishery is run by the band and collects, cleans and sells walleye caught by band members in the tribal portion of Red Lake (see map).

RedLakeWhen we first started buying fish from the band it shipped directly from them, but in recent years we have had to purchase it indirectly from a food service distributor.  Lake Superior whitefish is bought from commercial fishermen in Minnesota and Wisconsin.  In the past, we bought our whitefish from Lake Superior Fish in Superior, WI.  But, more recently, probably due to the growing popularity of the “buy local” movement, that source has dried up.  We have switched to Bodin Fisheries in Bayfield, WI. However, at this time we are not able to get either wild walleye or whitefish.  It is not completely clear exactly what all the issues are with the fish supply.  But we can look at some local history and biology to learn a few things.

In 1998 MPR reported that:
The problems at Red Lake started decades ago. The federal government opened commercial fishing in 1918 to provide food for Minnesotans during World War I. The harvest was increased during World War II, and the regulations put in place then have not changed in 55 years. Federal regulations set a maximum walleye harvest and ostensibly controlled the commercial fishing, but for decades there was little or no oversight. It was just ten years ago that the Red Lake tribe started a fish biology department. The tribe manages 85 percent of the lake; the state of Minnesota oversees the remaining 15 percent that’s outside reservation boundaries. Minnesota DNR regional fisheries manager Bob Strand says Red Lake is in critical condition.
In the late 1980s commercial fishing took nearly one million pounds of walleye a year from Red Lake – that was the legal harvest. Some contend another one million pounds were taken illegally.
Any member of the Red Lake band was free to do subsistence netting – catching fish to feed their family. Many used the freedom as it was intended, but some subsistence netters took thousands of pounds of walleye to sell on the black market. Tribal and state officials are circumspect about placing blame, but commercial fisherman and Red Lake tribal member Bill May says greed led to a declaration of war on walleye.

Red Lake, at 260,000 acres, is Minnesota’s largest inland lake and consists of two basins. In 1999, the Red Lake Band and the DNR reached an historic recovery agreement which outlawed netting of any kind in Red Lake and controlled walleye fishing in both the reservation and public portions of the lake.  Additionally, both the band and the state DNR began stocking programs.  The harvest resumed in 2006 and the band and the DNR co-operate to monitor harvest levels.  Fishing this year has been OK but right now the ice is too thin to get the gear out on the ice.  In the public portion of the lake, the limit is three walleye, only one of which can be longer than 17”.

Out in Lake Superior the story is a little different.  Fishing nets are allowed.

Net Design

Net Design

Until about 1890 whitefish were the mainstay of the Lake Superior commercial fisherman, but in the three decades that followed they became virtually extinct in many areas. Great Lakes Fishing was not regulated until a law was passed in Michigan in 1929.  Prior to that it was literally catch as catch can.

From Zenith City:
Herring fishing reached its peak in the early 1890s, providing 78 percent of herring caught in the United States. In 1897 Sam Johnson, a Swedish immigrant who learned to fish on the Baltic, founded ZCA_IND_SamJohnson_001_DPLSam Johnson & Sons Fisheries Inc. (See photo) directly across the street from Booth Fisheries. Other Duluth fisheries active at the time included H. Christianson & Sons, Hogstad Fisheries, Scandia Fish Company, Bray Fish Company, Goldish Fisheries, A. Kemp Fisheries, and Sivertson Brothers….  The industry reached its peak in 1915 with a record catch of 20 million pounds in Duluth alone. In the 1920s, more than two hundred fisherman operated between Beaver Bay and the Pigeon River. But the 1930s were a different story. The lake’s catch dwindled to below 8 million pounds. The industry never quite recovered. Predatory lamprey eels and over-harvesting nearly wiped out the trout in the 1950s. Today the Lake Superior fishing industry is all but a memory; the annual harvest is less than two thousand pounds….  In 1940 the Sivertsons purchased the Hogstad Fisheries, which had purchased A. Booth in 1928. In the 1960s it began operating as the Lake Superior Fish Company, which it had acquired with its purchase of Goldish Fisheries. The company still operates today, and two of Sivertson’s grandchildren and their families remain involved. A. Kemp Fisheries, established in Duluth in 1930 by Aron and Abe Kemp, still operates. In the 1970s the company became Louis Kemp’s, named for its owner (a childhood friend of Bob Dylan, who also managed Dylan’s 1976 “Rolling Thunder” tour), who developed a process for making surimi, artificial crab meat made of pollock and whitefish. Today, Louis Kemp’s is a subsidiary of Trident Seafoods Corporation of Seattle, selling its Crab Delight throughout the world.fishingboat_62555_7

Nowadays, the Lake Superior fishery is highly studied and regulated.  Of all the Great Lakes, Superior is the most pristine and the fish have the lowest levels of toxic contaminants.
Historically, Superior has produced far fewer fish than Lake Michigan.

From the Minnesota Sea Grant website:
Therein lies the difference between Lakes Michigan and Superior. During the course of the incredible changes in species composition that took place after the 1940s, Lake Michigan ended up with a prolific forage fish that supported an enormous trout and salmon stocking program, while Lake Superior ended up with only a fraction of the forage base that it had prior to the sea lamprey invasion.
In addition, Lake Michigan annually receives 42,000 more tons of nitrogen and 2,250 more tons of phosphorous than Lake Superior. The larger nutrient loading into the smaller Lake Michigan may make it more productive than it was in the past….
Because Lake Superior has more natural reproduction of lake trout than other Great Lakes, it may be better off in the long run. Native lake trout became extinct in Lake Michigan, but remnant populations in Lake Superior survived the lampreys’ onslaught. Today Lake Superior has many areas with natural reproduction and significant numbers of native lake trout (identified by their lack of clipped fins). The Lake Michigan trout and salmon fishery remains almost totally dependent on stocking. The collapse of the salmon fishery in some areas of Lake Michigan and the recent major losses of hatchery production in Michigan and Wisconsin from a new virus suggest that there are risks in relying so heavily on stocking to support a fishery.
The biggest biological threat to Lake Superior’s recovery may continue to be exotic species….
Three new exotic species from Europe may also threaten the Lake’s recovery. The ruffe, a small perch; the spiny water flea or B.c., a large predatory zooplankton; and the zebra mussel, a small biofouling clam have all developed reproducing populations in the Lake Superior basin. Of the three new exotics, spiny water flea populations have developed most extensively in the lake and may be capable of inflicting the greatest ecological changes in Lake Superior, but only time will tell.

LakeSUperiorFoodWeb
The actual reason why demand has so far exceeded supply in the last two years is not completely clear.  The winters of 2013-14 and 2014-15 were both unusually cold.  (Remember the “polar vortex”?)  And there is not nearly so much nitrogen, nor phosphorous, dissolved in Superior as in the other great lakes.

I sent an email to Dr. Robert Sterner at UMD’s Large Lakes Observatory asking this question and here is what he said:
We measured primary productivity in the offshore of Lake Superior many times in bottles that were suspended at given depth for an entire daylight period.  We measured the rate that carbon was incorporated into organisms.  This rate generally can depend on a handful of things: the biomass of photosynthetic organisms, the temperature, light and nutrients, as well potentially as the kind of organisms present.  However, when we looked at our data we found that far and away the one factor that we could use to predict the rate of photosynthesis in our 1-day incubations was light.  We didn’t even need to include the biomass of the organisms in order to do a good job predicting the rate of primary productivity.  Part of the reason why is that without light no photosynthesis can take place, so the other factors don’t matter.
However, this does not mean the nutrients (or other factors) can be ignored.  One reason biomass or phosphorus might have had minor relevance in our study was that both of these were basically low and fairly uniform everywhere we looked.  If we do the thought experiment of polluting Lake Superior with tons of phosphorus (an awful thought indeed), greening it up, we’d then be measuring higher primary productivity everywhere in the lake.
I haven’t read too much this year about the low fish abundances but I have heard that some of the species are at low abundance, affecting commercial harvests.  I think some fisheries biologists are thinking about what effect the two recent very cold winters had.  In addition, we have evidence from my lab that algal abundance is in a state of decline in the lake, meaning probably less food for fish to eat and thus fewer fish.  We are far from having a smoking gun to prove all that, but that’s why we need more research into how the Lake Superior ecosystem works.

I also heard from Dr. Liz Minor about the same topic:
Sterner’s work shows that light is the major variable in primary production (algae growth).  This has to do with how deeply light can penetrate (it is absorbed by water itself, sediments, and colored dissolved organic matter, as well as the algae themselves).  The other factor in light limitation is the depth of the surface mixed layer, which is determined by the temperature structure in the lake water column. In the summer the lake has a warm surface layer that is less dense than the deep layer and the floating algae get trapped in the surface layer.  This is good for them because it keeps them near the light. In the spring and fall the lake surface water is cool and when it reaches 4 degrees c (the temperature when water is most dense) the whole water column mixes.  This is bad for floating algae because they get mixed deeper than the light can penetrate.
N and P can act as limiters in lake systems too, if enough light is available. There are times of the year and places in Lake Superior where P seems limiting, because its main source is run off from the land and the lake has a pretty small watershed for its size.

More Science articles can be found here.LevelTemperatureHarvestLevelTemperatureHarvest

So where does that leave us as a restaurant?  One place is to look towards farm fishing.  UMD has set up an experimental fish farm in Silver Bay producing leafy vegetables and Tilapia (see photos).  They sent us some samples but at this time we are not able to deal with whole unscaled tilapia.  Recently I saw an advertisement for a farm in Iowa.  A couple of brothers have converted a hog farm into a production facility for barramundi, which is a sea bass like fish native to Australia.  This fish is available to us through the food service already skinned and filleted – so it is easy to manage.  We are going to begin experimenting with it this week.  We’re hopeful.  Fish is a very important part of modern diets and is less damaging to the environment than other meats.  What you eat is more important than where it is from.

We continue to try to manage bringing our customers what they want in terms of variety and quality while at the same time informing our purchasing decisions with as much knowledge as possible.  As always, your input is welcomed.

Barrimundi

Barrimundi