Readers Want to Know
Smelt may look vicious close-up, but the small fish make for good eating.
Where did all the smelt go?
Fishing for smelt used to be a spring ritual in the 1960s and 70s, enjoyed by many in the region. But now the runs are much smaller. The major short-term smelt crashes in the Great Lakes remain mysterious, but the quick answer to the reason we can't catch smelt in Lake Superior like we did in the good old days is because a healthy population of lake trout (thanks to lamprey control and good fisheries management) has caught them first.
For the long answer, read on to learn where smelt came from and what they did when they invaded the Great Lakes.
Where Did Smelt Come From?
Many people are surprised to hear that smelt are not native to the Great Lakes. Smelt are an Atlantic Ocean fish that spawns in freshwater. To help ensure the success of Atlantic salmon stocking efforts in the Great Lakes, Michigan fishery managers stocked smelt into the St. Marys River in the early 1900s. None of those attempts were successful. A 1912 stocking of smelt into Crystal Lake in Michigan led to a population that eventually entered Lake Michigan through connected waters and were first found in Lake Michigan in 1923. They quickly spread to other Great Lakes. They were first found in Lake Superior in 1930, however, they were not found in the Minnesota waters of Lake Superior until 1946.
What Did They Do?
Smelt numbers in the Great Lakes increased dramatically as sea lamprey reduced or eliminated top predators like lake trout. At its peak, the commercial harvest of smelt in Lake Michigan was 4.8 million pounds in 1941. Hints as to the fate and impact of smelt in Lake Superior occurred in lakes Michigan and Huron over the winter of 1942-43, when mass mortality caused an abrupt decline. At the time, fisheries experts suspected a disease was the cause, but had no evidence. The spring of 1944 saw the emergence of the largest year class of whitefish ever recorded for lakes Michigan and Huron. The cisco (formerly known as lake herring) also responded with a strong year class that delayed their decline into oblivion for about ten years. Was the decline in smelt responsible for the rebound of whitefish and cisco? It is generally agreed that the reduced smelt population played a major role in the reproductive success of those two species.
Now to Lake Superior
Here again, the smelt didnít amount to much until the lamprey took its toll on lake trout. As the lake trout population declined, smelt numbers increased exponentially. Commercial harvest of smelt in Lake Superior went from 21,000 pounds in 1953 to over 4 million pounds in 1976.
However, a curious thing occurred during this meteoric rise. Despite lake trout numbers being driven down by sea lamprey, which meant that predation on cisco was minimal, cisco almost vanished in Lake Superior as they had in the other Great Lakes. Commercial fishermen at the time thought cisco numbers would skyrocket and even planned a new marketing and processing campaign.
So what happened? In hindsight it is clear that smelt, prob≠≠≠ably through predation on cisco larvae, caused cisco to crash as they had elsewhere in the Great Lakes, although commercial fishing pressure may have played a role as well.
So Ė Where Did All the Smelt Go?
Remember what happened to smelt in Lakes Michigan and Huron in 1943? They inexplicably crashed in one year. The same thing happened on Lake Superior in 1979. Smelt numbers crashed and we donít know why. On Lakes Huron and Michigan they suspected disease, but we donít have a clue as to what happened there or in Lake Superior. In Lakes Michigan and Huron, smelt eventually gained momentum again and produced a commercial harvest of over 9 million pounds in 1958 before they declined again. Smelt in Lake Superior have not recovered from that fateful year of 1979.
It is generally agreed that the lack of a smelt comeback is because we now have a significant number of predators back in the system. Predators are feeding heavily on smelt and even prefer smelt to the more abundant cisco as food.
As long as they stick around, we will probably never see the short-lived (1960 to 1978) good old days of smelt parties in the spring. There will probably always be smelt in Lake Superior and their runs will vary in size from one year to the next, but we wonít likely see the days when you could dip net a pickup load of smelt in a night or two. The numbers of lake trout (not counting cohos, chinooks, steelheads, brown trout, eelpout) that are back in Lake Superior can eat more smelt per year than were ever commercially and sport harvested from the lake, even in the smelt heyday.
By Sea Grant Staff