Lake Herring Transport Study about to Take Off
BY DOUG ALOISI, GENOA NFH
Lake herring populations throughout the Great Lakes have been declining throughout the late 1900's and 2000's for a number of reasons. Overfishing and the introduction of invasive species are thought to be two of the primary suspects. Recent reductions in non-native prey species populations (such as alewife) in a number of the Great Lakes gave fisheries management biologists hope that the restoration of native forage species such as lake herring (or cisco), might now be possible.
Tasked with starting a captive brood line with wild collected eggs, the Genoa National Fish Hatchery (NFH) received wild collected lake herring eggs from northern Lake Huron in November of 2016. Due to lake herring not being reared at Genoa NFH previously, and seemingly not in any federal hatchery since the early 1900's, we have begun to search out the intricacies of raising this interesting fish. These fish are tiny at hatch. Herring fry metamorphose into a little fish from two little swimming eyeballs at roughly one inch in size. The fish are very fragile, and we suspect that they have very specific transportation needs. Fish that are roughly two inches in size will develop delicate scales that could be lost during transport. If this happens, the herring’s osmotic balance and immune system may be negatively affected. This could cause post stocking survival to also be negatively affected.
After consulting with the U.S. Geological Survey’s Hammond Bay Michigan station, it was decided to do a quick experiment on post stocking survival after a 12 hour distribution ride. This trip length will mimic the travel distance to the Jordan River NFH in Michigan, where the lake herring will likely end up in a few years. The future broodstock must clear three fish health examinations, before they are transferred to another hatchery. Information garnered during the study will determine the best method of transport to future hatchery homes, and eventually to wild releases once cooperative management plans have been vetted through the relevant management agencies. We look forward to learning more about this interesting and valuable species in order to further native fish restoration efforts in the Great Lakes.