Photo by MKeigley
Rob Elliott is a fisheries biologist with the US Fish and Wildlife Service. From his office near Green Bay Wisconsin, he helps look after native fish species across all of Lake Michigan.
This fall he will travel to western Michigan to join several of his colleagues from the Michigan DNR, Little River Band of Ottawa Indians, and other USFWS offices to form the last line of defense for one of our favorite watershed residents, the lake sturgeon. If you are wondering why the sturgeon require our protection that is definitely the right question to ask. The answer is complicated and a little background might be helpful.
First, you need to be familiar with a particularly nasty predator that found its way into the Great lakes nearly 100 years ago. The sea lamprey, contrary to popular opinion is a fish, not an eel and is uniquely equipped to decimate populations of important species of large game fish.
They are native to the Atlantic Ocean and are incredibly resilient, remaining largely unchanged for more than 340 million years and have survived through at least four major extinction events. While sea lampreys resemble eels, they are not related and are set apart by their unique mouth: a large oral sucking disk filled with sharp, horn-shaped teeth surrounding a razor sharp rasping tongue.
Sea lampreys attach to fish with their suction cup mouth then dig their teeth into flesh for grip. Once securely attached, sea lampreys rasp through the fish’s scales and skin with their sharp tongue. They feed on the fish’s body fluids by secreting an enzyme that prevents blood from clotting, similar to how a leech feeds off its host.
When unchecked their population explodes with truly disastrous impact. In the sixties prior to attempts at control, sea lamprey predation on valuable fish stocks was so high it became a key factor in the collapse of the Great Lakes ecosystem. They killed more than 100 million pounds of fish annually.
Since those dark days, successful control measures have been implemented which has reduced the population by over 90% and allowed for the rehabilitation of a healthy Great Lakes ecosystem. It is a never-ending problem however because if control is relaxed the population can quickly rebound with predictably tragic results.
The sea lamprey control program, administered by the Great Lakes Fishery Commission, relies on exploiting sea lamprey vulnerability in the larval stage of their life cycle when they live in Great Lakes tributaries including the Muskegon River. Lampricides—pesticides selective to lampreys and the primary control tactic—are released in the tributaries to kill the larva.
It is a massive undertaking since all Great lakes tributaries must be treated on a three-year rotating schedule and the Muskegon is on the calendar this fall. Technicians from the Great lakes Fishery Commission and the US Fish and Wildlife Service will deploy lampricides in the Muskegon River between Croton Dam and Muskegon Lake for a 12-hour period beginning September 11. They schedule the treatment to have as little negative impact as possible on other species including lake sturgeon and salmon.
Unfortunately, there was an unexpected consequence following the most recent treatment three years past. Several juvenile sturgeon died as a result. That is why Rob Elliott is involved this year. It is not Rob’s job to kill lampreys. His job is to protect sturgeon and he is willing to go to great lengths to get that done.
“We plan to collect as many young sturgeon as we can prior to the lampricide application. The best way to do that is at night, from boats with long nets and spotlights. We will keep them in holding pens away from the lampricide until the river is free of chemicals, and then put them back where we found them. It is labor intensive and not an ideal long-term solution but effective in that the majority of the fish in the river are unharmed.”
Rob has no issue with the lamprey treatment program and understands better than most the potential threat inherent in an uncontrolled lamprey population. “There is no middle ground with lampreys. Either you aggressively control their population or you suffer the consequences.”
Rob explains that the Muskegon is a very fertile breeding ground for lampreys and must be treated on a regular basis. He and his colleagues have determined that Muskegon River sturgeon are more susceptible to the treatment than populations in other streams due to the high alkalinity of our water. “We’re still studying that, and of course treatment methods continue to evolve. But for now, we really don’t want to risk losing many of these fish. There is a small but growing population of sturgeon in the Muskegon River. We want to see that trend continue.”
Fortunately, for Rob, he is not in this alone. Several dedicated sturgeon advocates including Marty Holtgren, a noted environmental consultant who manages projects for the MRWA, and Corey Jerome who is the fisheries biologist with the Little River Band of Ottawa Indians will join him. You can find contributions from both in the spring 2017 edition of the Riverview.
On September 23 after the all clear, MRWA volunteers will release some of the young sturgeon that were collected prior to the sea lamprey treatment back into the river at Ed Henning Park. The river is sure to be clear by then and many of us will be paddling from Croton to Newaygo that same day. To celebrate we plan a community event with a sturgeon release ceremony, entertainment, food and a raffle.
Yet there is much to do before then and volunteers to help carry the load are welcome. Please visit www.mrwa.org if you are interested in helping out or for more information about the activities at Henning Park.
Don Henning, editor MRWA Riverview