SALMON IN THE SCHOOLS
I apologize for falling behind on my blogging, but today I'm back to tell you about another of the conservation projects John Ball Zoo supports right here in our own backyard. That project is Salmon in the Schools, and in conjunction with John Ball Zoo School, we completed our ninth year last Thursday! But before I go into the program, a little background.
You may know that the Great Lakes fishery was decimated in the fifties and sixties by overfishing and (more importantly) the introduction of exotic species. When engineers constructed canals to bypass Niagra Falls and allow freighter travel to and from the Atlantic Ocean, they opened the door for some unwanted guests. Among the worst were Sea Lamprey and Alewife. Sea Lamprey are primitive eel-like fish. They have toothy suction cups for mouths, and use them to parasitize and often kill large fish. Lamprey found no competition or predators in the Great Lakes, but did find an easy meal in the Lake Trout. Alewife are a species of Atlantic herring that also swam to the lakes, and with the lamprey decimating the trout there was no top predator to keep them in check. That resulted in them disrupting the populations of some of the other native species, as well as experiencing waves of massive, beach-fowling die offs when the lakes could no longer support their numbers. We needed solutions, and one came in the form of Chinook (or King) Salmon. They're a hardy and fast-growing Pacific species well-suited to the lakes' cold, deep waters. The DNR began stocking Lakes Michigan and Huron in 1967 to control the Alewife, as well as well as provide a new subject for the lucrative commercial and sport fishing industries.
Okay, that was a longer intro than I'd intended. Hope I didn't lose you. Anyway, a number of Michigan schools participate in a captive rearing program, and Zoo School is one of them. Every November we receive fertilized Chinook eggs from the Wolf Lake Fish Hatchery and raise them in an off exhibit area of the Aquarium. Salmon require cold water (about 50 degrees), meaning the water must be chilled. The other schools attach chilling systems to their tanks, but luckily we're able to run ours off the same machine that regulates temperatures for everything from the penguins to the tide pool. The eggs are in a five gallon aquarium, which is then placed in a fifty-five gallon one. Both are filled with pebbles. The smaller tank is intended to help keep the eggs together and easy to monitor. Once the salmon hatch and finish absorbing their yolk sacs (early the following year) the small tank is removed and daily feedings begin A pair of kids visits the Aquarium four times each day to feed, with keepers feeding twice more at the start and end of the day. So many hungry mouths eating that frequently makes for a very messy fish tank, so three times per week it's siphoned clean and given a large water change. When possible, the Zoo Schoolers help with this aspect as well. As the salmon grow, the food changes in both size and nutritional aspects to remain appropriate for them. By May the salmon are three to four inches long and shiny silver (at this stage they're called "smolt") and ready to move on. We carefully transfer them to a large insulated cooler and take them to the boat lauch at Riverside Park where the water is relatively calm. After acclimating them to the different temperature and water conditions of the Grand River, the kids set the salmon free to swim the rest of the distance to the open waters of Lake Michigan.
And from the Zoo Schoolers:
"Doing this project, I learned a lot about salmon. It's amazing to see how they grow in so little time - from an egg until now! I loved this project!!! "
"The salmon raising project was one of the coolest things I've ever done! It was a fun test to show your responsibility towards caring for animals. Watching them be released showed how amazing an outcome can be if you put effort and responsibility into it. Quite a life lesson!
"Taking care of the salmon was just one of the many different projects we had throughout the school year that was very enjoyable and gave the students a great experience. This was a special responsibility that was given to us and it didn't got to waste. Students jumped at the opportunity to take care of these creatures which included: feeding them, checking temerature of the water, and on occasion clean the tank. At the end we finally had to say goodbye and released them into the Grand River on May 22, 2014. "