The following is an excerpt from a DNR report dated December 9, 2011:
The fishing during 2010 was excellent in many regions of Lake Huron. What is not widely known is that after the alewife crashed in 2003 and the salmon fishery declined, fishing in much of the Lake is currently as good as it was during the peak nearly 10 years ago. The species found in the catch have been changing but the resulting diverse fishery has been very good. In 2010, rainbow trout (steelhead) became a very important component of the fishery in much of Lake Huron. Since the loss of alewife, there has been much less baitfish in the mid waters for the salmon and trout to eat but the fish are beginning to adapt. Research has shown that the successful rainbow trout has learned to feed on the surface for terrestrial insects, in the mid waters for smelt and on the bottom for goby. Lake trout, which is also becoming a very important part of the catch, developed similar feeding habits by swimming back and forth from the bottom to the surface searching for food. The walleye fishery in Saginaw Bay has recovered and fishing is excellent not only in the Bay but at many ports to the north and south including Thunder Bay which has developed into a high-quality reliable spring and summer fishery. Chinook salmon continue to be important in the catch in the north from Alpena to the Straits and along with rainbow trout, lake trout, walleye, Coho salmon, brown trout, catfish and Atlantic salmon they make up an excellent diverse fishery throughout the Lake. During last season when all the catch rates from the fish mentioned above are considered together, the fishing in 2010 was comparable to the best years at several locations.
Why did the Alewife Crash and Food Web Change Dramatically in 2003?
The food web starts with energy from the sun, which is absorbed by tiny one-cell plants known as algae or phytoplankton. Very small animals about 1/100 to ½ inch in length that are known as zooplankton eat the algae and become food for small fish like smelt and goby which are eaten by larger fish like trout and salmon. Generally, lakes with more algae produce more food for fish. When the zebra and quagga mussels were introduced during the 1990s, they eventually spread to the deep waters of Lake Huron where they efficiently filtered the mid waters and consumed much of the algae. As a result, the zooplankton numbers decreased dramatically causing the alewife and smelt todecline to record low levels because of lack of food. Since the mussels trapped the food as they filtered the water, the area around the mussels on the bottom became rich with nutrients and bottom dwelling fish like goby survived very well. After the food web changed, there was much less food in the mid waters but there was still a concentration of food on the surface as terrestrial insects and an increase in food on the bottom. Lake Huron is beginning to produce more baitfish with a large number of bottom feeding goby, resurgence of emerald shiners and smelt consistently producing good year classes.
Editor's note: Overall, fishing has improved significantly, especially in the area of Lake Huron near Rogers City. Thanks to Frank Krist and the Great Lakes Fisheries for the above information.
