Salmon River Corridor
On the Salmon River this week I, Salmon River Steward Liz Wolff, assisted with a salmon stocking. Learning the proper techniques for releasing the fish was fascinating. Rather than setting them free in an area with slow moving water, it's best to release them in a location where the water is moving more rapidly, thus containing more oxygen. The water temperature is also crucial. Placing the fish into water that measures more than a couple degrees colder or warmer than they are used to may be a shock to their systems. One of the most interesting things I learned was how important it is to disinfect waders and other equipment after being in the water. Cleaning off the gear helps prevent the spread of non-native organisms from one body of water to another which could potentially harm living things within the system.
River Steward Liz Wolff filling bucket with water during Salmon stocking. Photo by Ross.
Salmon River Steward Greg Chapman points out another potentially harmful entity that can be found both in Lake Ontario and the Salmon River. As we start seeing more Salmon being caught on the Salmon River, one thing to look for is the presence of sea lampreys, or the scars that these parasitic fish leave behind. Sea lampreys are native to the Atlantic Ocean, and are an undesirable addition to Lake Ontario. They were likely introduced to the lake when the Erie Canal was completed in the early 19th century, and have since spread throughout the Great Lakes.
Lamprey washed ashore at Deer Creek Marsh Wildlife Management Area. Photo by River Steward Greg Chapman.
Sea lampreys are parasites that feed upon many species of fish, including sport fish like salmon and trout. They feed by attaching themselves to fish and sucking out fluids. Salmon and trout are sometimes caught with lampreys attached in the Salmon River; however, often the only evidence of a lamprey's past attachment is the presence of a round scar or wound, about 1 to 2 inches in diameter.
Close-up of lamprey teeth. Photo by River Steward Greg Chapman.
Although lampreys continue to be a nuisance, their numbers are greatly reduced from what they were in the past. When Pacific salmon first began returning to the Salmon River Fish Hatchery following initial stocking efforts in the late 1960s, the fish averaged 14 lamprey scars apiece. Since then, several strategies have been employed to bring lamprey numbers under control, including the application of a chemical lampricide called TFM(3-trifluoromethyl-4-nitrophenol)to streams. TFM is more dense than water, and applied to tributaries of the Great Lakes and other nursery habitats of lampreys. The chemical is able to effectively reach and kill them before the young lamprey mature and migrate to the lake, where they begin feeding as adults. Today, lamprey numbers are much lower than in the past, and sport fish populations are healthier as a result.
Healthy fish populations are part of what makes the Salmon River a great place for anglers, especially during the fall. So take a trip to the river and fish for yourself or come just to see what all the excitement is about. The stewards are happy to listen to your questions and point you in the right direction!