Management

Fish management branches take periodic creel census and fish samples to determine such things as rate of growth, lake populations, aging, state of health, diet, and fish movements. As well, water quality sampling is done to maintain constant checks of oxygen levels, the pH level, and pollutant factors. When biologists determine that fishing pressure is responsible for stock depletion, they shorten fishing seasons and reduce daily quotas. If stocking is required, large healthy fish are caught to be used as parents of the planted stock.

But there is one threat to the lake trout that management people haven't found a reliable solution for —the deadly lamprey. Mature lake trout inhabiting inland lakes have very few predators. Even in those lakes where lake trout coexist with northern pike as the dominant species, their predation is limited. Since the opening of the Welland Canal, however, the lake trout has practically disappeared in parts of the Great Lakes. The lamprey, originally from the ocean, moved steadily inland via the new waterway and began to decimate the populations with their parasitic nature. Lamprey attach themselves to their prey and feed on their flesh and blood. Only the odd lake trout can escape the lamprey's grasp but the majority eventually die with the lamprey still in place. Although lamprey control measures have come too late to save the Great Lakes trout from nearly total annihilation, their plight has prompted further investigations which revealed declining fish populations in many of our popular inland lakes.

Click to Listen!