Fisheries management often is an enigma wrapped inside a riddle, and the more we learn, the more we realize how much we don’t know. That’s why I respect fisheries biologists.
To provide us with quality fisheries, they must “manage” not only the fish, but the fishermen. Plus, they must factor in the effects of development, pollution, water degradation, introduction of exotic species, and many other variables.
Up in Minnesota, anglers and biologists have compiled some impressive statistics regarding the fragility of a fishery.
On a 160-acre private lake this winter, 97 northern pike have been caught and released 431 times. Additionally, 24 measured 30 inches or longer and had been caught an average of 6.83 times each.
“Now think about how long it takes a fish to grow,” said Dallas Hudson, one of the anglers who initiated the idea of not spearing or keeping northern pike caught on hook and line. “A northern in our lake will take six years to reach 24 inches and nine years to reach 30 inches and weigh 7 or 8 pounds.
“So it becomes pretty obvious what happens if people keep not only the bigger fish, but the medium-sized fish, say 24 to 30-inch northern. You end up with what we have in many Minnesota lakes: stunted fish.”
Fisheries supervisor Doug Kingsley added, “Dallas’ work shows us pretty clearly how vulnerable northerns, in particular, are to being caught. When you can catch the same fish 15 times over, and sometimes two times in the same day, it seems clear that in many lakes we need to limit the harvest of larger fish if we want bigger northern pike in our lakes.’’
For example, the work by Hudson and his associates clearly suggests that--- at least on smaller lakes--- larger northern pike can be overharvested. Still, many Minnesota anglers likely would oppose reducing the current harvest regulation, which allows three northern daily, with one longer than 30 inches. Plus, spear fishermen convinced the legislature to pass a law in 2011 that limits the establishment of length-based harvest regulations on 100 state lakes.
Out in Arizona, fisheries managers are trying to figure out how to reign in an exploding population on non-native gizzard shad that threatens the health of bass and crappie fisheries at Apache and other Salt River impoundments.
In Lake Havasu, however, the combination of two introduced species seems to have ignited a premiere fishery for redear sunfish, also known as “shellcracker.” Just recently, Hector Brito caught a 5.8-pound lunker, which likely will be declared a world record. In 2011, Bob Lawler caught the previous record --- 5.55 pounds--- also at Lake Havasu.
In the Northwest, meanwhile, champions of native species have been blaming bass for decades for the decline of salmon fisheries. In truth, dams destroyed salmon habitat and blocked habitat, while creating impoundments where bass have thrived.
Still, nature is resilient. That’s why this year’s projected spawning run of fall-run Chinook (king) salmon on the Columbia could be the largest since 1938. That was the year after the Bonneville Dam was completed, blocking their migration route and enabling the fish to be counted.
Fisheries managers suspect that the healthy run is attributable to good ocean conditions for the salmon while they are out at sea, as well as a mandated water releases from spill gates at dams on the Columbia and Snake River dams, allowing small salmon to move downstream.