query: Do eddie's only occur in fresh water?
passage: Upwelling
The major upwellings in the ocean are associated with the divergence of currents that bring deeper, colder, nutrient rich waters to the surface. There are at least five types of upwelling: coastal upwelling, large-scale wind-driven upwelling in the ocean interior, upwelling associated with eddies, topographically-associated upwelling, and broad-diffusive upwelling in the ocean interior.
passage: Lake Erie
Lake Erie is home to one of the world's largest freshwater commercial fisheries. Lake Erie's fish populations are the most abundant of the Great Lakes, partially because of the lake's relatively mild temperatures and plentiful supply of plankton, which is the basic building block of the food chain. The lake's fish population accounts for an estimated 50% of all fish inhabiting the Great Lakes. The lake is "loaded with superstars" such as steelhead, walleye (American usage) or pickerel (Canadian usage), smallmouth bass, perch, as well as bass, trout, salmon, whitefesh, smelt, and many others. The lake consists of a long list of well established introduced species. Common non-indigenous fish species include the rainbow smelt, alewife, white perch and common carp. Non-native sport fish such as rainbow trout and brown trout are stocked specifically for anglers to catch. Attempts failed to stock coho salmon and its numbers are once again dwindling. Commercial landings are dominated by yellow perch and walleye, with substantial quantities of rainbow smelt and white bass also taken. Anglers target walleye and yellow perch, with some effort directed at rainbow trout. A variety of other species are taken in smaller quantities by both commercial and sport fleets.