Sustainable exploitation of Ontario's aquatic resources calls for a new management approach. This vast resource includes more than 250,000 lakes and offers angling opportunities for many popular species (e.g., walleye Sander vitreus (formerly Stizostedion vitreum), lake trout Salvelinus namaycush, brook trout S. fontinalis, northern pike Esox lucius, smallmouth bass Micropterus dolomieu, largemouth bass M. salmoides, and muskellunge E. masquinongy). In pioneer days, the “apparently inexhaustible abundance of resources” fostered an open‐access policy promoting the recreational use of these resources for the benefit of the economy. After World War II, there was a rapid increase in angling effort and by the 1970s many lakes were being overexploited. Clearly, an unrestricted, open‐access policy was no longer appropriate. The result has been a rapid proliferation of fishing regulations as exceptions to divisionwide regulations that were created to protect lakes where problems were detected. The growing complexity of these regulations is the result of a management approach that has focused on individual lakes. This complexity is not popular with the angling public, and evaluation of its benefits has proven difficult because a change in regulations on one lake may affect fishing effort on other lakes. We argue that a larger spatial and temporal scale of management is needed when a resource is widely dispersed across a large population of lakes. This new approach should incorporate (1) consensus on biologically achievable objectives, (2) periodic, unbiased assessment of the state of the resource, (3) periodic evaluation to decide whether current management practices are meeting objectives, and (4) adaptive management in choosing among alternative management actions. Recent progress towards establishing this management approach in Ontario is discussed.

1. Bythotrephes cederstroemi (Crustacea: Onychopoda: Cercopagidae) invaded Harp Lake, Ontario in 1993, since when the zooplankton community has shifted from dominance of small‐bodied to large‐bodied species. During 1995 diets of adult lake herring (Coregonus artedii), Harp Lake’s primary planktivorous fish, were examined to determine the extent to which this conspicuous zooplankter has become integrated into the lake’s foodweb and whether fish condition has been affected in consequence. 2. Bythotrephes and Daphnia galeata mendotae were strongly preferred prey, whilst Holopedium gibberum and calanoid and cyclopoid copepods were negatively selected by lake herring. Predation on Bythotrephes and Holopedium was not size‐selective, although D. galeata mendotae and calanoid copepods (Leptodiaptomus minutus and L. sicilis) consumed by herring were significantly larger than co‐occurring conspecifics in the lake. 3. Caudal spines of Bythotrephes may form boluses in lake herring stomachs. However, the number of caudal spines in fish digestive tracts did not differ significantly from the number of Bythotrephes’ mandible pairs, indicating that the former were not differentially retained. 4. Lake herring weight‐at‐length relationships in lakes in Muskoka, Ontario, invaded by Bythotrephes did not differ from those in adjacent non‐invaded lakes, indicating that Bythotrephes invasion of lakes apparently has not affected condition of lake herring.

Angler diary programmes (n=46, 1979–1997) implemented in Ontario by the Ontario Ministry of Natural Resources are reviewed, and the different uses of angler diary programmes, levels of participation and differences in programme design are reported. In Ontario, angler diary use is common, but successful application is limited. This review revealed a variety of uses and approaches for administering angler diary programmes. Problems arise when programmes are initiated without the complete commitment of the administrators and agency, or when there is no regular review so adaptive changes can be made. If administrators realize the potential biases and problems associated with diaries, and design programmes to control them, angler diaries can provide favorable cost‐effective results. With reduced funding and staffing constraints, angler diary programmes could become the primary method of data collection for specialized and remote fisheries.

The large predaceous European zooplankter Bythotrephes cederstroemi is now present in eight large recreational lakes in south-central Ontario, Canada: Lake Muskoka, Lake Joseph, Lake Rosseau, Fairy Lake, Mary Lake, Peninsula Lake, Lake Vernon, and Go Home Lake. These observations represent the first evidence that B. cederstroemi has invaded inland lakes in Canada, and we suggest that close monitoring is now needed to establish whether or not pelagic food webs of the lakes will respond.

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