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This chapter discusses the ecology of northern pike including variability, habitat, reproduction, feeding, and other behaviors. The pike’s relatively low genetic variability compared to other fish stems from low effective population sizes and population bottlenecks, which can be traced back to earlier glacial periods when the geographic range of pike was limited. Northern pike can tolerate a broad range of environmental conditions but thrive in moderately productive mesotrophic to eutrophic freshwater lakes and rivers. With regard to gender and reproduction, the sex of northern pike can be identified accurately via the external appearance of their urogenital areas, where eggs and milt are expelled.

This chapter outlines the history and development of northern pike conservation and management in Minnesota. Concerns about the small sizes of pike in many lakes with large pike populations first emerged in the 1980s. The Minnesota Department of Natural Resources (MMDNR) responded by implementing expanded bag limits, in an attempt to reduce numbers of pike by allowing people to keep more small pike from high-density, slow-growing populations. Unfortunately, creel surveys showed that anglers did not use the expanded bag limits even after they claimed they would. The MMDNR eventually approved the creation of fish hatches to serve as an alternative to natural reproduction.

This chapter describes the sampling tools used by researchers to study the northern pike populations of Minnesota. Experimental gill netting and trap netting have been the two principal techniques for sampling fish populations. The experimental gill nets and trap nets are designed to catch different sizes of fish in order to compare pike populations and to study population trends. However, both these methods have the unfortunate effect of killing fish. The chapter then examines modern methods of sampling such as tagging and radio and ultrasonic telemetry. Researchers mark fish with unique identifiers to examine northern pike migrations between water bodies and for mark-recapture experiments designed to estimate population numbers and exploitation rates. Researchers use radio and ultrasonic telemetry to monitor movements, activity patterns, and habitat use of northern pikes.

This concluding chapter raises three questions concerning the future of northern pike management in Minnesota: (1) How will the state partition the use of pike resources among all the groups interested in pike fishing? (2) To what extent will human population growth and land development alter shorelines and watersheds surrounding public waters? (3) Will the sports of recreational fishing and spearing retain their historical prominence in Minnesota culture? It argues that Minnesota is blessed with a huge northern pike resource; pike populations are plentiful in lakes, streams, and rivers throughout the state. They are plentiful enough that pike management today is a matter of trying to provide adequate fishing opportunities for the different fishing groups.

This chapter examines the effects of fishing on northern pike populations. In lakes where pike have good access to spawning and nursery habitat, overfishing generally leads to higher densities of small pike because long-term exploitation can result in compensatory recruitment, where fishing actually stimulates the addition of new small pike to the population. An 11-year study at Heming Lake, Manitoba, showed that although pike populations increased with growing fishing pressure, the average size of pike declined. Another study found that the age when pikes matured corresponded with their mortality rates. Increasing levels of fishing intensity seemed to induce higher total mortality rates and earlier ages at first reproduction.