Fisheries and water management

Objective: Explain fish stock and recruitment, distinguish their meanings, and apply them to a described case.

Fish stock: A fish stock is a population or management unit assessed for a fishery. Recruitment: Recruitment adds individuals to a population stage or fishery category under a stated definition. Fishery outcomes depend on reproduction, recruitment, habitat, harvest, and environmental variation. A stock estimate is uncertain and should be updated rather than treated as an exact permanent count. Bycatch can affect species outside the target population. Water management must consider seasonal timing as well as annual totals. Adaptive management uses explicit goals, monitoring, and revision; it is more than changing a policy arbitrarily after an unfavorable result. Application: Managers estimate abundance for a defined harvested population. This most directly illustrates fish stock. Young fish enter the age group counted by an assessment. This most directly illustrates recruitment.

Objective: Explain bycatch and sustainable harvest, distinguish their meanings, and apply them to a described case.

Bycatch: Bycatch is incidental capture of organisms other than the intended target. Sustainable harvest: A sustainable harvest seeks to maintain populations and ecosystem functions under changing conditions. Fishery outcomes depend on reproduction, recruitment, habitat, harvest, and environmental variation. A stock estimate is uncertain and should be updated rather than treated as an exact permanent count. Bycatch can affect species outside the target population. Water management must consider seasonal timing as well as annual totals. Adaptive management uses explicit goals, monitoring, and revision; it is more than changing a policy arbitrarily after an unfavorable result. Application: Fishing gear captures unwanted species along with target fish. This most directly illustrates bycatch. A catch limit is revised when abundance declines. This most directly illustrates sustainable harvest.

Objective: Explain environmental flow and adaptive management, distinguish their meanings, and apply them to a described case.

Environmental flow: Environmental flow describes water quantity, timing, and quality needed to support ecosystems and associated uses. Adaptive management: Adaptive management uses monitoring to revise actions as evidence and conditions change. Fishery outcomes depend on reproduction, recruitment, habitat, harvest, and environmental variation. A stock estimate is uncertain and should be updated rather than treated as an exact permanent count. Bycatch can affect species outside the target population. Water management must consider seasonal timing as well as annual totals. Adaptive management uses explicit goals, monitoring, and revision; it is more than changing a policy arbitrarily after an unfavorable result. Application: A river plan preserves seasonal flows for aquatic habitat. This most directly illustrates environmental flow. Managers alter a practice after measured outcomes differ from expectations. This most directly illustrates adaptive management.