1. Fishery Biology

2. Fisheries Management n Provide people with a sustained, high, and ever-increasing benefit from their use of aquatic resources n Problems - late-1800s - industrial revolution – Improved access to fish – Improved effectiveness of fishing equipment – Improved processing and distribution of fish

3. Problems resulted in: n Overexploitation (overfishing) in many areas – Catch exceeded maximum sustainable yield n Environmental degradation n Populations exhibit decline n Some commercial species driven to or near extinction

4. Dealing with the problem n Fish culture n Fish rescue n Fishing regulations n A progressive movement

5. Fish populations served: n Primary purpose - provide food n Secondary purpose - provide economic value – “crops” to be planted, managed, harvested Maximum sustainable yield (MSY) - efficiency

6. Fish population abundance changes: n Additions – Growth – Recruitment – immigration n Losses – Natural mortality – Fishing mortality – emigration

7. Population Dynamics n Led to conclusion that greatest long-term yield of fish achieved by allowing small fish to grow before harvesting them n But no scientific proof!

8. Ecology and Fisheries n Ecology as a science provided hypotheses, principles, and fisheries provided natural laboratories for testing them

9. Early Focus of Fisheries Science n Describe, survey fish, etc., in important waters n Determine physicochemical characteristics n Gather fish life history, ecology information

10. New Data n Confirmed that habitat destruction, overfishing had negative impacts on fish populations n Led to growth of fisheries management, development of most techniques still used today

11. Recreational Fishing Growth n Demands for regulations on competing commercial harvests n Eliminate markets for commercially caught freshwater predatory fish

12. Regulation of Recreational Fishing n First highly restrictive, uniformly implemented – Closed seasons, minimum size, equipment restrictions, creel limits (daily catch) n Next changed to uniformly liberal regulations n Now back to stricter regulations

13. Primary Funding for Inland Fishery Management in U.S. n Federal Aid in Sport Fish Restoration Act (1950) – Dingell-Johnson (D-J) Act – 10% excise tax on specified fishing equipment

14. Primary Funding for Inland Fishery Management in U.S. n Wallop-Breaux Act (1985) n Expanded range of items taxed (e.g., boat fuel) n Extended funding to marine recreational fisheries n Doubled previous level of funding ($332 million in 1992)

15. Different Fish Problems in Different U.S. Regions n Pacific NW - Pacific salmon - reduced runs – Reduced future generations

16. Different Fish Problems in Different U.S. Regions n SE - raising fish in farm ponds – Predator, prey balance for best fishing

17. Different Fish Problems in Different U.S. Regions n Midwest, Mideast - techniques for removal, control of unwanted fishes – Commercial netting – Chemical fish poisons

18. Fish Stocking Changes n Initially widespread, promiscuous introductions of fish eggs, larvae n Now more selective stocking, where growth and survival are probable – Raised in hatcheries to larger size for better survival – “put-and-take” stocking of catchable-size fish

19. Habitat Modifications n Habitat-related limits to fish size, abundance n Improve habitat to remove limits n Add artificial structures to lakes, streams n Build artificial lakes – Farm ponds – Reservoirs

20. MSY focus changing during last half-century n More than simply maximizing physical yield n Additional concerns – Economic - e.g., aesthetic values – Sociological - e.g., limited access to fishery – Ecological - e.g., multi-species management

21. Optimum Sustainable Yield n Includes broad range of concerns n Unique management goal for each fishery n More realistic – Recognizes existence of ecosystem, human need diversities n Greatly complicates management

22. Important additional roles of fisheries management n Habitat management – Instream flow studies – Watershed land use - mitigation – Habitat rehabilitation - streams, wetlands

23. Important additional roles of fisheries management n Organism management – Single-species vs. multi-species management – Endangered, rare species management – Management of non-harvested species n Prey n Competitors – Aquaculture

24. Important additional roles of fisheries management n People management – Methods for assessing user demands, values