I. What is a Fishery? II. What is Fisheries Management? III. What is Fisheries Science? I. Brief history of the evolution of fisheries science.

I. What is a Fishery? II. What is Fisheries Management? III. What is Fisheries Science? I. Brief history of the evolution of fisheries science.

Archeological records Spears: 90,000 BP Nets: 40,000 BP Fish hooks: 35,000 BP Earliest communities dependent on fishing Lake Mungo (Australia) 30,000 BP Crete 8,000 BP Fishing as recreation? Egyptian aristocracy 4,000 BP Culture of fishes 2,000-3,000 BP

Harvest likely had little effect on populations Technology Spatial extent Increasing effects on fish populations Vessels Fishing gear Preservation techniques (drying, smoking, salting) Canning (long-term storage and longdistance distribution)

I believe then that the cod fishery, the herring fishery, pilchard fishery, the mackerel fishery, and probably all the great sea fisheries are inexhaustible: that is to say that nothing we do seriously affects the numbers of fish. And any attempt to regulate these fisheries seems consequently from the nature of the case to be useless. T.H. Huxley, London Fisheries Exhibition (1883)

The first principle of conservation is development, the use of the natural resources now for existing on this continent for the benefit of the people who live here now. There may be just as much waste in neglecting the development and use of certain natural resources as there is in their destruction. Gifford Pinchot (1910)

Individuals acting independently and in their own selfinterest ultimately deplete a shared, limited resource even with it is clear that it is not in anyone s long-term interest to do so

Declines and extirpations Marine fisheries Arctic cod and haddock Newfoundland fisheries Yellowfin tuna Anchovy Anadromous and freshwater fisheries Pacific salmonids American shad Lake sturgeon

Underlying premise is that every fish population had the potential to produce a harvestable surplus and the largest surplus that could be annually harvested from that population (i.e., MSY) could be estimated by rigorous scientific analysis (i.e., stock assessment) The highest theoretical equilibrium yield that can be continuously taken from a stock under existing environmental conditions without significantly affecting the population. =

Estimating MSY: Surplus production models Single-cohort models Age-structured models Virtual population analysis Cohort analysis Yield-per-recruit models Stock-recruitment models

Percentage of fisheries where fishing effort exceeds f MSY FAO 2004

Yield Recruits MSY Yield f MSY Fishing effort??? Spawners

General problems Assumptions are problematic (constant environmental conditions) Many models are too simplistic (fail to incorporate age- or size-specific rate functions) Lack of reliable data Lack of enforcement! Socioeconomic issues Ignores economics Stakeholder involvement and buy-in Biological-ecological perspective Single-species focus! Overfishing of target and non-target fishes

MSY 1930s-1970s Here lies the concept, MSY. It advocated yields too high, And didn t spell out how to slice the pie. We bury it with the best of wishes, Especially on behalf of fishes. We don t know yet what will take its place, But hope it s good for the human race R.I.P. Peter Larkin (Keynote Address, 1976 Annual Meeting of the AFS)

A new era of fisheries science Many ideas associated with OSY (or problems with MSY) were formalized in a 1975 symposium (Roedel 1975) OSY recognizes: Broad range of considerations, not just maximizing physical yield Unique management goals exist for each fishery What s optimum?

Magnuson-Stevens Act conservation and management measures: prevent overfishing while achieving optimum yield from each fishery; be based on the best available scientific information; not discriminate among residents of different states; consider efficiency in the utilization of fishery resources, although economic allocation cannot be the sole purpose; take into account variations among fisheries, fishing resources and catches; minimize costs and avoid unnecessary duplication; take into account the importance of fishery resources to fishing communities in order to provide for sustained participation of such communities and, to the extent practicable, minimize adverse economic impacts on such communities; minimize bycatch and, where bycatch cannot be avoided, minimize the mortality of such bycatch; promote the safety of human life at sea to the extent practicable. The Secretary is to establish advisory guidelines, based on the national standards, to assist in the development of fishery management plans. 1851.

Mission statement: To protect and manage the forest, fish, and wildlife resources of the state and to facilitat and provide opportunity for all citizens to use, enjoy and learn about these resources

There is no equation or set value for OSY Examples: Maximum Economic Yield (MEY) Trophy fish management

Revenue and cost MSY MEY Cost Revenue f MEY f MSY Fishing effort Fisheries that are unlimited are unprofitable. Michael Graham, The Fish Gate (1943)

Yield MSY OSY 1 Yield OSY 2 f OSY2 f OSY1 f MSY Fishing effort

Ideas associated with OSY have blossomed

I. Direct effects of harvest activities I. Direct effects on target species II. I. Population size II. III. III. Demographic structure Genetic diversity Direct effects on nontarget species Direct physical disturbance and habitat destruction II. Indirect effects of harvest activities I. Effects mediated by biological interactions: predation and competition II. Effects on the structure of assemblages and communities III. Effects on energy and nutrient dynamics I. Discards and offals II. Changes in food web structure

Fisheries target the largest fish In a population In an ecosystem Fishing down the food web hypothesis Pauly et al. (1998) Hypothesized that the selective behavior of fishery would cause a reduction in mean trophic level

Marine Inland

Pauly et al. 2002

Recognition that fishing has consequences on the entire ecosystem Target species Incidentally harvested organisms Physical disturbance and habitat destruction Biotic interactions Energy and nutrient dynamics

U.S. Commission of Fish and Fisheries (1871) Spencer Baird was the first Commissioner Ecological studies as one of his first priorities According to Baird, our understanding of fish would not be complete without a thorough knowledge of their associates in the sea, especially of such as prey upon them or constitute their food

E-BM: emphasizes the protection of ecosystem structure, functioning, and key processes; is place-based in focusing on a specific ecosystem and the range of activities affecting it; explicitly accounts for the interconnectedness among systems, such as between air, land, and sea; and integrates ecological, social, economic, and institutional perspectives, recognizing their strong interdependences. Elements: Sustainability Goals Sound ecological models and understanding Complexity and connectedness The dynamic character of ecosystems Context and scale Humans as ecosystem components Adaptability and accountability - Christensen et al. 1996 EcoApps 6:665-691

Multispecies MSY Multispecies VPA Food web modeling e.g., Ecosim Indicators e.g., Mean trophic level