Marine Fisheries Enhancement: Coming of Age in the New Millennium

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1 Marine Fisheries Enhancement: Coming of Age in the New Millennium Ken Leber (inspired by Lee Blankenship, Rich Lincoln, Carl Walters, Ray Hilborn, Kai Lorenzen, Johann Bell, Neil Loneragan, Katsumi Tsukamoto, Terje Svasand, Stan Moberly, and the scientists who have fostered and advanced the modern science of fisheries enhancement)

2 Will the Oceans Help Feed Humanity? (Duarte et al., 2009) Human population size late yesterday was ~ 7,073,208,500 million; since then it has increased by ~ 99,750 more people (~150/min). ( By 2050, the human population is projected to reach > 9.2 billion, which is within estimates of the maximum carrying capacity of the planet A fundamental question for science is whether it is possible to increase food production enough to feed a human population of that magnitude Will fisheries be sustainable as human population pressures and accompanying coastal development pressures continue

3 Fishery Management Toolbox Harvest Management: We can control fishing catch & effort seasonal closures, size and catch limitations, area closures, incentives (catch shares), number of angler licenses (limited entry), spatial planning Habitat Management: We can identify, protect and restore essential habitat EFH, MPAs, spatial planning, habitat preservation and restoration, artificial habitats Marine Fisheries Enhancement: But can fishery managers also boost fish population abundance by stocking hatcheryreared fish to increase the number of young fish (new recruits) in the population? in certain situations...

4 Coupling Fisheries Management and Aquaculture Culture-Based Fisheries Types: ` Stock Enhancement: release of cultured organisms into wild populations to overcoming limitations in juvenile recruitment Restocking: release of cultured organisms to help restore depleted spawning biomass Sea Ranching: recurring release of cultured juveniles into the ocean for harvest at a larger size (put-grow-take) Lake Ranching: Stocking cultured catadromous fishes into lakes to create additional fisheries (e.g. considered for Israel s Lake Galilee)

5 Coupling Fisheries Management and Aquaculture: Definitions (Cont.) Culture-Based Fisheries Types: Stock Enhancement Restocking Sea Ranching Supplementation: moderate releases of cultured fish into very small and declining populations to reduce extinction risk and conserve genetic diversity Reintroduction: temporary releases to reestablish a locally extinct population (Lorenzen et al, Reviews in Fisheries Science, 18(2): )

6 Scientific Development of Marine Fisheries Enhancement : Technological and Tactical Constraints: Marine fish aquaculture undeveloped until 1980s No way to identify small fishes until 1963 Potential of stock enhancement and conservation hatcheries retarded by the absence of fisheries science in their conduct

7 Scientific Development of Marine Fisheries Enhancement Scientific and Strategic Development: Since 1989, progress has occurred at two levels: Scientific Advances identify fishery contribution / evaluate survival / improve release strategies Strategic Advances - Adoption of a careful and responsible approach

8 Scientific Development of Marine Fisheries Enhancement Early Constraints to Successful Enhancement Aquaculture constraints Assessment constraints Pioneering Work to Quantify Stocking Effects Tsukamoto; Kitada; Tanaka; Yamashita; colleagues in Japan Svåsand, Jørstad, Kristiansen and colleagues in Norway Polovina; Stoner; Willis; Kent; Leber; Blankenship; Smith; et.al. in US Lorenzen; Cowx; Bannister and colleagues in the UK Støttrup and colleagues in Denmark Bell in Solomon Islands Rimmer, Russell and colleagues in Australia 1880 s 1980 s 1990 s Recent Approach Improved Experimental Design Comprehensive Assessment Efforts 2000 s

9 Strategic Development of Marine Fisheries Enhancement By early 1990 s, reforms in salmon enhancement; marine folks start special sessions on marine stock enhancement at WAS & EAS annual conferences Focused on effects and effectiveness of stocking, not aquaculture 1993, International Working Group on Stock Enhancement ( IWGSE ) formed in 1993 in Spain Platform Paper: Responsible Approach at 1994 AFS Symposium IWGSE fostered awareness of RA in their publications, presentations 1997, International Symposium on Stock Enhancement and Sea Ranching ( ISSESR ) PUSH, IMR, with IWGSE scientists; Every 4-5 yrs; Norway- 1997, Japan-2002, US-2006, China-2011, (Australia )

10 A Responsible Approach to Marine Stock Enhancement * (Spawned by Lee Blankenship, Devin Bartley, Don Kent, Ken Leber, Stan Moberly, Terje Svåsand, Katsumi Tsukamoto [and Rich Lincoln]) Stay Within Context of Fisheries Management Plan: 1. Prioritize Species for Enhancement 2. Make Stocking Plan that Fits with and Helps Achieve the Goals of the Fishery Management Plan and Identify the Expectations Develop Sound Enhancement Strategy: 3. Define Quantitative Measures of Success 4. Use Genetic Resource Mgmt. to Prevent Deleterious Effects 5. Use Disease and Health Management 6. Consider Ecological, Biological, & Life-History Patterns 7. Identify Hatchery Fish & Assess Stocking Effects 8. Use an Empirical Process to Define Optimal Release Strategies 9. Identify Economic & Policy Guidelines 10. Use Adaptive Management (* Blankenship & Leber, Am. Fish. Soc. Symposium 15:67-175) PDF is online at

11 Fishery Science Perspective - Where Hatcheries Can Go Wrong 1. Replacement of wild with hatchery recruits, with no net increase in total stock 2. Unregulated fishing effort responses to presence of hatchery fish can cause overfishing of wild stock 3. Overexploitation of forage resource base for the stocked species 4. Genetic impacts on the long-term viability of the wild stock Stress that it is critical to monitor the impacts of enhancement as the program develops to have evidence in hand if debate about effectiveness surfaces (Carl Walters & Steve Martell, 2004) See also their Code of Responsible Conduct for Enhancements

12 Code of responsible conduct for marine stock enhancement* Make certain that management priorities and acceptable trade-offs are absolutely clear Do careful stock assessments to show that the target stock is recruitment overfished or can no longer rear successfully in the wild Show that enhanced fish can recruit successfully in the wild Show that total abundance is at least initially increased by the hatchery fish contribution Show that fishery regulations are adequate to prevent continued overfishing of the wild population, unless there has been an explicit decision to write off the wild population Show that the hatchery production system is actually sustainable over the long run, when it is to be a permanent component of the production system (*Walters & Martell, 2004)

13 Responsible Approach updated (Lorenzen, Leber, and Blankenship Rev. Fish. Sci. 18(2): )

14 Most Enhancements are Weak in 5 Areas Lack of a clear fishery-management perspective Fishery stock assessments & modeling are integral to exploring the potential of stocking, yet both are found lacking in most stock enhancement efforts Establishing an institutional framework for enhancements is largely ignored Involvement of stakeholders in planning and execution of stocking programs is key from the start, but is rarely an integral part Adaptive management is not well integrated into enhancement plans (Lorenzen, Leber, and Blankenship Rev. Fish. Sci. 18(2): )

15 Key areas of expertise needed in marine fisheries enhancement Fisheries science Fisheries management Population ecology Adaptive management Population genetics Marine aquaculture Aquatic animal health Behavioral ecology Resource economics Community ecology Social science, institutional analysis & design Statistics and experimental design Tagging technology Communications and outreach

16 Monitoring is Essential

17 Monitoring Requirements Essential to manage enhancement, understand impacts Mark all (or high and known %) of the fish released from hatcheries Mark as many wild juveniles as possible at same sizes/locations as hatchery fish are being released Experimentally vary hatchery releases over wide range - year to year, area to area, on/off alternation (temporal blocking envir. vs ecol.) Monitor changes in recruitment, production, fishing effort; not just % contribution of hatchery fish to fishery production Monitor changes in fishing mortality of tagged hatchery & wild fish Monitor reproductive success of hatchery and hatchery-wild hybrids ( Carl Walters & Steve Martell, 2004 )

18 Legacy from the Past Allure of a Quick Fix If not implemented responsibly, enhancements may lull fishery managers into false confidence Isolation from the Fisheries Science Community Often run with no connection to existing fishery management process, with hatcheries isolated and operating independent from stock assessment and fisheries monitoring programs This isolation, coupled with poor track record of early hatcheries, has led to bias against fishery enhancements Thus, imperative that existing & developing programs incorporate modern concepts about planning/conducting enhancements ( Leber, K.M Marine Fisheries Enhancement: Coming of Age in the New Millennium)

19 Enabling Factors for Expanding Successful Marine Enhancements Greater awareness among all stakeholders of the issues, pitfalls, progress and opportunities Use of Adaptive management is critical for managing enhancement programs for success Adapt the Responsible Approach to local circumstances Seek Assistance from established expertise in this field and the key associated fields (In: Leber, K.M., in press)

20 StockEnhancement.org/science/publications.html 65 Fisheries Enhancement Publications

21 Key Issues to Consider Is Enhancement needed? Which form of enhancement (restocking, stock enhancement or sea ranching)? Have stock assessments been done to evaluate current status of the reef fishes and other species targeted for enhancement? This would greatly increase the capability of models to predict enhancement yields. Adaptive management is critical for managing enhancement impacts for success is tagging and monitoring of stocking impact well integrated into enhancement management plan? Is help needed to adapt the Responsible Approach to local circumstances

22 Adaptive Management is Crucial Recognized Production - Enhancement Management Dichotomy Management Plan Production Adaptive Stocking Impact Assessment P.Eff. Loop Release Strategy E.Eff. Loop Increased Control (Leber, Advances in Marine SE: Shifting Emphasis to Theory & Accountability. In Stickney & McVey )

23 Issues to Prompt Discussions 1. Methods for quantifying sociological impact of stock enhancement 2. Where are the success stories with marine fishes 3. Is there a truly urgent need for US technologies to increase seafood production? 4. Why, then, all the concern about minutia in enhancement? 5. Why isn t there more assessment of success in existing marine stock enhancement programs? 6. Genetically modified organisms? 7. How would you go about enhancing a wild stock? (given the precautionary approach needed).