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Technical University of Denmark Danish Institute for Fisheries Research Danish marine stocking experiments applying the Responsible Approach Technical University of Denmark Danish Institute for Fisheries Research The Responsible approach Prioritise and select target species for enhancement • Community survey • Local experts In Denmark, fishermen (commercial and recreational) make suggestions for specific species in specific areas. OR, aquaculture enterprise make suggestions for releases Expert group then looks at the potential for restocking or stock enhancement of the specific species in the specific area Source: Blankenship & Leber, 1995 Technical University of Denmark Danish Institute for Fisheries Research The Responsible approach Develop a species management plan that identifies harvest opportunity, stock rebuilding goals and genetic objectives • Goals and objectives for restocking or stock enhancement • Clearly identified genetic structure and geographic distribution of the stock • Production and management objectives need to be outlined Source: Blankenship & Leber, 1995 Technical University of Denmark Danish Institute for Fisheries Research The Responsible approach Age at release Magnitude per year Requirements Female for broodstock Capital costs* Running costs Area requirement Scenario I 3-month 26 million Scenario II First-feeding 474 million Scenario III Eggs 13 billion 406 4.41 mill € 1.93 mill € Broodstock 594m², Egg incubators 108m², Live feed production 396m², Hatchery 2484m², Ongrowing 5355m². 594 341,200 € 204,000 € Broodstock 594m², Egg incubators 30m², 6,558 1.62 mill € 744,000 € Broodstock 2078m², Egg incubators 356m², Running costs: 2 million DKr Economic analysis Expected return: 13-20 million DKr Technical University of Denmark Danish Institute for Fisheries Research The Responsible approach Define quantitative measure of success • Set quantitative goals • Use simple indicators The Danish Baltic Sea Case Study: Goal of 10% increase in average year class recruits. Increase the Spawning Stock Biomass by min. 10% while < 140.000 tons. Source: Blankenship & Leber, 1995 Technical University of Denmark Danish Institute for Fisheries Research Number of 2-year-old recruits Good environmental conditions SSB ca. 65 000 t in 2005 Poor environmental conditions Technical University of Denmark Danish Institute for Fisheries Research The Responsible approach Use genetic resource management to avoid deleterious genetic effects • Identify genetic risks and consequences of enhancement and how to mitigate • Implement genetic controls in the hatchery and a monitoring and evaluation program for wild stocks • Implement a sufficiently large broodstock • Implement spawning protocols that ensure genetic biodiversity. Source: Blankenship & Leber, 1995 Technical University of Denmark Danish Institute for Fisheries Research The Responsible approach Use disease and health management • Establish maximum acceptable levels of infections and parasites in the hatchery established on the basis of wild stock health screening results. BVP monitoring program established for Danish Baltic Sea broodstock Source: Blankenship & Leber, 1995 Technical University of Denmark Danish Institute for Fisheries Research The Responsible approach Use an empirical process for defining optimum release strategies Trial at 1% increase target. Source: Blankenship & Leber, 1995 Technical University of Denmark Danish Institute for Fisheries Research The Responsible approach Use adaptive management. Continuous process to improve stocking results by reviewing all components, some degree of monitoring and adapting. New ideas for refining stock enhancement/ restocking constantly considered and integrated in the management process. Source: Blankenship & Leber, 1995 Technical University of Denmark Danish Institute for Fisheries Research Conclusion • Dynamic new science where progress is being made • Broad-based, multi-disciplinary, or “ecosystem approach” integrating biotechnical with a range of other considerations, esp. stakeholder involvement and local choices • Look at the field critically with risk assessment and costbenefit analysis, with a view to improve it through integration, monitoring, evaluation, adaptation and dissemination of information