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Genetic Risks Associated with Marine Aquaculture

出版	U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northwest Fisheries Science Center, 2012
URL	http://books.google.com.hk/books?id=gFibAQAACAAJ&hl=&source=gbs_api

註釋"All the genetic consequences of marine aquaculture are proportional to the fraction of successful natural spawners that are escaped fish. Therefore, by far the best strategy to minimize opportunities for adverse genetic interactions is to ensure that farmed fish do not escape in the first place. Once fish escape, experience suggests that even concerted efforts to recapture them will be only marginally successful at best. Because no aquaculture system in the marine environment can ensure 100% containment through either physical or reproductive containment measures, it is important to consider the scale of operations permitted to provide adequate safeguards for natural populations, given some inevitable level of escapes. Although escaped farmed fish can have ecological consequences for marine ecosystems as soon as they escape, they have direct genetic effects only if they survive to successfully reproduce and contribute genes to natural populations. Therefore, this report is concerned with situations in which natural populations of the targeted aquaculture species occur in or near the geographic vicinity of the aquaculture operation ... The factors that determine how likely escaped fish are to spawn with local natural populations are diverse and almost certainly vary widely across species and geographic areas (and perhaps over time as well). Because these factors have a strong influence on actual genetic risks posed by marine aquaculture, achieving a better understanding of how they function should be an important research priority. In evaluating evolutionary consequences of marine aquaculture, it is important to consider their proposed duration. Effects that might be inconsequential if only a single pulse event is involved can become substantial if they continue repeatedly across years and generations. ... A key decision in any aquaculture operation is choosing the broodstock source and this issue is also of keen interest to regulators. It is useful to briefly contrast two extreme scenarios regarding the broodstock source: Strategy 1 uses a recently developed stock based on individuals collected from the local area, while Strategy 2 uses a productive but highly domesticated stock derived from nonlocal populations ..."--Page 61-62.