Stocking strategies

Abstract

Stocking, transfer and introduction of fish are commonly used to mitigate loss of stocks, enhance recreational or commercial catches, restore fisheries or to create new fisheries. However, many stocking programmes are carried out without definition of objectives or evaluation of the potential or actual success of the exercise. This paper describes a strategic approach to stocking aimed at maximizing the potential benefits. A protocol is discussed which reviews factors such as source of fish, stocking density, age and size of fish at stocking, timing of stocking and mechanism of stocking. The potential genetic, ecological and environmental impacts of stocking are described.

Social-ecological interactions, management panaceas, and the future of wild fish populations

“…Many natural water bodies have been impaired by habitat changes (16) (Table S5), increasing the likelihood of wild population replacement after formation of stocking as a panacea. Almost ironically, habitat impairments often motivate stocking programs (8,11), such that stocking practices may actually put an additional burden on already threatened or declining wild stocks. Generally, our prediction that long-term replacement of wild by planted organisms can occur in a self-organized SES, such as recreational fisheries, forestry, or hunting, should be considered a worst-case yet plausible scenario.…”

“…This allowed examination of stocking impacts both in terms of density dependence (7) and hybridization-induced fitness depression (30). The stocking-descended subpopulation (for simplicity, hereafter called hatchery fish) consisted of recently stocked young of the year (YOY), a life stage often stocked in recreational fisheries (7,8), and naturally spawned hatchery fish. Progeny from both pure hatchery and hatchery-wild crosses were assigned to the hatchery subpopulation to account for the often-reported reduced fitness in hatchery fish or hybrids relative to wild fish (30,31).…”

“…Stocking, defined here as the repeated injection of juvenile fish from various sources (mainly hatchery-bred offspring from hatchery or wild spawners) to support wild fish populations (7,8), is a common management practice in fisheries involving billions of individuals released annually across the world (7,9). Stocking is perceived by many as the most obvious solution to declining populations (10,11), but conservation biologists increasingly warn against unintended and often irreversible repercussions for aquatic biodiversity, ranging from genetic to community scales (e.g., 1,[12][13][14].…”

Repeuplements en Alevins Nourris Et Démographie De La Population De Truite (Salmo Trutta L.) Dans Le Redon, Un Affluent Du Lac Léman Interrompu Par Un Obstacle

“…La solution de la création d'ouvrages d'aide à la remontée a été différée dans certains affluents pour des problèmes de coûts, dans la mesure où il faut équiper non pas un seul mais souvent toute une série d'obstacles. Comme dans de très nombreux cas (CUINAT, 1971;COWX, 1994;LAIKRE et al, 2000, VOLLESTAD et HESTHAGEN, 2001, la solution palliative du repeuplement a souvent été pratiquée pendant des décennies. Cependant, l'évolution actuelle dans le bassin lémanique est, prioritairement à la solution du repeuplement, à la réouverture des accès vers l'amont des affluents pour la fraie de la truite de lac.…”

Recapture and condition of pond-reared, and hatchery-reared 1 + European grayling stocked in addition to wild conspecifics in a small river

“…To re-establish threatened or extinct populations and expand the recreational fishery, hatchery-reared fish are commonly stocked. The success of stocking fish in natural waters depends on a variety of factors (Cowx, 1994). Hatchery-reared salmonids often have slower growth and lower fecundity and survival in the wild than do resident wild fish (Weber and Fausch, 2003).…”