Benefits of repeated stocking with adult, hatchery‐reared brown trout, Salmo trutta, to recreational fisheries?

Abstract

Recaptures of adult, hatchery-reared, brown trout, Salmo trutta L., and fishing time from anglers were used to evaluate the benefits of stocking programmes with repeated releases of adult brown trout. The recapture rate varied between 17% and 29%. The time between stocking and capture (referred to as residence time) varied between 1 and 160 days (median 3-49 days). Between 67% and 84% of trout caught in the river were recently released fish. Fishing effort increased after stocking, thereby increasing the impact of angling on wild stocks. Stocking with adult brown trout decreases the impact of angling on wild trout only if the time spent fishing by all anglers is kept stable. Furthermore, because of the short residence time of stocked trout, long-term impacts through competition for space and food, or genetic impact through introgression, are limited.angling, brown trout, catch per unit effort, movement, recapture rates, stocking.

Application of the SES Framework for Model-based Analysis of the Dynamics of Social-Ecological Systems

“…The success of a stocking measure is influenced by the size of the stocked fish, the conditions in the water body, and the number of fish in the stocked and wild fish population because all of these factors impact the competition between wild and stocked fish (Lorenzen 2005). Practical stocking guidelines in Germany often recommend stocking small-sized fish because it is believed that they can more easily adapt to the conditions in the water body and the problem of overstocking is supposed to be avoided because of natural regulation (Baer et al 2007). However, there are alternative perspectives that larger sized fish might offer better returns because of higher survival in the stocked water system, but this comes at a higher cost of production (Lorenzen 2005).…”

Stock–catch analysis of carp recreational fisheries in Czech reservoirs: Insights into fish survival, water body productivity and impact of extreme events

“…In addition, a detailed study of the carp recreational fisheries in the Czech Republic can provide general insights that could be applied elsewhere, given that few rigorous studies of stock-catch relationships exist (Welcomme and Bartley, 1998). Previous research has addressed various aspects of the stocking process such as the survival of stocked fry and juvenile fish (e.g., Aprahamian et al, 2003;Hervas et al, 2010), relative contributions of wild and stocked fish to catches (e.g., Baer et al, 2007;Heard, 2003), and the interplay between stocking, yield and abiotic and biotic factors across reservoirs (e.g., Allen et al, 2006;De Silva, 2001Nguyen et al, 2005). As we show here, time series of annually stocked and caught fish alone can be used to unravel the long-term dynamics of culture-based recreational fisheries.…”

“…This simple approach is reasonable in the absence of better knowledge about average time to recapture. Indeed, stocking events can result in high catches shortly after the stocking because they attract increased attention and lead to temporarily higher fishing effort by the anglers and because the newly-stocked fish are often easy to catch (Baer et al, 2007;Pivnička andČihař, 1986). Improved statistical methods, such as lag-correlation analysis, can identify most likely time lags between stocking and harvest (e.g., Quiros and Mari, 1999).…”

“…It is regularly used in recreational fisheries to satisfy angler expectations and demands, including increased catches and availability of multiple fish species for exploitation (Arlinghaus and Mehner, 2005;Baer et al, 2007;Britton et al, 2007). Stocking may be used to enhance or supplement natural reproduction or to create culture-based fisheries, i.e., fisheries based predominantly on the recapture of stocked fish (Lorenzen et al, 2001).…”

Effects of brown trout ( Salmo trutta L.) stocking and catch‐release practice on angling catches in the River South Rena in southeast Norway

“…Overexploitation and reduced catches may be met by different means like increased minimum legal size to increase the spawning stock of indigenous populations (Anderson & Nehring, ; Cooke & Schramm, ; Pinder, Raghavan, & Britton, ; Pope, Wilde, & Knabe, ; Simonović et al, ). Supplemental stocking may increase the fishable stock (Cowx, ), but can also cause reduction of wild fish populations (Vincent, ), and lead to increased angling impact on wild stocks (Baer, Blasel, & Diekmann, ). Bag limit and CR (BL‐CR) are measures to reduce the mortality caused by fishing (Anderson & Nehring, ; Cooke et al, ), and studies have focused on the effects of CR on unintentional fish mortality and physiological stress (Anderson & Nehring, ; Havn et al, ; Pope et al, ).…”