28 research outputs found
Eficácia da ivermectina oral no controle de Psoroptes ovis e Leporacarus gibbus em coelhos naturalmente infestados
Population dynamics of roundjaw bonefish Albula glossodonta at a remote coralline Atoll inform community-based management in an artisanal fishery
Fisheries management requires knowledge on the population dynamics of exploited stocks. To that end, the present study used a mark–recapture approach to characterise the population demographics of roundjaw bonefish Albula glossodonta (Forsskål) and their interaction with a data-limite
The Postrelease Survival of Walleyes Following Ice-Angling on Lake Nipissing, Ontario
Natural resource agencies have developed catch-and-release regulations for Walleyes Sander vitreus of prohibited size and number to reduce mortality in many recreational fisheries. The efficacy of such regulations is contingent upon the released fish surviving, but survival data on Walleyes captured by ice-angling are lacking. We estimated the survival of Lake Nipissing (Ontario, Canada) Walleyes that were captured by both active and passive ice-angling methods using a variety of hook types and lures baited with Emerald Shiners Notropis atherinoides. We also assessed the role of de-hooking methods on the survival of deeply hooked Walleyes. After the angling event, Walleyes (n = 260) were held for 24 h in a submerged holding pen to estimate postrelease survival. Average mortality after the 24-h holding period was 6.9%. Fewer Walleyes captured by active angling were deeply hooked (9.3%) than passively caught fish (50.4%), and deeply hooked Walleyes were observed to have more frequent postrelease mortality (14.8%) than shallow-hooked Walleyes (3.0%). There was no significant difference in mortality rates of Walleyes caught by passive angling (9.8%) or active angling (2.8%); mortality rates of fish caught on circle hooks (6.1%), J-hooks (8.2%), and treble hooks (5.6%) also did not differ. Neither air temperature nor the presence of barotrauma had a significant effect on mortality of captured Walleyes. Survival did not significantly differ between deeply hooked fish that had the line cut (11.1%) and those that had the hook removed (22.6%). Results from this study suggest a relatively high incidence of Walleye survival after catch-and-release angling through the ice
The nexus of fun and nutrition: Recreational fishing is also about food
Recreational fishing is a popular activity in aquatic ecosystems around the globe using a variety of gears including rod and line and to a lesser extent handlines, spears, bow and arrow, traps and nets. Similar to the propensity to engage in voluntary catch-and-release, the propensity to harvest fishes strongly varies among cultures, locations, species and fisheries. There is a misconception that because recreational fishing happens during non-work (i.e. leisure) time, the nutritional motivation is negligible; therefore, the role of recreational fishing in supporting nutrition (and thus food security) at regional, national or global scales is underappreciated. We consider the factors that influence whether fish will be harvested or released by examining the motives that underlie recreational fishing. Next, we provide an overview of the magnitude and role of recreational fishing harvest in supporting nutrition using regional case-studies. Then, we address issues such as contaminants and parasites that constrain the ability of fish harvested by recreational fishers to be consumed. Although recreational fishing is foremost a leisure activity, the harvest of fish for personal consumption by recreational fishers has contributed and will continue to contribute to human nutrition by providing an accessible, affordable and generally highly sustainable food source, notwithstanding concerns about food safety and possibly overfishing. Attempts to better quantify the role of fish harvested by recreational fishers and the relative contribution to overall food security and personal nutrition will provide resource managers and policymakers the information needed to guide management activities and policy development
Pan-Holarctic assessment of post-release mortality of angled Atlantic salmon Salmo salar
Recreational Atlantic salmon Salmo salar fisheries are culturally and economically important, but confronted with global population declines, catch-and-release has frequently replaced harvest in these fisheries. Many studies have evaluated the effects of catch-and-release angling on Atlantic salmon; however, studies typically focused on a single system and had small sample sizes. Using data from Atlantic salmon catch-and-release studies conducted in 12 rivers throughout the pan-Holarctic range of wild Atlantic salmon, we modeled delayed mortality data using logistic regression. The model was based on 512 salmon (75 ± 15 cm TL) captured and released with electronic tags (i.e. radio or acoustic transmitters), which permitted the determination of fish fate after release (delayed mortality). The percentage of salmon categorized as survivors after release was high (93%). Salmon with longer body length tended to be played for longer durations (R2 = 0.60) but there was no significant effect of fish length or playing time on mortality. Water temperature at capture emerged as a significant predictor of delayed mortality of salmon. Individuals captured by flies had significantly higher survival (96%) compared to lure (86%) and natural bait (85%) caught salmon. Data from throughout the range of Atlantic salmon confirm that fish captured by anglers adhering to best practices have high probability of surviving catch-and-release angling