After the spawn and on the hook: Sea trout Salmo trutta biophysical responses to different components of catch and release in a coastal fishery

This study investigated the biophysical responses of sea run brown trout Salmo trutta to catch-and-release in the coastal fishery around Gotland, Sweden. It used information recorded on individual angled S. trutta (n = 162), including fight time, handling time, total air exposure time, injury, bleeding, fish length, body condition, spawning status, water temperature, hook location and difficulty of hook removal. Reflex action mortality predictors (equilibrium, operculum beats, tail grab response, body flex response and vestibular-ocular response), tests of blood glucose and lactate, and observation of hooking injury were used to measure the relative impact of the angling event on the fish's physical state and stress experienced. The results of this study suggest low rates of post-release mortality and generally limited stress responses to angling events, and relatively high post-release survival supported by the recapture of many tagged S. trutta. However, a number of scenarios were identified in which stress responses are likely to be compounded and where anglers should take additional action to reduce sublethal physiological disturbances and the risk of delayed mortality. Particular care should be taken to limit cumulative total air exposure to <10 s, and to reduce handling time and risk of additional injury in angling events with extended fight times, when water temperatures >10°C, or where S. trutta show evidence of being physically compromised by injury or having recently spawned. The results also indicate the importance of using appropriately sized single hooks rather than larger treble hooks to reduce hooking injury and handling time during unhooking.

Length-weight relationships of two conservation-concern mahseers (Teleostei: Cyprinidae: Tor) of the river Cauvery, Karnataka, India

Length-weight (LW) relationships are presented for two conservation-concern species of mahseer (Tor spp.) from southern India’s river Cauvery.  Constructed from angler catch data, these are the first available LW relationships for the Critically Endangered Tor remadevii and the non-native and locally invasive Tor khudree.  For T. remadevii, the value of b, the allometric parameter, was 2.94 (95% CI: 2.75–3.14) and was not significantly different from 3.0, indicating isometric growth (t = 0.61, P = 0.54).  For T. khudree, b was greater at 3.18 (95% CI: 3.01–3.38), but with this also not significantly different from 3.0 (t = 1.91, P = 0.06).  Outputs are discussed with reference to species conservation and recreational catch-and-release fisheries.

Searching for responsible and sustainable recreational fisheries in the Anthropocene

Recreational fisheries that use rod and reel (i.e., angling) operate around the globe in diverse freshwater and marine habitats, targeting many different gamefish species and engaging at least 220 million participants. The motivations for fishing vary extensively; whether anglers engage in catch-and-release or are harvest-oriented, there is strong potential for recreational fisheries to be conducted in a manner that is both responsible and sustainable. There are many examples of recreational fisheries that are well-managed where anglers, the angling industry and managers engage in responsible behaviours that both contribute to long-term sustainability of fish populations and the sector. Yet, recreational fisheries do not operate in a vacuum; fish populations face threats and stressors including harvest from other sectors as well as environmental change, a defining characteristic of the Anthropocene. We argue that the future of recreational fisheries and indeed many wild fish populations and aquatic ecosystems depends on having responsible and sustainable (R&S) recreational fisheries whilst, where possible, addressing, or at least lobbying for increased awareness about the threats to recreational fisheries emanating from outside the sector (e.g., climate change). Here, we first consider how the concepts of R&S intersect in the recreational fishing sector in an increasingly complex socio-cultural context. Next, we explore the role of the angler, angling industry and decision-makers in achieving R&S fisheries. We extend this idea further by considering the consequences of a future without recreational fisheries (either because of failures related to R&S) and explore a pertinent case study situated in Uttarakahand, India. Unlike other fisheries sectors where the number of participants is relatively small, recreational angling participants are numerous and widespread, such that if their actions are responsible, they have the potential to be a key voice for conservation and serve as a major force for good in the Anthropocene. What remains to be seen is whether this will be achieved, or if failure will occur to the point that recreational fisheries face increasing pressure to cease, as a result of external environmental threats, the environmental effects of recreational fishing and emerging ethical concerns about the welfare of angled fish.

Practices and attitudes of Indian catch-and-release anglers: identifying opportunities for advancing the management of recreational fisheries

Recreational fishing, a popular leisure activity, can potentially support conservation of species and provide socio-economic benefits to local economies.  Nonetheless, there are ecological concerns regarding this pastime, especially in developing economies such as India where little information is available concerning impacts on fish populations.  An online survey targeting recreational anglers practicing catch-and-release (C&R) in India (n=200) revealed 25 states/union territories as prime angling locations, with Mahseer (Tor spp.) constituting the main target species group (53%).  Angling season (28%) and pristine river surroundings (14%) were stated as major factors important for angling, while overfishing (31%) and the use of illegal fishing techniques were highlighted as chief threats to fish species.  Respondents were in favour of strictly adhering to C&R guidelines (23%), controlling illegal fishing techniques and pollution (18%) and spreading awareness and education among local stakeholders (18%) to protect fish.  Over 75% of respondents were also willing to contribute both their time and money to conservation initiatives focusing on key sport fish.  With anglers targeting multiple fishing locations throughout India, there is a need for consistent governance structures and policy instruments to support the development of sustainable recreational fisheries while minimising conflict with other stakeholder groups.  The impacts of C&R fisheries interactions on individuals and populations (especially for threatened species) need to be studied in the Indian context.  Direct participation by recreational anglers in C&R research could strengthen broader conservation and management initiatives throughout the country by increasing stewardship.