Length-Based Assessment of an Artisanal Albulid Fishery in the South Pacific: a Data-Limited Approach for Management and Conservation

Data-limited fisheries assessment methods have great potential to help inform small island communi

Substantial impacts of subsistence fishing on the population status of an Endangered reef predator at a remote coral atoll

Napoleon wrasse Cheilinus undulatus has declined drastically throughout most of its range, owing, in large part, to overexploitation. In Anaa, French Polynesia, the species is harvested as part of the subsistence catch by fishers using rockpile traps, spearguns, handmade harpoons, and baited handlines. We sampled 70 Napoleon wrasse captured by artisanal fishers of Anaa between 2015 and 2018 to assess the status of this population, and we applied data-poor fisheries models to assess the stock status of this iconic reef predator. The species was determined to be overexploited at a rate of 0.82 based on values of natural (0.14; Hoenig method) and fishing (0.58; difference of total and natural mortality) mortality as components of total mortality (0.72; Beverton-Holt estimation). The left-skewed length distribution (mean = 36 ± 13 cm SL) suggested an under-representation of large adults in the population, which would predominantly be terminal males in this sequentially hermaphroditic protogynous fish. This was not considered to be reflective of poor sel

Technoscience and the modernization of freshwater fisheries assessment and management

Inland fisheries assessment and management are challenging given the inherent com- plexity of working in diverse habitats (e.g., rivers, lakes, wetlands) that are dynamic on organisms that are often cryptic and where fishers are often highly mobile. Yet, technoscience is offering new tools that have the potential to reimagine how inland fisheries are assessed and managed. So-called ‘‘technoscience’’ refers to instances in which science and technology unfurl together, offering novel ways of spurring and achieving meaningful change. This paper considers the role of technoscience and its potential for modernizing the assessment and management of inland fisheries. It first explores technoscience and its potential benefits, followed by presentation of a series of synopses that explore the application (both successes and challenges) of new tech- nologies such as environmental DNA (eDNA), genomics, electronic tags, drones, phone apps, iEcology, and artificial intelligence to assessment and management. The paper also considers the challenges and barriers that exist in adopting new technologies. The paper concludes with a provocative assessment of the potential of technoscience to reform and modernize inland fisheries assessment and management. Although these tools are increasingly being embraced, there is a lack of platforms for aggregating these data streams and providing managers with actionable information in a timely manner. The ideas presented here should serve as a catalyst for beginning to work collectively and collaboratively towards fisheries assessment and management systems that harness the power of technology and serve to modernize inland fisheries management. Such transformation is urgently needed given the dynamic nature of environmental change, the evolving threat matrix facing inland waters, and the complex behavior of fishers. Quite simply, a dynamic world demands dynamic fisheries management; technoscience has made that within reach.publishedVersio

Keepemwet Fishing—An emerging social brand for disseminating best practices for catch-and-release in recreational fisheries

There is a growing body of catch-and-release (C&R) science showing that adjusting the way fish are caught, handled, and released can reduce impacts on individuals and populations. However, a major caveat is that C&R will be a more effective conservation tool if best practice guidelines stemming from the science are understood, embraced, and adopted by recreational anglers. In recognition of this, Keepemwet Fishing (KWF) has emerged as a nonpartisan movement to provide simple, clear, and accurate C&R guidelines that transcend species and subcultures within the recreational angling community. The foundations of the KWF movement are science-based best practices, clear translations of the science, and a diverse and growing set of stakeholder groups that are sharing the Keepemwet sentiment via social media and other communication channels. We highlight the power of this grassroots movement, as well as potential hurdles that KWF and other social brands will need to overcome to broaden their effectiveness in making C&R guidelines more accessible and appealing to the public. Given the apparent increase in bottom-up attempts to disseminate best practices to anglers, the lessons learned from the KWF movement have the potential to be of great benefit to other groups engaged in angler outreach related to best practices and broade

Factors influencing postrelease predation for a catch-and-release tropical flats fishery with a high predator burden

Postrelease predation (PRP) of fishes released by anglers is a potentially significant contributo

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

Consequences of catch-and-release angling on the physiology, behaviour and survival of wild steelhead Oncorhynchus mykiss in the Bulkley River, British Columbia

Steelhead, the anadromous form of rainbow trout (Oncorhynchus mykiss), is one of the most coveted recreationally targeted salmonids worldwide, and catch-and-release (C&R) is commonly used as a conservation strategy to protect wild stocks. Nevertheless, little research has examined how wild steelhead respond to capture and handling. During a summer-run recreational fishery on the Bulkley River in British Columbia, we used non-lethal blood sampling and radio telemetry to assess the physiological stress response, post-release behaviour, and survival of wild steelhead exposed to either 0 s, 10 s, or 30 s of air exposure, over a range of water temperatures, fight times, and landing methods. Steelhead that were air exposed following landing had greater reflex impairment and moved further downstream immediately following release than fish kept in the water, though there was no observed difference in movement two weeks after cap

A practical method to account for variation in detection range in acoustic telemetry arrays to accurately quantify the spatial ecology of aquatic animals

Acoustic telemetry is a popular tool for long-term tracking of aquatic animals to describe and quantify patterns of movement, space use, and diverse ecological interactions. Acoustic receivers are imperfect sampling instruments, and their detection range (DR; the area surrounding the receiver in which tag transmissions can be detected) often varies dramatically over space and time due to dynamic environmental conditions. Therefore, it is prudent to quantify and account for variation in DR to prevent telemetry system performance from confounding the understanding of real patterns in animal space use. However, acoustic receiver DR consists of a complex, dynamic, three-dimensional area that is challenging to quantify. Although quantifying the absolute DR of all receivers is infeasible in the context of most acoustic telemetry studies, we outline a practical approach to quantify relative variation among receiver DR over space and time. This approach involves selecting a set of sentinel receivers to monitor drivers of variation in detection range. Each sentinel receiver is subject to a range testing procedure to estimate detection efficiency (DE; the proportion of total transmissions detected by the receiver), at a range of distances from the receiver, to derive the maximum range (MR; distance from the receiver where DE is 5%) and Midpoint (distance from the receiver where DE is 50%). A reference transmitter is then placed at the Midpoint, providing a standardized measure of long-term variation in DE, with each station having similar freedom of variance. Variation in reference tag DE is then combined with MR to calculate a DR correction factor (DRc). A modelling approach is then used to estimate DRc for all receivers in the array at spatial and temporal scales of ecological interest, which can be used to correct animal detection data in various ways. We demonstrate this method with a hypothetical dataset, as well as empirical data from an acoustic telemetry array to delineate spatio-temporal patterns of fish habitat use. This is a flexible and practical approach to account for variation in acoustic receiver performance, allowing more accurate spatial and temporal patterns in aquatic animal spatial ecology to be revealed

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

Fishing in the dark: The science and management of recreational fisheries at night

Recreational fshing is a popular activity around the globe, generating billions of dollars in economic beneft based on fsheries in marine and inland waters. In most developed countries, recreational fsheries are managed to achieve diverse objectives and ensure that such fsheries are sustainable. While many anglers fsh during daylight hours, some target fsh species during the night. Indeed, sensory physiology of some species makes them vulnerable to capture at night, while being more difcult to capture during the day. However, night creates a number of challenges for recreational fsheries assessment and management. In some jurisdictions, fshing is prohibited at night (through both effort and harvest controls) or there are specifc restrictions placed on night fsheries (e.g., no use of artifcial lights). Here, we summarize the science and management of recreational fsheries at night covering both inland and marine realms. In doing so, we also provide a review of different angling regulations specifc to night fsheries across the globe, as well as the basis for those regulations. We dis