Wildlife Science Center

Chronic gastric instability (CGI), potentially part of the gastric dilatation and volvulus (GDV) syndrome, was identified in four free-ranging Virginia opossums (Didelphis virginiana) treated at the Wildlife Rehabilitation Center of Minnesota in Roseville, Minnesota. These individuals displayed lack of expected weight gain, inappetence, gastric gas distension, and delayed gastric emptying time. One was diagnosed with GDV via diagnostic radiology, whereas the other three were diagnosed with suspected CGI using radiographs, ultrasound, and confirmed with exploratory surgery. Clinical signs fully resolved after surgical intervention and supportive management in all four cases. This case series illustrates the clinical signs, diagnostics, and treatment of CGI in Virginia opossums.

Freshwater ecosystems provide numerous services for communities worldwide, including irrigation, hydropower, and municipal water; however, the services provided by inland fisheries – nourishment, employment, and recreational opportunities – are often comparatively undervalued. We provide an independent estimate of global lake harvest to improve biological and socioeconomic assessments of inland fisheries. On the basis of satellite‐derived estimates of chlorophyll concentration from 80,012 globally distributed lakes, lake‐specific fishing effort based on human population, and output from a Bayesian hierarchical model, we estimated that the global lake fishery harvest in the year 2011 was 8.4 million tons (mt). Our calculations excluded harvests from highly productive rivers, wetlands, and very small lakes; therefore, the true cumulative global fishery harvest from all freshwater sources likely exceeded 11 mt as reported by the Food and Agriculture Organization of the United Nations (FAO). This putative underestimate by the FAO could diminish the perceived importance of inland fisheries and perpetuate decisions that adversely affect these fisheries and millions of people.

Decision support tools can aid decision making by systematically incorporating information, accounting for uncertainties, and facilitating evaluation between alternatives. Without user buy‐in, however, decision support tools can fail to influence decision‐making processes. We surveyed fishery researchers, managers, and fishers affiliated with the Lake Whitefish Coregonus clupeaformis fishery in the 1836 Treaty Waters of Lakes Huron, Michigan, and Superior to assess opinions of current and future management needs to identify barriers to, and opportunities for, developing a decision support tool based on Lake Whitefish recruitment projections with climate change. Approximately 64% of 39 respondents were satisfied with current management, and nearly 85% agreed that science was well integrated into management programs. Though decision support tools can facilitate science integration into management, respondents suggest that they face significant implementation barriers, including lack of political will to change management and perceived uncertainty in decision support outputs. Recommendations from this survey can inform development of decision support tools for fishery management in the Great Lakes and other regions.

Abstract Climate is a critical driver of many fish populations, assemblages, and aquatic communities. However, direct observational studies of climate change impacts on North American inland fishes are rare. In this synthesis, we (1) summarize climate trends that may influence North American inland fish populations and assemblages, (2) compile 31 peer-reviewed studies of documented climate change effects on North American inland fish populations and assemblages, and (3) highlight four case studies representing a variety of observed responses ranging from warmwater systems in the southwestern and southeastern United States to coldwater systems along the Pacific Coast and Canadian Shield. We conclude by identifying key data gaps and research needs to inform adaptive, ecosystem-based approaches to managing North American inland fishes and fisheries in a changing climate. El clima es un factor forzante clave para muchas poblaciones y ensambles de peces y de comunidades acuáticas. Sin embargo, son pocos los estudios observacionales acerca de los impactos del cambio climático en los peces de aguas continentales en Norte América. En esta síntesis (1) se resumen las tendencias climáticas que pueden influir en las poblaciones y ensambles de peces de aguas continentales en Norte América, (2) se compilan 31 trabajos arbitrados que documentan los efectos del cambio climático sobre las poblaciones y ensambles de peces de aguas continentales en Norte América y (3) se comentan cuatro casos de estudio que representan una variedad de respuestas observadas que van desde los sistemas de aguas cálidas en el suroeste y sureste de Los EE.UU., hasta los sistemas de aguas frías a lo largo de la costa del Pacífico y del escudo canadiense. Finalmente, se identifican huecos de información clave y necesidades de investigación tendientes a proporcionar información para diseñar enfoques ecosistémicos con el fin de manejar a los peces y a las pesquerías de aguas continentales en Norte América de cara a un clima cambiante. Le climat est un facteur critique pour de nombreuses populations de poissons, bancs et communautés aquatiques. Cependant, les études d'observation directe des impacts des changements climatiques sur les poissons continentaux d'Amérique du Nord sont rares. Dans cette synthèse, nous (1) résumons les tendances climatiques qui peuvent influencer les populations et communautés de poissons continentaux d'Amérique du Nord, (2) compilons 31 études examinées par des pairs sur les effets documentés du changement climatique sur les populations et communautés de poissons continentaux dl'Amérique du Nord, et (3) mettons l'accent sur quatre études de cas représentant une variété de réponses observées allant des systèmes d'eaux chaudes dans le sud-ouest et sud-est des États-Unis aux systèmes d'eau froide le long de la côte du Pacifique et du Bouclier canadien. Nous concluons en identifiant les lacunes en matière de données clés et les besoins de recherche pour informer sur les approches fondées sur les écosystèmes adaptatifs à la gestion des pêches et des poissons continentaux d'Amérique du Nord face au changement climatique.

At present, inland fisheries are not often a national or regional governance priority and as a result, inland capture fisheries are undervalued and largely overlooked. As such they are threatened in both developing and developed countries. Indeed, due to lack of reliable data, inland fisheries have never been part of any high profile global fisheries assessment and are notably absent from the Sustainable Development Goals. The general public and policy makers are largely ignorant of the plight of freshwater ecosystems and the fish they support, as well as the ecosystem services generated by inland fisheries. This ignorance is particularly salient given that the current emphasis on the food-water-energy nexus often fails to include the important role that inland fish and fisheries play in food security and supporting livelihoods in low-income food deficit countries. Developing countries in Africa and Asia produce about 11 million tonnes of inland fish annually, 90 % of the global total. The role of inland fisheries goes beyond just kilocalories; fish provide important micronutrients and essentially fatty acids. In some regions, inland recreational fisheries are important, generating much wealth and supporting livelihoods. The following three key recommendations are necessary for action if inland fisheries are to become a part of the food-water-energy discussion: invest in improved valuation and assessment methods, build better methods to effectively govern inland fisheries (requires capacity building and incentives), and develop approaches to managing waters across sectors and scales. Moreover, if inland fisheries are recognized as important to food security, livelihoods, and human well-being, they can be more easily incorporated in regional, national, and global policies and agreements on water issues. Through these approaches, inland fisheries can be better evaluated and be more fully recognized in broader water resource and aquatic ecosystem planning and decision-making frameworks, enhancing their value and sustainability for the future.

Abstract Electronic training collars, or shock collars, have received relatively little application as a non‐lethal management tool for reducing livestock losses caused by gray wolves ( Canis lupus ). One of the major obstacles to using shock collars on wolves has been the lack of a safe and efficient collar design. We developed a new shock‐collar design and tested it for safety and efficacy on captive wolves. Our design used a radiocollar with a shock unit mounted on the back. Shock units were fitted with rounded probes that contact the back of a wolf's shaved neck and with externally mounted batteries to increase battery life. We tested our design in 5 different captive trials conducted during 2003–2005 at the Wildlife Science Center, Minnesota, USA, and eliminated neck damage shown in previous shock‐collar research, while retaining the ability to effectively deliver a shock. We extended battery life to 80 days. We believe this new shock‐collar design could be used as a safe and efficient alternative to lethal control in certain situations for wild wolves. © 2013 The Wildlife Society.

ABSTRACT Recreational fishing constitutes the dominant or sole use of many fish stocks, particularly in freshwater ecosystems in Western industrialized countries. However, despite their social and economic importance, recreational fisheries are generally guided by local or regional norms and standards, with few comprehensive policy and development frameworks existing across jurisdictions. We argue that adoption of a recently developed Global Code of Practice (CoP) for Recreational Fisheries can provide benefits for moving recreational fisheries toward sustainability on a global scale. The CoP is a voluntary document, specifically framed toward recreational fisheries practices and issues, thereby complementing and extending the United Nation's Code of Conduct for Responsible Fisheries by the Food and Agricultural Organization. The CoP for Recreational Fisheries describes the minimum standards of environmentally friendly, ethically appropriate, and—depending on local situations—socially acceptable recreational fishing and its management. Although many, if not all, of the provisions presented in the CoP are already addressed through national fisheries legislation and state-based fisheries management regulations in North America, adopting a common framework for best practices in recreational fisheries across multiple jurisdictions would further promote their long-term viability in the face of interjurisdictional angler movements and some expanding threats to the activity related to shifting sociopolitical norms. RESUMEN las pesquerías recreativas constituyen el uso dominante, y a veces el único, de diversas poblaciones de peces, particularmente en ecosistemas dulceacuícolas en pueblos occidentales industrializados. No obstante, a pesar de su importancia social y económica, la pesca recreativa es comúnmente regulada por normas y estándares locales o regionales, con marcos políticos y de desarrollo poco comprensibles y una comunicación inter-jurisdiccional deficiente. En este trabajo se argumenta que la adopción de un Código Global de Prácticas (CGP), de reciente creación, para pesquerías recreativas puede ofrecer beneficios útiles para el tránsito de la pesca recreativa hacia la sustentabilidad a escala global. El CGP es un documento voluntario, especialmente diseñado para las prácticas y temas relativos a la pesca recreativa, por lo que complementa y extiende el Código de Conducta de la Pesca Responsable elaborado por La Organización de las Naciones Unidas para la Alimentación y la Agricultura. El CGC para pesquerías recreativas describe los estándares mínimos, ambientalmente amigables, éticamente apropiados y socialmente aceptables en las prácticas y manejo de la pesca recreativa. Si bien muchas, si no es que todas, las previsiones presentadas en el CGC ya comienzan a tratarse en la legislación pesquera nacional y en las regulaciones estatales de manejo en los Estados Unidos de Norteamérica, la adopción de un marco común que defina las mejores prácticas en las pesquerías recreativas a través de diversas jurisdicciones, promoverá aun más su viabilidad a largo plazo. Tal promoción se está dando de cara a movimientos inter-jurisdiccionales en pro de la pesca con línea y de amenazas crecientes a la actividad que están relacionadas al cambio en las normas sociopolíticas.el sábalo americano representa una invasión nociva o una introducción benéfica.