Fisheries Abstracts

Pacific Lamprey (Entosphenus tridentatus) have been an important part of the ecological community and co-evolved with aquatic species of the western rivers of the United States. Scarce information on Pacific Lamprey has hindered conservation and management efforts. To assess and conserve Pacific Lamprey, we developed a conservation initiative composed of three parts: assessment, conservation agreement, and regional implementation plans. We applied a novel ranking system that characterized risk to Pacific Lamprey throughout the U.S. range. We found that the majority of watersheds are at relatively high risk of extirpation, with few secure. The risk assessment results were instrumental in gaining partners’ support for a conservation agreement, with the goal of achieving long-term persistence and supporting traditional tribal cultural use of Pacific Lamprey. This extensive support has led to a collaborative effort in developing implementation plans and delivering numerous conservation actions. This approach for assessing Pacific Lamprey status and identifying restoration priorities is easily transferable to other species. by Christina Wang and Howard Schaller Access your special Members-Only content →  • Click here to read the Spanish abstract.    

Learning to Manage and Managing to Learn: Sustaining Freshwater Recreational Fisheries in a Changing Environment ABSTRACT: Freshwaters are being transformed by multiple environmental drivers, creating uncertainty about future conditions. One way of coping with uncertainty is to manage for resilience to unanticipated events while facilitating learning through adaptive management. We outline the application of these strategies to freshwater recreational fisheries management using a case study in Wisconsin, USA, where black bass (Micropterus spp.) populations are increasing, while Walleye (Sander vitreus) populations are decreasing. Managing for heterogeneity in functional groups (e.g., age classes and prey species of sport fishes), fishery objectives, and regulations can increase resilience, although heterogeneity must be balanced with replication to facilitate learning. Monitoring designed to evaluate management objectives and inform about critical uncertainties, when combined with heterogeneity, creates opportunities for adaptive management, another critical resilience strategy. Although barriers exist to implementing resilience strategies, management designed to accommodate uncertainty and illuminate its consequences is needed to maintain critical fisheries in a rapidly changing world. by Gretchen J. A. Hansen, Jereme W. Gaeta, Jonathan F. Hansen, and Stephen R. Carpenter Access your special Members-Only content →  • Click here to read the Spanish abstract.  

ABSTRACT: Geographic information systems (GIS) are powerful tools for analysis and interpretation of spatial data commonly encountered in fisheries science. We presented details of GIS use in fisheries management in a prior study and found cost to be a factor limiting GIS use. This article introduces fisheries managers to free or open-source GIS. Free or open-source GIS are readily available, powerful tools capable of performing a variety of spatial analyses. We strongly encourage managers wishing to perform spatial analyses, but who are unable to purchase software, to consider free GIS. by Ben C. Neely and Brandon L. Eder Access your special Members-Only content →  • Click here to read the Spanish abstract.

ABSTRACT: Monitoring of fishing activities is an essential component of successful fisheries management that can provide verifiable fishery-dependent data on fishing activities and help assess performance and success of fisheries management plans. Fishery managers and stakeholders have often struggled in developing and implementing effective monitoring programs due to lack of information, funding, and peer-to-peer learning from existing monitoring programs. This article draws on the experience of over 25 national and international monitoring experts and reflects the most important lessons learned from commercial fisheries regarding the development and implementation of effective monitoring programs. The article discusses a set of “guiding principles,” developed in consultation with the monitoring experts, which provide fishery managers and stakeholders with cumulative knowledge and references to more easily develop comprehensive, appropriate, and effective monitoring approaches. by Erika A. Zollett, Robert J. Trumble, Jill H. Swasey, and Shawn B. Stebbins Access your special Members-Only content →  • Click here to read the Spanish abstract.  

Ecosystems that change through time impose new scientific challenges for fisheries management advice. We present a case study to illustrate our view on how to face such challenges. The Pink Shrimp fishery in the Southern Gulf of Mexico has collapsed. Annual yields were about 24,000 metric tons during the mid-1950s to early 1970s; currently, they are about 1,200 metric tons. Overfishing was assumed as the main cause, but single-species models failed to provide the advice necessary for recovery. An inverse relationship between stock abundance and temperature was demonstrated, and a decline in recruitment and primary production (since 1970s) was observed. We constructed a trophic model for the ecosystem using Ecopath with Ecosim, incorporating the annual mean anomaly of the Atlantic Multidecadal Oscillation as a climate change index to force primary production. Signals were propagated throughout the food web, and biomasses were simulated for the period of 1956 to 2011. Ecosystem changes were estimated with the highest carrying capacity by the mid-1970s then declining with time; Pink Shrimp follows such a decline. Balanced harvesting was simulated and the “ecosystem reference level” was identified as a maximum harvesting of 40% (catch/biomass ratio) for all resources for a sustainable ecosystem. Conventional single-species management resulted in population crashes. by Francisco Arreguín-Sánchez, Pablo del Monte-Luna, and Manuel J. Zetina-Rejón Access your special Members-Only content →  • Click here to read the Spanish abstract.  

ABSTRACT: The global proliferation of dams within the last half century has prompted ecologists to understand the effects of regulated rivers on large-river fishes. Currently, much of the effort to mitigate the influence of dams on large-river fishes has been focused on downriver effects, and little attention has been given to upriver effects. Through a combination of field observations and laboratory experiments, we tested the hypothesis that abiotic conditions upriver of the dam are the mechanism for the lack of recruitment in Pallid Sturgeon (Scaphirhynchus albus), an iconic large-river endangered species. Here we show for the first time that anoxic upriver habitat in reservoirs (i.e., the transition zone between the river and reservoir) is responsible for the lack of recruitment in Pallid Sturgeon. The anoxic condition in the transition zone is a function of reduced river velocities and the concentration of fine particulate organic material with high microbial respiration. As predicted, the river upstream of the transition zone was oxic at all sampling locations. Our results indicate that transition zones are an ecological sink for Pallid Sturgeon. We argue that ecologists, engineers, and policy makers need to broaden the regulated-river paradigm to consider upriver and downriver effects of dams equally to comprehensively mitigate altered ecosystems for the benefit of large-river fishes, especially for the Pallid Sturgeon. Christopher S. Guy, Hilary B. Treanor, Kevin M. Kappenman, Eric A. Scholl, Jason E. Ilgen, Molly A. H. Webb Access your special Members-Only content →  • Click here to read the Spanish abstract.  

ABSTRACT: Bluefish (Pomatomus saltatrix), a highly migratory cosmopolitan predator, is the only extant representative of the family Pomatomidae. It has been the subject of many studies due to its commercial and recreational value, but much less research has been conducted on its global population structure. Here we investigate the population structure of this species and the effects of present and past oceanographic barriers to dispersal in its North Atlantic, Mediterranean, Marmara, and Black sea populations. We employed mitochondrial (cytochrome b and cytochrome oxidase subunit I genes) and nuclear (eight microsatellite loci) DNA as molecular markers. Three main genetic units of Bluefish were identified: American (West Atlantic waters), Spanish (East Atlantic–Western Mediterranean regions), and Turkish (Eastern Mediterranean, Marmara, and Black seas). Our results suggested that Bluefish is panmictic in the northwest Atlantic Ocean but not in the Mediterranean Sea. The common ancestor of the studied populations was traced back to the interglacial cycle Aftonian II, and the separation between clades was estimated to have occurred during glacial periods, likely due to migrations to refuges and the closure of the Mediterranean Sea. In conclusion, paleoclimate seems to have been fundamental for shaping the present genetic lineages of Pomatomus saltatrix. by Laura Miralles, Francis Juanes, Antonio F. Pardiñas, and Eva Garcia-Vazquez Access your special Members-Only content →  • Click here to read the Spanish abstract.

ABSTRACT: This article contributes to the ongoing debate regarding the sustainability of fishmeal and fish oil in aquaculture diets. It demonstrates why the “Fish In, Fish Out” metric, which is frequently used to show how many units of wild fish is needed to produce one unit of farmed fish, is not a valid tool for measuring the sustainability or efficiency of aquaculture production. Additionally, the metric diverts attention away from the human health implications of how we raise fish. It substitutes the mass of seafood for the arguably more important value-added dimension – the long chain omega-3 content per unit mass, which is low in fish raised on diets low in marine ingredients. Fishmeal and fish oil produced by sustainable fisheries remain some of the most ecologically efficient ingredients that contribute to the overall gain of seafood biomass. Because many aspects of our health and wellbeing depend on wild fisheries, we must insist on well-managed fish harvest for the health of the world’s population Byelashov, Oleksandr A., and Mark E. Griffin, 2014. Fish In, Fish Out: Perception of Sustainability and Contribution to Public Health. Fisheries 39(11): 531-535. Access your special Members-Only content → • Click here to read the Spanish abstract.

ABSTRACT: Exposing the next generation to nature can foster a stronger appreciation for aquatic resources, yet it may not always be possible to allow students to experience natural aquatic environments. Aquaponics, the combination of aquaculture with hydroponics, can be an effective tool in schools and classrooms to reunite students with plants and animals, promote systems thinking, and encourage hands-on learning. In this article, we bring awareness to aquaponics in education, its potential as a novel platform for learning, and the realities of aquaponics in order to guide educators in managing their expectations for an aquaponics system. Specifically, running an aquaponics system requires diverse knowledge and skills, which makes it appealing as a teaching tool but may also present day-to-day technical challenges. Additionally, educational settings may affect long-term care, available space, and funding. We present strategies for addressing these realities of aquaponics in education and highlight two educational aquaponics programs. Hart, Emily R., James B. Webb, Craig Hollingsworth, and Andy J. Danylchuk, 2014. Managing Expectations for Aquaponics in the Classroom: Enhancing Academic Learning and Teaching an Appreciation for Aquatic Resources. Fisheries 39(11): 525-530. Access your special Members-Only content → • Click here to read the Spanish abstract.