32,774 research outputs found

    Literature Review of Gear-based Management Options in the Caribbean for Four Reef Fishing Methods: Fish Traps, Spears, Hook and Line, and Beach Seines

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    Many Caribbean reef fisheries have been overexploited for decades and often their decline has been accelerated by a loss of habitat. Improved management of Caribbean reef fisheries is vital to ensure their future sustainability. Reef fisheries in the Caribbean are difficult to manage due to the use of multiple fishing gear types, the number of species harvested, and the dispersed landing sites used by the fishers. Additionally, there is very little published information available on Caribbean reef fisheries and limited research into the effects of management. This review provides a synthesis of the published literature on four gears commonly used in Caribbean reef fisheries: fish traps, spears, hook and line, and beach seines, summarizing evidence on best management practices for each gear. The authors provide brief descriptions of each of the four gear types as well a synthesis of their use, biological impacts, and ecosystem impacts.The management recommendations are general recommendations on gear restrictions that could be applied to any Caribbean reef fishery

    Distribution of Terrestrial Isopods (Crustacea: Isopoda) Throughout Michigan: Early Results

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    Results are reported from the first two years of a multi-year study on the distribution of terrestrial isopods (Crustacea: Isopoda) in Michigan. During the first year of the study (1997), intensive investigations were carried out us­ing pitfall traps in a small area of Midland, MI. The study was resumed in 2001 with opportunistic collection and hand-sorting of litter samples for terrestrial isopods throughout 30 Michigan counties. As a result of this data collection, the species Haplophthalmus danicus, previously unrecorded in the state, has been located in seven counties, and 83 new county records have been established for eight other terrestrial isopod species in Michigan. In particular, this study adds extensively to distributional knowledge for four species so far: Hyloniscus riparius, Trichoniscus pusillus, Oniscus asellus, and Armadillidium vulgare. Another species, Armadillidium nasatum, previously reported only inside greenhouses in three somewhat southern locations in the state, was found as clearly well-established outdoor populations in two additional counties further north. Habitat/microhabitat information is presented for all species

    Polycentrism and Flux in Spatialized Management: Evidence from Maine\u27s Lobster (Homarus americanus) Fishery

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    Spatial approaches to fisheries management hold great promise but require continued conceptual and policy development. Polycentrism and flux emerge as useful concepts, drawing lessons from more customary, informal resourceuse patterns to produce more innovative “spatialized” policies within existing governance architectures. Empirical evidence from Maine shows that pioneering efforts have been limited by the single-species focus of conventional management hierarchies. As entry limits have consolidated the fishing fleet and eliminated flexible, diversified, and adaptive business strategies, cross-species and habitat externalities have become problematic. State lobster (Homarus americanus Milne- Edwards, 1837) comanagement zones have achieved some successes, including trap limits and improved industry-management communications, but incur significant transaction costs and raise equity and stewardship concerns. Kindred proposals for spatial refinement of groundfish management and locally based area-management councils lack support from the state Department of Marine Resources, Atlantic States Marine Fisheries Commission, New England Fishery Management Council, and National Marine Fisheries Service. Broader and more transparent deliberation of explicitly spatial and ecosystem approaches might be advanced by citizen panels convened to foster polycentric decision structures and accommodate more integrative management strategies

    Hog Daddy and the Walls of Steel: Catch Shares and Ecosystem Change in the New England Groundfishery

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    The U.S. National Oceanic and Atmospheric Administration implemented marketbased fishery management in the New England groundfishery as catch shares, controlling aggregate harvests through tradable annual catch quotas allocated to fishing groups called sectors. Policy supporters assert that resulting markets raise conservation incentives. In compliance with the Magnuson–Stevens Fishery Conservation and Management Act, species assessments permit catch shares to replace more spatially and temporally specific constraints on fishing gear, time, areas, and daily harvest limits. Qualitative evidence from field interviews and participant observation questions the efficacy of catch shares. Fishing industry members observe that increased presence of large trawl vessels in previously protected areas damages fish subpopulations and benthic habitat. Regulatory bioeconomic models fail to consider these lay observations. The consequent inability of quota markets to recognize the materiality of human–environment relationships at the spatiotemporal scales of fishing activity, and to internalize associated externalities, may have devastating consequences for the fishery

    Activity and Diversity of Collembola (Insecta) and Mites (Acari) in Litter of a Degraded Midwestern Oak Woodland

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    Litter-inhabiting Collembola and mites were sampled using pitfall traps over a twelve-month period from four sub-communities within a 100-acre (40-ha) oak-woodland complex in northern Cook County, Illinois. Sampled locations included four areas where future ecological restoration was planned (mesic woodland, dry-mesic woodland, mesic upland forest, and buckthorn-dominated savanna) and a mesic woodland control that would not be restored. Fifty-eight mite and 30 Collembola taxa were identified out of 5,308 and 190,402 individuals trapped, respectively. There was a significant positive relationship between litter mass and both mite diversity and the ratio of Oribatida to Prostigmata and a significant negative relationship between Collembola diversity and litter. Based on multivariate analysis, Collembola and mite composition differed by sub-community and season interaction

    MAINE'S LOBSTER FISHERY - MANAGING A COMMON PROPERTY RESOURCE

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    Resource /Energy Economics and Policy,

    Multi-species and multi-interest management: An ecosystem approach to market squid (Loligo opalescens) harvest in California

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    Market squid (Loligo opalescens) plays a vital role in the California ecosystem and serves as a major link in the food chain as both a predator and prey species. For over a century, market squid has also been harvested off the California coast from Monterey to San Pedro. Expanding global markets, coupled with a decline in squid product from other parts of the world, in recent years has fueled rapid expansion of the virtually unregulated California fishery. Lack of regulatory management, in combination with dramatic increases in fishing effort and landings, has raised numerous concerns from the scientific, fishing, and regulatory communities. In an effort to address these concerns, the National Oceanic and Atmospheric Administration’s (NOAA) Channel Islands National Marine Sanctuary (CINMS) hosted a panel discussion at the October 1997 California Cooperative Oceanic and Fisheries Investigations (CalCOFI) Conference; it focused on ecosystem management implications for the burgeoning market squid fishery. Both panel and audience members addressed issues such as: the direct and indirect effects of commercial harvesting upon squid biomass; the effects of harvest and the role of squid in the broader marine community; the effects of environmental variation on squid population dynamics; the sustainability of the fishery from the point of view of both scientists and the fishers themselves; and the conservation management options for what is currently an open access and unregulated fishery. Herein are the key points of the ecosystem management panel discussion in the form of a preface, an executive summary, and transcript. (PDF contains 33 pages.

    The Drosophilids of a Pristine Old-Growth Northern Hardwood Forest

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    The current study summarizes the results of a species inventory survey for drosophilid flies (family Drosophilidae, order Diptera) in a primeval forest in northern Michigan. The two main goals of the investigation were to list the species inhabiting the Huron Mountain Club and to collect live specimens for the illustrations in the book Drosophilids of the Midwest and Northeast . From 2014 to 2016, I found 22 drosophilid species, which belong to the two subfamilies Steganinae and Drosophilinae. Future long-term studies are planned to test how the drosophilid populations respond to climate change

    Hypercarnivorous apex predator could provide ecosystem services by dispersing seeds

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    Large ?hypercarnivorous? felids are recognized for their role as apex predators and hence as key elements in food webs and ecosystem functioning through competition and depredation. Here we show that cougars (Puma concolor), one of the largest and the most widely ranging apex felid predators with an strictly carnivorous diet, could be also effective secondary long distance seed dispersers, potentially establishing direct and non-herbivore mediated interactions with plant species at the bottom of the food web. Cougars accidently ingest and disseminate large amounts of seeds (31,678 seeds in 123 scats) of plant species initially consumed by their main prey, the Eared Dove Zenaida auriculata. The germination potential of seeds for three of the weedy/invasive plant species more abundantly found in cougar scats (19,570 seeds) was not significantly different from that observed in seeds obtained from dove gizzards, indicating that seed passage through cougar guts did not affect seed germination. Considering the estimated cougar density in our study area, dispersal of seeds by cougars could allow a mean, annual seed spread of ~5,000 seeds per km2. Our results demonstrate that strictly carnivorous, felid predators could have broad and overlooked ecological functions related to ecosystem structuring and functioning.Fil: Sarasola, José Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Zanón Martínez, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Costan, Andrea Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Ripple, William. State University of Oregon; Estados Unido
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