12 resultados para Jennings, Ferris
em Aquatic Commons
Resumo:
Marine ecosystems compose the major source (85%) of world fisheries production (Garcia and Newton, 1997). Although only a few fish species tend to dominate fishery catches (Jennings et al., 2001), a large diversity of fishes representing varied taxonomic levels, ecological guilds, and life histories is commonly taken. Recently, 66% of global marine resources were determined to be either fully, heavily, or over-exploited (Botsford et al., 1997). Considering the current state of many fisheries, the large diversity of species taken globally, and the general lack of resources to adequately assess many stocks, it has become important to develop shortcuts that may provide methods fisheries scientists can use to determine which stocks are in danger of overexploitation and which recovery plans are appropriate when biological data are limited (Stobutzki et al., 2001).
Resumo:
Fishing is widely recognized to have profound effects on estuarine and marine ecosystems (Hammer and Jansson, 1993; Dayton et al., 1995). Intense commercial and recreational harvest of valuable species can result in population collapses of target and nontarget species (Botsford et al., 1997; Pauly et al., 1998; Collie et al. 2000; Jackson et al., 2001). Fishing gear, such as trawls and dredges, that are dragged over the seafloor inflict damage to the benthic habitat (Dayton et al., 1995; Engel and Kvitek, 1995; Jennings and Kaiser, 1998; Watling and Norse, 1998). As the growing human population, over-capitalization, and increasing government subsidies of fishing place increasing pressures on marine resources (Myers, 1997), a clear understanding of the mechanisms by which fishing affects coastal systems is required to craft sustainable fisheries management.
Resumo:
Body length measurement is an important part of growth, condition, and mortality analyses of larval and juvenile fish. If the measurements are not accurate (i.e., do not reflect real fish length), results of subsequent analyses may be affected considerably (McGurk, 1985; Fey, 1999; Porter et al., 2001). The primary cause of error in fish length measurement is shrinkage related to collection and preservation (Theilacker, 1980; Hay, 1981; Butler, 1992; Fey, 1999). The magnitude of shrinkage depends on many factors, namely the duration and speed of the collection tow, abundance of other planktonic organisms in the sample (Theilacker, 1980; Hay, 1981; Jennings, 1991), the type and strength of the preservative (Hay, 1982), and the species of fish (Jennings, 1991; Fey, 1999). Further, fish size affects shrinkage (Fowler and Smith, 1983; Fey, 1999, 2001), indicating that live length should be modeled as a function of preserved length (Pepin et al., 1998; Fey, 1999).
Resumo:
John Otterbein Snyder (1867–1943) was an early student of David Starr Jordan at Stanford University and subsequently rose to become an assistant professor there. During his 34 years with the university he taught a wide variety of courses in various branches of zoology and advised numerous students. He eventually mentored 8 M.A. and 4 Ph.D. students to completion at Stanford. He also assisted in the collection of tens of thousands of fish specimens from the western Pacific, central Pacific, and the West Coast of North America, part of the time while stationed as “Naturalist” aboard the U.S. Fish Commission’s Steamer Albatross (1902–06). Although his early publications dealt mainly with fish groups and descriptions (often as a junior author with Jordan), after 1910 he became more autonomous and eventually rose to become one of the Pacific salmon, Oncorhynchus spp., experts on the West Coast. Throughout his career, he was especially esteemed by colleagues as “a stimulating teacher,” “an excellent biologist,” and “a fine man.
Resumo:
At her launch on 19 October 1882 in Wilmington, Del., the Albatross was the world’s first large deep-sea oceanographic and fisheries research vessel, and she would go on to have a distinguished 40-year career, ranging from the north Atlantic Ocean to the Gulf of Mexico, around Cape Horn in 1887–88, and into the North Pacific. By 1908, Deputy Fish Commissioner Hugh M. Smith reported that “The Albatross has contributed more to the knowledge of marine biology than has any other vessel.” And, of course, her career continued for another 13 years, being decommissioned in late 1921, serving later as a training vessel for nautical cadets, and disappearing from the records in Hamburg, Germany, in late 1928.
Resumo:
Although selected aspects of the commercial fishery in the Virgin Islands have been documented since the early 1930's (Fiedler and Jarvis, 1932; Idyll and Randall, 1959; Hess, 1961; Swingle et al. 1970; Brownell, 1971; Brownell and Rainey, 1971; Sylvester and Dammann, 1972, and Olsen et al., 1978), fish corrals and their use have not been described. This account, based on personal observations made during 1985-86, summarizes commercial fishing methods in the Virgin Islands (U. S. and British), documents the use of fish corrals, and serves as an introduction to the methodologies of this harvesting technique. Interviews of commercial fishermen about how and when fish corrals are used provided information not available from direct observation. Local common names for gear type and fish species are shown in parentheses.
An analysis of some morphometric characteristics of the spiny lobster, Panulirus argus, in St. Lucia
Resumo:
The US Fish and Wildlife Service Cape Romain National Wildlife Refuge (CRNWR) and the Center for Coastal Environmental Health and Biomolecular Research (CCEHBR) at Charleston are interested in assessing the status of our coastal resources in light of increased coastal development and recreational use. Through an Interagency Agreement (FWS #1448-40181-00-H-001), an ecological characterization was undertaken to describe the status of and potential impacts to resources at CRNWR. This report describes historic fisheries-independent or non-commercial data relevant to CRNWR that can be used to evaluate the role of the Refuge as habitat for nearshore and offshore fish species. The purpose of this document is two-fold, first to give resource managers an understanding of fisheries data that have been collected over the years and, second, to illustrate how these data can be applied to address specific management issues. This report provides an overview of historic fisheries data collected along the southeast coast, as well as basic summaries of that data relevant to CRNWR, indicating how these data can be used to address specific questions of interest to Refuge managers and biologists.
Resumo:
There has been much recent interest in the effects of fishing on habitat and non-target species, as well as in protecting certain areas of the seabed from these effects (e.g. Jennings and Kaiser, 1998; Benaka, 1999; Langton and Auster, 1999; Kaiser and de Groot, 2000). As part of an effort to determine the effectiveness of marine closed areas in promoting recovery of commercial species (e.g. haddock, Melanogrammus aegelfinus; sea scallops, Placopecten magellanicus; yellowtail flounder, Limanda ferruginea; cod, Gadus morhua), nontarget species, and habitat, a multidisciplinary research cruise was conducted by the Northeast Fisheries Science Center (NEFSC), National Marine Fisheries Service. The cruise was conducted in closed area II (CA-II) of the eastern portion of Georges Bank during 19–29 June 2000 (Fig. 1). The area has historically produced high landings of scallops but was closed in 1994 principally for groundfish recovery (Fogarty and Murawski, 1998). The southern portion of the area was reopened to scallop fishing from 15 June to 12 November 1999, and again from 15 June to 15 August 2000. While conducting our planned sampling, we observed scallop viscera (the noncalcareous remains from scallops that have been shucked by commercial fishermen at sea) in the stomachs of several fish species at some of these locations, namely little skate (Raja erinacea), winter skate (R. ocellata), red hake (Urophycis chuss), and longhorn sculpin (Myoxocephalus octodecemspinosus). We examined the stomach contents of a known scavenger, the longhorn sculpin, to evaluate and document the extent of this phenomenon.