Download or read book Comparison of two trawls used for monitoring juvenile fish abundance in North Carolina written by Paul Stanley Phalen and published by . This book was released on 1989 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book North Carolina Publications written by and published by . This book was released on 1989 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Annual Conference Southeastern Association of Fish and Wildlife Agencies written by Southeastern Association of Fish and Wildlife Agencies and published by . This book was released on 1989 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Flounder Fishery of the Gulf of Mexico United States written by Stephen J. VanderKooy and published by . This book was released on 2000 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Research written by and published by . This book was released on 1969 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Checklist of State Publications written by Library of Congress. Exchange and Gift Division and published by . This book was released on 1990 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Trawls for Monitoring and Harvesting Fish Populations in Lake Oahe South Dakota written by William Roland Nelson and published by . This book was released on 1974 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trawls of various designs and sizes were compared to evaluate their use for monitoring and harvesting fish populations in Lake Oahe. Catches of a 20.7-m semiballoon trawl, selected to monitor changes in the fish populations from 1965 to 1970, showed a downward trend in the abundance of all species, except walleye; the decline was largest in the lower area of the reservoir with a slight increase in the upper area. Of two trawl designs tested, semiballoon trawls captured more fish per hour than high-rise trawls, and a 15.9-m semiballoon trawl with a 3.8-cm mesh cod end captured fish at the highest and most consistent rate. The size and species composition of the fish caught in small-mesh trawls differed from thos caught in trap nets. Trawl cataches were too small to recommend or warrant their use as a commercial fishing gear, but the use of both small mess trawls and trap nets should improve accuracy in monitoring fish populations in this reservoir.
Download or read book Effects of Land Use Change on Juvenile Fishes Blue Crab and Brown Shrimp Abundance in the Estuarine Nursery Habitats of North Carolina written by Gregory F. R. Meyer and published by . This book was released on 2011 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. coastal region is home to more than half of the American population. Also, the coastal counties' population is growing much faster than that of inland counties. With a high density and an increasing population, there are rapid changes in land-use and land-cover (LULC) types, characterized mostly by the increase in areal coverage of anthropogenic land uses (agriculture and developed), while "natural/unaltered" land uses (forest and wetland) are in decline. The human population growth and land-use and land-cover changes caused by humans generate nutrients and pollutants to coastal waters, which can affect water quality and aquatic life. Trends in the land-use and land-cover changes that might impact fish and invertebrate species abundance at 71 selected estuarine stations sampled by the North Carolina Division of Marine Fisheries (NCDMF) juvenile sampling program (Program 120) were analyzed. Land use categories of interest were forest, wetland, agriculture, and developed areas. The selected fish and invertebrate species were: Atlantic croaker (Micropogonias undulatus), Atlantic menhaden (Brevoortia tyrannus), pinfish (Lagodon rhomboides), southern flounder (Paralichthys lethostigma), spot (Leiostomus xanthurus), blue crab (Callinectes sapidus), and brown shrimp (Farfantepenaeus aztectus). Geographic information system (GIS) data, remotely sensed data and statistical techniques were used to quantify the LULC type changes between 1980 and 2000 within the immediate coastal watersheds of North Carolina. Forest has been the most affected, losing about 30.1% of its total area to the increase (~24.1%) of agriculture area. The wetland and developed land use varied depending on location, but their overall changes were small when the whole study area was considered. The long-term trends in abundance of juveniles of selected fish and invertebrate species indicated declines at certain sampling stations, and increases at others. In order to determine whether land use changes were correlated with changes in the selected species, and also to find which other factors might influence changes in their abundance, I analyzed seven predictor variables [(1) percent land use change within local catchments centered on the NCDMF sampling sites, (2) number of pollution point sources in large USDA Natural Resources Soil Conservation watersheds, (3) number of people in US Census tracts within watersheds, (4) water temperature, (5) water salinity, (6) station depth, and (7) distance to inlet (minimum distance by water to an ocean inlet) for each NCDMF juvenile fish and invertebrate trawl sampling program station] in a classification and regression tree statistical analysis to predict normalized change in trawl catch for the selected species in NCDMF Program 120 data between 1980 and 2004. Land use changes were found to be influential to the number of blue crab, southern founder and Atlantic croaker, and declines were observed at 47 stations when land use changes were greater than 13% (blue crab), at 30 stations when land use changes were greater than 21% (southern flounder), and 6 stations when land use changes were greater than 53% (Atlantic croaker). Water salinity was found to be more important than land use change for southern flounder catch, and increased catch was observed at stations with salinity 14 ppt. No significant changes due to land use could be associated with changes in Program 120 trawl catch of brown shrimp, Atlantic menhaden, pinfish or spot. There was a long-term increase in pinfish in the Program 120 data. Pinfish increased most at stations where bottom temperature was 25 C. Atlantic menhaden declined at stations where bottom temperature was 24 °C. Brown shrimp abundance was increased at stations where the distance to inlet was 21 km and highest when salinity was 14 ppt. Spot showed an increase in abundance when distance to inlet was greater than 42 km and the human population was 883 people/census tract in the year 2000. Land use change impacts were observed in the classification and regression tree analysis for blue crab at 66% of the NCDMF stations, 42% of stations for southern flounder, and 8% of stations for Atlantic croaker. These three species were ranked first, second, and fourth in commercial value in North Carolina fisheries, and were the only species of those selected for this study that were considered to be overfished in 2000 by the NCDMF. Thus, land use change had the greatest impact on species that were targets of intensive commercial fishing and had low adult spawning stock. This result suggests an interaction between commercial fisheries harvest and land development for agriculture along the coast. Recruitment of these species may have been low because of reduced spawning stock due to commercial harvests, and this reduced recruitment was most noticeable where land use changes were high. Species that were not intensively harvested (pinfish) or had stable adult stock sizes as determined by the NCDMF (brown shrimp, Atlantic menhaden, and spot) were able to produce many recruits, and this high recruitment may have allowed colonization of areas with marginal habitat due to land use changes. Few stations showed declines in abundance of the juvenile stages of these latter species, suggesting that land use change was not a significant factor between 1980 and 2004. However, post-recruitment mortality (survivorship after June throughout the summer and fall) was not monitored by NCDMF and should be studied in the future. The results of this study serve as an early warning to coastal managers regarding the potential impact of coastal land use changes. The abundance and growth of these valuable fishes and invertebrates in North Carolina estuarine nursery habitats could be reduced in the future, given the national trends in coastal development and fishery harvests.
Download or read book MONTHLY CHECKLIST OF STATE PUBLICATIONS written by and published by . This book was released on 1990 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Research 1973 written by United States. National Oceanic and Atmospheric Administration and published by . This book was released on 1973 with total page 1200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Trawling and Dredging on Seafloor Habitat written by National Research Council and published by National Academies Press. This book was released on 2002-08-09 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concerns over the potential ecological effects of fishing have increased with the expansion of fisheries throughout the marine waters of the United States. Effects of Trawling and Dredging on Seafloor Habitat describes how assessment of fishing impacts depends on gear type, number and location of bottom tows, and the physical and biological characteristics of seafloor habitats. Many experimental studies have documented acute, gear-specific effects of trawling and dredging on various types of habitat. These studies indicate that low mobility, long-lived species are more vulnerable to towed fishing gear than short-lived species in areas where the seabed is often disturbed by natural phenomena. Trawling and dredging may also change the composition and productivity of fish communities dependent on seafloor habitats for food and refuge. The scale of these impacts depends on the level of fishing effort. This volume presents color maps of fishing effort for all regions with significant bottom trawl or dredge fisheries-the first time that such data has been assembled and analyzed for the entire nation.
Download or read book Marine Fisheries Review written by and published by . This book was released on 1980 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1980 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1980 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improving the Collection Management and Use of Marine Fisheries Data written by National Research Council and published by National Academies Press. This book was released on 2000-12-10 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Congress has promoted fisheries science for over a century and its involvement in fisheries management took a great leap forward with passage of the Fisheries Conservation and Management Act of 1976. In the past decade, Congress has requested advice from the National Research Council (NRC) on both national issues (e.g., individual fishing quotas and community development quotas) and the assessments related to specific fisheries (Northeast groundfish). This report was produced, in part, in response to another congressional request, this time related to the assessments of the summer flounder stocks along the East Coast of the United States. Following the initial request, the NRC, National Marine Fisheries Service (NMFS), and congressional staff agreed to broaden the study into a more comprehensive review of marine fisheries data collection, management, and use.
Download or read book Water Resources Research Catalog written by United States. Office of Water Research and Technology and published by . This book was released on 1973 with total page 1208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beginning with vol. 9, only new and continuing but modified projects are listed. Vols. 8- should be kept as a record of continuing but unchanged projects.
Download or read book Oceanic Abstracts written by and published by . This book was released on 1997-04 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:
