Aquaculture and Fisheries Commons^™

Global Connectivity Of Southern Ocean Ecosystems, Eugene J. Murphy, Nadine M. Johnston, Eileen E. Hofmann, Richard A. Phillips, Jennifer A. Jackson, Andrew J. Constable, Sian F. Henley, Jessica Melbourne-Thomas, Rowan Trebilco, Rachel D. Cavanagh, Geraint A. Tarling, Ryan A. Saunders, David K.A. Barnes, Daniel P. Costa, Stuart P. Corney, Ceridwen I. Fraser, Juan Höfer, Kevin A. Hughes, Chester J. Sands, Sally E. Thorpe, Philip N. Trathan, José C. Xavier

CCPO Publications

Southern Ocean ecosystems are globally important. Processes in the Antarctic atmosphere, cryosphere, and the Southern Ocean directly influence global atmospheric and oceanic systems. Southern Ocean biogeochemistry has also been shown to have global importance. In contrast, ocean ecological processes are often seen as largely separate from the rest of the global system. In this paper, we consider the degree of ecological connectivity at different trophic levels, linking Southern Ocean ecosystems with the global ocean, and their importance not only for the regional ecosystem but also the wider Earth system. We also consider the human system connections, including the role of …

Experimental Analysis Of The Effects Of Hydroscape Structure On Fishes In A Dynamic Wetland, Michael R. Bush

FIU Electronic Theses and Dissertations

Hydroscape structure can play a critical role in animal behavior, abundance, and community structure dynamics. Hydroscape configuration can be dynamic and can change quickly in ephemeral systems. However, ephemeral freshwater wetlands are among the most impacted systems in the world and restoration efforts often rely on incomplete information when establishing management objectives. Further understanding how alterations in hydroscape structure in dynamic systems affect animals is critical for conservation and management success.

To determine impacts that changing hydroscape conditions can have on consumers in freshwater wetlands, I examined the effects of a large-scale physical model on fish behavior, abundance, and community …

Angler Effort And Catch Within A Spatially Complex System Of Small Lakes, Christopher J. Chizinski, Dustin R. Martin, Kevin L. Pope, Tony J. Barada, Jeffrey J. Schuckman

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Spatial layout of waterbodies and waterbody size can affect a creel clerk’s ability to intercept anglers for interviews and to accurately count anglers, which will affect the accuracy and precision of estimates of effort and catch. This study aimed to quantify angling effort and catch across a spatially complex system of19 small (<100 ha) lakes, the Fremont lakes. Total (±SE) angling effort (hours) on individual lakes ranged from 0 (0) to 7,137 (305). Bank anglers utilized 18 of the 19 lakes, and their mean (±SE) trip lengths(hours) ranged from 0.80 (0.31) to 7.75 (6.75), depending on the waterbody. In contrast, boat anglers utilized 14 of the 19 lakes, and their trip lengths ranged from 1.39 (0.24) to 4.25 (0.71), depending on the waterbody. The most sought fishes, as indexed by number of lakes on which effort was exerted, were anything (17 of 19 lakes), largemouth bass Micropterus salmoides (15 of 19 lakes), and channel catfish Ictalurus punctatus (13 of 19 lakes). Bluegill Lepomis machrochirus, crappie Pomoxis spp., and largemouth bass were caught most frequently across the lakes, but catch rates varied considerably by lake. Of the1,138 parties interviewed, most parties (93%) visited …

The Aquarium Trade As An Invasion Pathway In The Pacific Northwest, Angela L. Strecker, Philip M. Campbell, Julian D. Olden

Environmental Science and Management Faculty Publications and Presentations

The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation of the ornamental pet trade as an invasion pathway in the Pacific Northwest region of the United States, where a moderate climate and a large human population present ample opportunities for the introduction and establishment of aquarium trade species. Results from a regional survey of pet stores found that the number of fish (n=400) and plant (n=124) species currently in the aquarium trade is vast. Pet stores import thousands of …

Temporal Shifts In Demography And Life History Of An Anadromous Alewife Population In Connecticut, Justin P. Davis, Eric T. Schultz

EEB Articles

Populations of anadromous alewives (Alosa pseudoharengus) are declining throughout much of their range, particularly in southern New England where fishery moratoriums have recently been instituted in three states. The alewife run at Bride Brook, a coastal stream in East Lyme, Connecticut, was studied from 2003-06 to assess shifts in demography and life history. Annual censuses of abundance, along with sampling for size, age, and spawning history structure were conducted. These data were compared to similar data in 1966-67 at this site. Recent alewife runs at Bride Brook featured lower abundance and younger, smaller fish that were less likely to be …

Estimating Predation On Declining River Herring: Tag-Recapture Study Of Striped Bass In The Connecticut River, Eric T. Schultz, Justin P. Davis, Jason Vokoun

EEB Articles

Populations of anadromous alewife Alosa pseudoharengus and blueback herring Alosa aestivalis, collectively referred to as river herring, have declined in the Connecticut River. A hypothesis for why river herring have declined is that predation pressures have increased associated with recent increases in abundance of striped bass Morone saxatilis. Information on striped bass abundance, size structure, and consumption rates are required to test this hypothesis. This study was designed to provide estimates of striped bass population size in the Connecticut River during the spring migration season, via an intensive mark-recapture exercise and either an open or robust mark-recapture model. …

Anadromous Rainbow Smelt And Tomcod In Connecticut: Assessment Of Populations, Conservation Status, And Need For Restoration Plan, Heather A. Fried, Eric T. Schultz

EEB Articles

(beginning of rainbow smelt executive summary)

Evidence indicates that anadromous rainbow smelt (Osmerus mordax) populations in Connecticut and elsewhere in the northeast United States have severely declined. Several sampling programs have documented declines in Connecticut’s smelt populations over the last three decades (Marcy 1976a, Marcy 1976b, Millstone Environmental Laboratory 2005). Similar declines have also been documented in the Hudson River (ASA Analysis & Communication 2005) and in Massachusetts (personal communication, Brad Chase, MA Division of Marine Fisheries 2004). Recreational and commercial fisheries in the region for this species have virtually ceased (Blake and Smith 1984). The Connecticut Fish Advisory Committee …

Assessment Of Anadromous Alewife And Blueback Herring Populations In Connecticut Coastal Streams And Connecticut River Tributaries, Justin P. Davis, Eric T. Schultz

EEB Articles

Alewife (Alosa pseudoharengus) and blueback herring (A. aestivalis) occur in anadromous populations that have a largely overlapping distribution from Florida to Newfoundland (Loesch 1987). Anadromous populations of these species are commonly collectively referred to as “river herring”. Adults inhabit coastal shelf waters until sexual maturity is reached at age 3-5 (Neves 1981). Sexually mature individuals make spawning migrations, commonly referred to as “runs”, into freshwater systems during spring months (Loesch 1987). Spawners can survive and return to spawn in subsequent years (Mullen et al. 1986). Juveniles reside in freshwater for 3-7 months, at which time they undertake a gradual migration …

Agenda: Biodiversity Protection: Implementation And Reform Of The Endangered Species Act, University Of Colorado Boulder. Natural Resources Law Center

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

Conference organizers and/or faculty included University of Colorado School of Law professors Betsy Rieke, David H. Getches, Michael A. Gheleta and Charles F. Wilkinson.

All across the country--in Congress, in state legislatures and in urban and rural communities--people are discussing why we should or should not protect biodiversity and how best to do so. Since the Endangered Species Act is up for reauthorization, a variety of reform proposals are being debated. Speakers--including natural resource scholars, experts from the private and nonprofit sectors, and government officials--will examine the rationale for biodiversity protection, the legal framework of the Endangered Species Act, and …

Identification Of Tire Leachate Toxicants And A Risk Assessment Of Water Quality Effects Using Tire Reefs In Canals, S. M. Nelson, G. Mueller, D. C. Hemphill, U.S. Bureau Of Reclamation

Publications (WR)

Cover is an important component of aquatic habitat and fisheries management. Fisheries biologists often try to improve habitats through the addition of natural and artificial material to improve cover diversity and complexity. Habitat-improvement programs range from submerging used Christmas trees to more complex programs using sophisticated artificial habitat modules. Used automobile tires have been employed in the large scale construction of reefs and fish attractors in marine environments and to a lesser extent in freshwater and have been recognized as a durable, inexpensive and long-lasting material which benefits fishery communities.

Recent studies by the U.S. Bureau of Reclamation have quantified …

Red Swamp Crayfish Ecology In Lake Mead, Suzanne E. Leavitt, Jennifer Stephens Haley, Mikell Hager, Donald H. Baepler, Nevada Department Of Wildlife

Publications (WR)

Red swamp crayfish (Procambarus clarkii) were trapped in Flamingo Wash, an urban wash of Las Vegas, during four periods of 1988. Life history and reproductive success were determined. The trapped crayfish were marked and released into a study cove in Lake Mead as part of an experimental stocking program. Retrap data from the study cove were used to determine life history, habitat preferences, and movement patterns of the stocked crayfish. In addition, a literature search was done on red swamp crayfish ecology, including food preferences, life history, habitat preferences and fish predation.

Fish Aid: The Lake Mead Fertilization Project, Richard Axler, Larry Paulson, Peter Vaux, Patrick Sollberger, Donald H. Baepler

Publications (WR)

Sport fishing at Lake Mead in Nevada and Arizona is a resource valued at nearly $100 million per year to southern Nevada. During the past two decades, salmonids, mostly trout, have disappeared entirely, the largemouth bass catch has drastically declined despite greater fishing pressure, and the condition factors for striped bass have steadily deteriorated. It appears that a major reduction in phosphorus loading caused by the upstream impoundment of the Colorado River to form Lake Powell in 1963 and advanced wastewater treatment removal of phosphorus from domestic wastewater inflows in 1981 are the principal factors responsible for decreased production at …

Benthic Invertebrates And Crayfish Of Lake Mead, Susan K. Peck, William L. Pratt, James E. Pollard, Larry J. Paulson, Donald H. Baepler

Publications (WR)

The objectives of this study were to:

1. Establish baseline densities of benthic invertebrates and relative abundance of crayfish in Lake Mead.

2. Evaluate the distributions of benthic organisms and crayfish in relation to existing habitat conditions and 1imnological characteristics of Lake Mead.

3. Measure seasonal changes in abundances of benthic organisms and crayfish in Lake Mead.

4. Compare observations of Procambarus clarkii life history in Lake Mead to reports from other aquatic systems.

5. Evaluate the importance of benthic organisms and crayfish as food sources for game fish in Lake Mead.