Aquaculture and Fisheries Commons^™

Quantifying Antarctic Krill Connectivity Across The West Antarctic Peninsula And Its Role In Large-Scale Pygoscelis Penguin Population Dynamics, Katherine L. Gallagher, Michael S. Dinniman, Heather J. Lynch

CCPO Publications

Antarctic krill (Euphausia superba) are considered a keystone species for higher trophic level predators along the West Antarctic Peninsula (WAP) during the austral summer. The connectivity of krill may play a critical role in predator biogeography, especially for central-place foragers such as the Pygoscelis spp. penguins that breed along the WAP during the austral summer. Antarctic krill are also heavily fished commercially; therefore, understanding population connectivity of krill is critical to effective management. Here, we used a physical ocean model to examine adult krill connectivity in this region using simulated krill with realistic diel vertical migration behaviors across …

Evaluating A Possible New Paradigm For Recruitment Dynamics: Predicting Poor Recruitment For Striped Bass (Morone Saxatilis) From An Environmental Variable, Julie M. Gross, Philip Sadler, John M. Hoenig

VIMS Articles

Understanding what causes large year classes and predicting them has been called the holy grail of fisheries science, one of the last great unanswered questions. Recruitment prediction, or forecasting, is an important component for setting fishery catch limits. We propose a new approach, called the “poor-recruitment paradigm”, for predicting recruitment using environmental variables. This approach hypothesizes that it is easier to predict poor recruitment rather than good recruitment because an environmental variable affects recruitment only when its value is extreme (lethal); otherwise, the variable may be benign and not influence recruitment. Thus, good recruitment necessitates all environmental conditions not be …

Gear Specific Catch Rates And Population Dynamics Of Channel Catfish In The Mississippi River, Colby Gainer

MSU Graduate Theses

Perpetual anthropogenic alterations have imposed deleterious effects on aquatic ecosystems. In the Mississippi River, channelization, dams, and loss of floodplain connectivity have all been reputed as detrimental. Dynamic rate functions (i.e., recruitment, growth, and mortality) are the driving forces behind fish populations. Understanding population dynamics is important for guiding management decisions. Knowledge of vital rates can provide pivotal information that will determine spatiotemporal population-level changes within the system. In the Mississippi River, Channel Catfish are a commercially and recreationally important species. However, limited population demographic information currently exists in the Upper Mississippi River. We sought to determine the most effective …

Population Demographics Of Silver Carp Hypophthalmichthys Molitrix In Kentucky Lake, Allison M. Lebeda

Murray State Theses and Dissertations

Invasive species continue to threaten aquatic ecosystems in the United States. Silver Carp Hypophthalmichthys molitrix have successfully infiltrated much of the Mississippi River Basin, including Kentucky Lake – a large reservoir located on the Tennessee River in Western Kentucky. Although Silver Carp have been present in Kentucky Lake for at least a decade, until recently, very little was known about the population, how often successful reproduction is occurring, or the environmental conditions that facilitate strong year-classes. Hence, it is difficult for managers to predict the potential impact of Silver Carp on native species. Silver Carp were collected from Kentucky Lake …

Western Prairie Stream Fisheries: An Assessment Of Past And Present Fish Assemblage Structure, Biotic Homogenization, And Population Dynamics In Western South Dakota Streams, Stephen Jones

Electronic Theses and Dissertations

Biodiversity is declining globally, especially in in aquatic systems. Prairies are one of the most endangered ecosystem types in North America, and their conversion into agriculture or development as a result of urbanization has had negative effects on prairie stream fish communities. Continued monitoring of fish assemblage change and the population dynamics of prairie stream fishes will provide researchers and managers with valuable information needed to detect and mitigate past and future negative impacts on prairie stream aquatic ecosystems. Sampling was conducted in the mainstem and tributaries of the Grand, Moreau, Cheyenne, Bad, and White rivers within western South Dakota. …

Measuring Fertilization In Populations Of Sea Scallop (Placopecten Magellanicus): Developing And Testing Methods In The Laboratory And Field, Skylar Bayer

Electronic Theses and Dissertations

Most marine organisms are broadcast spawners, releasing their sperm and eggs into the water column. Methods of measuring in situ fertilization have proven successful with a few model species, which are reviewed in my introductory chapter. However, many commercially exploited species, such as the sea scallop Placopecten magellanicus, have been neglected. Sea scallop populations have greatly increased from fishing closures, but the mechanism behind this response is uncertain, particularly in regard to fertilization. In this dissertation I developed a methodology of measuring fertilization success and spawning events of P. magellanicus, tested it in laboratory and field settings, and …

Management Strategy Evaluation For The Atlantic Surfclam (Spisula Solidissima) Using A Spatially Explicit, Vessel-Based Fisheries Model, Kelsey M. Kuykendall, Eric N. Powell, John M. Klink, Paula T. Moreno, Robert T. Leaf

CCPO Publications

The commercially valuable Atlantic surfclam (Spisula solidissima) is harvested along the northeastern continental shelf of the United States. Its range has contracted and shifted north, driven by warmer bottom water temperatures. Declining landings per unit of effort (LPUE) in the Mid-Atlantic Bight (MAB) is one result. Declining stock abundance and LPUE suggest that overfishing may be occurring off New Jersey. A management strategy evaluation (MSE) for the Atlantic surfclam is implemented to evaluate rotating closures to enhance Atlantic surfclam productivity and increase fishery viability in the MAB. Active agents of the MSE model are individual fishing vessels with …

Spatial And Temporal Dynamics Of Western Australia’S Commercially Important Sharks, Matias Braccini, R. Mcauley, Alastair Harry

Fisheries research reports

This project took advantage of an unprecedented deployment of acoustic receiver infrastructure around the Western Australian coast to monitor a large number of sharks implanted with acoustic tags. This research was undertaken to better understand the temporal and spatial dynamics of commercially-important sharks in Western Australia, which has enabled a re-evaluation of the risks of cryptic sources of catch and bycatch to dusky and sandbar shark stocks and development of population simulation models with which to test the implications of spatially-different histories of fishery management, as well as future spatial-management arrangements for whiskery and gummy sharks stocks.

Review Of Potential Fisheries And Marine Management Impacts On The South-Western Australian White Shark Population, S.M Taylor, J.M Braccini, R. Mcauley, W.J Fletcher

Fisheries research reports

Following five fatal incidents involving white sharks (Carcharodon carcharias) off the lower west coast of Western Australia between September 2011 and July 2012, as well as other highly-publicised non-fatal encounters with this species, in 2012 the State Government funded several new initiatives to better understand white sharks in Western Australia and the likely effectiveness of any community safety interventions in Western Australian waters.

Spatiotemporal Variation In Flow-Dependent Recruitment Of Long-Lived Riverine Fish: Model Development And Evaluation, Daisuke Goto, Martin J. Hamel, Jeremy J. Hammen, Mathew L. Rugg, Mark A. Pegg, Valery E. Forbes

School of Biological Sciences: Faculty Publications

Abstract Natural flow regimes can play a major role as an overarching ecosystem driver in reproduction and recruitment of riverine fishes. Human needs for freshwater however have altered hydrology of many riverine systems worldwide, threatening fish population sustainability. To understand and predict how spatiotemporal dynamics of flow regimes influence reproductive and recruitment variability, and ultimately population sustainability of shovelnose sturgeon (Scaphirhynchus platorynchus), we develop a spatially explicit (1D) individual-based population model that mechanistically (via energetics-based processes) simulates daily activities (dispersal, spawning, foraging, growth, and survival). With field observations of sturgeon and habitat conditions in a major tributary of …

Determining Scaphirhynchus Sturgeon Population Demographics And Dynamics: Implications For Range-Wide Management, Recovery, And Conservation, Martin J. Hamel

School of Natural Resources: Dissertations, Theses, and Student Research

Sturgeons (Acipenseridae) have experienced world-wide declines as a result of anthropogenic effects such as over-harvest, habitat degradation, altered flow regimes, and pollution. Nearly all European and Asian sturgeon species have experienced population declines and have subsequently been classified as either threatened or endangered. North American sturgeons have experienced a similar plight in that all eight native sturgeon species are listed as endangered, threatened, or of special concern. Direct linkages between North American sturgeon declines and anthropogenic effects are difficult to assess due to scale considerations, fluctuating environmental conditions, difficulty in capture, and the interaction of all these effects. To recover, …

Mortality Estimate Of Chinese Mystery Snail, Bellamya Chinensis (Reeve, 1863) In A Nebraska Reservoir, Danielle M. Haak, Noelle M. Chaine, Bruce J. Stephen, Alec Wong, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The Chinese mystery snail (Bellamya chinensis) is an aquatic invasive species found throughout the USA. Little is known about this species’ life history or ecology, and only one population estimate has been published, for Wild Plum Lake in southeast Nebraska. A recent die-off event occurred at this same reservoir and we present a mortality estimate for this B. chinensis population using a quadrat approach. Assuming uniform distribution throughout the newly-exposed lake bed (20,900 m2), we estimate 42,845 individuals died during this event, amounting to approximately 17% of the previously-estimated population size of 253,570. Assuming uniform distribution throughout all …

Distributions Of Sharks Across A Continental Shelf In The Northern Gulf Of Mexico, J. Marcus Drymon, Sean P. Powers, John Dindo, Brian Dzwonkowski, Terry A. Henwood

University Faculty and Staff Publications

Declines in shark populations have sparked researchers and fishery managers to investigate more prudent approaches to the conservation of these fish. As managers strive to improve data collection for stock assessment, fisheries-independent surveys have expanded to include data-deficient areas such as coastal regions. To that end, a catch series from a nearshore survey off Alabama was combined with data from a concurrent offshore survey with identical methodology to examine the depth use of sharks across the continental shelf (2–366 m). The combined data set contained 22 species of sharks collected from 1995 to 2008: 21 species in the offshore data …

Potential Effects Of Catastrophic Cyanobacteria Blooms On Caribbean Spiny Lobster Population Dynamics In Florida Bay Usa, Donald C. Behringer, Mark J. Butler Iv

Biological Sciences Faculty Publications

No abstract provided.

A Bioenergetics-Based Population Dynamics Model Of Pacific Herring (Clupea Harengus Pallasi) Coupled To A Lower Trophic Level Nutrient–Phytoplankton–Zooplankton Model: Description, Calibration, And Sensitivity Analysis, Bernard A. Megrey, Kenneth A. Rose, Robert A. Klumb, Douglas E. Hay, Francisco E. Werner, David L. Eslinger, S. Lan Smithg

United States Fish and Wildlife: Staff Publications

We describe an approach to dynamically couple a fish bioenergetics-based population dynamics model to the NEMURO lower trophic level nutrient–phytoplankton–zooplankton model. The coupled models, denoted NEMURO.FISH and configured for Pacific herring (Clupea harengus pallasii) on the west coast of Vancouver Island, are capable of simulating the daily dynamics of the lower trophic levels and the daily average weight and numbers of individual herring in each of 10 age classes over multiple years. New recruits to the herring population are added each June based on either constant recruitment or dynamic recruitment generated from an environmental Ricker spawner–recruitment relationship. The …

Reproductive Success Of Piping Plovers On Alkali Lakes In North Dakota And Montana, Robert K. Murphy, Michael J. Rabenberg, Marriah L. Sondreal, Bruce R. Casler, Debra A. Guenther

United States Fish and Wildlife: Staff Publications

Low reproductive success is thought to be a chief cause of the steady decline in numbers of piping plover (Charadrius melodus) that nest in the northern Great Plains. Surprisingly, few reproductive success data are published from alkali lakes in the region, where most breeding pairs of piping plover nest. During 1994 to 1997 we measured nest success and fledging rates of piping plovers at 32 alkali lakes across northwestern North Dakota and northeastern Montana, at the center of the species' breeding range in the Great Plains. Annual nest success and fledging rates averaged 38% (Mayfield estimate; 20 to …

Understanding The Success And Failure Of Oyster Populations: The Importance Of Sampled Variables And Sample Timing, Thomas M. Soniat, Eric N. Powell, Eileen E. Hofmann, John M. Klinck

CCPO Publications

One of the primary obstacles to understanding why some oyster populations are successful and others are not is the complex interaction of environmental variables with oyster physiology and with such population variables as the rates of recruitment and juvenile mortality. A numerical model is useful in investigating how population structure originates out of this complexity. We have monitored a suite of environmental conditions over an environmental gradient to document the importance of short time-scale variations in such variables as food supply, turbidity, and salinity. Then, using a coupled oyster disease population dynamics model, we examine the need for short rime-scale …

A Model Of The Population Dynamics Of The Blue Crab In Chesapeake Bay, Betty Springer Hester

OES Theses and Dissertations

This study has particular application to the blue crab fisheries in Chesapeake Bay, an economically important industry whose successful management has been hindered by relatively poor understanding of the population dynamics. Recent biological studies have indicated a systematic spawning behavior which seems designed for ejection of larvae seaward from the bay entrance where they spend their pre-metamorphosis stages in the neuston. A physical mechanism for retention of the larvae in sufficient proximity to the bay entrance for their return at the proper time which involves the action of wind stress in shallow waters is proposed. Since the supply of blue …

Population Dynamics And Net Production Of Brown Trout (Salmo Trutta) In Two Areas Of A High Gradient Mountain Stream, Jeffrey C. Gosse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimates of the brown trout (Salmo trutta) population were made in two areas of the Blacksmith Fork River, Cache County, Utah, from June 1972 to June 1973. Additional data were obtained on movement, growth, mortality, biomass, production, and yield.

Population density was highly variable in the area where habitat alterations had occurred, but was relatively uniform where the habitat was undisturbed. The brown trout exhibited little movement except during spawning season. Instantaneous growth and mortality rates are provided for each age group.

Mean annual biomass in the two areas was 12.0 and 10.2 grams per square meter and …