Aquaculture and Fisheries Commons^™

Optimizing Strategies To Hydraulically Plant Atlantic Salmon Eggs Based On Fry Dispersal Patterns, Ernest J. Atkinson

Electronic Theses and Dissertations

The Gulf of Maine Distinct Population Segment of Atlantic Salmon has suffered from habitat loss and exploitation over the last century. Hatchery supplementation has prevented the extirpation of the species, but stocking methods represent tradeoffs between survival, domestication, and logistics. Egg planting, the use of eyed embryos, maximizes natural rearing opportunities which can be important for adaptation. This method, however, is logistically demanding and requires significant labor over large spatial, but short temporal, scales dictated by the ontogeny of the fish. However, the survival and dispersal behavior of Atlantic Salmon fry immediately after emergence from eggs planted in artificial nests …

Assessing Habitat Suitability Of Ribbed Mussels (Geukensia Demissa) In Georgia Salt Marshes By Examining Predicted Mussel Densities And Mussel Population Parameters, William K. Annis Jr

Electronic Theses and Dissertations

Geukensia demissa (ribbed mussel) is an ecology important bivalve that has the potential to contribute to salt marsh restoration. Understanding the factors that contribute to the distribution of mussels can help inform managers on choosing locations to optimize the survivorship of mussels in restoration projects. This study sought to model mussel densities across the coast of Georgia and to compare predicted mussel densities with mussel population parameters as means to gauge habitat suitability. Mussel densities were collected through field surveys across a range of salt marshes along the coast of Georgia and were compared with spatial data such as distance …

Spatio-Temporal Dynamics Of Atlantic Cod Bycatch In The Maine Lobster Fishery And Its Impacts On Stock Assessment, Robert E. Boenish

Electronic Theses and Dissertations

Of the most iconic fish species in the world, the Atlantic cod (Gadus morhua, hereafter, cod) has been a mainstay in the North Atlantic for centuries. While many global fish stocks have received increased pressure with the advent of new, more efficient fishing technology in the mid-20^th century, exceptional pressure has been placed on this prized gadoid. Bycatch, or the unintended catch of organisms, is one of the biggest global fisheries issues. Directly resulting from the failed recovery of cod in the GoM, attention has been placed as to possible sources of unaccounted catch. Among the most …

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 …

Understanding The Impact Of Commercial Harvest On White Suckers (Catostomus Commersonii) In Maine, Megan A. Begley

Electronic Theses and Dissertations

The State of Maine issues an unlimited number of commercial permits for the harvest of White Suckers Catostomus commersonii in Maine’s inland waters. The fishery provides a necessary source of fresh lobster Homarus americanus bait to coastal communities at a time when other bait sources are scarce. The impacts of the increasing number of permits and subsequent numbers of fishermen on the white sucker population is unknown. The Maine Department on Inland Fisheries and Wildlife (MDIFW) has closed a number of waters due to concerns that overfishing and incidental catch of other fish species may occur.

In Chapter 1, we …

Phenotypic Divergence Of Indigenous And Translocated Arctic Charr (Salvelinus Alpinus) Populations In Maine, Wendy K. Michaud

Electronic Theses and Dissertations

Selection on traits related to trophic ecology is recognized as an important contributing factor in adaptive divergence and speciation. For several freshwater fish species, including Arctic charr (Salvelinus alpinus), such selection is commonly reflected in relationships between diet, habitat use and phenotypic divergence. Trophic specializations that emerge have been extensively studied among sympatric forms, but much less is known of the extent of this type of divergence in allopatry. Trait differences among these forms are also thought to reflect thousands of years of evolution, making it difficult to examine root causes of such divergence in natural populations. Here, I address …

Endocrine Disruption In Atlantic Salmon (Salmo Salar) Exposed To Pesticides, Benjamin W. Spaulding

Electronic Theses and Dissertations

Since the early 19801s, the numbers of adult Atlantic salmon (Salmo salar) returning to Maine's rivers have been in a general decline. In addition, estimates of parr, freshwater smolt and emigrating smolt populations indicate low overwinter survival rates. Overall, these low numbers, along with several other factors, resulted in the Atlantic salmon in eight rivers in Maine being classified as a distinct population segment under the Endangered Species Act. Because many of the listed rivers are found near lowbush blueberry barrens, I investigated the endocrine disrupting potential and effects of selected blueberry pesticides on Atlantic salmon. An E-SCREEN assay was …

The Relationship Between Green Sea Urchin Spawning, Spring Phytoplankton Blooms, And The Winter-Spring Hydrography At Selected Sites In Maine, Lindsay C. N. Seward

Electronic Theses and Dissertations

The relationship between green sea urchin spawning, spring phytoplankton blooms, and hydrography were examined at multiple spatial scales during the winter-spring of 2000 at selected sites along the coast of Maine. To determine factors contributing to the variation observed in the timing of green sea urchin spawning, sea urchins, phytoplankton, and oceanographic variables were sampled biweekly at four sites in central Maine and three sites in eastern Maine. Water column properties and phytoplankton was intensively examined at sites in central Maine, while sites in eastern Maine were less well characterized. Analysis of gonad indices showed that spawning was protracted in …

The Value Of Rockweed (Ascophylum Nodosum) As Habitat For Tidepool Fishes, Amy Marie Gullo

Electronic Theses and Dissertations

Tidepool fishes are an interesting and commercially valuable guild of fishes that reside in tidepools at low tide. Tidepool fishes of the North Atlantic Coast reside in tidepools only during the late spring to Ml months, and are typically juveniles of subtidal adult species. Tidepool fishes on the Pacific Coast of North America have been studied extensively, but species of the North Atlantic Coast have rarely been studied. An important area of study is the use of different tidepool microhabitats by fishes, specifically the use of rockweed (AscophyZZum nodosum) fringe, which is present in many tidepools. Rockweed is an algal …

Adaptation Of Striped Bass To Sea Water Following Direct Transfer From Freshwater: Morphological, Biochemical, And Physiological Parameters, Judy A. King

Electronic Theses and Dissertations

There has been heightened interest in the biology of striped bass (Morone saxatilis) because of increased pollution in their native spawning grounds and because of their extensive use in landlocked sport fisheries. Their euryhalinity makes them an excellent species for osmoregulation studies. The objective of this research was to study the rate of adaptation of striped bass gills to sea water (3% salt) after direct transfer from freshwater using biochemical (ion transport enzyme levels), physiological (chloride efflux), and ultrastructural methods. Striped bass have specialized osmoregulatory cells located on the interlamellar and afferent surfaces of their gill filaments as shown by …