Broodstock management status and some suggestions to control negative selection and inbreeding in hatchery stocks in Bangladesh

The freshwater river systems and floodplains of Bangladesh are the breeding grounds for 13 endemic species of carps and barbs and a large number of other fish species, including a number of exotic carps and other species that have been introduced for aquaculture. Since 1967, breeding of endemic and exotic aquaculture species for seed producton through hypophysation techniques has become a common practice. The paper describes the present status of broodstock management, identifies problems, and suggests some guidelines to control negative selection and inbreeding in hatchery stocks in Bangladesh.

Present status of mangrove crab (Scylla serrata (Forskal)) culture in China

The status of mangrove crab (Scylla serrata) culture in China and suggestions on how this may become an important sector in the place are presented.

Status and conservation of Reeves shad resources in China

An endangered fish species in China, Reeves shad (Tenualosa reversii), is finding hope of restoration and conservation in aquaculture and induced breeding efforts spearheaded by the Yangtze River Fisheries Management Commission. The history and sensitive traits of the Reeves shad are described featuring the species' life history, population dynamics and management of the Reeves shad resources.

The Status of Eelgrass, Zostera marina, as Bay Scallop Habitat: Consequences for the Fishery in the Western Atlantic

Zostera marina is a member of a widely distributed genus of seagrasses, all commonly called eelgrass. The reported distribution of eelgrass along the east coast of the United States is from Maine to North Carolina. Eelgrass inhabits a variety of coastal habitats, due in part to its ability to tolerate a wide range of environmental parameters. Eelgrass meadows provide habitat, nurseries, and feeding grounds for a number of commercially and ecologically important species, including the bay scallop, Argopecten irradians. In the early 1930’s, a marine event, termed the “wasting disease,” was responsible for catastrophic declines in eelgrass beds of the coastal waters of North America and Europe, with the virtual elimination of Z. marina meadows in the Atlantic basin. Following eelgrass declines, disastrous losses were documented for bay scallop populations, evidence of the importance of eelgrass in supporting healthy scallop stocks. Today, increased turbidity arising from point and non-point source nutrient loading and sediment runoff are the primary threats to eelgrass along the Atlantic coast and, along with recruitment limitation, are likely reasons for the lack of recovery by eelgrass to pre-1930’s levels. Eelgrass is at a historical low for most of the western Atlantic with uncertain prospects for systematic improvement. However, of all the North American seagrasses, eelgrass has a growth rate and strategy that makes it especially conducive to restoration and several states maintain ongoing mapping, monitoring, and restoration programs to enhance and improve this critical resource. The lack of eelgrass recovery in some areas, coupled with increasing anthropogenic impacts to seagrasses over the last century and heavy fishing pressure on scallops which naturally have erratic annual quantities, all point to a fishery with profound challenges for survival.

Cook Inlet Belugas, Delphinapterus leucas: Status and Overview

Of the five populations of beluga, Delphinapterus leucas, in Alaska, the most isolated is the one in Cook Inlet (Hazard, 1988; Hill and DeMaster, 1998) (Fig. 1). The geographic and genetic segregation of this stock (O’Corry-Crowe et al., 1997), combined with the beluga’s tendency toward site fidelity in summer, makes this population especially vulnerable to impacts from large or persistent harvests.

The Great Whales: History and Status of Six Species Listed as Endangered Under the U.S. Endangered Species Act of 1973

In the history of whaling from prehistoric to modern times, the large whales, sometimes called the “great whales,” were hunted most heavily owing in part to their corresponding value in oil, meat, and baleen. Regional populations of North Atlantic right whales, Eubalaena glacialis glacialis, were already decimated by 1700, and the North Atlantic gray whale, Eschrichtius robustus, was hunted to extinction by the early 1700’s (Mitchell and Mead1).

The Status of Queen Conch, Strombus gigas, Research in the Caribbean

Today there are approximately 230 published scientific papers on queen conch, Strombus gigas. Publication on this species began in the 1960's and increased rapidly during the 1980's and 1990's (Fig. 1). The increase in publication after 1980 was associated with three particular areas ofendeavor. First, many articles were published to document the rapid depletion of conch stocks throughout the Caribbean Sea. Second, substantial progress was made in understanding processes related to growth, mortality, and reproduction in queen conch. Third, because of the apparent and widespread decline in conch, several research laboratories, especially in Florida, Puerto Rico, Venezuela, and the Turks and Caicos Islands began experiments related to hatchery production of juvenile conch. The primary intent was to replenish wild stocks by releasing hatchery-reared animals. Today, hatchery production has been relatively well perfected, and the increase in numbers of scientific papers related specifically to culture has slowed. A thorough review of the history of conch mariculture was provided by Creswell (1994), and Davis (1994) summarized the details of larval culture technique.

The Bowhead Whale, Balaena mysticetus: Its Historic and Current Status

The bowhead whale, Balaena mysticetus, is currently listed as endangered under the Endangered Species Act of 1973 and as depleted under the Marine Mammal Protection Act of 1972. Literature on the species is updated since 1984, and elements are reviewed that may contribute to the evaluation of the status of bowhead whale stocks.

The Threatened Status of Steller Sea Lions, Eumetopias jubatus, under the Endangered Species Act: Effects on Alaska Groundfish Fisheries Management

In April 1990, the Steller sea lion, Eumetopias jubatus, was listed as threatened under the U.S. Endangered Species Act by emergency action. Competitive interactions with the billion-dollar Alaska commercial groundfish fisheries have been suggested as one of the possible contributing factors to the Steller sea lion population decline. Since the listing, fisheries managers have attempted to address the potential impacts of the groundfish fisheries on Steller sea lion recovery. In this paper, we review pertinent Federal legislation, biological information on the Steller sea lion decline, changes in the Alaska trawl fishery for walleye pollock, Theragra chalcogramma, since the late 1970's, andpossible interactions between fisheries and sea lions. Using three cases, we illustrate how the listing of Steller sea lions has affected Alaska groundfish fisheries through: I) actions taken at the time of listing designed to limit the potential for directhuman-related sea lion mortality, 2) actions addressing spatial and temporal separation of fisheries from sea lions, and 3) introduction of risk-adverse stock assessment methodologies and Steller sea lion conservation considerations directly in the annual quota-setting process. This discussion shows some of the ways that North Pacific groundfish resource managers have begun to explicitly consider the conservation ofmarine mammal and other nontarget species.

Status, Constraints, and Opportunities for Salmon Culture in the United States: A Review

This paper reviews and analyzes the major factors constraining the development of salmon culture in the United States. A brief review of economic factors in the seafood sector contributing to the industry's recent growth is offered, and the present status of the major producing regions is summarized. The major constraints, which include marketing problems, policy and regulatory constraints, production costs, disease, financiing, and environmental uncertainty, are discussed, followed by recommendations for improving the industry's development.

The Status of Loggerhead, Caretta caretta; Kemp's Ridley, Lepidochelys kempi; and Green, Chelonia mydas, Sea Turtles in U.S. Waters: A Reconsideration

Assessing the status of widely distributed marine species can prove difficult because virtually every sampling technique has assumptions, limitations, and biases that affect the results of the study. These biases often are overlooked when the biological and nonbiological implications of the results are discussed. In a recent review, Thompson (1988) used mostly unpublished population census data derived from studies conducted by the National Marine Fisheries Service (NMFS) to draw conclusions about the status of Kemp's ridley, Lepidochelys kempi; Atlantic coast green turtles, Chelonia mydas; and the loggerhead sea turtle, Caretta caretta.

A comparative survey of the fish populations of 10 West-Midlands meres of SSSI status

This is a comparative survey of the Fish Populations of 10 West-Midlands Mere of Site of Special Scientific Interest Status. The meres of the Shropshire-Cheshire plain (West Midlands) comprise over 60 water bodies. Water quality in the meres ranges from naturally eutrophic to nutrient limited and some of them have received Site of Special Scientific Interest status (SSSIs). This survey was commissioned in order to obtain quantitative information on the fish fauna of selected SSSIs and evaluate the likely impact of fish on other species within the community. The current survey was concerned with 10 of the West Midlands’ meres, a cross section of sites was selected. Sites were widely distributed from Marton Pool in the south-western part of Shropshire to Tabley moat in Chesire. Meres varied in size, depth and nutrient status. All were to be sampled using the methods outlined. The report is divided into different sections for clarity and ease of reference. The materials and methods section provides an outline of the location and status of each mere and information on known fish species present. The results were considered individually and comparatively, relative abundance of fish, species present, their diet, sex, age, parasite burdens and growth. Inter-site comparisons were made using information derived from echo-soundings, growth rate, diet, and species abundance for each site. The final section will be in the form of a general discussion, comparative information from longer term studies, conclusions and recommendations.

The River Ehen salmonid fishery - current status and a summary of fisheries work 1993-1996

This is the report on the River Ehen salmonid fishery - current status and a summary of fisheries work during the period 1993-1996, produced by the Environment Agency North West in 1997. This report draws together a number of investigations and surveys undertaken following the 1993 Strategic fisheries survey of the River Ehen. It specifically details the historic catch data available for this catchment for both salmon and sea trout and examines the current stock levels based on this data. Concerns over sea trout stock levels are raised and a detailed examination of the possible limiting factors involved is included. Information from surveys on the River Keekle is analysed with reference to its potential for sea trout production both currently and with the proposed clean up on Oatlands tip. Salmon production in the historically acidified River Liza sub catchment is examined along with ways of boosting production further following recent reductions in acidic episodes. Future and current issues and actions required in the catchment are listed along with the responsible party and estimated costs involved.