Fishery resources of waters along the route of the trans-Alaska pipeline between Yukon River and Atigun Pass in north central Alaska /

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Towards balanced exploitation and management of the fishery resources of Uganda

A casual study of the hydrological map of Uganda would convince every serious fisherman and fisheater that he is most favoured to be in Uganda. The extent and distribution of the country's aquatic system plus the rich variety of fish species there is promises a fishery potential of considerable magnitude: The open waterways comprised by the Uganda portions of Lakes Victoria, Albert and Edward; and Lakes Kyoga, George plus minor lakes Wamala, Kijanebarora, mutanda, etc. occupy about 15% of the total surface area (91,000 m2; Depart. Land Survey, 1962). Most of the nation's fish supplies are currontly from this source. 1.2. A rich network of permanent and seasonal rivers and streams filling and/or emptying various water systems covers most of Uganda. This aquatic network is associated with a fish fauna whose immense significance as a source of protein is perhaps better appreciated by the local subsistance fisherman and consumer than by the fisheries scientist and manager in this country. Many species of this fish fauna have strong affinities with the open water systems while some are typically riverine. 1.3. Then there are wetlands composed mainly of expanses of swamp, but including some areas of bog. These cover about 2% of the country. While the variety of fish fauna found here is limited by the rather hostile nature of the environment (comparatively de-oxygenated under a canopy of dense stands of emergont vegetation) several specialised fishes e.g. Clarias spp. and Protpterus aethiopicus (Kamongo) occur here. Availability of permanent and seasonal sources of water, well distributed throughout most areas of Uganda, opens up immense potential for a variety of aquaculture practices. However, while active exploitation of much of these fishery resources is currently underway, important questions regarding the magnitudes of the various resource potentials and dynamics, and about suitable levels and modes of exploitation, are yet unanswered. These gaps in knowledge go about the fishery resources of Uganda would hinder formulation of adequate development and management schemes. This short paper examines some of the above problems and suggests some approaches towards balanced oxploitation and management of the fisheries of Uganda.

Fishery biology and management of Protonibea diacanthus (Sciaenidae) aggregations in far Northern Cape York Peninsula waters

The sciaenid Protonibea diacanthus is a large, long-lived predatory fish of inshore northern Australian waters, which forms annual aggregations that are fished extensively by traditional (subsistence) and recreational fishers. There are now widespread concerns that the resource is being overexploited. Indigenous fishers of the Cape York Northern Peninsula Area (NPA) relate that large adult fish (up to 1500 mm total length (TL)) made up the bulk of the catch from the sciaenid aggregations until about 1994. In contrast, sexually mature P. diacanthus comprised only a small component (12 fish out of 270=4.4%) examined in a 1999–2000 sampling programme that was biased towards the largest individuals available. At 790 mm TL, the minimum size at first maturity for female P. diacanthus in this study is much smaller than the 920 mm TL reported previously in Queensland waters. Developing ovaries were observed in specimens sampled from sciaenid aggregations which formed in NPA waters between May and September 2000. However, no fish with ripe or spent gonads were found in the study, so the current timing and location of the spawning season for P. diacanthus in the region remain unknown. Food items observed in the analysis of the diet of P. diacanthus from the NPA included a variety of teleosts and invertebrates. The range of animal taxa represented in the prey items support the description of an ‘opportunistic predator’ attributed to the species. In our sampling, the stomach contents of fish caught during the time of the aggregation events did not differ from those observed at other times of the year. A total of 114 P. diacanthus were tagged and released at aggregation sites during the study period, and 3 fish (2.6%) were subsequently recaptured. The low rate of tag returns from the wild stock tagging programme, both in this study (2.6%) and from recreational fisher tag/release programmes for the sciaenid elsewhere in Queensland (6.5%), were not explained by tag loss nor mortality, given the high retention rate of tags and the zero mortality seen in tank trials. In response to the biological findings from this study, indigenous community councils of the NPA imposed a 2-year fishing moratorium for P. diacanthus. Surveys at aggregation sites in 2002 and 2003 established that much larger fish (mean size 103.5 cm TL) were again present on the grounds, albeit in very low numbers. These recent preliminary results highlight the critical need for continued monitoring and management of the P. diacanthus fishery in the NPA, if prospects for resource recovery are to be realised. The NPA initiative has provided a rare opportunity to negotiate a co-management strategy, based on scientific data and traditional knowledge, for the recovery of a cultural and economically significant fished resource.

Marine resources, biophysical processes, and environmental management of a tropical shelf seaway: Torres Strait, Australia-Introduction to the special issue

This special issue of Continental Shelf Research contains 20 papers giving research results produced as part of Australia's Torres Strait Co-operative Research Centre (CRC) Program, which was funded over a three-year period during 2003-2006. Marine biophysical, fisheries, socioeconomic-cultural and extension research in the Torres Strait region of northeastern Australia was carried out to meet three aims: 1) support the sustainable development of marine resources and minimize impacts of resource use in Torres Strait; 2) enhance the conservation of the marine environment and the social, cultural and economic well being of all stakeholders, particularly the Torres Strait peoples; and 3) contribute to effective policy formulation and management decision making. Subjects covered, including commercial and traditional fisheries management, impacts of anthropogenic sediment inputs on seagrass meadows and communication of science results to local communities, have broad applications to other similar environments.

Queensland Coastal Wetlands Resources Mapping Data

1:100,000 coastal wetland vegetation mapping for Queensland including mangrove communities, saltpans and saline grasslands. Mapping taken from Landsat TM images with ground truthing. Additional metadata is available for details of techniques and accuracy for each section of coastline. Data Currency for each section of coast: NT border to Flinders River - 1995 SE Gulf of Carpentaria - 1987, 1988, 1991, 1992 Cape York Peninsula - 1986-88, 1991 Cape Trib to Bowling Green Bay - 1997-99 The Burdekin Region - 1991 The Bowen Region - 1994-95 The Whitsunday Region - 1997 Repulse Bay - 1989 Central Qld - 1995, 1997 The Curtis Coast Region - 1997 Round Hill Head to Tin Can Inlet - 1997 Moreton Region - 1995. Article Links: 1/ #1662. Queensland Coastal Wetland Resources: the Northern Territory Border to Flinders River. Project Report. Information Series QI00099. 2/ #1663. Queensland Coastal Wetland Resources: Sand Bay to Keppel Bay. Project Report. Information Series QI00100. 3/ #1664. Queensland Coastal Wetland Resources: Cape Tribulation to Bowling Green Bay. Project Report. Information Series QI01064. 4/ #1666. Coastal Wetlands Resources Investigation of the Burdekin Delta for declaration as fisheries reserves. Report to Ocean Rescue 2000. Project Report. 5/ #1667. Queensland Coastal Wetland Resource Investigation of the Bowen Region: Cape Upstart to Gloucester Island. Project Report. 6/ #1784. Resource Assessment of the Tidal Wetland Vegetation of Western Cape York Peninsula, North Queensland, Report to Ocean Rescue 2000. Project Report. 7/ #1785. Marine Vegetation of Cape York Peninsula. Cape York Peninsula Land Use Strategy. Project Report. 8/ #3544. Queensland Coastal Wetland Resources: The Whitsunday Region. Project Report.Information Series QI01065. 9/ #3545. Queensland Coastal Wetland Resources: Round Hill Head to Tin Can Inlet. Project Report. Information Series QI99081.

Management implications of climate change impacts of fisheries resources

This application was developed in response to the widely recognised concern that climate change will result in changes to marine life and ecosystems, and hence fisheries, throughout Australia with tropical marine ecosystems in northern Australia identified as being particularly vulnerable. These changes are predicted to vary spatially depending on local climate and biophysical processes. Northern Australia is one of three major Australian regions predicted to be impacted. The project addresses the important FRDC strategic challenge of improving the management of aquatic natural resources to ensure their sustainability through research and management that accounts for the effects that climate change may have on the resources.

Fisheries resources of the Bohle River, Queensland.

The fisheries resources of the Bohle River and its small catchment area adjacent Townsville, north Queensland, were investigated through available literature, scientific research surveys and analysis of commercial and recreational catch and effort data. Research surveys produced a total of 4383 fish from the waters of the Bohle River during 1997-1998. These were classified into 104 fish species from 49 families. Gillnetting, cast netting, fish trapping and crab potting techniques were used in the estuarine waters of the Bohle River with freshwater reaches in the upper catchment surveyed by electrofishing. This range of survey techniques was used to estimate the relative abundance of ten commercially and recreationally important species: Barramundi (Lates calcarifer), king threadfin (Polydactylus macrochir), blue threadfin (Eleutheronema tetradactylum), mangrove jack (Lutjanus argentimaculatus), banded and spotted grunter (Pomadasys kaakan and Pomadasys argenteus), pikey and yellowfin bream (Acanthopagrus berda and Acanthopagrus australis), tilapia (Oreochromis spp.), jungle perch (Kuhlia rupestris) and mud crab (Scylla serrata). The results of each survey method are discussed with a focus on spatial and temporal patterns in diversity and catch rate.

Stock assessment of the Queensland east coast common coral trout (Plectropomus leopardus) fishery

Common coral trout Plectropomus leopardus is an iconic fish of the Great Barrier Reef (GBR) and is the most important fish for the commercial fishery there. Most of the catch is exported live to Asia. This stock assessment was undertaken in response to falls in catch sizes and catch rates in recent years, in order to gauge the status of the stock. It is the first stock assessment ever conducted of coral trout on the GBR, and brings together a multitude of different data sources for the first time. The GBR is very large and was divided into a regional structure based on the Bioregions defined by expert committees appointed by the Great Barrier Reef Marine Park Authority (GBRMPA) as part of the 2004 rezoning of the GBR. The regional structure consists of six Regions, from the Far Northern Region in the north to the Swains and Capricorn–Bunker Regions in the south. Regions also closely follow the boundaries between Bioregions. Two of the northern Regions are split into Subregions on the basis of potential changes in fishing intensity between the Subregions; there are nine Subregions altogether, which include four Regions that are not split. Bioregions are split into Subbioregions along the Subregion boundaries. Finally, each Subbioregion is split into a “blue” population which is open to fishing and a “green” population which is closed to fishing. The fishery is unusual in that catch rates as an indicator of abundance of coral trout are heavily influenced by tropical cyclones. After a major cyclone, catch rates fall for two to three years, and rebound after that. This effect is well correlated with the times of occurrence of cyclones, and usually occurs in the same month that the cyclone strikes. However, statistical analyses correlating catch rates with cyclone wind energy did not provide significantly different catch rate trends. Alternative indicators of cyclone strength may explain more of the catch rate decline, and future work should investigate this. Another feature of catch rates is the phenomenon of social learning in coral trout populations, whereby when a population of coral trout is fished, individuals quickly learn not to take bait. Then the catch rate falls sharply even when the population size is still high. The social learning may take place by fish directly observing their fellows being hooked, or perhaps heeding a chemo-sensory cue emitted by fish that are hooked. As part of the assessment, analysis of data from replenishment closures of Boult Reef in the Capricorn–Bunker Region (closed 1983–86) and Bramble Reef in the Townsville Subregion (closed 1992–95) estimated a strong social learning effect. A major data source for the stock assessment was the large collection of underwater visual survey (UVS) data collected by divers who counted the coral trout that they sighted. This allowed estimation of the density of coral trout in the different Bioregions (expressed as a number of fish per hectare). Combined with mapping data of all the 3000 or so reefs making up the GBR, the UVS results provided direct estimates of the population size in each Subbioregion. A regional population dynamic model was developed to account for the intricacies of coral trout population dynamics and catch rates. Because the statistical analysis of catch rates did not attribute much of the decline to tropical cyclones, (and thereby implied “real” declines in biomass), and because in contrast the UVS data indicate relatively stable population sizes, model outputs were unduly influenced by the unlikely hypothesis that falling catch rates are real. The alternative hypothesis that UVS data are closer to the mark and declining catch rates are an artefact of spurious (e.g., cyclone impact) effects is much more probable. Judging by the population size estimates provided by the UVS data, there is no biological problem with the status of coral trout stocks. The estimate of the total number of Plectropomus leopardus on blue zones on the GBR in the mid-1980s (the time of the major UVS series) was 5.34 million legal-sized fish, or about 8400 t exploitable biomass, with an 2 additional 3350 t in green zones (using the current zoning which was introduced on 1 July 2004). For the offshore regions favoured by commercial fishers, the figure was about 4.90 million legal-sized fish in blue zones, or about 7700 t exploitable biomass. There is, however, an economic problem, as indicated by relatively low catch rates and anecdotal information provided by commercial fishers. The costs of fishing the GBR by hook and line (the only method compatible with the GBR’s high conservation status) are high, and commercial fishers are unable to operate profitably when catch rates are depressed (e.g., from a tropical cyclone). The economic problem is compounded by the effect of social learning in coral trout, whereby catch rates fall rapidly if fishers keep returning to the same fishing locations. In response, commercial fishers tend to spread out over the GBR, including the Far Northern and Swains Regions which are far from port and incur higher travel costs. The economic problem provides some logic to a reduction in the TACC. Such a reduction during good times, such as when the fishery is rebounding after a major tropical cyclone, could provide a net benefit to the fishery, as it would provide a margin of stock safety and make the fishery more economically robust by providing higher catch rates during subsequent periods of depressed catches. During hard times when catch rates are low (e.g., shortly after a major tropical cyclone), a change to the TACC would have little effect as even a reduced TACC would not come close to being filled. Quota adjustments based on catch rates should take account of long-term trends in order to mitigate variability and cyclone effects in data.

Improved utilization and increased availability of fishery products as an effective control of aggravated animal protein deficiency - induced malnutrition in Nigeria

The estimated potential of Nigerian fish resources is 1,830,994 tonnes(t) whereas the demand based on per capita consumption of 12.0kg and a population of 88.5 million is 1.085 million tonnes. Supply is presently less than 500,000 tons. The gap between demand and supply have to be met through improved utilization and increased availability of fish and fishery products. The role of fish in nutrition is recognized, since it supplies a good balance of protein, vitamins and minerals and a relatively low caloric content. This paper appraises the consumption and utilisation pattern of fish in Nigeria, the spoilage of fish and prevention of losses as a means of increasing the availability of fish for human consumption and consequent control of aggravated animal protein deficiency - induced malnutrition. The paper further highlights the point that without increased landings, increased supply of fish can be achieved through reduction of postharvest loss of what is presently caught. The use of newly designed smoke - drying equipment to achieve such goal is highlighted. The paper also emphasises the need to put into human food chain those non-conventional fishery resources and by-catch of shrimp and demersal trawl fishes by conversion into high value protein products like fish cakes, fish pies and salted dried cakes

Conservation needs of fisheries resources and reorientation for sustainable captive and culture practices

A discussion is presented on the importance of conservation of fishery resources, considering in particular the situation in Nigeria and providing also an outline of various legislations made by government. Suggestions are given regarding the following: education on the importance of conservation; fish farming or aquaculture; restocking or rejuvenation of depleted water bodies; stock assessment; monitoring and surveillance; provision of fishing inputs; and, extension research linkage

The role of communication in the management of Nigeria's capture fisheries resources

Development and management indices identified in the capture fishery resources focus on stock management, freshwater and marine pollution by organic and inorganic compounds including silting, plankton sustainability, fishing methods, biological productivity, energy cycles, ornamental fish and sanctuaries. The issue of post-harvest handling and processing is also discussed. The paper also identifies fisheries sectorial problems at the artisanal and industrial level both at sea and at shore, in the processing plant, infrastructure, manpower and marketing issues. The paper suggests that advocacy should be incorporated into extension and communication programme ensuring some changes in attitudes of all stakeholders in the fisheries game. The paper concludes stating that policy makers should stop paying lip-service to the fisheries sub-sector and should create a separate Ministry for Fisheries

Reef Habitats in the Middle Atlantic Bight: Abundance, Distribution, Associated Biological Communities, and Fishery Resource Use

One particular habitat type in the Middle Atlantic Bight is not well recognized among fishery scientists and managers, although it is will known and used by recreational and commercial fisheries. This habitat consists of a variety of hard-surface, elevated relief "reef" or reef-like environments that are widely distributed across the predominantly flat or undulating, sandy areas of the Bight and include both natural rocky areas and man-made structures, e.g. shipwrecks and artificial reefs. Although there are natural rock and shellfish reefs in southern New England coastal waters and estuaries throughout the Bight, most reef habitats in the region appear to be man-made reef habitat modification/creation may be increasing. Very little effort has been devoted to the study of this habitat's distribution, abundance, use by living marine resources and associated biological communities (except on estuarine oyster reefs) and fishery value or management. This poorly studied and surveyed habitat can provide fish refuge from trawls and can be a factor in studies of the distribution and abundance of a variety of reef-associated fishery resources. This review provides a preliminary summary of information found on relative distribution and abundance of reef habitat in the Bight, the living marine resources and biological communities that commonly use it, threats to this habitat and its biological resources, and the value or potential value of artificial reefs to fishery or habitat and its biological resources, and the value or potential value of artificial reefs to fishery or habitat managers. The purpose of the review is to initiate an awareness among resource managers about this habitat, its role in resource management, and the need for research.

Our living oceans: report on the status of U.S. living marine resources, 6th edition

The National Marine Fisheries Service (NMFS) is dedicated to the stewardship of living marine resources (LMR’s). This is accomplished through science-based conservation and management, and the promotion of healthy ecosystems. As a steward, NMFS has an obligation to conserve, protect, and manage these resources in a way that ensures their continuation as functioning components of healthy marine ecosystems, affords economic opportunities, and enhances the quality of life for the American public. In addition to its responsibilities within the U.S. Exclusive Economic Zone (EEZ), NMFS plays a supportive and advisory role in the management of LMR’s in the coastal areas under state jurisdiction and provides scientific and policy leadership in the international arena. NMFS also implements international measures for the conservation and management of LMR’s, as appropriate.NMFS receives its stewardship responsibilities under a number of Federal laws. These include the Nation’s primary fisheries law, the Magnuson Fishery Conservation and Management Act. This law was first passed in 1976, later reauthorized as the Magnuson-Stevens Fishery Conservation and Management Act in 1996, and reauthorized again on 12 January 2007 as the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act (MSRA). The MSRA mandates strong action to conserve and manage fishery resources and requires NMFS to end overfishing by 2010 in all U.S. commercial and recreational fisheries, rebuild all overfished stocks, and conserve essential fish habitat.

A case study on the impact of industrial effluent disposal on the fishery of Amba River estuary, Maharashtra

The impact of waste discharge on fishery resources is a matter of great concern. The accepted norm in all environmental impact assessment studies is to avoid areas of high fishery potential while locating a marine outfall. Contemplating on this aspect a case study was conducted in the Amba River estuary before and after the establishment of a petrochemical complex at Nagothane. The treated wastewater from this complex is released through a subsurface outfall after adopting effective control measures for marine disposal of waste. Experimental trawling was done at five locations covering a distance of 30 km during 1990 to 1991. The catch rate within the estuary varied from 0.6 to 255 kg/h (av 24 kg/h). The trend indicated considerable decrease in fishery potential from the mouth of the estuary (av 64 kg/h) to the upstream location (av 11 kg/h). A total of 49 species of fishes, 16 species of prawns, 7 species of crabs and 1 species of lobster were identified from the collections. Number of species gradually increased from the interior segment at Dharamtar (8) to the outer area near Revas (18). A comparison of the quantitative and qualitative nature of the post outfall and pre outfall data revealed only marginal difference. The study indicates that if necessary precautions are taken to render the waste harmless the marine ecology will hardly be affected.

200 mile Exclusive Economic Zone and fishery development in Sri Lanka

Following details of the marine fishery resources of Sri Lanka, prospects for fishery development with respect to the 200-mile Economic Zone are examined, outlining also the 5-year fisheries development plan (1979-83).