Search

Understanding the parameters required for a reliable hatchery seed production of the endemic geoduck clam Panopea zelandica (Quoy and Gaimard, 1835) is crucial if New Zealand is to develop a geoduck aquaculture industry. To provide the foundation for routine geoduck larval rearing practices, this study reports on physiological, morphological, and behavioral characteristics throughout the larval developmental process. P. zelandica larvae were reared at 17 °C and 35 ppt, and fed continuously with Tisochrysis lutea and Chaetoceros calcitrans in a flow-through system. The initial veliger stocking densities ranged from 50 to 200 larvae mL − 1 , while residual algal levels were maintained at 20,000 to 80,000 cells mL − 1 in three rearing batches. Larval behavior and morphology were described through observation using video recordings, photomicrographs and scanning electron microscopy. The larval development took 16–19 days from first D-veliger and metamorphosis occurred across a wide size range (300–375 μm shell length). The increase in shell length was linear over time and correlated with the deposition of striae in the prodissoconch II. The ingestion rate followed a power function with time and was closely correlated with the development of the alimentary system, including mouth, esophagus, stomach, style sac, intestine, and digestive gland. Rearing with an initial stocking density of 100 larvae mL − 1 and residual algal background of 20,000 cells mL − 1 resulted in about 76% survival and 15 μm d − 1 growth rate. The results of the preliminary production trials inform rearing practices and provide biological descriptions that appear to be effective as a baseline protocol for the successful commercial production of P. zelandica larvae. Statement of relevance This is the first detailed study of larval development within hatchery conditions for the New Zealand endemic geoduck clam ( Panopea zelandica ). We identified timing of larval developmental stages, including metamorphosis and growth and feeding parameters that are relevant for successful rearing practices of this species for commercial production.

Shellfish aquaculture can result in conflicts among stakeholders who perceive impacts and tradeoffs regarding sense of place, aesthetic, recreational, economic, and ecological values. Pacific geoduck clams (Panopea generosa Gould 1850) are grown in intertidal plots using gear- and labor-intensive techniques that result in a high value export product. A confluence of issues has resulted in on-going social and legal tensions surrounding geoduck aquaculture in southern Puget Sound, Washington (WA), USA. Using interviews and document analysis, we explored stakeholder perspectives and policy issues related to geoduck aquaculture in southern Puget Sound. Twenty-three stakeholders were interviewed, including state agency employees, representatives of the aquaculture industry, nongovernmental organizations, landowners, a tribal member, and an academic. Nine state hearings board decisions on challenges to aquaculture permits were also analyzed. Stakeholders articulated a variety of perspectives regarding a...

Pacific geoduck aquaculture is a growing industry, however, little is known about how geoduck respond to varying environmental conditions, or how the industry will fare under projected climate conditions. To understand how geoduck production may be impacted by low pH associated with ocean acidification, multi-faceted environmental heterogeneity needs to be included to understand species and community responses. In this study, eelgrass habitats and environmental heterogeneity across four estuarine bays were leveraged to examine low pH effects on geoduck under different natural regimes, using targeted proteomics to assess physiology. Juvenile geoduck were deployed in eelgrass and adjacent unvegetated habitats for 30 days while pH, temperature, dissolved oxygen, and salinity were monitored. Across the four bays, pH was lower in unvegetated habitats compared to eelgrass habitats. However this did not impact geoduck growth, survival, or proteomic abundance patterns in gill tissue. Temperature and dissolved oxygen differences across all locations corresponded to differences in growth and targeted protein abundance patterns. Specifically, three protein abundance levels (trifunctional-enzyme β-subunit, puromycin-sensitive aminopeptidase, and heat shock protein 90-α) and shell growth positively correlated with dissolved oxygen variability and inversely correlated with mean temperature. These results demonstrate that geoduck may be resilient to low pH in a natural setting, but other abiotic factors (i.e. temperature, dissolved oxygen variability) may have a greater influence on geoduck physiology. In addition this study contributes to the understanding of how eelgrass patches influences water chemistry.

The global geoduck market evolved substantially over the past four decades. This paper identifies the key transitional periods and discusses the catalysts that contributed to the evolution of the global geoduck market since its commercial inception during the 1970s. Specifically, this paper focuses on how the transition to rights-based fisheries management in Canada's wild geoduck fishery fostered changes in product form and ex-vessel prices that impacted the entire wild geoduck industry. This evolution in turn facilitated the emergence of intertidal and subtidal geoduck aquaculture, which led to further changes in the global geoduck industry including changes in: sources of supply, volume of production, trade patterns, primary markets, preference for product attributes, and fishery value. The global geoduck industry is still evolving, and this paper identifies and discusses the key drivers and constraints facing the market as it moves forward.

Intertidal aquaculture for geoducks (Panopea generosa Gould, 1850) is expanding in southern Puget Sound, Washington, where gently sloping sandy beaches are used for field culture. Geoduck aquaculture contributes significantly to the regional economy, but has become controversial because of a range of unresolved questions involving potential biological impacts on marine ecosystems. From 2008 through 2012, the authors used a ''before-after-control-impact'' experimental design, emphasizing spatial scales comparable with those used by geoduck culturists to evaluate the effects of harvesting market-ready geoducks on associated benthic infaunal communities. Infauna were sampled at three different study locations in southern Puget Sound at monthly intervals before, during, and after harvests of clams, and along extralimital transects extending away from the edges of cultured plots to assess the effects of harvest activities in adjacent uncultured habitat. Using multivariate statistical approaches, strong seasonal and spatial signals in patterns of abundance were found, but there was scant evidence of effects on the community structure associated with geoduck harvest disturbances within cultured plots. Likewise, no indications of significant ''spillover'' effects of harvest on uncultured habitat adjacent to cultured plots were noted. Complementary univariate approaches revealed little evidence of harvest effects on infaunal biodiversity and indications of modest effects on populations of individual infaunal taxa. Of 10 common taxa analyzed, only three showed evidence of reduced densities, although minor, after harvests whereas the remaining seven taxa indicated either neutral responses to harvest disturbances or increased abundance either during or in the months after harvest events. It is suggested that a relatively active natural disturbance regime, including both small-scale and large-scale events that occur with comparable intensity but more frequently than geoduck harvest events in cultured plots, has facilitated assemblage-level infaunal resistance and resilience to harvest disturbances.

In Washington state, commercial culture of geoducks (Panopea generosa) involves large-scale out-planting of juveniles to intertidal habitats, and installation of PVC tubes and netting to exclude predators and increase early survival. Structures associated with this nascent aquaculture method are examined to determine whether they affect patterns of use by resident and transient macrofauna. Results are summarized from regular surveys of aquaculture operations and reference beaches in 2009 to 2011 at three sites during three phases of culture: (1) pregear (-geoducks, -structure), (2) gear present (+geoducks, +structures), and (3) postgear (+geoducks, -structures). Resident macroinvertebrates (infauna and epifauna) were sampled monthly (in most cases) using coring methods at low tide during all three phases. Differences in community composition between culture plots and reference areas were examined with permutational analysis of variance and homogeneity of multivariate dispersion tests. Scuba and shoreline transect surveys were used to examine habitat use by transient fish and macroinvertebrates. Analysis of similarity and complementary nonmetric multidimensional scaling were used to compare differences between species functional groups and habitat type during different aquaculture phases. Results suggest that resident and transient macrofauna respond differently to structures associated with geoduck aquaculture. No consistent differences in the community of resident macrofauna were observed at culture plots or reference areas at the three sites during any year. Conversely, total abundance of transient fish and macroinvertebrates were more than two times greater at culture plots than reference areas when aquaculture structures were in place. Community composition differed (analysis of similarity) between culture and reference plots during the gear-present phase, but did not persist to the next farming stage (postgear). Habitat complexity associated with shellfish aquaculture may attract some structure-associated transient species observed infrequently on reference beaches, and may displace other species that typically occur in areas lacking epibenthic structure. This study provides a first look at the effects of multiple phases of geoduck farming on macrofauna, and has important implications for the management of a rapidly expanding sector of the aquaculture industry.

Aquaculture for the Pacific geoduck (Panopea generosa) is a small but expanding industry in Washington state, where geoducks are native and genetic interactions between wild and cultured geoducks are likely. To examine the potential genetic implications of geoduck aquaculture, genetic diversity, and effective number of breeders (Nb), five contiguous year-classes of cultured geoducks were compared with a wild population. The results from five microsatellite loci indicate the cultured year-classes exhibited reduced allelic richness and Nb as well as increased mean pairwise genetic relatedness. However, examination of relationships within year-classes using sibship assignment revealed that many parents contributed progeny to each year-class. The geoducks in each year-class were comprised of 9 to 25 full-sib groups as well as a large number of individuals unrelated to others at the full-sib level. No clear pattern emerged regarding changes in genetic diversity during the 5-y time span of this study. ...

Marine fishes are known to be a good quality source of protein and rich in essential amino acids Moreover it contains high amount of monounsaturated and polyunsaturated fatty acids that might favourably improve lipid profiles and reduce risk of coronary heart disease CHD The present study was carried out to determine the nutritional evaluation of raw marine fishes of Landing site and market The result shows that Lutjanus sebae from landing site tend to have the highest moisture content when compared with market fish of The landing site of C malabaricus had the highest protein and ash content of and whereas the market fish reduced to and The L sebae collected from the landing site had the highest lipid and Carbohydrate content of and whereas the market fish had and Thus the present study revealed that the freshly captured fish have very good nutritional value than the market fishes

Aquaculture operations are a frequent and prominent cause of anthropogenic disturbance to marine and estuarine communities and may alter species composition and abundance. However, little is known about how such disturbances affect trophic linkages or ecosystem functions. In Puget Sound, Washington, aquaculture of the Pacific geoduck clam (Panopea generosa) is increasing and involves placing nets and polyvinyl chloride (PVC) tubes in intertidal areas to protect juvenile geoducks from predators. Initial studies of the structured phase of the farming cycle have documented limited impacts on the abundance of some species. To examine the effect of geoduck aquaculture on ecological linkages, the trophic relationships of a local ubiquitous consumer, Pacific staghorn sculpin (Leptocottus armatus), to its invertebrate prey were compared between geoduck aquaculture sites and nearby reference areas with no aquaculture. Mark-recapture data indicated that sculpin exhibit local site fidelity to cultured and reference areas. The stomach contents of sculpin and stable isotope signatures of sculpin and their prey were examined to study the trophic ecology of cultured and reference areas. Results showed that the structured phase of geoduck aquaculture initiated some changes to staghorn sculpin ecology, as reflected in sculpin diet through stomach content analysis. However, carbon and nitrogen stable isotopes revealed that the general food web function of sculpin remained unchanged. The source of carbon at the base of the food web and the trophic position of sculpin were not impacted by geoduck aquaculture. The study has important implications for geoduck aquaculture management and will inform regulatory decisions related to shellfish aquaculture policy.

Artemia is a Crustacean of Artemidae family, whose importance has been realized as of year 1930 in the field of aquaculture as live food source. Whereas under current global conditions, Artemia cannot be harvested from its natural habitats, today growing the same is deemed as one of the main approaches to achieve such species, as the environmental and genetic factors as well as type of Artemia directly affect the growing of this species. In this study, 2 species of local Artemia from Ghom Province, A. parthenogenetica, were cultured together with imported species, A. franciscana, in 6 constructed ponds, each in 3 treatments along the coast of Ghom’s Namak Lake for a 180-day period. The results indicate that cyst and biomass culture and production in the local specie are more suitable than the imported one and 80 and 66 kg/hectare of cyst were produced from Ghom’s local and A. franciscana imported species, respectively. 2,800 and 2,200 kg of biomass were also achieved from Ghom’s local and A. franciscana imported species, respectively during the study period. The final result of this study showed that adaptability of the local species with the local growing natural environments conditions was cost-effective. On the other hand, the results indicated that the suitable species for culturing in any given region is the relevant local species, which preserving the genetic reserves in each region also, the invasion of unwanted species is also prevented.

[EN] In this brief review, the evolution of Thermal-unit Growth Coefficient (TGC) is presented, from the initial model adapted to gilthead sea bream, until the Quantile TGC-Mixed Model. The two first adaptations were the effective temperature, and the quantile regression, that allowed the possibility of describing the evolution of weight distribution along the production cycle. The second adaptations consisted in considering the temperature seasonal curve and integrating the two growth exponents (1/3 and 2/3) in a mixed model. The final Quantile TGC-Mixed Model is a very interesting tool for evaluating production strategies in gilthead seabream and optimizing its economic profit, but each fish farm should have its own model in basis historical data

Redox potential is a frequently used measurement in studies under and around marine cage farms to assess the environmental status of marine aquaculture. This study presents an application of a geographic information system (GIS) to document sediment geochemical measures in cobia aquaculture in order to assess the condition of the benthic environment using the Chu-Wan marine fish farm as a case study. The objectives of the study was to combine GIS presentation with chemical measures as an important and innovative methodology in marine aquaculture environmental management. The results show a real distribution patterns for both redox potential and sulfide content in relation to position of the farm and the current pattern.

The trophic adaptability of a species may influence its dispersion potential and the ability to invade foreign territories. Understanding the factors that facilitate trophic adaptability may help the provision of forecasts about the potential dispersion of allocthonous species, even in a warmer and acidified world, according to the current trends of global changes. Various studies demonstrated the adaptability of Penaeus japonicus Bate to variable feeding regimes under natural conditions. To optimize artificial diets for the aquaculture of Penaeid shrimps, gut content data of specimens cultured in ponds were compared to contents from shrimps fed on natural macro benthic communities in a brackish-water lagoon. In addition, the feeding adaptability of this shrimp to scarcely diversified benthic associations was tested in aquaculture ponds. Our comparative analyses confirm that P. japonicus feeding pattern may be largely adapted to variations in the available benthic organisms, in different management conditions.

Little is known about elasmobranches in Pakistan despite their enormous diversity, commercial value and export earning adding into nation’s economy. In this study, preliminary data was gathered and document some observations on elasmobranches and their current state. Some regular observations have been made between 2015-2016 at monthly intervals for two key landing centers, the Karachi Harbour and Ibrahim Hyderi Fish Center. Specimens of small elasmobranches transported to the laboratory, whereas, larger specimens of more than 100cm TL were identified and measured at the Harbour. It was noted that family Carcharhinidae (grey sharks) locally called as “mangra” found in substantial amounts during winter and consistently landed throughout the year. Family Dasyatidae (batoid fishes) known as “pitten” in local dialect was in sufficient amount during summer whereas lower catches appeared in winter. Among guitar fishes Family Rhinobatidae most abundant family was found in the winter catches and the lowest in summer months. This study was aimed to evaluate potential of common elasmo branch species and gather data on abundance, seasonal variation and morphometry. It is expected that this baseline data would help biologists and conservatives for further investigation on elasmobranches in the area.

The aquaculture sector has established itself as a major global source of fish protein. This paper presents a review on the challenges of marine aquaculture and a systematic framework to tackle the issue of robust infrastructure development for open seas. The case is built around the Malaysian context but may be aptly applied to any other regions with similar demographic and oceanographic conditions.

An alternative technology for removal of nutrients released from mariculture is here suggested. Harvest of cyanobacteria Nodularia spumigena during summer blooms may compensate for release of N and P from mariculture or other sources. Not only content of N in the cyanobacteria but also prevention of N fixation will contribute to nutrient removal from the sea. The harvested product may be used for biogas production, biofuel or agricultural fertilizers.

Traditional agricultural methods and practices have rendered over 100 million hectares of land throughout the world, and over 5.7 million hectares in Australia, unsuitable for most forms of agriculture due to elevated salinity levels. Inland saline aquaculture is an adaptive approach to this environmental problem, and represents a potentially lucrative use for salt-affected land, with many economic, social and environmental benefits possible. Perhaps surprisingly, to date there has been relatively very little research conducted into the suitability (or otherwise) of inland saline aquaculture for the production of various species of microalgae and live feeds, which represent a crucial segment of the aquaculture industry. The key aim of this investigation was to test the hypothesis that all saline waters (natural sea water, artificial sea water and inland ground saline water) would produce uniform growth amongst the live feeds tested. This study expanded on the live feed species being tested to include Artemia (Artemia salina) rotifers (Brachionus plicatilis) and copepods (Cyclop ssp). While there were significant differences in the performance of all the tested live feed species, Nannochloropsis oculataand Brachionus plicatilisshowed better growth rates than those observed for natural seawater. It is hoped that these results can be used proactively by farmers seeking to diversify their crops to include the aquaculture of finfish in salt-affected areas of Australia and elsewhere.

Today's marine ecosystems experience multiple stressors that complicate management and pose risks to resource protection. Clam aquaculture has several potential environmental effects including disturbance, space occupation, and modification of nutrient availability, which were assessed through a crossed experimental design of eelgrass (Zostera marina L.) removal and geoduck clam (Panopea generosa Gould) addition in 1 m2 plots, in an eelgrass meadow in Puget Sound, Washington, USA. Gaps recovered via clonal growth, with gap edges requiring more than 1 year and gap centres almost 2 years. Clams neither increased nor impeded eelgrass recovery, and clams did not reduce winter density of eelgrass. During summer, clams reduced eelgrass density by 30% but increased shoot length by 13% and clonal branching by 9%. Eelgrass growth rates (~1 mgDW shoot-1 d-1) and C:N ratios (~11) did not differ across clam-addition treatments, indicating no enhancement by fertilization. At the end of the 2-year experiment, clams were harvested, and this disturbance reduced eelgrass density by 70% in the geoduck plots. As managers consider expansion of intertidal geoduck aquaculture regionally, these data indicate only a minor effect on eelgrass from the presence of clams themselves, but harvest disturbance is comparable with other studies of fishing in eelgrass. Nets and tubes that serve as predator-exclusion devices during the early stages of the 5-year crop cycle for geoduck clams remain to be examined for their ecological effects. Copyright © 2012 John Wiley & Sons, Ltd.

Aquaculture of the geoduck, Panopea generosa Gould, 1850, has increased dramatically during the past decade in southern Puget Sound, WA, and the effects of these intertidal aquaculture geoduck beds on local fauna is mostly unknown. This study examined the species composition, relative abundances, and biodiversity indices of mobile benthic fauna in geoduck farm areas of southern Puget Sound. Surveys of geoduck farms in two different stages of aquaculture production were carried out using a trapping strategy with two types of traps. The site in Eld Inlet had predator protection tubes around the planted geoduck. The site in Nisqually Reach was in grow-out phase with no predator protection. Nearby areas with no aquaculture were used as control sites. Traps yielded 1,161 individuals from 15 species of mobile benthic animals during the course of this study. The graceful crab, Cancer gracilis, accounted for 76.3% of all specimens. The effects of geoduck aquaculture on biodiversity were subtle and not co...

Geoduck clams (Panopea generosa Gould 1850) are large, deep-burrowing bivalves distributed from southeast Alaska to Baja California. This species supports a lucrative fishery in the states of Washington and Alaska, as well as in British Columbia, Canada, and geoduck aquaculture currently supplies approximately 30% of the market. To manage this species effectively, it is important to elucidate the population age structure. Geoduck ages are currently estimated by counting valve growth rings. We used bomb radiocarbon (14C) to validate geoduck age estimates derived from counts of growth bands in thin-sectioned valve inner hinge plates. Seven specimens with presumed birth years before, during, and after the bomb testing period (1957 to 1967) were sampled from the first 3–5 y of growth, and subsequently assayed for 14C using accelerator mass spectrometry. The 14C values from each of our specimens compared with reference 14C chronologies for the northeast Pacific were in accord at estimated birth years....

During 2010, the spiny lobster (Panulirus homarus) fishing season of Oman along the Arabian Sea coast was shifted from 15 October-15 December (2003-2008) to March-April (2010-2014) by the decision of the Ministry of Fisheries. The current status of the spiny lobster stock in the main fishing regions (Dhofar, Al-Wusta and Al-Sharqiyah) was examined based on monthly samples and surveys during the fishing season carried out from 2012 to 2014. An analysis of biological indicators such as size structure, number of undersized individuals captured, size at first maturity, sex composition shows that due to the new fishing season, the state of the lobster stock is improving. However, landings are still relatively low, therefore additional enforcement is needed to control the fishery out of the permitted season.

Sabah, which is located at northern part of Borneo Island, is well-known to be one of the states in Malaysia that has vastly coastline and fishing ground. Thus, the state play significant role in the development of marine fisheries sector in Malaysia. The implementation of Exclusive Economic Zone (EEZ) and SuluSulawesi Marine Eco-region (SSME) by national government had emulated the state in enhancing the development of fisheries management. Therefore, some important information about biological, sociological and economical dimension of fisheries in Sabah had been highlighted and discussed. Hence, various types of marine fisheries studies and data collection had been done in Sabah for quiet number of years and they proved to be helpful in understanding the exact status of marine fisheries stocks in Sabah, which are now hampered by common problems of fisheries management such as over-fishing and the destruction of fish habitat.

Driftnets in the Bulgarian marine zone and inland waters are discussed in the present case report. Consultations and questionnaires with relevant bodies, fishery responsible authorities, and research institutes took place during 2013. The first driftnet fishery identified is the Bulgarian fishery for Atlantic bonito (Sardasarda). There are a total of 135 vessels, the majority of which are less than12m in length, using drifting gillnets and are operating for around 25% of the year (around 90 days). Vessels tend to predominantly use driftnets but will also use drifting long lines to fish. As Atlantic bonito is a primary target of the fishery, it is evident that Council Regulation (EC) 1239/98 banning the use of driftnets to target Annex VIII species has not been effective. In addition, about 250 fishing vessels (from the total of 650 vessels) operated in the Danube River in 2012 targeting Pontic shad (Alosa immaculata) using a local driftnet called “Difana”. Most of them are small (5-6 m LOA) open boats powered by the outboard motors (10-20hp). Overall, about 30% of the shad is caught with driftnets and 70% with set gillnets (GNS). In the Bulgarian Danube River, 50% of the shad landed is caught using driftnets. In Bulgaria, 24 other species are also caught in driftnets but in much smaller percentages (i.e. less than 5% of the total catches are caught in driftnets). However, the existence of a fishery taking Atlantic bonito in the Black Sea suggests that control systems and tools in place within Bulgaria are currently not relevant to implementing Regulation (EC) 1239/98 in relation to Annex VIII species. There was also no evidence of derivative gears. There are no data available for detecting the aspects of the fishery that influence the probability of catching unauthorized/protected species.

Fish represent the main food protein eaten worldwide. Farming of fish has been a traditional practice in South East Asia for over 500 years [1], but with the recent collapse of major fish stocks around the globe and the increasing demand for fish, farming of fish species has turned into an intensive practice that is raising important concerns about its sustainability. With recent advances in genetics and marine biotechnology, aquaculture may undergo a further transformation with the addition of genetically modified organisms (GMOs) to farmed stocks. Genetic engineering of fish and shellfish has been under development for decades but until recently this has been restricted to research experiments [2]. However, after 20 years of pressures from aquaculture and biotechnology companies, the US Food and Drug Administration (FDA) is on the verge of approving genetically modified salmon in US markets [3]. This has opened major debates about the potential environmental outcomes and the possibility of approval by the global market. This article discusses the development of aquaculture over recent years with the advance of genetic engineering using salmon, ‘the king of fish’, as a case study.