Scallop Culture Research Articles

Bacteria in the culture of the scallop Argopecten purpuratus (Lamarck, 1819)

The scallop Argopecten purpuratus is one of themajor resources of commercial importance in Chilean aquaculture. One of themajor limiting factors for the culture of this species has been mass mortalityoccurring during production of juvenile “seed” organisms where massmortality of veliger larvae has been attributed to the presence of pathogenicbacteria in scallops and hatchery systems. Bacteriological studies havedemonstrated that in addition to bacterial pathogens, beneficial bacterialspecies capable of improving scallop larval survival may also be isolated fromscallops and hatchery systems. Research has been carried out on thedetermination of the feasibility of implementing beneficial bacteria in thecontrol of culture pathogens, thus reducing the need for chemotherapeuticmethods. The present review analyzes bacteriological research data on thedifferent roles of bacteria associated with scallop culture and discussesrecentdata on the implementation of beneficial bacteria in biological control ofpathogens in larval mass cultures of Argopectenpurpuratus.

The economic feasibility of small‐scale, commercial culture of the southern bay scallop (Argopecten irradians concentricus)

The economic feasibility of culturing southern bay scallops for the whole consumption market was examined for a small‐scale prototype facility. Projections of financial performance of production systems utilizing rack and longline methods were conducted. Estimates of initial capital investment and annual operating costs were derived. An annual cash flow and enterprise budget were developed. Initial capital investment was approximately $4,000. Annual operating costs were about $2,600. Net returns for both systems were estimated to be approximately $1,100. A sensitivity analysis was conducted on key production and management variables to assess how sensitive profit was to changes in market price, stocking density, survival, marketability, and cost of seed and cages. The findings suggest that bay scallop culture is marginally profitable at a small‐scale.

ホタテ貝養殖漁船の施設係留時入射波方向と横揺れ応答に関する研究

ホタテ貝養殖漁船の施設係留時入射波方向と横揺れ応答に関する研究

Estimating optimal population density for intermediate culture of scallops in spat collector bags

In a scallop restocking project in Îles-de-la-Madeleine, Québec, we investigated the spat growing within the collector bags, instead of using the usual pearl net method. To estimate optimal population density in the collector bags, we studied yield as a function of spat population density ( B– N curves) at three depths in the water column (10, 20, 30 m) and in a nearby lagoon. The B– N curves suggest that for 1-year-old spat, biomass at 10 m depth was maximum at ca. 1900 individual spat per bag. At higher population density, self-thinning occurred and yield decreased. The B– N curve for 20 m did not reach a maximum at the population densities encountered in the experiment. At population density ca. 2000 ind/bag, yield of individuals ≥2 cm shell height was greater at 20 m than at 10 m, apparently because of higher food availability at 20 m and presence of interspecific competitors at 10 m depth. Yields in the lagoon and at 30 m depth were not satisfactory. Intermediate culture should be done at 20 m depth, with at least 2000 ind/bag. The upper limit to this estimate could not be determined experimentally.

The potential for scallop culture – the next millenium

World scallop landings increased dramatically inthe last 20 y and in 1996 were about 1.7 million t (whole weight). Aquaculture was the reasonfor this increase and in 1996 accounted for about 90%of landings. Most production of scallops from cultureoperations was from China and Japan (88% of worldproduction) and to a much lesser extent from Chile. Aconsistent 1,000 t annual production from cultureoperations in other countries has rarely been met anddevelopment of the British Columbia scallop culture industry is used as an example to explain the slow progress in achieving higher production. Methods are discussed that could enable establishment of largeeconomically viable scallop culture industries. Thepotential for scallop culture remains high in manycountries but it will require a firm commitment bygovernments and industry to achieve this goal.

Effect of air exposure on scallop behaviour, and the implications for subsequent survival in culture

Scallop spat produced for continued culture normally requiretransportation between sites, and the associated stresses may causemortalities. In the present experiment, scallops of 40–55 mm shell heightwere emersed in air for time intervals up to 24 h and their behaviourexamined once re-immersed. Scallops were placed upside-down and thenumber of movements and the cumulative numbers righting in 5 min timeblocks were recorded. The greatest frequency for all behaviouralresponses was found at 15–17 °C in August. Responses were reducedin November and June (9–11 °C) and least at 5 °C in January.All effects of treatment, temperatures and season, and increases in airexposure were significantly different. Following the treatments, mortalitiesafter 10 days in culture was about 10–30% for scallops emersed for 18 and24 h in August and June. Scallops did not show significantly differentbehaviour whether they were emersed upright or inverted. However,scallops emersed at 15 °C had fewer responses than scallops held at 12 h should be avoided. At temperatures>9 °C, behavioural responses may be a simple and effective method toassess vitality which can assist in the management of scallop culture.

Aquaculture of sponges on scallops for natural products research and antifouling

Suspended culture of scallops (Pectinidae: Bivalvia) is plagued by invertebrate fouling. Scallops covered in an orange sponge ( Suberites ficus ssp. rubrus), however, do not have any other invertebrates fouling their shells and the sponge is easily removed. Sponges may also be valuable sources of bioactive compounds. Seven species of sponge were found to be associated with Chlamys opercularis but none were found associated with Pecten maximus. Standing crop of sponge on the scallop farm was just over one tonne. If all the scallops were covered by sponge this would rise to approximately 4.5 tonnes (from three million scallops). Primary cell cultures of ( S.f. rubrus) were successfully established but no cell lines were achieved. A number of techniques were tried for establishing cells and pieces of sponge tissue onto scallop shells but none gave satisfactory results. Likewise mechanical methods for sticking small pieces of sponge to scallop shells were deemed impractical even where they resulted in subsequent sponge growth. Improving natural settlement of sponges onto the scallops was the only economically practical method for increasing sponge yield for C. opercularis, though other methods would need to be devised for P. maximus.

Evaluation of alternative suspended culture methods for the commercial scallop, Pecten fumatus Reeve

Commercial scallops, Pecten fumatus, glued to plastic mesh disks showed growth and survival equal to or greater than similar sized scallops in conventional earhung and cage culture. In two experiments of 13 and 25 weeks duration, some aspects of disk culture, such as spacing between disks, scallop orientation and the choice of valve by which the scallops were glued, were examined to determine their effects on shell growth, somatic tissue weight increase, predation and survival. As disk spacing was increased through 40, 60, 80 to 100 mm, predation increased at disk spacing greater than 60 mm and total soft tissue mass peaked at 60 mm and above. There were no significant differences in soft body weight or shell height between scallops glued by either valve in either normal (flat left valve uppermost) or inverted (cupped right valve uppermost) orientation. However, scallops glued by the left valve had higher percentage survival and larger muscle weights regardless of orientation. By contrast, those glued by the right valve had heavier gonads. Orientation and the scallop culture technique employed significantly affected spionid polychaete infestation of the shell. Scallops glued by the left valve, with left or right valve uppermost, and glued by the right valve with this valve uppermost had significantly lower polychaete prevalence than scallops contained in cages, earhung or glued by the right valve with left valve uppermost.

Effect of Perkinsus qugwadi on various species and strains of scallops

DAO Diseases of Aquatic Organisms Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials DAO 36:143-151 (1999) - doi:10.3354/dao036143 Effect of Perkinsus qugwadi on various species and strains of scallops Susan M. Bower1,*, Janice Blackbourn2, Gary R. Meyer1, David W. Welch1 1Department of Fisheries and Oceans, Pacific Biological Station, Nanaimo, British Columbia V9R 5K6, Canada 2Island Scallops Ltd, 5552 West Island Hwy, Qualicum Beach, British Columbia V9K 2C8, Canada *E-mail: bowers@dfo-mpo.gc.ca ABSTRACT: Japanese scallops Patinopecten yessoensis, introduced into British Columbia, Canada, as a species for aquaculture, proved highly susceptible to an enzootic protistan parasite Perkinsus qugwadi (initially called SPX). Sporadic occurrence of the parasite among cultured scallops sometimes resulted in losses exceeding 90%. Native scallops (Chlamys rubida and Chlamys hastata) were resistant to infection and the pathogenic effects of the parasite. Weathervane scallops Patinopecten caurinus (not amenable to culture but closely related to the Japanese scallop) were not available to test for resistance to infection. Laboratory and field studies showed that first-generation progeny of Japanese scallops that survived an epizootic outbreak of P. qugwadi had a significant increase in resistance to infection and resulting mortalities. Hybrid scallops, resulting from a cross between Japanese scallop females (from the same group of scallops that survived an epizootic outbreak of P. qugwadi) and weathervane scallop males, had similar resistance to P. qugwadi. The identification of scallop stocks that are resistant to P. qugwadi has facilitated the development of a scallop culture industry in British Columbia. KEY WORDS: Perkinsus qugwadi · Patinopecten yessoensis · Scallops · Disease · Resistance Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in DAO Vol. 36, No. 2. Publication date: May 12, 1999 Print ISSN:0177-5103; Online ISSN:1616-1580 Copyright © 1999 Inter-Research.

A Preliminary Study on the Etiology of Mortalities in Scallop Culture of China

A Preliminary Study on the Etiology of Mortalities in Scallop Culture of China

A Comparative Study of Labor Circumstances in Gill Net Fishing and Scallop Culture

A Comparative Study of Labor Circumstances in Gill Net Fishing and Scallop Culture

Repopulation and culture of the pacific calico scallops in Bahia Concepcion, Baja California Sur, Mexico

The Pacific Calico scallop, Argopecten ventricosus (Sowerby), is the most important commercial species in Bahia Concepcion. Catches declined steadily from 1991 to 1993 as a result of overexploitation, forcing the adoption of management measures. The Government has now established regulations for exploitation and scallop culture development. In 1994, Centro Interdisciplinario de Ciencias Marinas (CICIMAR) and the Fisheries Department of the Mexican Government initiated research on the feasibility of increasing scallop biomass through a reseeding programme to protect artisanal fishing. The use of onion bags to collect spat in Bahia Concepcion (1988-1994) demonstrated that settlement was cumulative from January to March. At Punta Coloradito, there were two peaks, in January and early March. Commercial collectors were deployed in February at El Indio and in April at El Remate. In June, about one million juvenile scallops were placed in an enclosure, held until mid-August and then released. Mass mortality (>80%) of the scallops was observed in September, increasing to 99% in October. The high water temperature and predators may be responsible for the mortalities.

Effects of environmental oxygen deficiency on embryos and larvae of bay scallop,Argopecten irradians irradians

The experimental results showed that: 1) The embryonic development of bay scallop is inhibited at a dissolved oxygen range of 1.38–3.64×10−3 at 23°C, and completely blocked below the lower limit. 2) The tolerance of larvae to anoxia increased with larval sizes and was related to their oxygen debt. 3) The scallop larvae exhibited specific behavioral responses to oxygen deficiency, which finally led to velum disintegration and larval death. The possible relationship between environmental oxygen deficiency and the disease of disintegration of the larval velum is also discussed. In this study, considerable oxygen debt was found in bay scallop larvae, which was greater in small animals. Based on the works of previous authors, a new concept is proposed for the estimation of oxygen debt, namely, the compensatory rate of oxygen debt (CROD). This can be used in intra—or interspecific comparison of oxygen debt. The results can be helpful in the management of water quality and for the prevention of larval diseases encountered in scallop culture.

A trophic model for Tongoy Bay —a system exposed to suspended scallop culture (Northern Chile)

A steady-state model of 17 compartments was constructed for the Tongoy Bay ecosystem using the ECOPATH II software of Christensen & Pauly (1992). The system is driven by planktonic production which is governed by periodical intrusions of upwelling water from a nearby upwelling centre. Of the total system biomass (236.3 g/m 2), 47% is comprised of benthic invertebrates whose food intake exceeds that of pelagic fish and birds. Scallops in hanging cultures account for 71% of the biomass in the water column. The model suggests that benthic invertbrate predators are more important in the cycling of biomass than demersal fish. A significant part of the production of the groups Macrophytes, Zooplankton, Phytoplankton, Suspended Scallops and a minor portion of other groups enters the detritus pool, from which an important amount of biomass re-enters the filter feeder compartments through bacteria. Global system properties such as total system through put (T), development capacity (C), ascendency (A) (sensu Ulanowicz & Mann, 1981; Ulanowicz, 1986; Baird & Ulanowicz, 1993) were also calculated by the means of net work analysis implemented in the ECOPATH II software. Results indicate that Tongoy Bay is an intermediate sized system (in terms of the sum of flows, T) of low maturity and high capacity to withstand ecological perturbations. The mean transfer efficiency between trophic levels is 14.7%, the fishery's gross efficiency (primary production/catch and harvest) is 0.89%. In terms of global system properties these results are similar to those reported by Jarre et al. (1991) for the “open” Peruvian upwelling system during the peak period of anchovy catches (1963–1969). However, the mean trophic level of the fishery (3.6 for Tongoy Bay compared to 2.2 for the open upwelling system) and the biomass pathways differ significantly between these systems. Manipulation of the input data suggest that the bay has a potential for the production of biomass of filter feeders that is 10 to 15 times higher than the present production.

Survival of different size-groups of the scallop, Mizuhopecten yessoensis (Jay), after transfer from collectors to the bottom

Cultivation of the Japanese scallop, Mizuhopecten yessoensis (Jay), in Primorye Territory (Russia, Sea of Japan) involves collection of scallop spat, rearing them for 1 year in suspended collectors, and then seeding on the sea bottom where the scallops grow for 2 years to attain a commercial size of over 100 mm. Survival of juveniles after transfer to the bottom depends considerably on their size and environmental conditions in the area of cultivation. Well-aerated areas with sand or muddy sand bottoms, protected from heavy wave action, with almost stable high salinity, and with summer water temperatures not above 16–18°C were most favourable for scallop culture. Under these conditions, most juveniles with a shell height greater than 15–16 mm survived. There was a high mortality rate in seeded individuals during only a month after transfer. In less optimal environments of fine-grained sand or aleurite-muddy bottoms, only scallops which had an initial shell height greater than 19–20 mm survived. These molluscs showed a high survival rate in only 2–3 months after transfer when their shell heights exceeded 37 mm. On pebble-gravel-sand bottoms, only individuals larger than 22 mm survived. Observations on survival of young scallops with different shell heights in various areas allowed us to conclude that individuals with small shell height should not be planted under certain environmental conditions, or that sowing density should be increased here in order to optimize utilization of the scallop culture grounds.

The impact of toxic algae on scallop culture and fisheries

Abstract Harmful algal blooms occur worldwide and their associated phycotoxins are accumulated by filter‐feeding bivalve molluscs. Because only the adductor muscle of scallops has been traditionally marketed, scallops are not usually included in routine monitoring programs. A renewed interest in marketing both whole and “roe‐on”; scallops from various geographic regions along with intensified aquaculture ventures in areas prone to toxic blooms have provoked public health concerns regarding the safety of this resource. Our studies have focused on the sequestering and biotransformation of phycotoxins in scallops. Our results, coupled with a review of historic data, indicate that (1) toxins are not distributed evenly throughout the scallop tissues—more toxin is usually concentrated in the mantle and digestive gland; (2) some scallop tissues, e.g., digestive glands and mantles, remain highly toxic throughout the year; (3) toxicity varies considerably (43.5% coefficient of variation) between individual animals...

Scallop culture and its supporting system in Mutsu bay

Mutsu bay is one of the major scallop culture fields located at a northern part of Japan where fishermen got 520 thousand tons of scallop, being worth 11, 300 million yen (78 million dollars) in 1986. The fruitful result was brought after a few decade struggle to develop scallop culture techniques by the people concerned, and now, for stabilizing every year's production, the Aomori prefectural government has developed a remote survey system to catch the bay's on-time physical conditions and to advise fishermen on better ways of scallop culture work in the period. The administration is on the way to improve many fishing ports for keeping preferable conditions in the bay.

養殖施設の安全設計に関する研究 ２ 生物が付着したホタテ養殖用浮子およびロープの流水抵抗について

A study was conducted to determine the drag coefficients of float and rope presently used in scallop culture facilities. The drag forces of a polyethylene spherical float (30cm in diameter) and a polypropylene three-strand laid rope (24mm in diameter), with different encrusted conditions of marine organisms, were measured in an experimental flow tank.The experimental results were drawn in CD-Re diagrams (CD: drag-coefficient, Re: Reynolds number). The average value of CD was 0.75 for the floats encrusted with barnacles, blue mussels and plumed worms in 3.5×104<Re<105, and CD was 0.52 for the float scraped off marine organisms from the surface in 3.5×104<Re<8×104. For the rope when set normal to the flow, CD was 1.4 for the rope with amphipods and skeleton shrimps, and CD was 1.8 for the new rope without organisms in 2×103<Re<104.

養殖施設の安全設計に関する研究 Ｉ 生物が付着したホタテ養殖かごの流水抵抗について

Net cages become inevitably encrusted with marine organisms in scallop culture. The darg of the net cage composed of 10 compartments (0.5m in diameter and 2m high, covered with 0.8mm polyethylene mono-filament net of mesh size 4.0cm) encrusted with marine organisms is still not sufficiently clear. In this study, we measured the drag of three net cages (named cage A, cage B and unused cage) with different encrusted conditions of marine organisms in an experimental tank. The cage A was suspended by a main rope in an actual scallop culture facility for 3.5 months in winter season and marine organisms weighed 0.62kg in water without scallops. The cage B was used by a scallop culturist over a period of 14 months in the same facility, and its overall weight in the water consisted of 1.6kg of cage, 5.5kg of 100 scallops grown up to average size of 120mm, and 2.4kg of marine organisms. The unused cage was an empty new cage. The experimental results were drawn in CD-Re diagrams (CD: drag coefficient, Re: Reynolds number) For each of the three cages the change of CD to Re was small within the experimental range of 5.0×104<Re<3.0×105. The mean value of CD was 1.2 for cage A, 1.9 for cage B and 0.39 for the unused cage when set in normal to the water flow and 1.6, 1.8 and 1.4 when set in parallel, respectively.

Recent developments, status, and prospects of molluscan aquaculture on the Pacific coast of South America

A detailed review is given of recent developments, status, and prospects of molluscan aquaculture on the Pacific coast of South America. A brief history of the fishery and cultivation efforts reveals that in Colombia (Pacific coast), Ecuador, and Peru the production of molluscs is entirely based on the natural resources and is chiefly restricted to mussels, scallops ( Chlamys purpurata), and the mangrove cockles of the genus Anadara. Culture activities in these three countries are still in a preliminary experimental stage. In Chile, at least nine species of clams (such as Protothaca thaca, Ameghinomya antiqua, Mulinia spp., and Mesodesma donacium), three species of mussels ( Mytilus chilensis. Choromytilus chorus, and Aulacomya ater), the native oyster Ostrea chilensis, and the Chilean abalone Concholepas concholepas are of great commerical value. Large-scale aquaculture efforts, however, are restricted to M. chilensis, C. chorus, A. ater, and the Chilean oyster. First attempts to intensify the culture of scallops ( C. purpurata) in the north of Chile have had favorable results with respect to future large-scale developments. The introduction and cultivation of Crassostrea gigas is still in an experimental stage. Potential intensification and modernization of culture methods; technical, economic, and sociopolitical problems; and new opportunities and prospects for expansion are analyzed and discussed. The discussion includes an evaluation of the fishery and cultivation products in light of the world market. Enhanced production of underutilized species and enhanced use of underutilized areas for future mariculture installations are analyzed in light of potential new markets. Finally, a detailed list of problem areas is given to form a basis for future research efforts.