|
|
| Dear Asia-Pacific Marine Finfish Aquaculture Network list, �
The purpose of the e-News is to facilitate prompt information dissemination on marine fish research and developments, to complement the regular quarterly eMagazine (upgraded from the previous eNewsletter). The e-News will be circulated regularly based on the latest developments and news collected through the network. We welcome your contributions with research and development news items, market developments, upcoming events and others - please send to � Mr Sih Yang SIM; Dr Michael Phillips; and Dr Mike Rimmer �==============================================� 1. Billion-dollar Asian reef fish industry in peril � an article briefly describing the current reef fish fisheries and aquaculture condition in Indonesia. Reference was given to The Nature Conservancy marine fish pilot project in Komodo National Park, Indonesia. The project is farming four grouper species (tiger grouper, estuary grouper, leopard coral grouper and mouse grouper), mangrove jack snapper and seabass. The first 500 kg of fish produced by this pilot project has been sold to Hong Kong buyers in June 2004. For full article visit http://www.enn.com/news/2004-09-01/s_26807.asp 2. Controversial fish farm bid sinks � a marine fish farming project proposed for Moreton Bay, Queensland (Australia) in 2001 by Sun Aqua to farm snapper and yellow tail kingfish has been rejected by the government. The refusal of the project was because Sun Aqua was not able to adequately demonstrate that the additional nutrient such as nitrogen that would be generated from the cage culture farm would not flushed into Moreton Bay. For full article visit http://www.heraldsun.news.com.au/common/story_page/0,5478,10625918%5E1702,00.html 3. Giant aquaculture plan back on track � an offshore marine farm project covering 2,600 hectare of water area is back on track after a two years government moratorium. The marine farm is a few kilometers off the coast of Canterbury, New Zealand. The government has now partially uplifting the moratorium and allows the aquaculture project to apply for resource consents. For full article visit http://www.nbr.co.nz/home/column_article.asp?id=10044&cid=4&cname=Business+Today 4. Aquaculture to improve livelihood of fishermen � Malaysia Agriculture and Agro-Based Ministry is developing an aquaculture program in Kelatan which is expecting to benefit some 1,800 poor fishermen. The program will cover a total of 2,400 hectare of land area and the program is aiming to generating income of RM 2,000 to RM 4,000 (US$ 790 to 1,050) per month for the fishermen. The two main activities under this program will be prawn breeding and marine fish cage culture activities. For full article visit http://thestar.com.my/news/story.asp?file=/2004/8/15/nation/8671030&sec=nation 5. World's 1st fully cultivated tuna to debut in market � an article on the Kyoto New Service (Japan Economic Newswire, September 2, 2004 Thursday). The researchers at Kinki University in Osaka (Japan) said that the world's first fully aquacultured bluefin tuna raised from eggs will shortly be shipped to market. The researchers at the university's Fisheries Laboratory in the town of Kushimoto, Wakayama Prefecture, have succeeded in farming Pacific northern bluefin tuna from eggs to market size, unlike existing farming practice that rears wild caught juvenile to market size. Three 1-meter-long bluefin tuna each weighing about 20 kilograms, will be sold in various stores, including Hankyu Department Stores Inc.'s Umeda main store in Osaka. Although these fully farmed tunas are relatively small compared with wild caught juvenile, they are rich in fat, which is prized as a delicacy. The laboratory began tuna aquaculture research in 1970 and succeeded in having tuna lay eggs in an artificial environment for the first time in the world in 1979. But after 1983, the laboratory made little progress as the tuna stopped laying eggs inside floating cages. However, the laboratory succeeded in having tuna lay eggs once again for two consecutive years from 1995, with improved aquaculture technology. The laboratory also succeeded in incubating about 1.63 million eggs laid by the F1 tuna in June 2002, thus completing the full cycle of fish farming -- from eggs production, to larvae rearing, to eggs production of F1 broodstock. Three other laboratories in Japan as well as laboratories in the European Union, Australia and other countries and territories are also studying tuna farming. 6. Aquaculture, Volume 238, Issue 1-4, Pages 1-544 (September, 2004) - In this issue there are several articles which may be of interest:
Full abstracts can be accessed from the website: http://www.sciencedirect.com/science/journal/00448486. 7. �Aquaculture Engineering, Volume 31, Issue 3-4, Pages 135-341 (October 2004) � In this issue there are several articles which might be of interest:
8. Weekly Marine Fish Wholesales Prices in China � August/September, 2004
The following web link provides marine fish wholesales prices in Southern China and Hong Kong. For details average prices visit http://www.enaca.org/modules/news/index.php?storytopic=14&storynum=10. 9. Aquatic Sciences and Fisheries Abstracts (ASFA) � NACA is now able to access to the Aquatic Sciences and Fisheries Abstracts (ASFA) database of scientific publications. The following are recent publications on marine finfish aquaculture and related topics.
10. Mariculture in the Asia-Pacific region: Recent Developments and New Challenges, NACA will organize a special session on mariculture for the 7th Asian Fisheries Forum, (Penang, Malaysia, Nov 29-Dec 3, 2004) in partnership with FAO, WFC, ACIAR, TDH and others. The session will be for one day, and combine invited presentations together with tropical mariculture papers submitted to the conference organizers. The aspects that will be covered including the following:Marine farming species, including marine fish, mollusks, seaweeds
NACA extends the invitation to participate in this symposium to all researchers, the industry as well as policy makers and administrators involved in �farming the seas� of the Asia-Pacific region. � For further information contact:� 11. Upcoming Events in 2004
Aquatic Sciences and Fisheries Abstracts Section� Reproductive performance in induced and spontaneous spawning of the mangrove red snapper,
Lutjanus argentimaculatus: a potential candidate species for sustainable aquaculture A reliable breeding technique was developed for the mangrove red snapper, Lutjanus argentimaculatus (Forsskal 1775), to help sustain the aquaculture of this immensely popular species in Southeast Asia. Using standardized indices of female maturity (based on mean oocyte diameter of greater than or equal to 0.40 mm), time of injection (1000-1130) and sex ratio (one female to two males), a single injection of 100 mu g kg super (-1) luteinizing hormone-releasing hormone analogue (LHRHa) (n=16 fish), but not 50 mu g kg super(-1) (n=five fish), successfully induced egg (62.5% success rate) and larval (43.8%) production. Human chorionic gonadotropin (hCG) at 500 IU kg super (-1) (n=five fish) also failed to induce spawning, but doses of 1000 (n=22 fish) and 1500 IU kg super(-1) (n=15 fish) gave spawning (77.3% and 80.0% respectively) and hatching success rates (72.7% and 60.0% respectively) that were not significantly different from those of 100 mu g kg super(-1) LHRHa. No spawning was observed in saline-injected controls (n=seven fish). While mean spawning latency, egg diameter, egg production per spawn, percent egg viability, hatching rate, percent of normal larvae and cumulative survival of eggs to normal larvae did not differ significantly among the effective hormones and doses, 1000 IU kg super(-1) hCG had a higher percentage (76.5%) of total spawns with egg production per spawn in excess of one million than those of 1500 IU kg super(-1) hCG (50.0%) and 100 mu g kg super(-1) LHRHa (40.0%). Mangrove red snapper spontaneously spawned from March-April to November-December with a peak of egg collection and spawning in May-June. Egg collection per spawn ranged from 0.05 to 6.35 million. Spontaneous spawning of mangrove red snapper exhibited lunar periodicity with spawns mostly occurring 3 days before or after the last quarter and new moon phases and occurred consistently between 02:00 and 04:00 hours. High fecundity and good egg quality, coupled with the ability to respond to induce spawning or natural spawning in captivity, provide a sound basis for improving the sustainability of red snapper aquaculture in Southeast Asia. (Up)� Simultaneous detection of marine fish pathogens by using multiplex PCR and a DNA microarray We coupled multiplex PCR and a DNA microarray to construct an assay suitable for the simultaneous detection of five important marine fish pathogens (Vibrio vulnificus, Listonella anguillarum, Photobacterium damselae subsp. damselae, Aeromonas salmonicida subsp. salmonicida, and Vibrio parahaemolyticus). The array was composed of nine short oligonucleotide probes (25-mer) complementary to seven chromosomal loci (cyt, rpoN, gyrB, toxR, ureC, dly, and vapA) and two plasmid-borne loci (fatA and A.sal). Nine primer sets were designed to amplify short fragments of these loci (100 to 177 bp) in a multiplex PCR. PCR products were subsequently labeled by nick translation and hybridized to the microarray. All strains of the five target species (n = 1 to 21) hybridized to at least one species-specific probe. Assay sensitivities ranged from 100% for seven probes to 83 and 67% for the two remaining probes. Multiplex PCR did not produce any nonspecific amplification products when tested against 23 related species of bacteria (n = 40 strains; 100% specificity). Using purified genomic DNA, we were able to detect PCR products with <20 fg of genomic DNA per reaction (equivalent to four or five cells), and the array was at least fourfold more sensitive than agarose gel electrophoresis for detecting PCR products. In addition, our method allowed the tentative identification of virulent strains of L. anguillarum serotype O1 based on the presence of the fatA gene (67% sensitivity and 100% specificity). This assay is a sensitive and specific tool for the simultaneous detection of multiple pathogenic bacteria that cause disease in fish and humans. (Up)� Prospects of commercial mariculture in India Fish production of the country has been growing continuously with improvement in productivity and utilization of untapped resources. The fishery sector contributes about 1.28% of the total GDP and 4.12% of the GDP from agriculture sector. What is important is the fact that fish production has grown [at] 5.71% annum during the 7th plan period and [at] 2.18% per annum during the 9th plant period of the country. A closer scrutiny of the production trend would reveal that the growth rate in marine fish production has taken a negative trend (-0.94%) during the 9th plan as against a positive growth rate (3.93%) during the 7th plan. The growth rate in inland fish production also reflects a slow down to 5.6% during the 9th plan as against the growth rate of 6.84% during the 8th plan. The present fish production and the production potential being 6 million tones and 8.4 million tones respectively, the unabridged gap is 2.4 million tones. The present production in marine fisheries is close to the harvestable potentials, estimated to be 3.9 million ton. Most of the balance potential being in the form of deep sea and oceanic resource, considerable inputs may be required in terms of fishing technique, deployment of resource specific fishing vessels and associated infrastructure. Viewed against this backdrop, the Government of India as target of increase in fish production from 5.8 million tones to 8.0 million tones and fisheries export from Rs.6000 crore to Rs.10,000 crore during the 10th plan period may appear to be a stiff target considering the harvestable potential. It is proposed to achieve the target through stabilization in marine fish production and doubling of production through aquaculture. It may not be possible to achieve this target through inland aquaculture since the balance potential in the inland sector is merely 1.3 million tone, the overall potential of the inland fish production being 4.5 million tones. It is in this context that mariculture assumes great importance for a country, which has not exploited its seaward side of its coastline for aquaculture. (Up)� Distribution of marine birnavirus in cultured marine fish species from Kagawa Prefecture, Japan To determine the distribution of marine birnavirus (MABV) in cultured populations of different marine fish species, 1291 pooled tissue samples from 2672 fish belonging to 22 species and one hybrid were collected from Kagawa Prefecture, Japan, during 1999-2001. Using cell-culture MABV was isolated from three species: yellowtail, Seriola quinqueradiata Temminck & Schlegel (positive number /sample number, 10/419), amberjack, S. dumerili (Risso) (4/72), and Japanese flounder, Paralichthys olivaceus (Temminck & Schlegel) (41/481). Using PCR on MABV-negative samples, the MABV genome was detected in the same three species [yellowtail (9/409), amberjack (4/68) and Japanese flounder (93/440)] and two additional species, spotted halibut, Verasper variegatus (Temminck & Schlegel) (5/11), and goldstriped amberjack, S. lalandi Valenciennes (1/5). These MABV-positive species can be taxonomically divided into two groups: the genus Seriola and flatfish. In Japanese flounder, MABV was detected during all seasons, and the infection rate was correlated with water temperature. Aquaculture sites with MABV-positive fish were evenly distributed over the surveyed area, suggesting that MABV is widely distributed at aquaculture sites in Kagawa Prefecture. The nucleotide sequence at the variable region, the VP2/NS junction, revealed that the 39th base mutation occurs host-specifically for flatfish. Flatfish are suspected to be the main reservoir of MABV and might be responsible for establishing the infection cycle in aquaculture environments. (Up)� Effects of high levels of ammonia, pH and salinity in algal feeds on the mass production of rotifers The rotifer, Brachionus plicatilis, has been widely used as a live food for feeding the larval stage of marine fishes. Successful aquaculture of marine fish requires adequate and reliable production of high-quality, nutritious rotifers. One method of culturing rotifers is to feed them microalgal diets that promote rapid growth and reproduction. The rotifers used in our aquaculture studies of the tautog and black sea bass were fed the algal strain Tetraselmis sp. (PLY 429). This alga not only promotes rapid reproduction of the rotifers, but also contains the n-3 and n-6 polyunsaturated fatty acids that have been shown to promote growth and survival in larval marine fish. Tetraselmis was cultured under semicontinuous conditions in three large, open rectangular fiberglass tanks that received constant fluorescent lighting. These tanks were maintained between 200-300 L. Rotifers were fed Tetraselmis from two of the three tanks on a rotating basis. Initially, for about 1 week, rotifers showed an increase from 4 to 16 million. After that time, the rotifer population declined to five million and remained at that level for 2 wk. During that time, and for the next 3 mo, sporadic measurements of ammonia, salinity, and pH were taken in each of the three algal tanks. High levels of unionized ammonia (>1 mg/l), and abrupt changes in salinity (plus or minus 5 ppt) and pH ( plus or minus 1 pH unit) in the algal tanks coincided with decreases in the rotifer population. Those measurements indicated that either individual fluctuations in salinity, pH and ammonia, or a combination of two or more of these factors adversely affected rotifer production. We conclude that changes in salinity, pH, and ammonia levels, as well as increased numbers of bacteria and ciliates in algal cultures can be counterproductive to maintaining high rotifer populations. It is recommended that algal tanks be monitored daily during high rotifer production times for salinity, pH, and ammonia levels. Also, large open algal tanks should be monitored on a regular schedule for bacteria (Vibrio) and ciliates. Some alternatives to using live algae include concentrated algal pastes, baker's yeast and commercial products. (Up)� Diseases of tunas, Thunnus spp. Much is known about those aspects of tuna health which can be studied in wild populations, e.g. helminth parasites. However, because aquaculture of these species is in its infancy, knowledge of microbial, nutritional and environmental diseases is limited. This review is an attempt to bring together the available information on those diseases of Thunnus spp. which cause significant morbidity, mortality or economic loss. In doing so it has become clear that much more research needs to be undertaken on the physiology of the species (southern, northern and Pacific bluefin tuna) currently used in aquaculture in order for the pathogenesis of some conditions to be properly understood. Attempts at hatchery culture of Pacific bluefin tuna has indicated that Thunnus spp. will be problematic to hatch and propagate. (Up)� ===================== End ====================�
|
