Larviculture Newsletter Issue 7


[GUIDE TO SUCCESS] [EDWARDSIELLA TARDA] [VACCINATION] [KURUMA PRAWN] [COAT PROTEIN] [WOLFFISH] [ZOOPLANKTON] [VITAMIN C ] [EUROPEAN SEA BASS] [WORKSHOP] [CONGRESS] [SYMPOSIUM] [CONFERENCE] [CONFERENCE PENAEID] [MARKETING] [SUB-MICRON FILTER] [SHORTAGE] [HATCHERIES] [SHRIMP NEWS] [ARTEMIA] [ENRICHMENT] [BRYOZOAN FOULING] [BUOYANT LARVAE] [POSTGRADUATE TRAINING]


GUIDE TO FINANCIAL SUCCESS FOR THE AQUACULTURE AND SEAFOOD BUSINESSES

Available October 1995. Aquafood Business Associates has developed a pragmatic financing guide for any seafood or aquaculture business - new and old alike. Guide to Financial Success for the Aquaculture and Seafood Businesses includes a new (pre-screened in 1995), never before published list of American and international venture capital companies interested in being contacted by aquaculture or seafood entrepeneurs. In addition to possible venture capital sources, the Guide includes listings of SBA preferred/certified banks, international money sources and venture capital clubs. It tells how to find private investors through networking and gives suggestions on preparing an effective business plan. Order from Aquafood Business Associates, P.O.Box 16190, Charleston SC 29412 USA (fax 803 795-9477). Price US$ 139 plus postage and handling (USA $6; Canada and Mexico $9; others $18.


INFECTION EXPERIMENTS WITH EDWARDSIELLA TARDA IN THE JAPANESE FLOUNDER (in Japanese)

Mekuchi, T., T. Kiyokawa, K. Honda, T. Nakai, K. Muroga-1995

Fish Pathology, 30(4):247-250

ABSTRACT:

Infection experiments in the Japanese flounder (Paralichthys olivaceus) with Edwardsiella tarda were conducted by intramuscular injection, intraperitoneal injection, immersion, and oral administration methods. Mortalities were produced by all the methods tested, LD50 being determined as 71 CFU/fish by intramuscular injection, 170 CFU/fish by intraperitoneal injection, 3.6 x 10^6 CFU/ml by immersion, and 1.3 x 10^6 CFU/fish by oral administration. These results show that the Japanese flounder has high susceptibility to E. tarda. Mortalities continuously occurred the observation period of 15 or 20 days showing a chronic nature of the disease. (Hiroshima Prefectural Fisheries Experiment Station, Ondo, Hiroshima 737-12, Japan)


VACCINATION TRIALS IN THE JAPANESE FLOUNDER AGAINST EDWARDSIELLOSIS (in Japanese)

Mekuchi, T., T. Kiyokawa, K. Honda, T. Nakai, K. Muroga-1995

Fish Pathology, 30(4):251-256

ABSTRACT:

The Japanese flounder (Paralichthys olivaceus) were vaccinated with formalin-killed cells (FKC) of Edwardsiella tarda by intramuscular injection, immersion and oral administration. Fish were also immunized by injection with diluted extracellular products (ECP) and intracellular components (ICC) of the bacterium, both of which were found lethal to flounder. As a result, mean serum agglutinating antibody titers against FKC rose in all the immunized fish groups except those vaccinated by immersion with FKC. When the immunized and control fish were challenged by injection and immersion with live cells, death was delayed in most of the immunized groups. However, clear protection was not observed in any group immunized with FKC, ECP or ICC.

(Hiroshima Prefectural Fisheries Experiment Station, Ondo, Hiroshima 737-12, Japan)


DYNAMICS OF VIBRIO SP. PJ IN ORGANS OF ORALLY INFECTED KURUMA PRAWN, PENAEUS JAPONICUS

de la Pena, L.D., T. Nakai, K. Muroga-1995

Fish Pathology, 30(1):39-45

ABSTRACT:

Kuruma prawns (Penaeus japonicus) were experimentally infected with Vibrio sp. PJ by the oral administration. At 3, 6, 8, 10, 12, 24, 36, and 48 h post-inoculation, prawns were sampled to determine the cell number and distribution of the pathogen in various organs by viable cell count and the enzyme-labeled antibody technique (ELAT).

Vibrio sp. PJ was detected by culture method from the stomach and hemolymph at 3 h and from the hemolymph and almost all the organs sampled at 6 h post-inoculation. However, the pathogen started to disappear from all the organs from 8 h to 12 h. At 12 h, it reappeared in the hepatopancreas and lymphoid organs. Twenty-four hours after inoculation, the pathogen was detected from the hemolymph and all the organs except the stomach and gills, and at 36 h the pathogen was found distributed in all the organs. Principally the same distribution pattern of the pathogen was found by ELAT.

These results seem to indicate that the process in the pathogenesis of Vibrio sp. PJ infection in orally challenged kuruma prawns consist of five stages namely, establishment of the pathogen, distribution of the pathogen, clearance of the pathogen by host prawn, secondary multiplication of the pathogen, and systemic infection. The results also suggest that the pathogen multiplied in the stomach in the establishment stage and in the hepatopancreas and lymphoid organs in the secondary multiplication stage.

(Faculty of Applied Biological Science, Hiroshima University, Higashi-Hiroshima 724, Japan)


COMPARISON OF THE COAT PROTEIN GENES OF FIVE FISH NODAVIRUSES, THE CAUSATIVE AGENTS OF VIRAL NERVOUS NECROSIS IN MARINE FISH

Nishizawa, T., K.-I. Mori, M. Furuhashi, T. Nakai, I. Furusawa,

K. Muroga-1995

Journal of General Virology, 76:1563-1569

ABSTRACT:

Striped jack nervous necrosis virus (SJNNV), a nodavirus, is the causative agent of viral nervous necrosis (VNN) in larval striped jack fish. In the present study, the SJNNV coat protein gene was sequenced and compared with that of four known insect nodaviruses and with four other fish nodaviruses causing VNN. The SJNNV coat protein gene was 1410 bases in length and contained a single ORF of 1023 bases encoding a protein of 340 amino acids. The sequence similarities between the coat protein gene of SJNNV and four insect nodaviruses were 28.6% or less at the nucleotide level and 10.6% or less at the amino acid level. A portion of the coat protein gene from four additional fish VNN viruses was amplified by PCR using primers designed for SJNNV and the amplified fragments (870-876 bases) were sequenced. The sequence similarities among SJNNV and the four VNN viruses were 75.8% or greater at the nucleotide level and 80.9% or greater at the amino acid level. In the fish nodaviruses a highly conserved region of 134 amino acids with sequence similarity of 92.5% or greater was detected. This conserved sequence was not found in the coat protein of insect nodaviruses. These results indicate that the fish nodaviruses that cause VNN are closely related to each other but are quite different from insect nodaviruses.

(Faculty of Applied Biological Science, Higashi-Hiroshima 724, Japan)


DEVELOPMENT OF WOLFFISH EGGS AT DIFFERENT TEMPERATURE REGIMES

Pavlov, D.A., E. Moksness-1995

Aquaculture International, 3:315-335

ABSTRACT:

Embryonic development of common wolffish (Anarhichas lupus L.) was studied at constant temperatures 5.0, 7.0, 9.0, 11.0, 13.0 and 15.0 C. Duration of development from egg activation to several morphological stages including 50% hatching was determined. At 5.0-11.0 C, the survival rate of eggs to hatching ranged from 51 to 88% with a tendency to increase at 5.0 and 7.0 C. Morphological anomalies, bacterial contamination and large mortalities were observed in eggs incubated at 13.0 and 15.0 C. The period of hatching lasted from 10 to 50 d in different egg groups. Embryo length and yolk sac volume at identical morphological stages of development showed only slight relation to temperature. At lower temperatures newly hatched larvae were longer and at more advanced stages of ontogeny. Normal numbers of fin rays in larvae (mean values 74 for dorsal fin and 46 for anal fin) were observed at 5.0 and 7.0 C and in most larvae at 9.0 C. At 11.0 and 13.0 C, many rays were absent, with mean values for dorsal fin 60 and 39 respectively and for anal fin 28 and 4 respectively. The approximate upper limit for normal development of fin rays appeared to be 9.0 C.

(Chair of Ichthyology, Department of Biology, Moscow State University, 119899 Moscow, Russian Federation)


TWO SYSTEMS FOR COLLECTION OF ZOOPLANKTON FOR THE CULTURE OF LARVAL AND JUVENILE FISH

Anderson, J.-1995

Aquaculture International, 3:336-354

ABSTRACT:

Two systems for enrichment and collection of natural zooplankton in cooling water recipients were developed for rearing fish fry. One system filters-off plankton from the cooling water with rotating dip-nets (diam. 60 cm). The rotation is powered by the kinetic energy of the water and the nets are continuously flushed clean by high-pressure sprays. The water from the nets, being enriched with plankton, is pumped continuously to a grading station where undesirable size fractions are removed, after which the water is distributed to the rearing pens. The system has been tested at a nuclear power station in the south-western part of the Bothnian Sea and found to be promising, with a collection of, on average, 280 g/day. The other system is based on attraction using underwater lamps and pumping of organisms into floating rearing pens. The system is automatic and powered by electricity from the grid. The technical performance has been good. The plankton has been size-graded by attaching net baskets around the lamps. At a nuclear power station on the western coast of the central Baltic Sea, the amount collected has, on average, been 45-570 g zooplankton/lamp/night. The collection system is considered to be of use in productive areas with moderate turnover of water. Both systems are in early stages of development and have not reached their full potential. Improvements are proposed and discussed.

(Institute of Coastal Research, Ävrö 16, S-572 95 Figeholm, Sweden)


EVALUATION OF VITAMIN C-ENRICHED ARTEMIA NAUPLII FOR LARVAE OF THE GIANT FRESHWATER PRAWN

Merchie, G., P. Lavens, J. Radull, H. Nelis, A. De Leenheer, P.

Sorgeloos-1995

Aquaculture International, 3:355-363

ABSTRACT:

The effect of high levels of ascorbic acid (AA) delivered through enriched live food has been verified through the successful culture of larval giant freshwater prawn, Macrobrachium rosenbergii. Two successive feeding trials were set up using a control (550 microgram AA/g DW) and two different AA-enrichment levels in Artemia (1300 and 2750 microgram AA/g DW). Under standard culture conditions, no differences in growth nor survival could be observed demonstrating that the nutritional requirements are below 550 microgram AA/g DW, which is the normal level occurring in freshly-hatched Artemia. However, a significantly positive effect could be demonstrated on the physiological condition of the postlarvae, measured by means of a salinity stress test, when vitamin C-boosted live food was administered. Since the AA levels in the predator larvae are linked with the enrichment levels in the live prey, it may be assumed that a positive influence on stress resistance was caused by feeding vitamin C-enriched Artemia. It is expected that under suboptimal conditions, supplementation of high vitamin C levels might also enhance production characteristics.

(Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Rozier 44, B-9000 Ghent, Belgium)


A STANDARD EXPERIMENTAL DIET FOR THE STUDY OF FATTY ACID REQUIREMENTS OF WEANING AND FIRST ONGROWING STAGES OF THE EUROPEAN SEA BASS DICENTRARCHUS LABRAX L.: COMPARISON OF EXTRUDEDAND EXTRUDED/COATED DIETS

Coutteau, P., G. Van Stappen, P. Sorgeloos-1996

Arch.Anim.Nutr., 49:49-59

ABSTRACT:

The stability of the coated lipid fraction of a standard weaning diet was verified by comparing growth and fatty acid incorporation for European sea bass fed diets with an identical formulation but prepared either by extrusion/coating or extrusion only. For each type of experimental diet, a (n-3) HUFA level of 1 and 2.5% of the dry diet was evaluated. European sea bass Dicentrarchus labrax L. were weaned and consequently reared for 23 days on the experimental diets in a recirculation system. A commercial weaning diet served as a control. Final individual dry weight of sea bass larve weaned and ongrown for a total period of 30 days on the various diets did not differ significantly. The (n-3) HUFA content of the fish tissue was a reflection of the dietary (n-3) HUFA content and was not influenced by the technique used to include the essential fatty acids in the diet. The (n-3) HUFA requirements of European sea bass during and immediately after weaning did not exceed 1% of the dry diet. The combined technique of cooking-extrusion of a basal diet followed by coating of a lipid emulsion proved to be a valid technique to prepare diet for studying quantitative fatty acid requirements of weaning and first ongrowing stages of marine fish. A standard diet with open formulation is proposed.

(Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Rozier 44, B-9000 Ghent, Belgium)


REGIONAL STUDY AND WORKSHOP

ON

AQUACULTURE SUSTAINABILITY AND THE ENVIRONMENT

"AQUACULTURE SUSTAINABILITY ACTION PLAN"

ASAP

October 1995

ASIAN DEVELOPMENT BANK

RETA 5534

NETWORK OF AQUACULTURE CENTRES IN ASIA PACIFIC

CONTENTS (EXCERPTS):

1. PREAMBLE:

This Aquaculture Sustainability Action Plan (ASAP) was prepared during the final workshop of the Regional Study and Workshop on Aquaculture Sustainability and the Environment. The Workshop was held in Beijing from 6 to 12 October 1995, hosted by the Ministry of Agriculture of People's Republic of China. The Regional Study was undertaken and jointly supported by the Network of Aquaculture Centres for Asia-Pacific (NACA) and the Asian Development Bank (ADB) under a regional technical assistance program (RETA 5534).

2. ON-FARM MANAGEMENT FOR SUSTAINABLE AQUACULTURE

2.1 FARMING SYSTEMS AND MANAGEMENT

The farming system components, including feed, fertiliser and chemical inputs, species and stocking density, water quality and quantity, soil and sediment management, the degree of integration of aquaculture with other agro-ecological systems, as well as social and economic factors, were important considerations for environmentally sustainable aquaculture, and all were discussed by the workshop.

The integration of aquaculture with agriculture in a unified farming system has proved to be sustainable.

In considering ways in which the design and management of farming systems might be further improved to enhance sustainability, the workshop considered that the following issues should receive the attention and focus of governments and farmers.

(a) Feed

(b) Water management

In considering that a supply of water of sufficient quality and quantity was essential to sustainable aquaculture development, the workshop made recommendations concerning water management as follows:

- farmers operating in clusters around a single intake/discharge system should coordinate water intake and discharge to avoid the risks of mutual pollution and conflict. Governments should establish mechanisms and provide assistance to avoid overcrowding and promote cooperation among small-scale farmers with a view to avoiding environmental deterioration and spread of pathogens through effluent discharge;

- research should be directed towards formulating water and effluent quality standards that can be used to establish BMP without conflict with other users;

- research should be undertaken on the sustainability of various aquaculture systems;

- as unregulated use of water resources is causing environmental damage to the aquaculture industry, governments should promote the integrated planning for the use of water resources; and

- each country should develop its own water management policies and systems but regional exchange of information on water management practices would help to develop Best Management Practices (BMPs).

(c) Sediment management

(d) Seed and broodstock

Farmers expressed concern about the availability and quality of seed. Farmers were concerned about genetic deterioration in some carps, and the health status of shrimp seed. In considering these issues, the workshop recommended:

- national fisheries authorities and the private sector should promote the use of healthy and genetically sound seed and broodstock. Governments should work with the private sector to develop guidelines for healthy seed and broodstock quality;

- research and development activities should give a high priority to development of captive shrimp; and

- research on genetic improvements of carp might be undertaken, and that hatchery operators be advised of methods for maintaining quality of the carp seed produced.

3. WIDER ENVIRONMENTAL MANAGEMENT ISSUES

3.1 SITE SELECTION

3.2 ENVIRONMENTAL MANAGEMENT

(a) Land and Water Resources

(b) Environmental Assessment

(c) Disease and Related Issues

The workshop expressed concern about the increasing economic losses resulting from fish and shrimp deseases outbreaks and made the following recommendations:

- governments should enhance the provision of extension services on health management. If not already existing, they should also consider the establishment of a central facility for aquatic health management to provide the necessary diagnostic and research support to farmers;

- rapid disease diagnostic procedures for shrimp, carp and other cultivated species should be further developed and made more widely available;

- research institutions should be strengthened in performing research in areas concerning disease diagnosis and prevention and for the development of disease tolerant aquaculture varieties;

- farmers are recommended to establish small-scale disease diagnostic laboratories through self-help groups and farmers associations with assistance from government agencies;

- to support the governments and farmers in aquatic health management, the national fish disease control network should link into a functional regional network; and

- the strengthening of regional centres of excellence in aquatic health management is highly desirable.

In their further efforts to reduce losses from shrimp and fish diseases, governments should work closely with the aquaculture industry to strengthen their knowledge and capacity for disease prevention and control.

3.3 SOCIAL PARTICIPATION

3.4 RESEARCH

4. POLICY ISSUES AND AQUACULTURE SUSTAINABILITY

4.1 AQUACULTURE LEGISLATION

4.2 INCENTIVES FOR COMPLIANCE

4.3 ZONING

4.4 WATER MANAGEMENT AND QUALITY

4.5 INSTITUTIONAL DEVELOPMENT

4.6 TRANSGENIC MATERIALS AND OTHER GENETIC MANIPULATIONS

4.7 IMAGE PROMOTION

4.8 FARMER ASSOCIATIONS AND THE PRIVATE SECTOR

5. OPPORTUNITIES FOR REGIONAL COOPERATION

5.1 RESEARCH

5.2 CAPACITY BUILDING AND REGIONAL MECHANISMS FOR TRAINING

5.3 FARM DESIGN AND WATER CONTROL FOR MINIMIZING ENVIRONMENTAL

IMPACTS

5.4 ESTABLISMENT OF A "SUSTAINABLE AQUACULTURE FUND"

5.5 NATIONAL INFORMATION

5.6 REGIONAL INFORMATION

5.7 DEVELOPMENT OF THE REGIONAL AQUACULTURE SUSTAINABILITY

DATABASE

6. IMPLEMENTATION OF AQUACULTURE SUSTAINABILITY ACTION PLAN


INTERNATIONAL CONGRESS ON THE BIOLOGY OF FISHES

July 14-18, 1996

San Francisco State University, San Francisco CA, USA

Organized by Physiology Section and American Fisheries Society

PROGRAMME:

The Physiology of Tropical Fish

Applied Environmental Physiology

Aquaculture Biotechnology Symposium

Feeding Ecology and Nutrition in Fish

Physiology of Migratory Fish

The Fish Egg: Its Biology and Culture

Physiological Monitoring of the Effects of Contaminants on Fish

Culture and Management of Sturgeon and Paddlefish

High Performance Fish II

For registration, contact Fish Biology Congress, c/o Alec Maule, NBS CR Lab, 5501A Cook Underwood Road, Cook, WA98605 USA

Enquiries: Phone(509)538-2299, Fax (509)538-2843, email: Alec_Maule@nbs.gov


VII INTERNATIONAL SYMPOSIUM ON NUTRITION AND FEEDING OF FISH

August 11-15, 1996

College Station, Texas, USA

For registration (before March 31), contact the Local Organizing Committee:

Delbert M. Gatlin and Steven R. Craig,

Department of Wildlife and Fisheries Sciences

Texas A&M University, 210 Nagle Hall

College Station, TX77843-2258, USA

Phone: 409-847-9333

Fax: 409-845-4096

e-mail: d-gatlin@tamu.edu

Objectives and Format of the Symposium:

The VII International Symposium on Nutrition and Feeding of Fish, held under the auspices of the International Union of Nutritional Sciences and the Subcommittee for Fish Nutrition, will be a forum to address established and emerging issues related to fish nutrition in the context of aquaculture. Approximately three and one-half days will be scheduled for the Symposium. Invited keynote lectures will address specific topics or issues that are of general interest or current importance. In addition, presentation of original research will be provided in oral and poster sessions arranged according to general topic areas including the following:

- Interrelationships between nutrition and endocrinology

- Nutrition and health interactions

- Product quality and other factors influencing aquaculture development

- Macronutrients and energy - requirements and metabolism

- Nutrition of broodstock and larvae

- Crustacean nutrition

- Practical aspects of diet formulation, feeding and aquacultural production


THE SECOND ASIA-PACIFIC MARINE BIOTECHNOLOGY CONFERENCE

AND

THE THIRD ASIA-PACIFIC CONFERENCE ON ALGAL BIOTECHNOLOGY

May 7-10, 1997

Phuket, Thailand

Organized by:

International Organizing Committee for Asian-Pacific Society of Marine Biotechnology (APSMB)

Local Organizing Committee (Chairperson, Prof.Dr. Piamsak Menasveta)

The following are the tentative focal topics for the conference

Session 1: Algal Biotechnology

Session 2: Aquaculture Biotechnology

Session 3: Environment Biotechnology

Session 4: Marine Natural Products

Session 5: Marine Microbial Ecology and Physiology

Requests for further information should be addressed to:

APMBC'97 Secretariat

National Center for Genetic Engineering and Biotechnology (BIOTEC)

Ministry of Science, Technology and Environment Building

Rama VI Rd., Bangkok 10400, Thailand

Tel. (622) 2457374 2455002

Fax (622) 2464850


SECOND INTERNATIONAL CONFERENCE ON THE CULTURE OF PENAEID

PRAWNS AND SHRIMPS

14-17 May 1996

Iloilo City, Philippines

Organized by:

Aquaculture Department, Southeast Asian Fisheries Development Center

PROGRAMME:

Shrimp Research at SEAFDEC/AQD

Penaeid Biology & Ecology (Dr. Peter Rothlisberg, CSIRO)

Contributed Papers in Biology, Ecology & Physiology Seed Production of Penaeids (Dr. Craig L. Browdy, Waddell Mariculture Center)

Contributed Papers in Seed Production

Pond Nutrient Dynamics (Dr. Simon Funge-Smith, University of Stirling)

Contributed Papers in Grow-out Culture

Penaeid Shrimp Nutrient Requirements & Feed (Dr. Shi-Yen Shiau, National Taiwan Ocean University)

Contributed papers in Nutrition & Feed Development

Shrimp Diseases & Current Diagnostic Methods (Dr. Donald Lightner, University of Arizona)

Contributed papers in Diseases & Environmental Issues

Vaccination & Immunostimulation in Shrimps (Dr. Toshiaki Itami, National Fisheries University)

Penaeid Genetics & Biotechnology (Dr. John Benzie, Australian Institute of Marine Science)

Contributed papers in Genetics & Biotechnology

Economics of Shrimp Hatchery & Grow-out (Dr. Yung C. Shang, University of Hawaii - Manoa)

Contributed papers in Socioeconomics, Processing, Marketing

There will be simultaneous workshops on the following topics:

Induced Maturation and Seed Production

Pond Culture and Nutrient Dynamics

Diseases, Genetics, and Biotechnology

Nutritional Requirements and Feed Development

If you need additional information about the conference, please contact:

The Secretariat, SICCPPS

SEAFDEC/AQD, Tigbauan 5021

Iloilo, Philippines

Tel: (63)33-3351009

Fax: (63)33-3351008

E-mail: tms-seafdec@phil.gn.apc.org


MARKETING AND SHIPPING

LIVE AQUATIC ANIMALS AND PLANTS

Industry Conference and Exhibition

Port of Seattle Convention Center

Seattle, Washington, U.S.A.

October 13-15, 1996

WHY AN INDUSTRY CONFERENCE?

Global markets for live seafoods are expanding rapidly. Meeting that market demand requires a thorough knowledge of the specialized requirements for live shipments.

Although the technology needed to support this industry phenomenon is readily available in many parts of the world, it is relatively unknown in the United States. Few domestic processors, distributors, and harvesters possess adequate systems and know-how for holding and shipping live aquatic animals and plants.

This conference will address the practical considerations of the live seafood industry with particular emphasis on:

- identifying new business opportunities and exploiting new markets

- providing consumers with a greater variety of products

- improving harvesting, handling, packaging, and shipping technology

- educational needs of present and potential workers involved in live shipping

DEADLINES FOR ORAL AND POSTER PRESENTATIONS

April 1, 1996 Abstracts and biographical sketches are due October 5, 1996 Complete papers are due

EXHIBITS

Companies interested in displaying commercial products and services at this national conference are invited to contact the conference manager at the address/phone/fax/e-mail below:

PROGRAM COMMITTEE

John B. Peters

Nor'Westerly Food Technology Services

2743 56th Avenue SW

Seattle, Washington 98116

Phone 206-938-0676 Fax 206-933-7937

e-mail: 103243.675@Compuserve.com

Brian Paust, Alaska Marine Advisory Program

University of Alaska

P.O. Box 1329

Petersburg, Alaska 99833

Phone 907-772-3381 Fax 907-772-4431

e-mail: ffbcp@acad1.Alaska.edu

CONFERENCE MANAGEMENT

Nor'Westerly Food Technology Services

2743 56th Avenue SW

Seattle, Washington 98116

Phone 206-938-0676 Fax 206-933-7937

e-mail: 103243.675@Compuserve.com


SUB-MICRON FILTER FOR BLOWER SYSTEM

date: 25 Jan 1996

From: Gregg Rivara <grivara@cce.cornell.edu>

To: Multiple recipients of list <aqua-l@upei.ca>

Can anyone direct me to a supplier of a 0.2 micron air filter for an air blower system (7 PSI, 100 CFM). I require this for an algal culture facility.

Ken Waiwood kwaiwood@wolves.sta.dfo.ca

Dept.Fisheries and Oceans 506-529-8854

Biological Station fax 506-529-5862

St.Andrews, N.B.,

Canada

E0G 2X0

COMMENTS 1:

We used to use two capsule filters from Fisher or VWR on a small algae system. The filters were autoclavable and lasted about a year (as long as you have a prefilter on the compressor's intake). Give me a call directly if you need the exact part #.

Gregg Rivara (grivara@cce.cornell.edu)

Cornell Cooperative Extension

3690 Cedar Beach Roach

Southold, NY 11971

516-852-8660

516-852-8662 (Fax)

COMMENTS 2:

Try Cole Parmer Instruments. I get my 0.2 micron filters from them.

HadleyN@cofc.edu

Nancy Hadley

MRRI

PO Box 12559

Charleston SC 29422-2559

(803) 762-5022/762-5071

Fax (803) 762-5110


THE BRINE SHRIMP SHORTAGE

A handful of fishermen on Utah's Great Salt Lake supply the world's shrimp hatcheries with brine shrimp eggs, also called Artemia cysts, an essential feed at most shrimp hatcheries. In March 1995, David Cole, president of Salt Creek, Inc., a harvester/distributor of brine shrimp eggs and other hatchery feeds, reported on the 1994/1995 egg harvest, one of the smallest on record and the reason why eggs were so expensive in 1995. Remember, Cole's comments are on last year'harvest. This year's harvest, the 1995/1996 harvest, got started in October, and preliminary indications are that it's going to be a good year!

Cole reported: The 1994/1995 brine shrimp egg harvest from Utah's Great Salt Lake will probably go down as one of the worst ever. Compared to normal harvests (and we've never really had one of them), this year's harvest was probably down 35% to 65%, with the latter more likely. That's based on unofficial estimates! Coupled with the previous year's small harvest, this has created a worldwide supply problem, affecting the brine shrimp harvesters, distributors and most importantly - shrimp hatcheries.

We estimate the 1994/1995 harvest total from October to February to be 1,600,000 finished processed pounds, plus or minus 15%. The quality of the harvest is comparable to that of the last three years. However, buyers should expect to see some low quality, non-branded product hit the market this year and next year.

The short supply has had its effect on prices. Wholesale and retail prices have moved up 300% or more. It seems likely that prices will continue to rise as supplies continue to tighten. It is predicted that nearly all stocks will be depleted before the 1995/96 harvest is ready for sale.

Unfortunately, there's no way of predicting the size of the 1995/96 egg harvest - but early indications are that it is going to be a good year!

(excerpts from article in World Shrimp Farming, Annual Report 1995 Shrimp News International)


ABOUT SHRIMP FARMING: HATCHERIES

Conclusion:

Hatcheries are the weakest link in the production cycle. Fluctuations in the availability of wild broodstock coupled with the unpredictability of maturation make them susceptible to failure. Also, feeding the various life stages of developing shrimp takes a major effort, and hatcheries are plagued with management, disease and water quality problems - but they are constantly improving and constantly increasing production. Hundreds of researchers in a dozen countries work on unraveling the mysteries of hatchery production, and thousands of hatcherymen in all the shrimp farming countries tinker with new techniques, designs and ideas to improve production. When hatcheries become more reliable - and they will - the production of farm-raised shrimp will take another leap forward!

(excerpts from article in World Shrimp Farming, Annual Report 1995 Shrimp News International)


ASIAN SHRIMP NEWS

COLLECTED VOLUME 1989-1995

Published by The Asian Shrimp Culture Council

ISSN 0859-4120

For information, contact:

Asian Shrimp Culture Council

C.P. Tower, 28th Floor

313 Silom Road, Bangkok 10500

Thailand

Telephone: 66-2-231-0828

Fax: 66-2-238-190


ECOLOGY AND POPULATION STRUCTURE OF THE ARTEMIA PARTHENOGENETICA POPULATION INHABITING A MAJOR SALTERN IN SRI LANKA

Kuruppu, M.M., S.U.K. Ekaratne-1995

International Journal of Salt Lake Research, 4:117-131

ABSTRACT:

The structure of the naturally occurring Artemia parthenogenetica population inhabiting the Mahalewaya Saltern in Sri Lanka was studied over an annual cycle, together with accompanying variations in the physico-chemical characteristics of its pond waters. Artemia was found only in the serially connected earthen ponds that serve as condenser pans in the saltern. Over the 12- month period of study, salinities in these ponds ranged from 81.5 to 199.6 ppt, temperatures from 28.2 tp 33.6 C, pH from 7.9 to 9.1 and dissolved oxygen from 1.1 to 9.0 mg L-1. The physico- chemical characters varied along a gradient across the three ponds, with salinity and temperature increasing with proximity of the condenser pans to the crystallizers of the saltern and dissolved oxygen values showing the opposite trend. The ponds containing Artemia were shallow and had a maximum depth of 37 cm. Gross primary productivity ranged from negative values to 686.4 mg C m-2 day-1. Rainfall was distributed non-uniformly almost throughout the year, most of it being experienced from August to October, with a 254 mm maximum in October and lesser rainfall from December to May. Population numbers ranged from zero to 125 individuals L-1 and declined with increasing salinities and temperatures which related, spatially, to increasing proximity of ponds to crystallizers and temporally, to the dry weather periods. Recruitment was best at low salinities and temperatures (104 to 114 ppt and 28.2 to 30.5 C) but also took place, although at reduced intensities, up to 174 ppt salinity and 32.2 C temperature. Populations were mostly dominated by instar I stage nauplii with adult stages predominating only during periods of high salinity and temperature. Water management practices for salt production in the salterns included maintaining shallow depths that lead to high water temperatures and pond irrigation procedures that resulted in abrupt salinity changes. Such practices limited the size of the Artemia population as well as prevented its spread into the numerous ponds of the saltern.

(National Aquatic Resources Agency, Crow Island, Colombo 15, Sri Lanka)


ARTEMIA AND ROTIFER ENRICHMENT

Date: 1 Feb 1996

From: PHadleyIII@aol.com

To: Multiple recipients of list <aqua-l@upei.ca>

I have used both Roti-Rich and the various Selco products for growing rotifers and for pre- and post-harvest enrichment. My preference is the "culture selco" but I don't know what level of enrichment it results in. The rotifers like it and it doesn't result in as much bacterial contamination as the Roti-Rich. Regular Selco and Super Selco are easy to use for enrichment but I have no data on their actual transfer to the rotifers and I had trouble with bacterial growth in the fish tanks I was feeding the rotifers to, despite pretty thorough rinsing.


BRYOZOAN FOULING IN HATCHERIES

Date: 31 Jan 1996

From: AAquatics@aol.com

To: Multiple recipients of list <aqua-l@upei.ca>

My experience with hatchery and nursery intake pipes is that chlorine bleach kills most everything, if the right concentration is maintained for the appropriate length of time. Total kills can take up to 24 hours. Fresh water (hyposaline?) uses up less of the disinfection potential than raw seawater. One major caution, long term exposure of pvc piping to high concentrations of chlorine will make the piping brittle and weak.

A preferred technique that my shellfish farmer friends use is to install two or more intake and supply pipes. While one (or more) are in use, at least one has been closed off (capped, valved or whatever) to put it an anaerobic cleaning cycle. On-line times typically run a few weeks. Off-line or anaerobic conditions of about a week to 10 days seem to work. Local conditions will vary.

Prefiltering with sand and/or bag filters, combined with a mild chlorine flush on a week to 10 day basis seems to work well as well.

Paul L. Hundley, Jr., P.E.

President/Principal Engineer

APPLIED AQUATICS, INC.

Marine and Aquacultural Water and Wastewater Treatment

936 Pine Hollow Road

Mt. Pleasant, SC 29464

USA

Tel: 803/971-9639

Fax: 803/971-9641

E-mail: AAquatics@aol.com


BUOYANT BIVALVE LARVAE

Date: 24 Jan 1996

From: EKRhodes@eworld.com

To: Multiple recipients of list <aqua-l@upei.ca>

I have been working with the State of Sonora shellfish hatchery in Bahia Kino, Mexico for a few months growing larvae of one of the pen shells, Atrina maura. This facility started producing seed of this species in 1994, but the overall success rate is quite low.

The pen shell larvae are very buoyant, and especially after water changes many float in clumps at the water surface. This is not the rafting behavior, usually seen as a good sign with oyster larvae. This floating phenomenon occurs following water changes either using a dry screening technique, or when the screens are kept in a water bath.

I am concerned that this buoyancy, especially pronounced after water changes is contributing to the poor culture success.

Does anyone have experience with buoyant larvae? Is it a problem? Any suggestions on methods to alleviate the condition?

Ed Rhodes

Apdo 151

Kino Viejo, Mexico

COMMENTS 1:

I see a lot of clumping at the surface with oyster larvae (C. gigas, O. lurida, O. edulis) after water changes. Mainly this is seen in older larvae, but this may be because they are more visible due to size. Usually they leave the surface after an hour or so, but if not I crank up aeration a bit, and that usually breaks them up back into the water column. Don't know if the clumping is "bad", but seems feeding might be difficult there, and individuals may get tangled up in mucus.

Some culturists use aeration, some don't. An experiment done several years ago suggested no statistically significant difference between aerated and non-aerated cultures, but I like to provide a small number of large bubbles at the bottom of the culture vessel, just to keep everything moving...wonder if the pen shell larvae hang at the surface tension in nature.

Will <wdborgeson@ucdavis.edu>

COMMENTS 2:

I have no experience with buoyant shellfish larvae, but I have used pure silicone antifoaming agent to reduce surface tension in other marine cultures. Good luck

David L. Berg phone: 516-385-2417 fax: 516-385-2420

e-mail: DaveLBerg@AOL.com

COMMENTS 3:

First, you should determine whether the larvae are, in fact, buoyant, or whether they are being trapped in the surface film.

I do not think that buoyancy is the problem, but you can:

1. Try slowly lowering the specific gravity of the culture water.

2. Prior to water changes try to adjust the specific gravity of the exchange water to exactly the specific gravity of the culture water, preferably by matching both salinity and temperature.

However, it sounds like they are bein trapped in the surface film. I understand that this has been found to be a major cause of mortality with experimental cultures of Aplasia. To eliminate the problem, culture vessels have been designed to eliminate the air/water interface, with water exchange through screens with an aeration tube/air lift.

BTW -- Do you think that it would be practical to use Atrina sp. in the discharge of a shrimp farm for the purpose of reducing microalgae, bacteria, and other suspended matter?

Don Hockaday hockaday@panam.edu

-----------------------------------------------------------------

Don Hockaday, Acting Director

The University of Texas - Pan American Coastal Studies Laboratory

105 East Marine Lab Drive; South Padre Island, Texas 78597

(201) 761-2644 fax (210) 761-2913 hockaday@panam.edu

-----------------------------------------------------------------

COMMENTS 4:

We have a similar problem with conch larvae and it all relates to water circulation. Having been involved with the Kino Bay hatchery at its inception I remember the very large larval tanks with several airstones (as I recall ~13' diameter by 9' tall?). This was fine for a species like C. gigas that is distributed fairly uniformly through the water column with relatively little water movement but a species that is affected less by minor water movements may require more vigorous circulation. You may want to use food coloring to assess the circulation and to see if or where dead spots occur. There are a variety of variables you may want to test including bubble size (a 2 micron pipet produces fairly large bubble with more water movement than an airstone) and an airlift for circular water movement (basically aeration within a 6" pvc collar suspended several inches off the bottom). If all else fails, it may be that your tanks are not appropriately designed for this species. A greater height/diameter ratio may provide more lift and, consequently, circulation.

Bob Glazer

Florida Marine Research Institute

2796 Overseas Highway, Ste 119

Marathon, FL 33050

305-289-2330

305-289-234 (fax)

GLAZER_B@SKELTON.DEP.STATE.FL.US


POSTGRADUATE TRAINING IN MARINE AND FISHERIES SCIENCE

Date: 7 Feb 1996

From: Graham Pierce <g.j.pierce@abdn.ac.uk>

To: Multiple recipients of list >aqua-l@upei.ca>

=====================================================

Postgraduate training in Marine and Fisheries Science at the University

of Aberdeen

=====================================================

MSc/Diploma Course

==================

This postgraduate course covers the biology, exploitation and management of the marine environment and its living resources.

The teaching resources and range of interests in marine biology and fisheries at the University are combined with specific areas of advanced expertise available at the Scottish Office Marine Laboratory in Aberdeen. The major input from research scientists responsible for providing advice on fishery matters to the UK government is a special feature of this course.

*Lecture courses

During the first semester and a half, both MSc and Diploma courses consist of an integrated series of lecture modules. There are associated practical exercises, essays and visits. Supporting material in the form of seminars and tutorials is provided throughout. Topics currently taught include:

-Marine Environment: physical and biological aspects; environmental quality and pollution

-Aquatic animal biology: reviews of fish and shellfish biology

-Animal population and community ecology: fish population dynamics; resource ecology; trophic relations and energy flow; marine applications of telemetry and remote sensing

-Resource utilization

-Fisheries: fisheries exploitation and management; fisheries economics, law and administration; gear technology and fish behaviour

-Aquaculture: aquaculture, fish diseases and parasites

-Computer and numerical skills

*Diploma

The Diploma course runs for 9 months. In addition to the lecture courses, students complete a dissertation or short practical exercise.

*MSc

The MSc runs for 12 months. In addition to the lecture courses, students carry out a period of practical research training, lasting approx. 4 months, culminating in the presentation of a thesis.

For application forms for MSc/Diploma or PhD and more information, please write to:

Postgraduate Admissions

Department of Zoology

University of Aberdeen

Tillydrone Avenue

Aberdeen

AB9 2TN

Scotland

UK

==============================================================

This information was provided by:

Dr Graham Pierce

Department of Zoology

University of Aberdeen

Tillydrone Avenue

Aberdeen

AB9 2TN

UK

Phone 44 (0) 1224 272866 Eurosquid World-Wide Web page:

Fax 44 (0) 1224 272396

http://www.abdn.ac.uk/~nhil104/

e-mail g.j.pierce@abdn.ac.uk