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5
Engineering and Research
ROLE OF SCIENCE AND TECHNOLOGY
IN ADDRESSING MAJOR CONSTRAINTS
A broad range of economic, institutional, environmental, and social con-
cerns can, to some extent, be addressed through advances in the science and
technology base supporting marine aquaculture. Problem areas that are
susceptible to mitigation through technological approaches include economic
feasibility, market structures and product form, the regulatory framework
for leasing and permitting, land and water use, ecological impacts, aesthetic
issues, use conflicts, and public attitudes.
Summaries of the major issues follow, with examples of where science
and technology can contribute to the resolution of related problems.
Economic Feasibility
Advances in technology can improve economic feasibility through (1)
the creation of new capability, (2) the design of more productive (higher-
yield) operations, and (3) the reduction of expenditures through more
effective and efficient operations and the substitution of cost-effective capi-
tal investment for labor. Specific opportunities for improving marine aqua-
culture in these areas include:
· new culture systems that make possible the production of marine spe-
cies in environmentally sound ways;
· improved technology for culture operations to utilize inputs more effi-
ciently, increase productivity, and reduce costs of production and waste
116
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ENGINEERING AND RESEARCH
117
disposal (e.g., water use and reuse, feeding technology, product inventory,
product handling, waste disposal);
· technology that improves the cost-effectiveness of operations through
intensification of culture systems, reduced operating costs, and increased
productivity; and
· technology that reduces production uncertainty (e.g., through disease
detection and treatment, inventory monitoring systems, and design of more
seaworthy facilities), thereby reducing risk and the associated costs of
capital, insurance, and other nonoperational factors.
Marketing and Product Information
Technology can enhance the quality and value of products in addition to
increasing productivity and reducing costs. Examples are:
· harvest, transportation, processing, and packaging technologies that
will allow aquaculture to deliver high-quality products in good condition to
appropriate markets;
· technologies that can maintain high-quality standards and ensure wholesome
and safe products; and
· new product forms for new and traditional aquaculture species.
Institutional and Regulatory Issues
Technology can be used effectively to address many institutional issues.
Opportunities include:
· technology to diminish the amount of water or land necessary for cul-
ture and auxiliary systems, thus minimizing land/water use conflicts;
· information systems to improve communication with the public, pro-
vide relevant facts, make information more accessible, and generally in-
crease understanding of the benefits and constraints of aquaculture;
· technology that will resolve issues associated with access to brood
A.'
_ ... .. . .. ~ a ~ ~ . - , 1 ~ _ _ 1_ · _
stock and seed/juvenile production from wild populations through achlev-
ing controlled reproduction, an understanding of improved nutritional
requirements, and better knowledge of species life cycles;
· technology to better identify and control disease-related problems; and
· technology for the identification of cultured fish in order to differenti-
ate among stocks for marketing and management purposes.
Environmental Issues
Marine aquaculturists must be sensitive to issues of common resource
use and must seek ways to reduce pollution and other environmental im-
pacts. Science and technology can contribute significantly to this goal by
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118
MARINE AQUACULTURE
· achieving waste treatment and removal, and water and feed delivery,
that alleviate pollution and discharge problems in culture and auxiliary
systems;
· providing means to minimize disease transmission in culture operations
and thereby improve disease prevention and management;
· providing improved culture and auxiliary systems (for open ocean pro-
duction, closed systems, and ocean ranching) that mitigate the ecological
impacts;
· providing alternative, nearshore, culture systems that can mitigate con-
flicts with recreational, commercial, and navigational use;
· providing innovative culture systems that address the aesthetic issues
associated with nearshore operations (i.e., by use of submerged cages, off-
shore production, closed systems, and ocean ranching);
· developing analytical techniques and computer models to simulate the
environmental impact of aquaculture operations (Brune, 1990~;
· improving stock sterilization capability that prevents reproduction in
cultured animals and prevents genetic dilution of wild stocks from escaped
fish;
· improving harvest, packaging, and transportation systems to alleviate
potential sanitation and public health concerns; and
· providing the capability to identify genes that control growth (a capa-
bility that has been achieved with nonfish food species).
Socioeconomic Issues
The development of technology for marine aquaculture not only can im-
prove the economic situation for producers but can contribute to the year-
round economic health of rural communities as well. Specific examples
include (1) providing employment for laborers who work on aquaculture
farms, and (2) creating or augmenting the need for suppliers and processors
that, in turn, provide employment.
INTERDISCIPLINARY SYSTEMS DESIGN
Marine aquaculture systems require individual elements designed so that
each can function effectively alone and can also function in concert with other
elements to comprise an interactive system. For example, a simple home
aquarium may be viewed as a system made up of a few common elements-
a tank, air pump, air diffuser, water pump, and filter. Aquaculture systems,
although conceptually similar, are much more complex in terms of design,
operation, and management. The biological functions of the fish must be
taken into account, including special requirements associated with intensive
culture operations. Consequently, the design of a commercially viable system
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ENGINEERING AND RESEARCH
119
involves considerations beyond purely engineering criteria for integrating
the elements into a working physical system (Huguenin and Colt, 1989~.
Design, operation, and management are further complicated by the need
for profitability, the risks and challenges associated with the intensive pro-
duction of animals, and the necessity of working in a frequently hostile
environment—the ocean. The project team must select an adequate site;
establish the physical, chemical, and biological requirements for the species
in culture; and also design a system that is economically viable. An inter-
disciplinary approach is needed to achieve all these objectives. The engineer,
the biologist, and the entrepreneur must collaborate effectively in order to
solve problems and develop improved technology for marine aquaculture, an
arrangement not easily achieved in an era of increasing specialization.
Although technology development is needed for the commercial success
of marine aquaculture, research on the biology of potential cultivars is also
essential. One of the principal constraints to economic viability is the lack
of sufficient biological information necessary as design criteria for fish
culture. Too little is known about life cycles, the means of controlling
reproduction, the environmental and nutritional requirements of larvae, the
causes and effects of stress, and biological and environmental requirements
in general. Effective interdisciplinary systems design can be realized only
if the biological criteria for design are well understood.
Following are discussions of the major areas in which interdisciplinary
research and developments can make significant contributions to the ad-
vancement of marine aquaculture and to the resolution of many outstanding
issues that presently constrain the industry. First, auxiliary systems that are
an essential part of all types of culture systems are discussed. Then culture
and confinement systems are discussed in the context of those that are
adaptable to nearshore locations, those that can be used onshore, and sys-
tems compatible with offshore production.
Auxiliary Systems for Fish Culture
Improvement and development of the various auxilliary systems that are
required for culturing fish are essential to the establishment of commer-
cially viable marine aquaculture. Aquaculture systems must ensure the con-
finement or physical support necessary to hold the animal, as well as pro-
vide the auxiliary elements required for healthy aquatic life (Fridley et al.,
19881. Key needs are adequate water with adequate oxygen, effective feed
and feeding systems for marine species, waste treatment, and sensors and
monitoring capability. Expert systems, including computer monitoring and
prediction capability, can be very helpful as well. Most of these needs are
provided by auxiliary systems and are basic to the cultivation or husbandry
of any animal, terrestrial or aquatic.
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120
Hatchery Systems
MARINE AQUACULTURE
The culture of most species requires a hatchery in which to collect, incu-
bate, and hatch eggs and/or rear larval fish and young juveniles. Hatcheries
require rigorous controls and careful management. The young animals are
intolerant of adverse water temperature and quality, and often are difficult
to feed. A variety of jars, racks, sacks, and other containers have been
developed to hatch eggs and to set the spat of shellfish. Special diets and
Hatchery tank with a Macdonald jar an incubation container that provides an en-
vironment conducive to egg development with minimum stress and minimum
opportunity for disease.
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ENGINEERING AND RESEARCH
121
special ways of presenting the feed have been created. Each species tends
to have some unique requirements that lead to continual innovation as
advances are made with current species and as new species are cultured.
Hatchery development can be a limiting factor in attempts to culture new
species. Hatchery limitations generally tend to be more biological than
technological. The intensive practices (high population density) of hatcher-
ies and the relatively short time that animals are in the hatchery generally
result in lower water requirements and smaller facilities than for the
grow-out stage of development. This smaller scale of operations tends to
limit the level of environmental and public concern. However, in the future,
the pursuit of offshore systems may present technology problems related
to the design of offshore hatcheries or to the transport of juveniles from
an onshore. h~tc.herv to an offshore culture facility. In anv case. the biologi-
cat information needed to produce high-quality stock consistently and eco-
nomically is often a limiting factor in achieving cost-effective hatchery
production.
Feed and Feeding Systems
The feeding habits and the morphology and composition of feed vary
greatly by species. Consequently, different artificial diets and feeding sys-
tems need to be developed in each kind of culture operation. A large body
of information is available on feeds and feeding systems for salmonids and
catfish (NRC, 1974a,b, 1977; Halver, 1988; Lovell, 1989~. Considerable in-
formation is also available regarding the nutritional and feeding require-
ments of oysters and lobsters (Conklin et al., 1983~. Future efforts should
build on existing knowledge and focus on the special needs of different
marine species. Of particular importance are nutritional requirements, ef-
fective feeding systems, improved efficiency of feed utilization, and alter-
native protein sources, especially in relation to protein quality and specific
requirements during different periods of the life cycle.
The larval and juvenile stages of many marine species are relatively
small perhaps 2-3 millimeters (mm) at the time initial feeding is required.
This factor presents unique problems with regard to the size of food of-
fered, the acceptability of prepared food versus live food and the delivery
system (Bromley and Sykes, 1985; Holt, 1990, 19921. Microencapsulated
diets have been under development to replace live feeds for larval and
juvenile stages, but they are not yet entirely sufficient (Kanazawa et al.,
19891. Research on better attractants to promote feeding or on improved
feed palatability should lead to lower feed conversion ratios (weight of
feed consumed to weight of fish produced generally between 1 and 31.
Nutritional requirements of a given species change with the transitions
from larval to juvenile to adult stages. Nutritional requirements need to be
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22
MARINE AQUACULTURE
better defined for each species and for each life history stage so that
rations can be tailored to meet the precise dietary requirements of the spe-
cies and stage (Ratafia and Purinton, 1989~. In the future, rations will be
tailored not only to the requirements of the species under culture but also to
the characteristics of the culture systems (e.g., pond system, water reuse
system).
Protein is the single most expensive and essential component of fish
feeds. Consequently, the substitution of less expensive sources of protein
for fish and other animal meals in feed could substantially reduce produc-
tion costs. Use of soybean meal to replace animal protein has been moder-
ately successful with some species (Cowery et al., 1971; Cho et al., 19741.
Other researchers have used poultry egg proteins (Davis et al., 1976; Conrad
et al., 1988) or nematodes (Biedenback et al., 1989) to replace fish protein.
Researchers have investigated a number of feed additives, including anti-
biotics and other medications (Strasdine and McBride, 1979; Marking et al.,
1988~; vaccines (McClean and Ash, 1990~; growth hormones (for review,
see Donaldson et al., 1978), drugs to increase metabolic efficiency (Santulli
et al., 19901; and synthetic reproductive hormones (Yamazaki, 1983~. Feed
formulations are being developed to provide natural or synthetic pigments
(Yamada et al., 1989) and to deliver stable and water-insoluble forms of
necessary vitamins (Shigueno and Itoh, 1988; Grant et al., 19891.
Because feed can release large amounts of nitrogen and phosphorus, and
thus cause localized eutrophication in some areas, improved feeds could
mitigate concerns about eutrophication. Ketola and his associates have
investigated the problem of phosphorous enrichment of receiving waters via
salmon feeds and the effects of feed improvements in reducing such re-
leases (Ketola, 1975, 1982, 1985, 1988, 1990; Ketola et al., 1985, 1990~.
Feeds that result in more efficient assimilation of nutrients are needed to
reduce the waste treatment requirements and limit environmental impacts.
Consideration should be given to the design of feeds that, if uneaten, can
contribute to other links in the food chain. Waste products from feeds, for
example, could serve as a primary source of nutrition in a serial polyculture
system (i.e., in which water and nutrients pass from one containment vessel
with one species to another vessel containing a different species) (Wang,
1988; 1990~.
The feasibility of altering the nutritional value of aquaculture products
for humans or of enhancing other components to improve the marketability
or palatability of farmed aquatic products is also under investigation. As-
sessments of the relative fatty acid profiles of farmed and wild fish are
already under way, partly as a result of interest in nutritional information
(Nettleton, 19901. This information will serve as a guide to the develop-
ment of "finishing diets" that will provide consumer-ready products with
the most nutritionally healthful compositions possible.
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ENGINEERING AND RESEARCH
123
The diversity of feeds pellets, algae, seaweed, small and large- re-
quired for different species in culture creates the need for a diversity of
feeding systems. Feeding systems in need of development include systems
for increasing the efficiency of utilization of the nutrient, decreasing waste
production (in terms of feed that is not consumed and feces production of
the culture species), delivering micronutrients and medications, and pro-
moting by-product usage. The development of feeds and feeding systems
that can provide feed at a rate consistent with the ability of the fish to
consume it would enhance the cost-effectiveness of all feeding systems.
Such systems would also provide environmental benefits from reduced
waste and water pollution in both the rearing and the effluent receiving
waters, including reduced release of additives such as antibiotics. Design
parameters that need to be understood include presentation of the food,
frequency and rate of feeding, physical properties of feed particles, and
impact of feeds and feeding methodology on wastage, growth, feed utiliza-
tion, and predator species. For example, broadcasting feed over the water
surface for juvenile finfish can be advantageous in getting the feed to the
fish, but the presence of the fish at the water surface may attract bird
predators.
Broadcast feeding of shrimp in lined seawater ponds.
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124
Waste Treatment Systems
MARINE AQUACULTURE
Treatment of wastes must be an integrated part of water reuse systems
(discussed later in this chapter) and also may be required in flow-through
and cage systems (Alabaster, 19821. Water disinfection and removal of
solid (excess feed and fecal material) and dissolved (ammonia and dis-
solved organics) wastes are essential in any onshore water reuse system.
In most cases, proper site selection for onshore or nearshore systems can
minimize problems associated with waste. Dispersal or dilution of wastes
for cage culture can be facilitated by proper site selection, but mech-
anical means of dispersing or treating wastes and filtering effluents are
needed for some situations. A fanlike pumping systems placed below
cages reportedly can flush large quantities of water through the system
(Aase, 1985~. In other cases, collection of wastes is required. Waste collec-
tion systems vary greatly for different culture systems. For intensive cul-
ture in ponds and tanks, solid waste collection sometimes can be accom-
plished with the simple addition of a settling tank or pond. However,
more cost-effective methods of waste collection and dispersal need to be
developed.
Reuse systems employ a wide variety of treatments to achieve the de-
sired water quality changes. These may include the following components:
filters, screens, clarifiers, oxygen injection, aeration, biofilters for dissolved
organics and ammonia removal, chemical ammonia removal, heat exchang-
ers, ultraviolet light disinfection, ozone disinfection, and chlorine disin-
fection (Miller and Libey, 1985; Malone and Burden, 1988~. Biofilters are
a critical component in the development of commercially viable recircu-
lating systems, and research in this area continues to be very active (e.g.,
Brune and Piedrahita, 1983; Kruner and Rosenthal, 1983; Miller and Libey,
1985; Rogers and Klemetson, 1985; Malone and Burden, 1988; and Kaiser
and Wheaton, 1991).
Dead and diseased organisms present another waste disposal issue faced
by marine aquaculturists. Management of this waste may be significantly
different from that of fish processing plants because the risk of disease
transmission to other cultured fish and to wild fish must be minimized in
aquaculture operations. However, it is also essential that processing plants
and other facilities take the steps necessary to ensure that diseases are not
transferred to wild populations. Clearly, both commercial fish processing
facilities and aquaculture processing facilities have to dispose of animal
wastes. The technical issue of disposal can be accomplished by utilizing
current land-based disposal methods including landfills or incineration.
However, the continued use of landfills and incineration in the future may
be problematic because of limits on their availability or environmental con-
cerns. Alternative means of disposal need to be developed.
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ENGINEERING AND RESEARCH
Design for a larval fish-rearing tank with an internal biofilter.
Sensors and Monitoring Systems
125
A sensor and monitoring system can provide valuable information and
thereby improve the chances of success for marine aquaculture. For ex-
ample, oxygen levels fluctuate in response to different internal or external
factors, and these variations can stress or even kill the animals if adequate
aeration is not provided. When fluctuations are not fatal, unsatisfactory
fish health and growth, inefficient feed utilization, and poor reproduction
can result (Wyban and Antill, 19891. Oxygen concentrations in ponds are
particularly troublesome and difficult to measure and predict (Losordo et
al., 1988; Piedrahita, 19914. Seemingly identical ponds within a single
farm often have different oxygen conditions. Oxygen levels are changing
constantly and can vary significantly even in the same pond.
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Paddlewheel aeration of an earthen aquaculture pond.
MARINE AQUACULTURE
Accurate and reliable sensors to monitor basic water quality parameters
in seawater are not presently available. Existing automatic systems for
continual in situ oxygen measurements are costly to install, require frequent
and skilled maintenance, and typically have a short operating life. The
marine environment causes rapid deterioration of equipment; metabolic by-
products and other impurities in seawater interfere with the measurement
process; and the cost for the multitude of measuring points needed is high.
Oxygen is just one of many parameters that are currently difficult to
monitor and control with available instrumentation (Kaiser and Wheaton,
1991~. Others parameters of special significance and technical challenge
are ammonia, carbon dioxide, pH, salinity, light transmission, and biomass.
Even when measurements are not especially complex technically- such as
the determination of flow, water level, and temperature existing equip-
ment is subject to biofouling and corrosion. Improved instrumentation and
automatic monitoring systems are needed to solve these problems.
Expert Systems
The widespread availability of relatively inexpensive computers, together
with the development of improved sensors and monitoring equipment, is
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ENGINEERING AND RESEARCH
147
fundamentals of breeding and a long-term commitment of people, facilities,
and funding (Doyle, 1983; Gjerdem, 1983; Kinghorn, 1983; Lester, 1983;
Refstie, 1990~. Systems have to be developed for the long-term husbandry,
selection, and special requirements of each broodstock, with precaution to
include escape-proof features to allay concerns over genetic impacts of
escapees on wild stocks.
Broodstock domestication for the future is likely to include a wide range
of species. Finfish species for which broodstock domestication is im-
perative include striped bass and its hybrids, Pacific salmon, sturgeon, red
drum, dolphin, snapper, grouper, and flounder for food fish, as well as
ornamentals. The shellfish species include penaeid shrimp, clams, and oys-
ters (particularly for disease resistance).
Biotechnology and Genetic Engineering
Production of Improved Strains
The United States has been the leader in the development of transgenic
species (species carrying introduced genes) for culture purposes. Transgenic
organisms may possess a variety of potential advantages including increased
growth rates, disease resistance, decreased aggression, sterile progeny, in-
creased tolerance of temperature, or other environmental conditions, and
improved market characteristics. According to Kapuscinski and Hallerman
(199Oa), a total of 14 species of transgenic fish had been produced as of
July 1989.
Other countries are already making use of the (largely American) tech-
niques of transgenic production. In the United States, advances in this area
await the establishment and implementation of a regulatory system that
provides for the use of transgenic organisms in aquaculture (Hallerman and
Kapuscinski, 1990; Kapuscinski and Hallerman, l990b).
Kapuscinski and Hallerman (199Ob) point out that the introduction of
nonnative genes into fish is likely to affect nontarget traits as well and that
the phenotypic performance of transgenic fish is virtually unknown. This is
in large part due to regulatory constraints on the release of transgenic fish
into outdoor production systems for cultural trials. Further, Tiedje et al.
(1989) note that uncontrolled introduction of transgenic fish into natural
aquatic communities should not be allowed because their ecological impacts
are entirely unknown. Thus, Kapuscinski and Hallerman (199Ob) recom-
mend that the American Fisheries Society take the following positions
with regard to transgenic fish:
1. Support research in such areas as "phenotypic characterization of trans-
genic lines, evaluation of the performance of transgenic lines, improvement
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— —1 ~ _ _,
MARINE AQUACULTURE
of sterilization techniques, and development of ecological risk assessment
models and protocols" to provide data for rational policy decisions.
2. Advocate caution in the use of transgenic fish. No introductions of
transgenic fish into production-scale aquaculture facilities should be al-
lowed until risk assessments and demonstrations of little possibility of envi-
ronmental impact have been completed. Further, "stockings of transgenic
fishes into natural waters should be barred unless and until a body of re-
search strongly indicates the merits of and ensures the ecological safety
of stocking a particular transgenic fish into a particular receiving natural
system."
3. Advocate regulations improving the comprehensiveness of the Coor-
dinated Framework (National Institutes of Health (NIH) and U.S. Depart-
ment of Agriculture (USDA) guidelines) in the United States. This recom-
mendation would require that all production of transgenic species to take place
under NIH guidelines and would establish mandatory federal regulatory
review and authority over proposed releases and transport of transgenic fish.
The application of selected or directed breeding to aquatic organisms has
been reviewed by a variety of authors (e.g., Doyle, 1983; Gjerdem, 1983;
Lannan and Kapuscinski, 1986; Shultz, 1986; Gall, 19901. Breeding pro-
grams in aquaculture are generally in their infancy, but efforts have been
initiated in a number of groups, especially finfish: Atlantic salmon (Friars
et al., 1990; Refstie, 19901; and coho salmon (Hershberger et al., 19904.
Selective breeding of mollusks has been limited principally to bivalves
(Purdom, 1987; Wada, 19871.
Hybridization and polyploidy may produce culture-adapted strains. Hy-
bridization has been documented among salmonids (for review, see
Chevassus, 1979, 1983) and several groups of algae (Sanbonsuga and
Neuschal, 1977, 1978; Cain, 1979; Guiry, 1984~. Another biotechnical op-
tion with potential for aquaculture is the production of monosex populations
(Purdom, 1983; Yamazaki, 1983; Billard, 19871. Gynogenetic or androge-
netic (all female or all male) offspring can be produced, resulting in non-
reproducing populations. A drawback is that the population may lack
vigor due to inbreeding (Thorgaard, 1986~.
Clearly, the United States has sufficient capabilties to make substantial
progress in the areas of biotechnology and genetic engineering for aquacul-
ture. Discussions among leading researchers suggest that application and
adaptation of such technologies in the culture of marine species could be
expected to result in numerous advances in marine aquaculture, including
the following:
· accelerated growth and maturation of brood animals via ploidy manipu-
lation, gene insertion, hormonal treatment, or other methods;
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ENGINEERING AND RESEARCH
149
· improved culture characteristics (growth, food conversion efficiency,
body composition, disease resistance, fecundity, hardiness, etc.) via selec-
tive breeding, hybridization, ploidy or sex manipulations, or transgenic
techniques;
· production of 100 percent sterile organisms for commercial grow-out
on farms or in pens, while reproductively competent organisms serve as
brood stock;
· use of mitochondrial DNA methods or other analyses to detect low-
level genetic change in cultured stocks to permit assessments of potential
impacts of released hatchery animals on wild populations; and
· insertion of genes coding for particularly desirable traits (e.g., homing
in salmon) into other species of cultured or "sea-ranched" animals.
Hedgecock and Malecha (1990) conclude that "it is very unlikely that
genetic engineering by direct genomic intervention and modification will
contribute to shrimp and prawn aquaculture in the next decade," due to the
lack of basic knowledge of genes that affect production characteristics and
of methods for inserting these genes into crustaceans. Biotechnology is
more likely to be employed as a tool in more traditional programs, espe-
cially for establishing genetic markers, manipulating gametes via cryopre-
servation and chromosome number, and controlling sex.
Disease Assessment and Treatment
Disease Diagnosis
The development of diagnostic tests has been identified as one of the
principal means of improving aquaculture productivity (Ratafia and Purinton,
1989~. Rapid, accurate, and inexpensive techniques for disease assessment
and certification for marine organisms in culture are essential prerequisites
to screening large numbers of fry, fingerlings, postlarvae, or spat rapidly for
certain critical diseases. Biotechnical methods, when applied to marine
aquaculture, should allow the establishment of meaningful, effective state
and national disease certification programs, which are critical for advance-
ment of the industry.
Some types of diagnostic tools have improved markedly in recent years,
and further advances are likely. Isoelectric focusing (Shaklee and Keenan,
1986) and mitochondrial DNA analyses (Brown and Wolfinbarger, 1989;
Palva et al., 1989; Reeb and Avise, 1990) permit detailed analyses of fish
and shellfish stocks and detection of minute genetic differences, sometimes
even within a limited geographic area. Fatty acid composition analysis
provides another way by which wild aquatic organisms can be differentiated
from cultured individuals of the same species. This effectively eliminates
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MARINE AQUACULTURE
the possibility of poaching protected wild stocks for sale as aquaculture
products.
Therapeutics
Disease treatment represents another as yet underdeveloped research area.
Currently, only six chemotherapeutics are approved for aquaculture use
by the Environmental Protection Agency (EPA) and the FDA. Seven other
chemicals, either EPA approved for aquaculture uses and exempt from FDA
registration or exempt from EPA registration entirely, are also being used
as chemotherapeutics (for review, see Williams and Lightner, 1988~.
The most comon approach to the administration of antibiotics and other
therapeutic agents is immersion (osmotic), injection, or oral intake with
feed (DeCrew, 1972; Strasdine and McBride, 1979; Austin et al., 1981;
Marking et al., 19881. Few vaccines have been developed for aquaculture
use. Immunization against Vibrio spp. and related bacteria genera has been
practiced among finfish culturists for several years, with treatment by
immersion or intraperitoneal injection (Cipriano et al., 1983; Schiewe et al.,
1988~. Similar methods of immunization are now being explored for
shrimp (Itami et al., 19891.
Experimental work also has been conducted on the use of gelatin capsule
implants for some antibiotics (Strasdine and McBride, 1979) and on various
types of water treatment, including ozonation (Wedemeyer et al., 1978;
Tipping, 1 987), ultraviolet irradiation, and chlorination (Bedell, 1 97 1;
Sanders et al., 19721. Formal actions by the U.S. Fish and Wildlife Service
and the USDA have ensured that federal and state animal scientists, the
pharmaceutical industry, and the USDA collaborate on determining needs
and developing research protocols for aquaculture-related drugs, which fall
under the category of minor-use animal drugs (Schmick, 1988~.
As the above discussion suggests, the need and potential for improve-
ments in disease treatment are substantial. The development of medications
and immunizations is badly needed, as are improved delivery systems for
antibiotics that will not result in the release of antibiotics to the rearing
waters. The cost of obtaining FDA approval is a major barrier, however.
SUMMARY
Advances in technology and an improved understanding of the biology
of relevant species are essential for marine aquaculture to overcome many
of the major constraints on future development. Some new and improved
technologies would solve specific technical problems directly and thereby
improve economic feasibility; other technologies would alleviate environ-
mental concerns and diminish conflicts with other coastal zone activities.
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ENGINEERING AND RESEARCH
151
Many of the technical constraints on marine aquaculture can be reduced or
eliminated by developing new and improved onshore and nearshore sys-
tems; developing new and improved auxiliary systems; and establishing the
biological, ecological, and engineering knowledge base required for making
sound decisions.
NOTE
1. The term cages and pens have been defined by Beveridge, 1987 as follows: cages are
enclosed on the bottom as well as the sides, typically by mesh or net screens, whereas the
bottom of pens is formed by the seabed.
REFERENCES
Aase, H. 1985. Effect of the use of flow developers in fish-rearing cages for
salmon, Fisherdirektoratets, Havforskningsinstitutt, Bergen, Norway.
Alabaster, John S. 1982. Report of the EIFAC Workshop on Fish-Farm Effluents.
EIFAC Technical Paper No. 41. European Inland Fisheries Advisory Commis-
sion, FAG. 186 pp.
Arnold, C.R., B. Reid, and B. Brawner. 1990. High density recirculating grow out
systems. Pp. 182-184 in Red Drum Aquaculture. University of Texas, Austin,
TAMU-SG-90-603.
Austin, B., D.A. Morgan, and D.J. Alderman. 1981. Comparison of antimicrobial
agents for control of vibriosis in marine fish. Aquaculture 26:1-12.
Balchen, J.G. 1987. Bridging the gap between aquaculture and the information
sciences. In Automation and Data Processing in Aquaculture, J.G. Balchen and
A. Tysso, eds. IFAC Proceedings 1987. No. 9. Pergamon Press.
Bedell, G.W. 1971. Eradicating Cerotomyxa Shasta from infected water by chlori-
nation and ultraviolet irradiation. Prog. Fish-Culturist 33:51-54.
Beveridge, M.C.M. 1987. Cage Aquaculture. Farnham, England: Fishing News
Books, Ltd. 332 pp.
Bevin, D. 1988. Problems of managing mixed-stock salmon fisheries. In Salmon
Production, Management, and Allocation Biological, Economic and Policy Is-
sues, William J. McNeil, ed. Oregon State University Press.
Biedenback, J.M., L.L. Smith, T.K. Thomsen, and A.L. Lawrence. 1989. Use of the
nematode Panagrellus redivivus as an Artemia replacement in a larval penaeid
diet. Journal of the World Aquaculture Society 20~21:61-71.
Billard, R. 1987. The control of fish reproduction in aquaculture. Pp. 309-305 in
Realism in Aquaculture: Achievements, Constraints, Perspectives, M. Bilio, H.
Rosenthal, and C. Sindermann, eds. Breden, Belgium: European Aquaculture
Society.
Bromley, P.J., and P.A. Sykes. 1985. Weaning diets for turbot (Scophthalmus
maximus L.), sole (Solea solea) and cod (Gadus morhua L.) Pp. 191-211 in
Nutrition and Feeding in Fish, C.B. Cowery, A.M. Mackie, and J.G. Bell, eds.
New York: Academic Press.
Brown, B.L., and L. Wolfinbarger. 1989. Mitochondrial restriction enzyme screen-
OCR for page 152
152
MARINE AQUACULTURE
ing and phylogenetic relatedness in the hard shell clam genus Mercenaria. Part
2. Population variation. Technical Report Virginia Department of Environmen-
tal Science No. TR-89-1.
Brune, D.E. 1990. Reducing the environmental impact of shrimp pond discharge.
ASAE Paper No. 90-7036. American Society of Agricultural Engineers, St.
Joseph, Mich.
Brune, D.E., and R.H. Piedrahita. 1983. Operation of a retained biomass nitrifica-
tion system for treating aquaculture water for reuse. Proceedings of the First
International Conference on Fixed-Film Biological Processes. 845-869.
Cain, J.R. 1979. Survival and mating behavior of progeny and germination of
zygotes from inter- and intraspecific crosses of Chlamydomonas eugametos and
C. moewusii (chlorophycease, Volvocales). Phycologia 18~1):24-29.
California Department of Fish and Game. 1989. Private striped bass broodstock
collection and rearing program: 1989 activities and eight-year progress report.
Unpublished manuscript, 10 pp.
Carey, J., and B. Kramer. 1966. Fish Hatchery Design Memorandum No. 14.1.
Dworshak Dam and Reservoir. Prepared for the U.S. Army Engineering District,
Walla Walla, Wash.
Chevassus, B. 1979. Hybridization in salmonids: Results and perspectives. Aqua-
culture 17:113- 128.
Chevassus, B. 1983. Hybridization in fish. Aquaculture 33:245-262.
Cho, C.Y., H.S. Bayley, and S.J. Slinger. 1974. Partial replacement of herring meal
with soybean meal and other changes in a diet for rainbow trout (Salmo gairdneri).
J. Fish. Res. Bd. Can. 31:1523-1528.
Cipriano, R.C., J.K. Morrison, and C.E. Starliper. 1983. Immunization of salmo-
nids against Aeromonas salmonicida. J. World Maricul. Soc. 14:201 -211.
Clarke, R., and M. Beveridge. 1989. Offshore fish farming. INFOFISH Interna-
tional (3/89~: 1 2- 1 5.
Conklin, D.E., L.R. D'Abramo, and K. Norman-Boudreau. 1983. Lobster nutrition.
Pp. 413-423 in Handbook of Mariculture, Vol. I: Crustacean Aquaculture, J.P.
McVey, ed. Boca Raton, Fla.: CRC Press.
Conrad, K.M., M.G. Mast, and J.H. MacNeil. 1988. Performance, yield, and body
composition of fingerling channel catfish fed a dried waste egg product. Prog.
Fish-Culturist 50:219-224.
Cowery, C. B., J.A. Pope, J.W. Adron, and A. Blair. 1971. Studies on the nutrition of
marine flatfish. Growth of the plaice Pleuronectes platessa on diets containing
proteins derived from plants and other sources. Marine Biology 10~2~:145-153.
Davis, E.M., G.L. Rumsey, and J.G. Nickum. 1976. Egg-processing wastes as a
replacement protein source in salmonid diets. Prog. Fish-Culturist 38:20-22.
DeCrew, M.G. 1972. Antibiotic toxicity, efficacy, and teratogenicity in adult
spring chinook salmon (Oncorhynchus tshawytscha). J. Fish. Res. Bd. Can.
29~11):1513-1517.
Donaldson, E.M., U.H.M. Fagerlund, D.A. Higgs, and J.R. McBride. 1978. Hor-
monal enhancement growth. Pp. 456-578 in Fish Physiology, Vol. VIII, W.S.
Haar, D.J. Randall, and J.R. Brett, eds. New York: Academic Press.
Doyle, R.W. 1983. An approach to the quantitative analysis of domestication
selection in aquaculture. Aquaculture 33: 167- 185.
OCR for page 153
ENGINEERING AND RESEARCH
153
Electric Power Research Institute (EPRI). 1990. A summary description of the sec-
ond workshop on the role of macroalgal oceanic farming in global change. July
23-24, Newport Beach, California. Electric Power Research Institute, Palo Alto.
Engineering Committee on Oceanic Resources (ECOR). 1989. Ocean Energy Sys-
tems. Report of ECOR International Working Group. Japan Marine Science
and Technology Association, Tokyo.
Fabi, G., L. Fiorentini, and S. Giannini. 1989. Experimental shellfish culture on an
artificial reef in the Adriatic Sea. Bulletin of Marine Science 44~21:923-933.
Flynn, G. 1990. Presentation to the committee. Halifax, Nova Scotia, June 11-15.
Forster, J. 1990. Presentation to the committee. Davis, Calif., March 19-20.
Friars, G.W., J.K. Bailey, and K.A. Coombs. 1990. Correlated responses to selec-
tion for grilse length in Atlantic salmon. Aquaculture 85: 171 - 176.
Fridley, R.B., R.H. Piedrahita, and T.M. Losordo. 1988. Challenges in aquacultural
engineering. Agricultural Engineering (May/June): 1 2- 1 5.
Gall, G.A.E. 1990. Basis for evaluating breeding plans. Aquaculture 85:125-142.
Gjerdem, T. 1983. Genetic variation in quantitative traits and selection breeding in
fish and shellfish. Aquaculture 33:51-72.
Gowen, R.J. 1988. Release strategies for coho and chinook salmon released into
Coos Bay, Oregon. In Salmon Production, Management, and Allocation Bio-
logical, Economic and Policy Issues, William J. McNeil, ed. Oregon State Uni-
versity Press.
Grant, B.F., P.A. Seib, M. Liao, and K.E. Corpron. 1989. Polyphosphorylated L-
ascorbic acid: A stable form of vitamin C for aquaculture feeds. Journal of the
World Aquaculture Society 20~3):143-157.
Grove, R.S., C.J. Sonu, and M. Nakumura. 1989. Recent Japanese trends in fishing
reef design and planning. Bulletin of Marine Science 44~2):984-996.
Guiry, M.D. 1984. Structure, life history, and hybridization of Atlantic Gigartina
teedii (Rhodophyta) in culture. Br. Phycol. J. 19~11:37-55.
Hallerman, E.M., and A.R. Kapucinski. 1990. Transgenic fish and public policy:
Regulatory concerns. Fisheries (B ethesda) 1 5 ~ 1 ): 1 2-20.
Halver, J.E. 1988. Fish Nutrition. New York: Academic Press. 489 pp.
Hedgecock, D., and S.R. Malecha. 1990. Prospects for the application of biotech-
nology to the development of shrimp and prawns. In Shrimp Culture in North
America and the Caribbean, P.A. Sandifer, ed. Advances in World Aquaculture,
World Aquaculture Society, Baton Rouge, La.
Hershberger, W.K., J.M. Myers, R.N. Iwamoto, W.C. McAuley, and A.M. Saxton.
1990. Genetic changes in the growth of coho salmon (Oncorhynchus kisutch) in
marine net-pens produced by ten years of selection. Aquaculture 85:187-198.
Holt, G.J. 1992. Experimental studies of feeding of larval red drum. Journal of the
World Aquaculture Society. (In press.)
Holt, G.J. 1990. Growth and development of red drum eggs and larvae. Pp. 46-50
in Red Drum Aquaculture. TAMU-SG-90-603. Texas A&M Sea Grant College
Program, College Station.
Huguenin, J.E., and J. Colt. 1989. Design and Operating Guide for Aquaculture
Seawater Systems. Developments in Aquaculture and Fisheries Science, 20.
New York: Elsevier Publishing. 264 pp.
Imai, T. (ed.) 1977. Aquaculture in Shallow Seas: Progress in Shallow Sea Culture
OCR for page 154
54
MARINE AQUACULTURE
(translated from Japanese). National Oceanic and Atmospheric Administration,
Washington, D.C. 615 pp.
Institution of Civil Engineers (ICE). 1990. Proceedings of the Conference on
Engineering for Offshore Fish Farming, Glasgow, Scotland, October 17-18. London:
Thomas Telford.
Itami, T., Y. Takahashi, and Y. Nakamura. 1989. Efficacy of vaccination against
vibriosis in cultured Kuruma prawns Penaeus japonicus. J. Aquatic Animal
Health 1:238-242.
Kaiser, G.E., and F.W. Wheaton. 1991. Engineering aspects of water quality moni-
toring and control. Pp. 210-232 in Engineering Aspects of Intensive Aquacul-
ture. Proceedings from the Aquaculture Symposium, Cornell University, Ithaca,
N.Y. Ithaca: Northeast Regional Agricultural Engineering Service.
Kanazawa, A., S. Koshio, and S. Teshina. 1989. Growth and survival of larval red
sea bream, Pagrus major and Japanese flounder, Paralichthys olivaceus fed
microbound diets. Journal of the World Aquaculture Society 20~2~:31-37.
Kapuscinski, A.R., and E.M. Hallerman. 1990a. Transgenic fish and public policy:
Anticipating environmental impacts of transgenic fish. Fisheries (Bethesda,
15(1~:2-1 1.
Kapuscinski, A.R., and E.M. Hallerman. 1990b. Transgenic fishes: AFS Position
Statement. Fisheries (Bethesda) 15~41:2.5.
Keen, E. 1988. Ownership and Productivity of Marine Fishery Resources. Blacksburg,
Va.: The McDonald and Woodward Publishing Company.
Kerr, N.M., M.J. Gillespie, S.T. Hull, and S.J. Kingwell. 1980. The design, con-
struction, and location of marine floating cages. Pp. 70-83 in Proceedings of the
Institute of Fisheries Management Cage Fish Rearing Symposium, University of
Reading. London: Janssen Services.
Ketola, H.G. 1975. Requirement of Atlantic salmon for dietary phosphorus. Trans.
Amer. Fish. Soc. 104~3~:543-551.
Ketola, H.G. 1982. Effect of phosphorus in trout diets on water pollution. Salmo-
nid 6~2):12-15.
Ketola, H.G. 1985. Mineral nutrition: Effects of phosphorus in trout and salmon
feeds on water pollution. Pp. 465-473 in Nutrition and Feeding of Fish, C.B.
Cowery, A.M. Mackie, and J.G. Bell, eds. London: Academic Press.
Ketola, H.G. 1988. Salmon fed low-pollution diet thrive in Lake Michigan. U.S.
Fish and Wildlife Service, Research Information Bulletin No. 62-25, April.
Ketola, H.G. 1990. Studies on diet and phosphorus discharges in hatchery efflu-
ents. Abstract, International NSMAW Symposium, Guelph, Canada, June 5-9.
Ketola, H.G., H. Westers, C. Pacor, W. Houghton, and L. Wubbels. 1985. Pollu-
tion: Lowering levels of phosphorus, experimenting with feed. Salmonid 9~21:1 1.
Ketola, H.G., M. Westers, W. Houghton, and C. Pecor. 1990. Effects of diet on
growth and survival of coho salmon and on phosphorus discharges from a fish
hatchery. American Fisheries Society Symposium No. 11.
Kinghorn, B.P. 1983. A review of quantitative genetics in fish breeding. Aquacul-
ture 31(2,3,4~:283-304.
Korringa, P. 1976. Farming Cupped Oysters of the Genus Crassostrea. A Mult
disciplinary Treatise. Amsterdam: Elsevier. 224 pp.
OCR for page 155
ENGINEERING AND RESEARCH
155
Kruner, G., and H. Rosenthal. 1983. Efficiency of vitrification in trickling filters
using different substrates. Aquacultural Engineering 2:49-67.
Lannan, J.E., and A.R.D. Kapuscinski. 1986. Application of a genetic fitness
model to extensive aquaculture. Aquaculture 57:81-87.
Lannan, J.E., R.O. Smitherman, and G. Tchobanoglas, eds. 1985. Principles and
Practices of Pond Aquaculture. Corvallis, Ore.: Oregon State University Press.
Lester, L.J. 1983. Developing a selective breeding program for penaeid shrimp
mariculture. Aquaculture 33:41-50.
Linfoot, B.T., and M.S. Hall. 1987. Analysis of the motions of scale-model, sea-
cage systems. In Automation and Data Processing in Aquaculture, J.G. Balchen
and A. Tysso, eds. IFAC Proceedings. No. 9. New York: Pergamon Press.
Losordo, T.M. 1991. Engineering consideration in closed recirculating systems.
Pp. 58-69 in Aquaculture Systems Engineering. Proceedings of the World Aqua-
culture Society and the American Society of Agricultural Engineers Jointly Spon-
sored Session at the World Aquaculture Society Meeting, San Juan, Puerto Rico.
Losordo, T.M., R.H. Piedrahita, and J.M. Ebeling. 1988. An automated data ac-
quisition system for use in aquaculture ponds. Aquacultural Engineering 7:265-
278.
Lovell, T. 1989. Nutrition and Feeding of Fish. New York: Van Nostrand Reinhold.
260 pp.
Malone, R.F., and D.G. Burden. 1988. Design of recirculating blue crab shedding
systems. Louisiana Sea Grant College Program, Center for Wetland Research,
Louisiana State University, Baton Rouge.
Marking, L.L., G.E. Howe, and J.R. Crowther. 1988. Toxicity of erythromycin,
oxytetracycline, and tetracycline administered to lake trout in water baths by
injection or by feeding. Prog. Fish-Culturist 50:197-201.
Mayo, R.D. 1989. A Review of Water Reuse. World Aquaculture Society Annual
Meeting, Los Angeles.
McLean, E., and R. Ash. 1990. Modified uptake of the protein antigen horseradish
peroxidase (HRP), following oral delivery of rainbow trout, Oncorhynchus mykiss.
Aquaculture 87~3/4~:373-380.
Meek, R. 1990. Presentation to the committee. Davis, Calif., March 19-20.
Miller, G.E., and G.S. Libey. 1985. Evaluation of three biological filters suitable
for aquacultural applications. J. World Maricul. Soc. 16:158-168.
National Research Council (NRC). 1974a. Nutrient Requirements of Trout, Salmon,
and Catfish. Board on Agriculture and Renewable Resources. Washington,
D.C.: National Academy Press.
National Research Council (NRC). 1974b. Research Needs in Animal Nutrition.
Board on Agriculture and Renewable Resources. Washington, D.C.: National
Academy Press.
National Research Council (NRC). 1977. World Food and Nutrition Study: Panel
on Aquatic Food Resources. Commission on International Relations. Washing-
ton, D.C.: National Academy Press.
National Science Foundation (NSF). 1991. Workshop on Engineering Research
Needs for Off-Shore Mariculture Systems. East-West Center, University of Ha-
waii, September 26-28.
OCR for page 156
156
MARINE AQUACULTURE
Nettleton, I.A. 1990. Comparing nutrients in wild and farmed fish. Aquaculture
Magazine 16(1):34-41.
Neuschal, M. 1990. Presentation to the committee. Davis, Calif., March 19-20.
Palmer, J.E. ted.) 1989. The application of artificial intelligence and knowledge-
based systems techniques to fisheries and aquaculture workshop report. Virginia
Sea Grant Publication 89-03.
Palva, T.K., H. Lehvaeslaiho, and E.T. Palva. 1989. Identification of anadromous
and non-anadromous salmon stocks in Finland by mitochondrial DNA analysis.
Aquaculture 81 (3/4~:237-244.
Piedrahita, R.H. 1991. Modeling water quality in aquaculture ecosystems. In
Aquaculture and Water Quality, D.E. Brune and J.R. Tomass, eds. Baton Rouge,
La.: World Aquaculture Society.
Purdom, C.E. 1983. Genetic engineering by the manipulation of chromosomes.
Aquaculture 33:287-300.
Purdom, C.E. 1987. Methodology on selection and intraspecific hybridization in
shellfish A critical review. Pp. 285-282 in Selection, Hybridization, and Ge-
netic Engineering in Aquaculture. Vol. 1, K. Tiews, ed. Heenemann Verlagsgellschaft
mbh, Berlin.
Ratafia, M., and T. Purinton. 1989. Emerging aquaculture markets. Aquaculture
Magazine (July/August) :32-46.
Reeb, C.A., and J.C. Avise. 1990. A genetic discontinuity in a continuously dis-
tributed species: Mitochondrial DNA in the American oyster, Crassostrea virginica.
Genetics 124(2~:397-406.
Reed, B. 1989. Evaluation of a recirculating raceway system for the intensive
culture of the penaeid shrimp Penaeus vannamei Boone. M.S. thesis, Depart-
ment of Biology, Corpus Christi State University, Texas.
Refstie, T. 1990. Application of breeding schemes. Aquaculture 85: 163- 169.
Richards, G.P. 1988. Microbial purification of shellfish: A review of depuration
and relaying. Journal of Food Protection 51 (31:218-251.
Rogers, G.L., and S.L. Klemetson. 1985. Ammonia removal in selected aquacul-
ture water reuse biofilters. Aquacultural Engineering 4:135-154.
Sanbonsuga, Y., and M. Neuschal. 1977. Cultivation and hybridization of giant
kelps (Phaeophyceae). Pp. 91-96 in Proccedings of the Ninth International Sea-
weed Symposium, A. Jensen and J. Stein, eds. Princeton: Science Press.
Sanbonsuga, Y., and M. Neuschal. 1978. Hybridization of Macrocystis (Phaeophyta)
with other float bearing kelps. J. Phycol. 14(2):214-224.
Sanders, J.E., J.L. Fryer, D.A. Leith, and K.D. Moore. 1972. Control of the infec-
tious protozoan Ceratomyka shasta by treating hatchery water supplies. Prog.
Fish-Culturist 34( 1 ): 1 3- 1 7.
Santulli, A., E. Puccia, and V. D'Amelio. 1990. Preliminary study on the effect of
short-term carnitine treatment on nucleic acids and protein metabolism in sea
bass (Dicentrarchus labrax L.) fry. Aquaculture 87(11:85-90.
Schiewe, M.H. A.J. Novotny, and L.W. Harrell. 1988. Vibriosis of salmonids. Pp.
323-327 in Disease Diagnosis and Control in North American Marine Aquacul-
ture, C.J. Sindermann and D.V. Lightner, eds. Amsterdam: Elsevier.
Schmick, R.A. 1988. The impetus to register new therapeutants for aquaculture.
Prog. Fish-Culturist 50: 190- 196.
OCR for page 157
ENGINEERING AND RESEARCH
157
Sedgwick, S. 1982. The Salmon Handbook. London: Andre Deutsch, Ltd.
Shaklee, J.B., and C.P. Keenan. 1986. A practical laboratory guide to the tech-
niques and methodology of electrophoresis and its application to fish fillet identi-
fication. CSIRO Marine Laboratories, Report 177. 59 pp.
Shigueno, K., and S. Itoh. 1988. Use of Mg-L-ascorbyl-2-phosphate as a vitamin C
source in shrimp diets. Journal of the World Aquaculture Society 19~41:168-174.
Shultz, F.T. 1986. Developing a commercial breeding program. Aquaculture 57:
65-76.
Strasdine, G.A., and J.R. McBride. 1979. Serum antibiotic levels in adult sockeye
salmon as a function of route of administration. J. Fish. Biol. 15:135-140.
Thompson, T. 1992. Boxed fish tank can deliver live U.S. seafood to Japan. Journal
of Commerce, January 3, p. 6B.
Thorgaard, G.H. 1986. Ploidy manipulation and performance. Aquaculture 57:57-64.
Tiedje, J.M., R.K. Colwell, Y.L. Grossman, R.E. Hodson, R.E. Lenski, R.N. Mack,
and P.J. Regal. 1989. The planned introduction of genetically engineered organ-
isms: Ecological considerations and recommendations. Ecology 70:298-315.
Tipping, J. 1987. Use of ozone to control ceratomyxosis in steelhead trout (Salmo
gairdneri). Ozone Science and Engineering 9:149-152.
Wada, K.T. 1987. Selective breeding and intraspecific hybridization molluscs.
Pp. 293-302 in Selection, Hybridization, and Genetic Engineering in Aquacul-
ture, Vol. 1, K. Tiews, ed. Berlin: Keenemann Verlagsgellschaft mbh.
Wang, J.K. 1988. Shared resources aquatic production systems. American Society
of Agricultural Engineers, ASAE Paper No. 88-5001. St. Joseph, Mich.
Wang, J.K. 1990. Managing shrimp pond water to reduce discharge problems.
Aquacultural Engineering 9:61-73.
Weaver, D. 1990. Presentation to the committee. Halifax, Nova Scotia, June 11-15.
Wedemeyer, G.A., N.C. Nelson, and C.A. Smith. 1978. Survival of salmonid
viruses infectious hematopoietic necrosis (IHNV) and infectious pancreatic ne-
crosis (IPNV) in ozonated, chlorinated, and untreated waters. J. Fish. Res. Bd.
Can. 35:875-879.
Weston, D.P. 1986. The Environmental Effects of Floating Mariculture in Puget
Sound. School of Oceanography, College of Ocean and Fishery Sci., University
of Washington, Seattle. 148 pp.
Williams, R.R., and D.V. Lightner. 1988. Regulatory status of therapeutics for
penacid shrimp culture in the United States. Journal of the World Aquaculture
Society 19(4):188-196.
Wyban, J.A., and E. Antill, eds. 1989. Instrumentation in aquaculture. Proceedings
of a Special Session at the World Aquaculture Society 1989 Annual Meeting,
Oceanic Institute, Hawaii. 101 pp.
Yamada, S., Y. Tanaka, M. Sameshima, and Y. Ito. 1989. Pigmentation of prawn
(Penaeus japonicus) with carotenoids. Effect of dietary astaxanthin, p-carotene,
and canthaxanthin on pigmentation. Aquaculture 87~3/4~:323-330.
Yamazaki, F. 1983. Sex control and manipulation in fish. Aquaculture 33:329-
354.
Representative terms from entire chapter:
world aquaculture
