Aquaculture cultures

MCKINNON A D, DUGGAN S, NICHOLS P D, RIMMER M A, SEMMENS G and ROBINO B (2003) The potential of tropical paracalanid copepods as live feeds in aquaculture. culture 223 89-106. 

Pubhc sector aquaculture involves production of aquatic animals to augment or estabUsh recreational and commercial fisheries. PubHc sector aquaculture is widely practiced in North America and to a lesser extent in other parts of the world. The FAO definition of aquaculture also indicates that farming implies ownership of the organisms being cultured, which would seem to exclude pubhc sector aquaculture. 

Aquatic plants are cultured in many regions of the world. In fact, aquatic plants, primarily seaweeds, account for nearly 25% of the world s aquaculture production (3). Most of the information available in the hterature relates to the production of such aquatic animals as moUuscs, cmstaceans, and finftsh. 

A key factor in obtaining binding support for aquaculture is development of a sound business plan. The plan needs to demonstrate that the prospective culturist has identified all costs associated with estabhshment of the faciUty and its day-to-day operation. One or more suitable sites should have been identified and the species to be cultured selected before the business plan is submitted. Cost estimates should be verifiable. Having actual bids for a specific task at a specific location eg, pond constmction, well drilling, building constmction, and vehicle costs helps strengthen the business plan. 

The amount of land required varies as well, not only as a function of the amount of production that is anticipated, but also on the type of culture system that is used. It may take several hectares of static culture ponds to produce the same biomass of animals as one modest size raceway through which large volumes of water are constantly flowed. Constmction costs vary from one location to another. Local labor and fuel costs must be factored into the equation. The experience of contractors in building aquaculture facihties is another factor to be considered. 

Animal aquaculture is concentrated on finfish, moUuscs, and cmstaceans. Sponges, echinoderms, tunicates, turtles, frogs, and alligators are being cultured, but production is insignificant in comparison with the three principal groups. Common and scientific names of many of the species of the finfish, moUuscs, and cmstaceans currently under culture are presented in Table 2. Included are examples of bait, recreational, and food animals. 

Provision ofHve foods is currently necessary for the early stages of many aquaculture species because acceptable prepared feeds have yet to be developed. Algae is routinely cultured for the early stages of moUuscs produced in hatcheries. Once the moUuscs are placed in growout areas, natural productivity is depended upon to provide the algae upon which the shellfish feed. 

Requirements for energy, protein, carbohydrates, Hpids, vitamins and minerals have been determined for the species commonly cultured (9). As a rule of thumb, trout and salmon diets will, if consumed, support growth and survival in virtually any aquaculture species. Such diets often serve as the control against which experimental diets are compared. 

Intensive or extensive culture of aquatic animals requires chemicals that control disease, enhance the growth of cultured species, reduce handling trauma to organisms, improve water quality, disinfect water, and control aquatic vegetation, predaceous insects, or other nuisance organisms. The aquacultural chemical need for various species have been described for rainbow trout, Oncorhjnchus mjkiss (1) Adantic and Pacific salmon, Salmo and Oncorhjnchus sp. (2) channel catfish, Ictaluruspunctatus (3) striped bass, Morone saxatilis (4) milkfish, Chanos chanos (5) moUusks (6) penaeid (Penaeus sp.) shrimp (7) and a variety of other marine species (8). 

Female sexual development and behaviour in mammals occurs by default and requires no ovarian secretion, and it is only in genetic males that the testis can secrete hormones which destroy this female pattern and superimpose that of the male. Sexual differentiation is not so well defined in fish, and larval exposure to both synthetic estrogens and androgens is widely used in aquaculture to produce monosex cultures. Endocrine disruption of sexual differentiation in fish may therefore reflect both the complexity and diversity of such processes between different species. Some care is required in use of the terms hermaphrodite and sex-reversal since a true hermaphrodite has both functional testes and ovaries and a sex-reversed fish is fully functional as its final sex—both produce the appropriate viable gametes. Such functional sex-reversal is not possible in mammals, but in some species of fish it is the normal developmental pattern. In most of the cases of hermaphroditism or sex-reversal reported in the non-scientific press, there is evidence only for a few ovarian follicles within a functional testis. This may be considered as feminisation or a form of intersex, and is very clearly endocrine disruption, but it is certainly neither sex-reversal nor hermaphroditism. In some cases the terms have even been used to infer induction of a single female characteristic such as production of yolk-protein by males. 

Seeding Introduction of microorganisms (such as ALKEN CLEAR-FLO 1000 series for aquaculture, 4000 series for grease, and 7000 series for industrial and municipal wastewater) into a biological oxidation unit to minimize the time required to build a biological sludge. Also referred to as inoculation with cultured organisms. 

Thrower, F.P. and J.W. Short. 1991. Accumulation and persistence of tri-n-butyltin in pink and chum salmon fry cultured in marine net-pens. Aquaculture 96 233-239. 

Shacklock, P.F. and G.B. Croft. 1981. Effect of grazers on Chondrus crispus in culture. Aquaculture 22 331-342. 

Aquacide, herbicide/algicide for aquaculture in U.S., 3 215t Aquaculture, 3 182-208 culture systems, 3 190-198 diseases, 3 206-207 economics, 3 184-185 harvesting, processing, and marketing, 3 207-208... 

Proposed aquaculture applications of degradable polymers include seaweed culture nets, fishing nets and lines, and temporary structures used for restoration of wet lands, beaches or other marsh areas [11-14], Weathering and hydrolysis are the most common degradation mechanisms encountered in aquatic applications. Continually submerged articles pose special challenges since temperatures are low and photodegradation and oxidation effects are limited. 

Molluscan shellfish play an important role in human nutrition and the world economy (Wild and Lehrer, 2005). Table 4.2 provides data on the worldwide production/catch of various molluscan shellfish species for 2005. The most widely available species are oyster, squid, clam, mussel, and scallop. Aquaculture has become an important contributor to the production of molluscan shellfish with the exception of the cephalopods. However, the popularity and frequency of consumption of various molluscan shellfish varies widely across various countries and cultures. Accurate information on comparative consumption patterns for molluscan shellfish in various countries does not exist. Molluscan shellfish are consumed as freshly cooked or even raw seafood items particularly in coastal communities. But mollusks also are consumed as processed foods in a variety of forms. 

Some antibiotics are also used in horticulture to control contamination of micropropagation, plant tissue culture, and in controlling bacterial diseases of fruit trees (Levy, 1992 FaUdner, 1998). Commonly used in horticulture are cephalosporins, neomycin, novobiocin, polymyxin, and sulfaguanidine. More than 20 tons of streptomycin and tetracycline are used by the horticulture industry in the United States per annum. Substantial amounts of antibiotics are also used in aquaculture, whereby they are either directly added to the water (therapy) or as part of the feed, resulting in high concentrations in the water and adjoining sediments. An examination of the levels of use of various PPCPs for various purposes is outline next. 

Ritar A. J, Smith G. G Thomas C. W. Ozonation of seawater improves the survival of larval southern rock lobster, Jasus edwardsii, in culture from egg to juvenile, Aquaculture 2006 261(3) 1014-1025. 

It has been suggested that microbial cata holism of off-flavor metabolites may be enhanced to provide an effective method ) control off-flavors. Indeed, microbial cultures have been reported to degrade relatively high levels of off-flavor metabolites (53, 54, 55), but whether microbial activity can be used practically to improve the flavor quality of aquaculture systems remains to be determined. 

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