Animal aquatic

Ambient concentrations as low as 20.0 p,g atrazine/L have been associated with adverse 

4 in the mottled sculpin Coitus bairdi, 3.0 in the amphipod Gammarus pseudolimnaeus, and 3.4 in mayflies Baetis sp. In studies with the freshwater snail Ancylus fluviatilis and fry of the whitefish Coregonas fera, atrazine was rapidly accumulated from the medium by both species and saturation was reached within 12-24h bioconcentration factors (BCFs) were 4-5 at ambient water concentrations of 50.0-250.0 p,g atrazine/L. Elimination of atrazine was rapid 8-62 min for Coregonus, and 18 min for Ancylus. No accumulation of atrazine was recorded in mol-lusks, leeches, cladocerans, or fish when contamination was by way of the diet. Atrazine accumulations in Daphnia pulicaria were significantly correlated with whole body protein content at low (8°C) water temperatures, and with fat content at elevated (20°C) water temperatures. 

The number of studies on lead in organisms has increased steadily in the world, and there is a large number of such studies, including birds, mammals, fish, and several invertebrates. However, this is not the case in Mexico, where the studies on this subject have been relatively few and isolated. Most of them have been devoted to organisms from the rivers and lagoons on Veracruz, Campeche and 

Tabasco states where other studies on lead have been conducted as described in other sections. 

Deleon and Perez (1983) reported the analysis of tissues from 21 fish species collected in 1976 in the same region. According to the authors, they demonstrated cytochemically the presence of lead without quantifying in two of the species (Arius melanopus and Umbrina coroides). Also, with their method lead was not found in the other 19 species. 

In samples obtained in 1977 and 1978, the same authors also used their cytochemical technique and reported the presence of lead in the esophagus and gut of 50% of the samples. They interpreted the results as indicative that ingestion of contaminated food is one of the important routes for lead in this case. They also found lead in liver, blood vessels, and erythrocytes and considered this as proof of the absorption and transport of the metal (Deleon and P6rez, 1984). 

In another related study, Perez et al. (1983) carried out the analysis of lead in several organs of fish samples from the same region. The highest concentrations were found in Guerres sp. In general, lead concentrations had the following order kidney brain stomach liver muscle gonads (see Table 15). 

These observations have been confirmed for freshwater zooplankton from three Canadian lakes. Investigations were carried out by means of a modified Phillip- 

Bast and von Oertzen listed energy contents of about 100 aquatic organisms with special attention to those found in the Baltic Sea [106]. Data were obtained by combustion in a modified Phillipson microcalorimeter (MBC-3) or taken from the literature and showed a range from about 12 to 29 kJ/g afdw. Highest values were observed in eggs (26.7 0.3 kJ/g afdw) and in larvae with yolk sacs (26.8 kJ/g afdw), smallest values on the lowest trophic level and in sediments [106]. 

Bomb calorimetry and biochemical analysis of holothunan (sea-cucumber) body tissues showed significant differences in the caloric contents of testis, gut, and body wall [112] which may be partly due to the calcium-carbonate content of the tissues (specially of the body wall). Holothurians with an average energy content of about 25 kJ/g afdw represent an important store of energy in the deep sea. 

Nagata [113] determined the energy transformation in an intertidal population of three gastropods (snails) which formed the more pronounced part of biomass and density in this habitat. Respiration and combustion measurements exhibited highly different contributions from 27,6 to 496 kJ/mVyear of these herbivores to the energy flow. The author regarded the caloric content of shell to zero because published combustion heats of 80 to 250 J/g were negligible compared with 13 to 21 kJ/g for flesh measured by him. 

It was found that the amphipod Corophium volutator collected in the Gulf of Gdansk/Poland experienced strong seasonal variations in its caloric content around a mean value of 18.2 kJ/g afdw for the females which are predominant in the population [119]. 

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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. 

Table 4. General Water Quality Requirements for Trout and Warmwater Aquatic Animals in Fresh Water ...

The water quahty criteria for each species should be deterrnined from the Hterature or through experimentation when Hterature information is unavailable. Synergistic effects that occur among water quahty variables can have an influence on the tolerance a species has under any given set of circumstances. Ammonia is a good example. Ionized ammonia (NH ) is not particularly lethal to aquatic animals, but unionized ammonia (NH ) can be... 

Aquatic animals are susceptible to a variety of diseases including those caused by viruses, bacteria, fungi, and parasites. A range of chemicals and vacciaes has been developed for treating the known diseases, although some conditions have resisted all control attempts to date and severe restrictions on the use of therapeutants ia some nations has impaired that abiUty of aquaculturists to control disease outbreaks. The United States is a good example of a nation ia which the variety of treatment chemicals is limited (Table 6). 

When treatment chemicals have to be employed, they may be iacorporated ia the food, used ia dips, flushes and baths, or allowed to remain ia the water for exteaded periods. Siace oae of the first respoases of aquatic animals to disease is reduction or cessation of feeding, treatments with medicated feeds must be initiated as soon as development of an outbreak is suspected. Antibiotics, such as terramycin, can be dissolved in the water, but may be less effective than when given orally. 

Vacciaes can be administered through injections, orally, or by immersion. Injection is the most effective means of vaccinating aquatic animals but it is stressflil, time-consuming, and expensive. The time and expense may be acceptable for use in conjunction with broodftsh and other valuable animals. 

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). 

Wasser-suppe, /. water gruel. -talk, m. brucite. -teilchen, n. water particle, -tiefe, /. depth of water draft (of ships), -tier, n. water animal, aquatic animal. 

Acid toxicity and aquatic animals. Edited by R. Morris, E.W. Taylor, O.J.A. Brown and J.A. Brown... 

Recently, attention has focused on the potential hazardous effects of certain chemicals on the endocrine system because of the abihty of these chemicals to mimic or block endogenous hormones, or otherwise interfere with the normal function of the endocrine system. Chemicals with this type of activity are most commonly referred to as endocrine disruptors. Some scientists believe that chemicals with the ability to disrupt the endocrine system are a potential threat to the health of humans, aquatic animals, and wildlife. Others believe that endocrine disrupting chemicals do not pose a significant health risk, particularly in light of the fact that hormone mimics exist in the natural environment. Examples of natural hormone mimics are the isoflavinoid phytoestrogens (Adlercreutz 1995 Livingston 1978 Mayr et al. 1992). 

Atchison, G.J., Sandheinrich, M.B., and Bryan, M.D. (1996). Effects of environmental stressors on interspecific interactions of aquatic animals. In M.C. Newman and C.H. Jagoe (Eds.), Quantitative Ecotoxicology A Hierarchical Approach. Lewis, Chelsea, Ml. 

Waste water rules have pH limits, a common range being between 6 and 10. There are also limits for fats and oils, solvents, heavy metals, and a variety of other compounds and ions. The fact that a compound with possible toxic or otherwise undesirable properties is not on the list does not mean it is permissible. Such a matter should be discussed with the proper authorities. The discharged water may also have to pass a test for toxicity to aquatic animals. As one frustrated manager of a chemical plant put it We can no longer put anything but pure tap water into the sewer Of course, it is not really that bad, but some of the requirements often come as a surprise. 

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