Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Fish Water Directive

During snow melt, pollutants are preferentially eluted early. Consequently, acidic pulses are released and may enter streams and lakes with little contact with soils (Johannessen and Henriksen, 1978 Jeffries, 1990). Base cation concentrations become diluted concurrently with elevated concentrations of strong acid anions. The associated pH and alkalinity depressions may have severe biological impacts on fish and other biota during their sensitive early life stages. The temperature of meltwater may be close to 0 °C and it tends not to mix downward with more dense lake water if the lake is covered with ice. The result is a shallow layer of relatively low pH water directly beneath the ice. Inorganic aluminum and DOC interactions cause variability in fish... [Pg.4918]

Fig. 6. Approaches to minimising entrapment and impingement of fish and large aquatic invertebrates, eg, blue crabs, on trash screens at intakes, (a) An inlet pump house with vertical traveling screens mounted flush with a river shoreline to minimise obstmctions to animal movements (b) parallel flow to direct fish to a recovery chamber that returns to the water body (c) a velocity cap atop a vertical, offshore inlet induces a horizontal flow which fish avoid... Fig. 6. Approaches to minimising entrapment and impingement of fish and large aquatic invertebrates, eg, blue crabs, on trash screens at intakes, (a) An inlet pump house with vertical traveling screens mounted flush with a river shoreline to minimise obstmctions to animal movements (b) parallel flow to direct fish to a recovery chamber that returns to the water body (c) a velocity cap atop a vertical, offshore inlet induces a horizontal flow which fish avoid...
The nature of the conditions of intensive production, however, can increase the risk of diseases and infections which can spread very rapidly and devastate large numbers of animals." Thus it is common practice for producers of poultry to add coccidiostats to their diets and vaccines to their drinking water in order to prevent coccidiosis and other infectious diseases such as bronchitis and Newcastle disease. A similar problem exists for intensively reared fish, where it is necessary to add antibiotics to their diets. A problem with intensively reared fish is that their diet is added directly into the water in which they live thus drugs and other additives in the diet are relatively easily dispersed into the local environment of fish farms, where they can increase bacterial resistance and also cause problems such as algal blooms. [Pg.92]

EEC Directive on information on water pollution 78/176/EEC Directive on titanium dioxide waste 78/659/EEC Directive on water standards for freshwater fish 79/115/EEC Directive on pilotage of sea vessels... [Pg.569]

Many geothermal reseiwoirs contain hot water at a temperature too low for electricity generation. However, the water can be used to heat buildings such as homes, greenhouses, and fish hatcheries. This heating can be either direct or through the use of heat pumps. [Pg.574]

Most fish is still caught at sea and must be cooled soon after it is taken on board, and kept cold until it can be sold, frozen or otherwise processed [45]. The general practice is to put the fish into refrigerated sea water tanks, kept down to 0°C by direct expansion coils or a remote shell-and-tube evaporator. The sea water must be clean and maybe chlorine dosed. At this condition, fish can be kept for up to four days. [Pg.191]

Water birds have not been shown to be directly affected by acidification. However, the prey of waterbirds may be of concern as these lower food-chain organisms may have elevated levels of toxic metals related to acidification of their habitat. Moreover, most water birds rely on some component of the aquatic food-chain for their high protein diet. Invertebrates that normally supply caJcium to egg-laying birds or their growing chicks are among the first to disappear as lakes acidify. As these food sources are reduced or eliminated due to acidification, bird habitat is reduced and reproductive rate of the birds is affected. The Common Loon is able to raise fewer chicks, or none at all, on acidic lakes where fish populations are reduced 37 and 5S). However, in some isolated cases, food supplies can be increased when competitive species are eliminated (e.g.. Common Goldeneye ducks can better exploit insects as food when competition from fish is eliminated). The collective influences of acidification are difficult to quantify on a specific area basis but for species that rely on a healthy aquatic ecosystem to breed, acidification remains a continuing threat in thousands of lakes across eastern North America 14). [Pg.56]

Suggestions that phosphatic minerals in mammals could be used, however, revived the interest in climate reconstruction in continental interiors. Aquatic, cold-blooded animals like fish have body temperatures and body water oxygen isotopic compositions that are directly dependent on the water in which they live. For these animals, a commonly used equation describes the relationships among temperature, water oxygen isotopic composition and phosphate oxygen isotopic composition as (Longinelli and Nuti 1973 verified by Kolodny et al. 1983, among others) ... [Pg.119]

The major routes of uptake of xenobiotics by animals and plants are discussed in Chapter 4, Section 4.1. With animals, there is an important distinction between terrestrial species, on the one hand, and aquatic invertebrates and fish on the other. The latter readily absorb many xenobiotics directly from ambient water or sediment across permeable respiratory surfaces (e.g., gills). Some amphibia (e.g., frogs) readily absorb such compounds across permeable skin. By contrast, many aquatic vertebrates, such as whales and seabirds, absorb little by this route. In lung-breathing organisms, direct absorption from water across exposed respiratory membranes is not an important route of uptake. [Pg.21]


See other pages where Fish Water Directive is mentioned: [Pg.67]    [Pg.67]    [Pg.93]    [Pg.100]    [Pg.208]    [Pg.353]    [Pg.208]    [Pg.353]    [Pg.486]    [Pg.127]    [Pg.509]    [Pg.194]    [Pg.77]    [Pg.509]    [Pg.417]    [Pg.1304]    [Pg.1304]    [Pg.889]    [Pg.306]    [Pg.54]    [Pg.772]    [Pg.71]    [Pg.262]    [Pg.265]    [Pg.146]    [Pg.119]    [Pg.473]    [Pg.476]    [Pg.42]    [Pg.37]    [Pg.37]    [Pg.57]    [Pg.234]    [Pg.52]    [Pg.78]    [Pg.107]    [Pg.113]    [Pg.121]    [Pg.308]    [Pg.244]   
See also in sourсe #XX -- [ Pg.66 ]




SEARCH



Water direct

© 2024 chempedia.info