Fishkill

mass death of aquatic animals, mainly fish.

It is caused by a decrease in the amount of oxygen dissolved in the water (to 5-30 percent of normal saturation) or by the appearance of toxic substances in the water (owing to the discharge of untreated industrial effluent or washing of toxic chemicals from land). The amount of oxygen decreases in bodies of water rich in organic matter (for example, bog water) and in stagnant water where algae (responsible for the blooming of water) and zooplankton are well developed. Fishkills generally occur in winter (from January to April) and at night in the summer in calm, warm weather. Fishkills sometimes occur in seas (for example, in the Sea of Azov in calm weather in summer). Certain fish (salmon, sturgeon, perch), crustaceans, and mollusks (pearly mussel, freshwater mussel) are particularly sensitive to an oxygen deficiency. Tench, Carassius, loach, chironomid larvae, and other organisms are less sensitive and survive longer. Control measures include saturating the water with oxygen and preventing toxic substances from entering the body of water.

REFERENCE

Zernov, S. A. Obshchaia gidrobiologiia, 2nd ed. Moscow-Leningrad, 1949.

N. S. STROGANOV

单词	fishkill
释义	fishkill fishkill (ˈfɪʃˌkɪl) na mass death among the fish population of a given area caused by pollution or other contaminants fish′kill` or fish′ kill`, n. the sudden destruction of large quantities of fish, as by pollution. [1960–65] Fishkill Fishkill mass death of aquatic animals, mainly fish. It is caused by a decrease in the amount of oxygen dissolved in the water (to 5-30 percent of normal saturation) or by the appearance of toxic substances in the water (owing to the discharge of untreated industrial effluent or washing of toxic chemicals from land). The amount of oxygen decreases in bodies of water rich in organic matter (for example, bog water) and in stagnant water where algae (responsible for the blooming of water) and zooplankton are well developed. Fishkills generally occur in winter (from January to April) and at night in the summer in calm, warm weather. Fishkills sometimes occur in seas (for example, in the Sea of Azov in calm weather in summer). Certain fish (salmon, sturgeon, perch), crustaceans, and mollusks (pearly mussel, freshwater mussel) are particularly sensitive to an oxygen deficiency. Tench, Carassius, loach, chironomid larvae, and other organisms are less sensitive and survive longer. Control measures include saturating the water with oxygen and preventing toxic substances from entering the body of water. REFERENCE Zernov, S. A. Obshchaia gidrobiologiia, 2nd ed. Moscow-Leningrad, 1949. N. S. STROGANOV
随便看	limoges, haute-vienne limoges plongée sous marine limoges porcelain limoges ware limon limonchik limoncillo limon, costa rica limon,costa rica limonene limoniaceae limoniad limoniads limoniform limonin limonite limonitic limonium limon, josé limonoate a-ring lactone limonum limophthisis limos limosa limosa haemastica

fishkill

fishkill

fish′kill`

or fish′ kill`,

Fishkill

Fishkill

REFERENCE