Английский язык: Сборник текстов и упражнений. Дьякова Н.П. - 36 стр.

scientists suggested explanation that decline in population in their area had been
caused by migration of animals due to some climatic and ecological reasons. But
after collecting and exchanging information it became clear that population of
steller sea lion dramatically decreased all over the Northern Pacific. And the rea-
sons were absolutely unknown.
    True, the reasons cannot be very definitely explained today as well. In 1989
the first joint aerial survey in the North America and Kamchatka-Kuril area was
carried out by American and Russian scientists. Complex estimation of state of
steller sea lion population in the Northern Pacific was made. All factors effecting
the number of population were analyzed. Thus some hypotheses appeared ex-
plaining decrease in steller sea lion population. But none of them can be fully ac-
cepted and proved. A lot of reasons can be fully accepted and proved. A lot of
reasons can be thought of as effecting the marine mammal population: changes in
ecological system, climate warming up or getting colder and some other pheno-
mena. Nowadays sea pollution is one of the most important problems. The Baltic
sea, for example, is so polluted by waste of chemical production that seal females
are loosing their breeding abilities. Situation in our area is not that bad but more
and more often we see that sea is polluted by fishing gear and packing materials.
At rookeries of steller seal lion and fur seal some animals can be found wrapped
with pieces of nets and trawls. And quite often animals die unable to get rid of
nets lost by fishermen. We observe a demographic «downfall» of the breed of an-
imals died in fish trawls. In 1970-th in Kamchatka waters in every trawl catch
there were about 20–30 Steller sea lions many of which died.

                                    Vocabulary

   sea offer                    калан
   to allow                     давать возможность, позволять
   fluctuation                  колебание
   steller sea lion             сивуч
   to diminish                  уменьшать (ся)
   decline                      спад, ухудшение
   dramatically                 резко
   joint aerial survey          совместный авиаучет
   to carry out                 проводить
   estimation                   оценка
   waste                        сбросы
   chemical                     production химические отходы
   to lose breeding             терять способность производить потомство
   fishing                      орудие лова
   rookery                      лежбище
   fur seal                     котик
   to get rid of                избавляться от
   downfall                     провал
   breed                        потомство
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