The reading passage and lecture are about the declination of sea otters, small mammals live in water. The author presents possible reasons to as what caused sea otters to decline. However, the lecturer casts doubt on each of the explanations presented in the article. She is of the opinion that sea otters decline has been caused by predation.
To begin with, the author argues that one of the reasons of sea otters declination is pollution. He states that increased number of chemicals in water could decline otter's resistance to deadly infections and cause their deaths. The lecturer, however rebuts this by mentioning that pollution theory is weakened mainly by the fact that there was no deaths of sea otters found along the Alaska beaches. Furthermore, she points out that if an otter is killed by a predator, it will not be found on shore.
Secondly, the authors contends that sea and sea lions along with other mammals are declining as well, which is the indication that otters were affecting other mammals too. It is mention in the article that orcas could have the same effect, but they usually prefer large prey. This point is challenged by the professor. He mentions that whales disappear from the place because of human hunters. So, orcas changed their diet and started to feed on smaller mammals instead. She elaborates that orcas causing decline of seals, sea lions and otters.
Finally, the author posits that otters decline due to their uneven pattern. Some experts suggest that environmental factors might have created uneven concentrations of pollutants. The lecturer, on the other hand, feels that it basically depends on the otters location if its convenient for orcas. She puts forth the idea that orcas are so big that they can not reach to shallow locations where sea otter populations have not decline.
The reading passage and lecture are about the declination of
sea
otters,
small
mammals
live
in water. The
author
presents possible reasons to as what caused
sea
otters to
decline
.
However
, the lecturer casts doubt on each of the explanations presented in the article. She is of the opinion that
sea
otters
decline
has
been caused
by predation.
To
begin
with, the
author
argues that one of the reasons of
sea
otters
declination is pollution. He states that increased number of chemicals in water could
decline
otter's resistance to deadly infections and cause their deaths. The lecturer,
however
rebuts this by mentioning that pollution theory
is weakened
mainly
by the fact that
there was no deaths
of
sea
otters found along the Alaska beaches.
Furthermore
, she points out that if an otter
is killed
by a predator, it will not
be found
on shore.
Secondly
, the
authors
contends that
sea
and
sea
lions along with other
mammals
are declining
as well
, which is the indication that otters were affecting other
mammals
too. It is mention in the article that orcas could have the same effect,
but
they
usually
prefer large prey. This point
is challenged
by the professor. He mentions that whales disappear from the place
because
of human hunters.
So
, orcas
changed
their diet and
started
to feed on smaller
mammals
instead
. She elaborates that orcas causing
decline
of seals,
sea
lions and otters.
Finally
, the
author
posits that otters
decline
due to their uneven pattern.
Some
experts suggest that environmental factors might have created uneven concentrations of pollutants. The lecturer,
on the other hand
, feels that it
basically
depends on the
otters
location if its convenient for orcas. She puts forth the
idea
that orcas are
so
big
that they can not reach to shallow locations where
sea
otter populations have not
decline
.