The article and the lecture are about sea otters which are a small type of mammal living along the western coast of USA. The article states that sea otter populations'declining may be related to increased pollution. The lecture cast doubts on the claims made in the article. Indeed, the lecturer sustains that predators'attack is the most probable root cause of sea otters'decline.
To begin with, the author of the reading points out that pollution is a consistent hypothesis as it could explain the uneven pattern of otter decline. This point is challenged by the lecturer, who argues that the pollution theory can't explain the change in the ecosystem occurred along the western coast. He says that the absence of sea otters'rests is the proof of concept that the pollution theory is wrong. He adducts two main reasons to support the predators hypothesis.
The first reason is that, chemical pollution produced by industrial chemicals would imply sea otters's death although no skeleton of these animals has been recovered. In addition, the lecturer suggests that the decline of other animals such as seals and sea lions is not a coincidence. He believes that this is a result of the predators'theory.
As second reason, he mentions that as whales are also disappearing due to human hunters, the ecosystem experienced a slight modification and as a result of this, orcas started to eat sea otters as well as other sea mammals. All together, these facts support the orca predation theory as the most likely cause of sea otters decline.
The article and the lecture are about
sea
otters which are a
small
type of mammal living along the western coast
of USA
. The article states that
sea
otter populations'declining may
be related
to increased
pollution
.
The
lecture cast doubts on the claims made in the article.
Indeed
, the lecturer sustains that predators'attack is the most probable root cause of
sea
otters'decline.
To
begin
with, the author of the reading points out that
pollution
is a consistent hypothesis as it could
explain
the uneven pattern of otter decline. This point
is challenged
by the lecturer, who argues that the
pollution
theory can't
explain
the
change
in the ecosystem occurred along the western coast. He says that the absence of
sea
otters'rests is the proof of concept that the
pollution
theory is
wrong
. He
adducts
two main reasons to support the
predators
hypothesis.
The
first
reason is that, chemical
pollution
produced by industrial chemicals would imply
sea
otters's
death although no skeleton of these animals has
been recovered
.
In addition
, the lecturer suggests that the decline of other animals such as seals and
sea
lions is not a coincidence. He believes that this is a result of the predators'theory.
As second reason, he mentions that as whales are
also
disappearing due to human hunters, the ecosystem experienced a slight modification and
as a result
of this, orcas
started
to eat
sea
otters
as well
as other
sea
mammals. All together, these facts support the orca predation theory as the most likely cause of
sea
otters decline.