Salmon face extinction, report says The
Daily Yomiuri 99.6.11
Salmon could become extinct by the middle of the next
century due to rising seawater temperatures as a result
of global warming, the World Wide Fund for Nature said in
a report published on Tuesday.
The report said hauls of red salmon in Alaska sharply
decreased in 1997 and 1998 when seawater temperatures
were above average.
Japanese and Canadian specialists discovered that
salmon suffer from malnutrition or starve to death in
warm water. This is because their metabolic rate
increases and they need to take in far more calories to
survive when the water is warm.
The ideal water temperature for salmon is from 7 C to
15 C.
The report said that if water temperatures continue to
rise at the current pace, habitats suitable for red
salmon will mostly disappear by the middle of the 21st
century. Other kinds of salmon vulnerable to warmer water
might also decrease.
Therefore, to survive , salmon either have to live at
greater depths in the sea or migrate to cooler northern
seas that are farther from their spawning rivers.
However, both these alternatives have problems.
According to recent research, salmon spend 70 percent
of their lives in waters less than 10 meters deep. It is
difficult for them to live at greater depths.
As for the second option, if the salmon move to
northern waters, they will have to consume their eggs and
body fat to get enough energy to reach their spawning
rivers.