Study shows rising temperatures could kill off Mediterranean fish


dpa German Press Agency
Published: Friday January 5, 2007


Athens- Rising temnperatures could end up killing off vast
numbers of fish that live in the Mediterranean in the next few
decades, a Greek study found Friday.
A study conducted by the Artistotle University in Thessaloniki,
and published in the Greek daily Kathimerini, found that a rise of
just a few degrees in sea temperatures would have a devastating
effect on sea life.

Greek researchers have been conducting tests for the last five
years to establish the impact that a rise in sea temperatures and an
increase in the amount of carbon dioxide in the water will have on
sea organisms.

"We are researching the lowest temperature above which the effect
on fish will be seen," Assistant Professor Vassilis Michailidis was
quoted by Kathimerini as saying.

"It is especially important that the tolerance levels of the
organism to changes in their environment be established," he added.

The earth's average temperature has increased by up to 1 degree
Celcius over the last few years and scientists predict that it will
increase by some 5 degrees Celcius over the next few decades.

"The fish in the Mediterranean, especially the sea bream that we
have studies ideally live in temperatures of 18-22C," said
Michailidis.

"Above 26C, fish cannot breath well and do not take in enough
oxygen," he added. "When the temperatures rises above 29C their
cardiac system does not operate well and there is an increased rate
of death."

The study also found that the increasing amount of carbon dioxide
in seawather, which makes it more acidic, is a threat to fish.

"The constant emissions of carbon dioxide will lead to a fall in
the pH value of seawater from 8.2 to 7.4 over the next 90 years,"
said Michailidis. "Experiments have shown that organisms should not
be exposed to these pH levels."

He said tat even if fish such as sea bream, which is common in
Greek waters survive these changes, many other organisms on which
fish feed will be killed.

© 2006 - dpa German Press Agency