CLIMATE CHANGE AND OCEAN ACIDIFICATION - Marine Pollution: What Everyone Needs to Know - page 168

boon for aquaculture and fish native to warmer waters could
be farmed in new places. However, fish and shellfish disease
is a greater problem for aquaculture in tropical countries.
Diseases are more deadly and progress quicker in warmer cli-
mates. Outbreaks in tropical regions can wipe out entire fish
stocks in a relatively short time, with major consequences for
the economy and food security. Such outbreaks could become
more severe with climate change.
Can climate change affect the size of animals?
As the climate changes, many species are expected to shift
to smaller sizes. One reason for this is the need for oxygen.
Aquatic animals are sensitive to low oxygen, which would
likely accompany climate change. A recent study tested how
organisms' mass changed with temperature. With each 1 o C
increase in temperature, aquatic animals that were 100 mg
reduced their body mass by 5%, while land animals of the
same size reduced their mass by only 0.5%. Using computer
modeling, scientists found that fish sizes could shrink by
about 20% from 2000 to 2050, due to warmer temperatures and
less oxygen. There has already been a decline in growth and
body size of North Atlantic cod in the United States, Canada,
and Europe in response to warmer water. Smaller fish can
have economic consequences on communities that depend on
fish for food and trade.
Can climate change affect predator/prey interactions?
Temperature stress can affect predator/prey interactions.
Many rocky shore intertidal organisms already live very
close to their thermal tolerance limits. At cooler sites, mussels
and barnacles are able to live high on up the shore, above the
range of their aquatic predators (mainly sea stars). However,
as temperatures rise they are forced to live lower down, plac-
ing them at the same level as predatory sea stars. Daily high