CLIMATE CHANGE AND OCEAN ACIDIFICATION - Marine Pollution: What Everyone Needs to Know - page 166

study by Schofield and colleagues, other species that depend
on ice, like Adelie penguins in Antarctica, are also decreasing,
while other penguin species have increased. Changing wind
patterns also affect Antarctica's plankton. Retreating sea ice
and stronger winds have caused seawater to mix more deeply,
a process that moves phytoplankton into deeper water, which
has less light for photosynthesis. As a result, phytoplankton
are declining, resulting in fewer krill (important food for
baleen whales) and fish larvae. Krill are also affected by the
loss of sea ice which is a refuge from predators.
The loss of sea ice also will stimulate major increases in
shipping over the North Pole and Arctic Ocean in the future.
Ships traveling in the Northwest Passage and through the cen-
tral Arctic Ocean will likely bring new, potentially invasive,
species to the Arctic as well as to northern ports. As the Arctic
ice melts, new ports will be connected and shorter passages
between existing ports will provide new opportunities for
invasive species to spread. Shorter routes also mean that more
organisms attached to the hull or in ballast water will survive
the voyage. Invasive species, as a type of biological pollution,
will be discussed at length in the next chapter.
Can climate change affect the distribution of species?
In response to warming, the geographical ranges of marine
species are likely to change, including migration to higher
latitudes (toward the poles) and to deeper depths where the
temperature is more suitable. Phytoplankton are predicted
to move toward the poles and away from the equator. If the
oceans continue to warm as predicted, there will be a fur-
ther decline in the abundance and diversity of phytoplankton
in tropical waters and a shift toward the poles. The pole-
ward movement of many marine animals has already been
observed. However, animals that already live in polar regions
are finding their habitat shrinking as the ice melts. Polar bears,
for example, require sea ice, which is disappearing from the