Download Plankton will suffer as oceans warm

Plankton will suffer as oceans warm
September 8, 2013, by Alex Kirby
One effect of the warming of the
oceans will be to depress the
growth
of
plankton,
with
consequences for fish and other
species
LONDON,
that
8
depend
on
September
it.
–
Researchers at two UK universities
have found that rising temperatures
in the world’s oceans will affect the
development of the plankton on
which most marine life feeds. The
research team, from the universities of ​East Anglia and ​Exeter​, has demonstrated that
the increasing warmth caused by a changing climate will upset the natural cycles of
carbon dioxide, nitrogen and phosphorous. This will affect the plankton, making it
scarcer and so causing problems for fish and other species higher up the food chain.
There are also likely to be implications for climate change, but just what they will be, the
team leader says, is far from clear. Plankton play an important role in the oceanic
carbon cycle by removing half of all CO2 from the atmosphere during photosynthesis –
the process during which plants and other organisms convert light, usually from the
Sun, into energy. The carbon then falls deep into the ocean and ends up on the sea
bed, where it remains safely isolated from the atmosphere for centuries. But the novel
point about the team’s work, published in ​Nature Climate Change​, is their discovery that
water temperature has a direct impact on maintaining the plankton’s delicate
ecosystem. This means the effects of oceanic warming will affect plankton and drive “a
vicious cycle of climate change”. Researchers from UEA’s School of Environmental
Sciences and the School of Computing Sciences investigated ​phytoplankton –
microscopic plant-like organisms which rely on photosynthesis to reproduce and grow.
The lead researcher, Dr Thomas Mock, says: “Phytoplankton, including micro-algae, is
responsible for half of the carbon dioxide that is naturally removed from the atmosphere.
“As well as being vital to climate control, it also creates enough oxygen for every other
breath we take, and forms the base of the food chain for fisheries, so it is incredibly
important for food security. “Previous studies have shown that phytoplankton
communities respond to global warming by changes in diversity and productivity. But
with our study we show that warmer temperatures directly impact the chemical cycles in
plankton, which has not been shown before.
1. What important role do plankton play in cycling carbon? Explain.
2. What ​kind ​of plankton would be responsible for cycling carbon?