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| Gray whale |
Some
800,000 years ago - about the time early human tribes were learning
to make fire – a tiny species of plankton called Neodenticula
seminae went extinct in the North Atlantic. Now, that microscopic
plant has come back again. It drifted into North Atlantic from the
Pacific through the Arctic Ocean.
The melting Arctic has opened a
passage across the Pole for the tiny algae. And while it's a food
source, it isn't being welcomed because it could change the marine
food web.
The tiny marine plant's migration is paired with the
arrival of a Pacific gray whale, spotted last year off the coasts of
Spain and Israel. Gray whale vanished from the Atlantic three
centuries ago, likely because of over-hunting.
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| Neodenticula seminae off Iceland |
Other
phytoplankton species, known as dinoflagellates,
are moving
steadily eastward across the Atlantic towards Scandinavia. That is
looking less innocent then Neodenticula
seminae because
many dinoflagellates are
harmful. Their bloom affects other marine creatures.
Jellyfish too
are increasing in the northeast Atlantic, often forming massive
blooms. Outbreaks of venomous warm-water jellyfish, Pelagia
noctiluca a
gluttonous predator of juvenile fish, have
become an annual event, forcing the closing of beaches.
 |
| Rootmouth jellyfish |
Simple
changes in temperature mean some species are no longer available when
their predators need them. Off Northwest Europe, the warming trend
has led to earlier spawning of cod, while phytoplankton have kept
their traditional biological schedule. The result is a mismatch
between the cod's larval and its food. The impacts of such changes
remain difficult to assess. The web of life in the oceans is complex.
Some impacts will combine to magnify their effects on ocean life;
others might neutralize each other; or marine life might alter
abruptly. [*]
Martin.Mundusmaris@gmail.com
info@mundusmaris.org
[*] after press release of project “Climate Change and European Marine
Ecosystem Research” www.clamer.eu
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