Other scientists as well as sport fishermen are
reporting unusual movements of fish, shrimp, crab and
other marine life, including increased shark sightings
closer to the Alabama coast.
Crowder, a marine biologist at Duke University, said
there were already signs that fish were being driven
from their habitat.
animals are already voting with their fins to get away
from where the oil spill is and where potentially there
is oxygen depletion," he said. "When you begin to see
animals changing their distribution that is telling you
about the quality of water further offshore. Basically,
the fish are moving closer to shore to try to get to
sightings and an accumulation of data from the site of
the ruptured well and from the ocean depths miles away
have deepened concerns that the enormity of the
environmental disaster in the Gulf has yet to be fully
understood. It could also jeopardise the Gulf's
billion-dollar fishing and shrimping industry.
conference call with reporters, Samantha Joye, a
scientist at the University of Georgia who has been
studying the effects of the spill at depth, said the
ruptured well was producing up to 50% as much methane
and other gases as oil.
finding presents a new challenge to scientists who so
far have been focused on studying the effects on the
Gulf of crude oil, and the 5.7m litres of chemical
dispersants used to break up the slick.
said her preliminary findings suggested the high volume
of methane coming out of the well could upset the ocean
food chain. Such high concentrations, it is feared,
would trigger the growth of microbes, which break up the
methane, but also gobble up oxygen needed by marine life
to survive, driving out other living things.
said the methane was settling in a 200-metre layer of
the water column, between depths of 1,000 to 1,300
metres in concentrations that were already threatening
water can go completely anoxic [extremely low oxygen]
and that is a pretty serious situation for any
oxygen-requiring organism. We haven't seen zero-oxygen
water but there is certainly enough gas in the water to
draw oxygen down to zero," she said.
could wreak havoc with those communities that require
oxygen," Joye said, wiping out plankton and other
organisms at the bottom of the food chain.
A&M University oceanographer issued a similar warning
last week on his return from a 10-day research voyage in
the Gulf. John Kessler recorded "astonishingly high"
methane levels in surface and deep water within a
five-mile radius of the ruptured well. His team also
recorded 30% depletion of oxygen in some locations.
without the gusher, the Gulf was afflicted by 6,000 to
7,000 square miles of dead zone at the mouth of the
Mississippi river, caused by run-off from animal waste
and farm fertiliser.
run-off sets off a chain reaction. Algae bloom and
quickly die, and are eaten up by microbes that also
consume oxygen needed by marine life.
huge quantities of methane, or natural gas, being
released from the well in addition to crude presents an
entirely new danger to marine life and to the Gulf's
lucrative fishing and shrimping industry.
are changing, and what impacts there are on the food web
are not going to be clear until we go out and measure
that," said Joye.