Minerals Report - International Seabed Authority

together with mucus that is secreted by a number of different organisms. Dr.
Juniper said that the tubeworms feed the mass growing on the animal
surfaces and then predators feed on the tubeworms. He apologized for not
being in a position to describe some of the other symbiotic relationships at
vent ecosystems but said these include a number of shellfish (clams and
mussels) which also have special bacteria living inside their tissues, and
which are also suspension or deposit feeders. He also said that some of the
predators are octopus that love the clams and fish and like to hang around the
hydrothermal vents in some areas.
Dr. Juniper however noted that there are major differences between
the Eastern Pacific vents, the mid-Atlantic ridge vents and the Western Pacific
vents.
He said that hydrothermal vents fauna at the Western Pacific Ridge
seem to be something of an intermediary between fauna at the Eastern Pacific
and the Mid-Atlantic Ridges. He also said that what probably happened is
that back in Geological time the hydrothermal vents fauna originated from
somewhere in the Eastern Pacific and had spread out by producing larvae.
He said that the animals colonize other sites by sending up larvae which are
fertilized eggs with arms and legs and that swim a bit, often with a little sack
on their back for eating. He noted however that the larvae have a very limited
life span. Dr. Juniper showed participants an area on the Eastern Pacific Ridge
and informed them that fauna were taken from this area and compared with
fauna 300km down the axis. He said that the fauna were found to be very
similar. He said that 3000km away the fauna were found to be very different
because these communities have been isolated for tens of thousands of years
since genetic information was not flowing back and forth. Dr. Juniper said
that in the last 10 years or scientists have witnessed several volcanic eruptions
on the seafloor and watched the recolonisation of the site afterwards. He
stated that the speed of recolonisation is surprising. He said that within a
couple of years an established and recognizable community is established
where everything was as it was 2 years before. In relation to mining therefore,
Dr. Juniper said that one could cautiously say that there is a tremendous
capacity for recolonization if there is a source of larvae to make this possible.
He emphasized that recolonization has to be from a breeding population that
is not disturbed.
INTERNATIONAL SEABED AUTHORITY 300