32
The Last Resource
new kind of food poisoning. Certain of the phytoplankton—par—
ticularly members of a group called dinoagellates—are highly
poisonous. One species of dinoagellate found in the Gulf of Mexico,
Gynmodzium brave, can occur in such large numbers that the water
looks red. The toxin of this red—dde organism probably accounts for
considerable kills of sh as well as presenting a potential danger to
people. Laboratory—test animals have died when fed on shellsh
which had ingested the dinoagellate. In May 1968, unusual
conditions off the Northumbrian coast led to the ‘owering’ of
another dinoagellate Gonyaulæx tamarensis, and more than eighty
people became ill after eating shellsh contaminated with its toxin.
Some 80 per cent of the breeding population of the shag in this area
and numerous other sea birds died as a result of this unusual bloom.
Obviously, then, any attempts to harvest phytoplankton would have
to be looked at very carefully, although there is probably no reason
why some of these marine plants should not be cultivated on special
farms where conditions and species could be rigorously controlled.
For the moment, the biggest contribution of plankton to the
world’s food resources is as the start of the sea’s food cycle. How—
ever, this is not their only asset. The various associations of animals
and plants found in the plankton can tell the shery scientist a great
deal about the movement of waters and more particularly about the
prospects for sheries. One of the most intensive surveys of plankton
is being carried out at the Oceanographic Laboratory at Edinburgh
under the direction of R. S. Glover; this laboratory continues a
survey of the North Sea started by Sir Alister Hardy in 1932. The
work is unique in that the collections of plankton are made by
machines called continuous plankton recorders which are towed
behind merchant ships, ocean weather ships, and shing vessels in
the course of their normal business. As the recorder moves along
through the water, the plankton is sieved out on to a moving ribbon
of gauze. It is then sandwiched with another ribbon of gauze as it is
rolled up inside a formalin—lled tank in the machine. At the end of a
voyage of perhaps 200 to 300 miles, the spool with its enmeshed
plankton is taken out of the sampler and sent to the laboratory where
the marine biologists can reconstruct the journey of the recorder in
terms of the animals, plants, sh eggs and larvae which it has
collected. The total distance sampled in this way during 1965—66
was 112,000 miles.
Until recently the plankton recorder was restricted in both its
The Last Resource
new kind of food poisoning. Certain of the phytoplankton—par—
ticularly members of a group called dinoagellates—are highly
poisonous. One species of dinoagellate found in the Gulf of Mexico,
Gynmodzium brave, can occur in such large numbers that the water
looks red. The toxin of this red—dde organism probably accounts for
considerable kills of sh as well as presenting a potential danger to
people. Laboratory—test animals have died when fed on shellsh
which had ingested the dinoagellate. In May 1968, unusual
conditions off the Northumbrian coast led to the ‘owering’ of
another dinoagellate Gonyaulæx tamarensis, and more than eighty
people became ill after eating shellsh contaminated with its toxin.
Some 80 per cent of the breeding population of the shag in this area
and numerous other sea birds died as a result of this unusual bloom.
Obviously, then, any attempts to harvest phytoplankton would have
to be looked at very carefully, although there is probably no reason
why some of these marine plants should not be cultivated on special
farms where conditions and species could be rigorously controlled.
For the moment, the biggest contribution of plankton to the
world’s food resources is as the start of the sea’s food cycle. How—
ever, this is not their only asset. The various associations of animals
and plants found in the plankton can tell the shery scientist a great
deal about the movement of waters and more particularly about the
prospects for sheries. One of the most intensive surveys of plankton
is being carried out at the Oceanographic Laboratory at Edinburgh
under the direction of R. S. Glover; this laboratory continues a
survey of the North Sea started by Sir Alister Hardy in 1932. The
work is unique in that the collections of plankton are made by
machines called continuous plankton recorders which are towed
behind merchant ships, ocean weather ships, and shing vessels in
the course of their normal business. As the recorder moves along
through the water, the plankton is sieved out on to a moving ribbon
of gauze. It is then sandwiched with another ribbon of gauze as it is
rolled up inside a formalin—lled tank in the machine. At the end of a
voyage of perhaps 200 to 300 miles, the spool with its enmeshed
plankton is taken out of the sampler and sent to the laboratory where
the marine biologists can reconstruct the journey of the recorder in
terms of the animals, plants, sh eggs and larvae which it has
collected. The total distance sampled in this way during 1965—66
was 112,000 miles.
Until recently the plankton recorder was restricted in both its