Many biologists in marine science spend much of
their time in the
laboratory utilizing marine organisms to study
biomedical uses of marine organisms, or looking
for products from
the sea. In this lecture the work of these marine
(as compared to biological oceanographers who
study marine ecosystems)
The Oceans and Human Health
A growing area of concern and investigation is
the role the marine
environment plays in human health. This an area
where both types
biologists interact. It is also an area that involves
professionals, marine chemists, physical oceanographers
types of policy experts. One specific area of
intense debate is
the role of climate variations and newly discovered
cholera with copepods in the coastal plankton.
See at your leisure
(i.e. its not of the test) Rita Colwell's article
in Science (Vol. 274
Dec. 20, 1996, pg. 2025-2031.
Another increasingly worrisome problem
involves what are called Harmful
Algal Blooms or HAB's. These seem
to be on the increase around the world.
Many HAB's, as discussed in previous lectures,
are the result of
a group that may or may not be classified as algae
at all depending
on who you talk to. Clearly the dinoflagellate
(Ptychodiscus breve) that is responsible
for red tides on the west Florida coast are photosynthetically active eukaryotes.
This species is responsible for over 100 manatee deaths due to lung lesions,
disruption of fisheries and even closing of sea-side golf courses and shopping
malls. The active agent in all of these is a very potent toxin called brevetoxin
that these dinoflagellate cells produce. Since 1995, another dinoflagellate
has become the key element in in a rage of concern in North Carolina and
Maryland is Pfiestera
piscicida. As the last part of its name suggests, this dinoflagellate
is a fish killer. This organism is heterotrophic although it seems to be
able to capture chloroplasts from autotrophs it consumes and then uses
them. Margulis's model for how eukaryotes derived from prokaryotes is therefore
perhaps vindicated. Again, it produces a toxin or group of toxins that
decompose tissue. In 1995, 14 million fish died in North Carolina. A lab
there also had a major problem with the toxin. If put into the air by bubbling
cultures to provide oxygen the toxin produces lesions in human brains leading
to memory loss.
have recently spread to Chesapeake Bay. In both
added to these coastal waters from agriculture,
hog farming in Carolina
and chicken farms in Maryland, are suspect in
where this "bug from hell" thrives.
A side note worth thinking about is the treatment
of the Pfiesteria
by politicians and the press. Scientists need
to think about how
to interact with society. One example, of how
science can be twisted
is the Time report on September 29, 1997 entitled
Massacre on the Bay.
While the article had some useful information,
it played up the
unproven chicken link and identified Pfiesteria
as a bacteria!