Red Tide and Harmful Algal Blooms - College of Marine Science
Red Tide and Harmful Algal Blooms - College of Marine Science
Red Tide and Harmful Algal Blooms - College of Marine Science
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Unit Three<br />
<strong>Red</strong> <strong>Tide</strong> <strong>and</strong> <strong>Harmful</strong> <strong>Algal</strong> <strong>Blooms</strong><br />
liter in seawater with relatively few<br />
toxic effects. However, a<br />
reproductive explosion in response<br />
to environmental cues can cause the<br />
population to soar, creating a bloom<br />
that can turn the water red.<br />
Scientists theorize that G. breve<br />
cysts, a resting stage in the G.<br />
breve life cycle, may be triggered by<br />
seasonal changes in environmental<br />
conditions. Cysts are most abundant<br />
in <strong>of</strong>fshore sediments. As this cyst<br />
resting on the ocean floor is<br />
reawakened, thous<strong>and</strong>s <strong>of</strong> new<br />
organisms are produced, flooding<br />
the water with more plankton. These<br />
organisms infiltrate the water column<br />
where they are driven by the winds<br />
<strong>and</strong> spread by the currents. The<br />
neurotoxin they produce effectively<br />
suffocates fish by inhibiting the<br />
respiratory response. Slow moving<br />
fish <strong>and</strong> bottom dwellers seem to be<br />
most affected, but the toxins can<br />
also kill horseshoe crabs <strong>and</strong> sea<br />
snails. Large fish kills are a public<br />
nuisance when they litter beaches<br />
<strong>and</strong> near shore waters.<br />
Reports <strong>of</strong> manatee deaths have<br />
been confirmed as a result <strong>of</strong><br />
concentrated levels <strong>of</strong> G. breve. This<br />
din<strong>of</strong>lagellate also causes respiratory<br />
problems <strong>and</strong> neurotoxic shellfish<br />
poisoning in humans.<br />
Implications <strong>of</strong> <strong>Harmful</strong> <strong>Algal</strong> <strong>Blooms</strong><br />
Since HABs are worldwide<br />
phenomena causing a variety <strong>of</strong><br />
disturbances, scientists are trying to<br />
better underst<strong>and</strong> their distribution<br />
<strong>and</strong> biology. Satellite remote sensing<br />
imagery is being used to follow<br />
HABs <strong>and</strong> record distribution data<br />
that is communicated to appropriate<br />
agencies. As this technology<br />
becomes more sophisticated, this<br />
information could be used to warn<br />
coastal communities so that the<br />
proper authorities could be prepared<br />
to clean up dead fish more efficiently<br />
or even intercept the fish at sea<br />
before they reach the beaches.<br />
Additionally this information can be<br />
used to identify shellfish beds that<br />
may be affected by the blooms,<br />
allowing for efficient purging times to<br />
reduce the economic impact on the<br />
shellfish industry.<br />
©Project Oceanography 38<br />
Spring 2001