Subtidal habitats: driving forces

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Subtidal habitats driving forces

• Keystone Species, Human Impacts

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Fresh water nutrient inputs increase
chlorophyll concentrations in water
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P or N nutrient limitation varies
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Dry season patterns of chlorophyll
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Wet season patterns of chlorophyll
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Red Tide sampling areas
http//www.ncddc.noaa.gov/website/HABSOS_nrt/top.h
tm
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Densities of red tide dinoflagellates
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Karenia brevis, the alga that causes red tide
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Karenia and its community context
Source http//www.whoi.edu/redtide/whathabs/whath
abs.html
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The devastaing effects of HABs are frequently
seen on the west coast of Florida where the
proliferation of the toxic dinoflagellate
Gymnodinium breve can result in massive fish
kills, closure of shellfish beds due to NSP and
skin and respiratory irritation to humans at the
seashore.
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Mammals and birds also are affected
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Increasing frequency of HAB
Sellner et al. 2003. J Ind Microbiol Biotechnol
30 383-406
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Anthropogenic effects?
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transport
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natural nutrient loading
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Questions to consider

• Are HAB natural? Does the answer influence our
  response?
• If causes are complex, should we give up on
  attempts to improve the situation?
• What strategies might be applied?