Keeping Coral Clean
Seaweed overgrowth is a major problem for coral reefs and also seems to be a consequence of excessive harvesting of herbivorous fish. Dixson and Hay (p. 804) examined this effect on Fijian reefs. Species of small herbivorous gobies and coral-associated damselfish were compared for their effect on the toxic Chlorodesmis seaweed in experiments that required caging colonies of the branching coral Acropora nasuta and the associated fish species. Only the gobies actively removed algal fronds attached to the cages and only one species (itself toxic to predators) ate them; the damselfish simply defected from the arena when toxic algae were present. The hydrophobic toxins exuded in the algal mucus lysed coral polyps releasing cell constituents that, together with the algal toxin, attract the gobies, which then eat the algal fronds. Interestingly, the toxic goby became more toxic to predators after consumption of the seaweed, which may help to drive symbiosis with a coral colony.
The Ocean Conservancy
pdf document, 35 pages, 2005
20th anniversary International Coastal Cleanup
The Ocean Conservancy promotes healthy and diverse ocean ecosystems and opposes practices that threaten ocean life and human life. Through research, education, and science-based advocacy, The Ocean Conservancy informs, inspires, and empowers people to speak and act on behalf of the oceans. In all its work, The Ocean Conservancy strives to be the world's foremost advocate for
the oceans.
The International Coastal Cleanup engages people to remove trash and debris from the world's beaches and waterways, to identify the sources of debris, and to change the behaviors that cause pollution.
Introduction
How to Use This Book
Quick Tips
- Shoreline Cleanup
- Underwater Cleanup
Estimating Weights and Distances
The World of Marine Debris
Activities That Produce Debris
Sample Data Card
Items Listed on the Data Card
Debris Items of Local Concern
Potentially Hazardous Items
Stranded or Entangled Animals
Natural Items
Peculiar Items
Other Volunteer Opportunities
- National Marine Debris Monitoring Program
- RECON
- Storm Drain Sentries
- Ocean Action Network
- Ocean Wilderness
More Information