|How Brittany and Florida coasts cope with green tides|In: International Journal of Environmental Studies. Gordon and Breach Science Publishers: New York; Paris; London. ISSN 0020-7233, more
Ulva Linnaeus, 1753 [WoRMS]; Marine
Eutrophication, Algae juice, Methanization, Environmental-social-economic impacts, Ulva, Harmful algal blooms
|Authors|| || Top |
- Charlier, R.H.
- Morand, Ph.
- Finkl, C.W.
Although the direct involvement of nitrogen and phosphorus has been shown, eutrophication remains poorly managed to this day. The excessive growth of some opportunist seaweeds is the consequence in coastal ecosystems close to agricultural or strongly urbanized and industrialized zones. In Brittany, a leading tourist region of France, green tides set down on the beaches big quantities of Ulva, of which some 100,000 m3 are harvested annually, with significant ecological and economic consequences. In Florida, although the macroalgae (notably Codium) drift about with the currents, they are of sufficient mass and spread over such areal extent to inhibit penetration of sunlight through the water column to the coral reef surface. They strand also on the beaches. Stabilization of algae by composting and methanization of hydrolyzed and pressed algae juice are two methods which have been studied in Brittany and can be used to enhance the value of the harvested seaweed, depending on local conditions and on evolution of needs in energy, basic materials or organic products. But the parallel made here between two very different ecosystems, both disturbed, leads above all to the question of what course to follow now to avoid a worldwide disaster.