[Coral-List] Offshore Drilling vs Removal of Offshore
edblume at mailbag.com
Sat Oct 11 14:43:41 EDT 2008
I'm not familiar with the debate. What are the reasons to take them down?
Date: Fri, 10 Oct 2008 00:12:48 -0500
From: Steve Kolian <stevekolian at hotmail.com>
Subject: [Coral-List] To: <coral-list at coral.aoml.noaa.gov>
Message-ID: <BAY109-W3DA0E66EE4354005F8D5EB0350 at phx.gbl>
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For many subscribers, offshore drilling in state and federal waters is a contentious political issue. In Louisiana, the political issue at hand is the removal of offshore platforms. These structures represent the only hard substratum which extends from the bottom of the continental shelf through the euphotic zone?in an area of thousands of miles is flat, featureless soft-bottom continental shelf.
Currently, about 150-200 platforms are being removed (explosives) from the Gulf of Mexico each year. Approximately, 1,540 idle platforms are scheduled for removal. There are 3,400 platforms scheduled to be removed within the next 10-15 years.
Offshore platforms have an average 17.5 year productive lifespan before they are removed. If they are properly maintained and avoid catastrophic weather events, they can remain standing for hundreds of years after their useful life in minerals production. They could be retrofitted to facilitate a number of eco-technology applications. Scores of alternate uses for retired platforms have been identified. These include:
The generation of energy from renewable resources, derived from wind, current, wave, ocean thermal, salinity gradients and bio-fuels;
Hydrogen production, i.e. the conversion of ocean energy and seawater into hydrogen via electrolysis;
Sequestration of greenhouse gases: MIT identified former marine petroleum fields as the safest place to store greenhouse gases. There are successful CO2 sequestration operations on offshore oil and gas platforms in the Nordic Sea.
Marine aquaculture, e.g. of coral and sponges, oyster depuration, non-cage mariculture of ornamental fish, etc;
Creation of marine sanctuaries;
Recreational fishing and diving parks;
Culture of pharmaceutically valuable marine organisms.
It is true that Tubastrea colonize the structures. We are observing that the macro invertabrate community on offshore platforms changes over time. First a variety of mollusk and algea colonize the structure (year 1-5) then octocoral, algae, bryozoans, tunicates, (5-10) Tubastrea are one of the first hermatypic coral species to colonize the structures (year 8-12) later other coral colonize. Large sponges (year 8-15) We find other species of coral settling on areas above Tubastrea (year 15-20). Other conditions affect community composition: turbudity, salinity, temperature, type of corrosion control on structure, As you can imagine, there is a great variety of communities inhabiting the 3,800 structures across the continental shelf.
Best Regards, Steve Kolian 225-910-0304 cell
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