Characterization of Algal-Invertebrate Mats at CMI Study Platforms: Developing Survey Design and Quality Assurance for Artificial Substrate Studies

Algal-invertebrate mats are communities of epibiota and biofouling organisms that are sessile and mobile and dwell on hard substrate. In the Gulf of Mexico, oil and gas platforms introduce hard substrate into a region dominated by soft bottoms. This artificial substrate is considered to be a largely new and distinct habitat with an estimated 4,000 hectares of new habitat created. This work will lead toward a functional understanding of the ecology associated with OCS structures. Ultimately, management decisions must be based upon a full understanding of what processes link platforms with the surrounding natural ecosystem. Trophodynamically, offshore platforms have not been studied in terms of rates and routes of production. Aside from organic discharges, OCS structures alone add neither food nor nutrients to the marine environment. Their biofouling community, however, may be very efficient, relative to plankton, in stripping both nutrients and suspended material from passing water and building a high standing stock community.

The objectives of this effort include describing the invertebrate-algal communities at three oil platforms currently being investigated under other CMI studies and developing a more cost-effective and scientifically rigorous means of surveying fouling communities that will be suitable for wider-area, longer-time studies, and be capable of supporting hypothesis testing.