1) Methodological Comparisons Invertebrate Surveys at A Santa Ynez Platform
This task will endeavor to answer the following questions:
Question 1. What invertebrates live on the 30 and 80-foot platform crossbeams?
Question 2. Do the assemblages vary between these two depths? Do they vary with platform side? Are assemblages inside the platform different from those on the outside?
Question 3. How do species richness and density estimates compare between two survey tools, scuba and ROV?
- UCSB will conduct an invertebrate survey on the platform horizontal crossbeams with UCSB AAUS-certified scuba divers. Scuba divers will use a still camera with lights to document the invertebrate assemblage.
- UCSB will adhere to all ExxonMobil safety requirements.
- ExxonMobil Upstream Research Company (EMURC) will facilitate an invertebrate survey at the platform with a ROV. The ROV will collect footage of invertebrate assemblages with a video system.
- UCSB marine biologists will provide recommendations on ROV flight path, data collection strategy appropriate for an invertebrate survey at a vertical offshore infrastructure and provide real-time guidance to the ROV operator during the ROV survey duration. Surveys will attempt to capture the platform base and platform crossbeams.
- In both diver and light-weight ROV surveys, still images and footage from the outer margins of these structures (those facing away from the platform), the in margins (facing into the platform) and all sides of the platform are collected to determine if crossbeam orientation affects assemblages.
- In the laboratory, the still images from the scuba survey and the video imagery from the ROV survey will be analyzed and organisms greater than 5 cm in size will be identified to lowest taxon, their size estimated, and their density assessed to compare estimates of invertebrate species densities and diversity using the two methods.