ABOVE: Microscopy was used to identify some of the organisms growing on the Thesis.

Sessile life forms, which are fixed in place on the wrecksite, are more likely to reflect chemical and physical conditions at that location, than free swimming organisms. This greatly simplifies the problem of evaluating the distribution of life on a site.

The Thesis was roughly surveyed by swimming up the port and starboard sides. The percentage coverage of the structure with organisms was noted at a series of representative locations. The analysis was refined by noting the species composition at these locations. On the Thesis there are two predominant groups of sessile organisms - dead mens fingers and sea firs, with locally important populations of tunicates and tube worms. Sea weeds are a minor part of the species mix on the wreck site. The notes made underwater were refined by review of video footage of the same areas.

The data is displayed in the FLASH animation above as a series of grids, coloured squares witin these indicates the proportion of the surface covered by a different classes of animals.

More refined studies were carried out by taking small samples of organisms from different areas on the ship. These were subject to microscopic analysis which showed that an extremely diverse group of species of sea firs are present on the site.