These habitats were selected to be very different in order to maximize the probability of finding relationships between benthos and sediment, especially for comparisons among habitats. The habitats appeared to be consistently different among three bays and bays were all within a few km in the same estuary, allowing tests of generality of any patterns found. The sediment and benthos differ among habitats, possibly both in response to structures on the surface of the substratum
and shading (Tolhurst and Chapman, in review)