looking for technical advice

[halicoryne]

Hello, everyone. I am a Marine Bilogy graduate student here in the Philippines and currently I am working on my special project about molllusks in mangoves. I am at a loss on how to compute for the density of mollusks attached or dwelling on the mangrove tree itself (the arboreal kind like Littorina). I have cited Sasekumar's method of caibrating every part of the mangrove tree but I dont know how to solve for the density since I did not employ the quadrat but I sampled one kind of tree in the 10m x 10m transect plot. Can anyone assist me with how to compute for the density?

[KristianT]

Hi there. I think the first thing you need to quantify, or at least take into account, is the tidal range. Are you looking strictly at terrestrial Littorina, or can they be covered by the tidal range. I would also look for similar patterns of mollusk habitat...i.e. lower branches, upper or entire tree? But looking for these patterns it might be easier to estimate total 'range' and therefore density.

I did something similiar for echinoderms - the difficulty lies in not necessarily measuring the total surface area of the tree, but rather the surface area that is colonized.