Measuring volume insitu

[Nicola Diane Chapman]

Hello,
I am studying the growth of local serpulid reefs in situ
 using photgrammetric methods.However I wish to measure an 
increase in volume as well as height.Image proplus and 
Optimas software packages can be used for increases in 
height once the photograph is placed on C.D.However I was 
wondering whether anyone knows of a software package to 
measure  INCREASES IN VOLUME. A comparative coral to these 
reefs would morphologically be acropora. 

If anyone can point me ina suitable direction I would be 
very grateful.

Thanks very much,
Nikki
--
Nicola Diane Chapman
Heriot-Watt University