More turtle grass

To: aquatic-plants at actwin_com
Subject: More turtle grass
From: mark.fisher at tpwd_state.tx.us
Date: Tue, 11 Feb 97 09:25:45 cst

     As far as I know, the only successful transplantings of turtle grass 
     occured using a plug technique.  This minimizes root trauma, but on 
     the negative side it makes turtle grass hard to collect intact, and 
     forces you to move large amounts of sediment.  It also creates a large 
     disturbance at the collection site.
     
     Other species (Halodule and Zostera) have been successfully 
     transplanted using bare shoots, but these are pioneer species, while 
     Thalassia is a climax species.
     
     I may be wrong, but I think Thalassia REQUIRES an anaerobic substrate, 
     which may explain why only the plug technique works, and also why 
     turtle grass grows poorly in disturbed sediments.  I have personally 
     measured 1.7 mM H2S within 5 cm of the sediment surface in healthy 
     Thalassia beds.
     
     One of my references reports 10 months until new shoots are observed 
     in transplanted Thalassia.  Also, cuts from boat propellers in shallow 
     turtle grass beds can take up to five years to recolonize.
     
     Thalassia may not be a good choice for aquarium cultivation, but the 
     other species may work.