GROWTH-RESPONSE OF THE SEAGRASS CYMODOCEA-NODOSA TO EXPERIMENTAL BURIAL AND EROSION

The response of Cymodocea nodosa (Ucria) Aschers. seedlings to experim ental burial and erosion was examined to test the extent of coupling b etween fluctuations in sediment depth and seagrass growth. Shoot survi vorship declined with erosion and with increasing burial depth, relati ve to the controls. Seagrass growth response, described by changes in internodal and leaf sheath length, the rate of appearance of new leave s, and shoot vertical growth showed a bell-shaped response to fluctuat ions in sediment depth. Shoot internodal and leaf sheath length, the r ate of appearance of new leaves, and vertical growth all increased wit h sediment depth from minimal values under erosion to maximal values a t burial of <7 cm. These results demonstrate that C. nodosa seedlings tolerate burial <7 cm, and that burial stimulates the growth of surviv ing seedlings. Examination of this growth response for C. nodosa and o ther seagrass species, which allows quantification of tolerable change s in sediment depth, may provide useful information for conservation o f seagrass populations.