Preliminary evidence on the interdependent effect of currents and porewater geochemistry on Thalassia testudinum Banks ex Konig seedlings

Currents and the chemistry of the porewater may have acted interdependently on the growth and development of Thalassia testudinum seedlings planted in sandy sediments and exposed to stagnant, medium and high current velocitie s under laboratory-controlled conditions. The most favorable growth conditi ons (identified by the highest biomass, largest blade area) tended to occur at the intermediate flow rates. Stagnant and high flows may have contribut ed to lower biomass through increased sulfide levels and reduced nutrient c oncentrations in the porewater, respectively. These preliminary data sugges t that co-varying porewater chemistry may have to be taken into considerati on when studying the effect of currents on seagrasses. (C) 1999 Elsevier Sc ience B.V. All rights reserved.