Seagrass canopy height reduction influences invertebrate habitat choice

Seagrasses provide habitat for feeding and spawning for many invertebrates, and act as a refuge from predators. This study documented the changes in invertebrate abundance in response to the trimming of seagrass blades to half height in Thalassia testudinum patches in Santa Rosa Sound, Pensacola Beach, Florida, USA. Short-seagrass plots had a reduced abundance when compared to untrimmed plots. Bittiolum varium (gastropod) and Hippolyte sp. (caridean shrimp) had the highest abundances, while Tozeuma carolinense (caridean shrimp) and polychaetes had the lowest abundances. In the laboratory, Hippolyte and Penaeus shrimps were placed in a mesocosm containing artificial seagrass to explore habitat choice based on seagrass length (long, short, or bare sand). Whether in mixed genera or solo groups, the overwhelming choice for both genera was long seagrass with no indication of agonistic interactions between the genera.