Amphipods and Mangrove Prop Roots by Megan and Danica

The amphipod Gammaridae resides in turf algae that covers the prop roots of the red mangrove tree (Rhizofora mangle) in Discovery Bay, Jamaica. Benthic and pelagic organisms prey upon amphipods and their algal habitat. This study focused on benthic predation related to whether the prop root touched the ground or did not touch the ground. If the root touched the ground it would allow greater benthic predation and lead to a smaller amphipod abundance in the root algae. The algae was collected in a 15cm section off of the root. Equal amounts of roots touching and not touching were sampled. The amphipods were counted and the algal biomass was measured. There was no difference in the amount of amphipods per area of algal coverage on the root. However, amphipod abundance was higher per gram of algae on the prop roots that were not touching the ground versus those that were. There was also less algal on the prop roots that were touching the ground compared to those that were. Benthic herbivorous predation on the amphipod habitat as well as predation by omnivorous crabs and shrimp on the amphipods led to less amphipods per gram of algae in prop roots that touched the ground.  

Megan (l) and Danica (r) counting amphipods.