Saved by the shell: Oyster reefs can shield juvenile blue crabs Callinectes sapidus

Juvenile blue crabs Callinectes sapidus use seagrass and other structured habitats as refuges from predation. Oyster reef provide structural complexity that may offer refuge, but the value of these for juvenile has not been examined. We quantified survival C. in oyster habitat versus unstructured soft-bottom habitat. In a field tethering experiment York River, lower Chesapeake Bay (USA), (10-50 mm carapace width [CW]) were tethered sand (n = 40) or 39) at subtidal sites 1-2 m deep. An underwater camera system was used to record predation activity during 24 h trials. crab significantly higher on (53.8%) than bare (15.0%), tended increase with CW both habitats. The main successful predators northern pufferfish Sphoeroides maculatus adult high rate suggests reefs include physical refuge predators. Restored natural could an alternative nursery crabs, expanding ecosystem services provided by restored reefs.