In response to a report of an oyster die-off from a concerned citizen, GTM NERR biologists re-assessed four oyster reefs in Robinson Creek- a tributary of the Tolomato River- that were previously monitored in 2015-16 under the GTM NERR Oyster Monitoring project. Monitoring results indicated that there was little change observed on the reefs between sampling periods except in the form of increased sedimentation. Despite this, there were visual observations of reef erosion and large shell deposits in the lower portions of the creek and in front of mangroves. These observations were also noted in other areas of the Tolomato and Guana River estuaries. This may suggest these alterations are due to physical changes in the environment (e.g., altered hydrology, increasing mangroves) and possibly long-term post-hurricane effects. Continued monitoring is planned to assess any further loss, change, and/or recovery of oyster reefs in the GTM NERR.