Aquatic Vegetation Survey

September 21–22, 2022

Two people in wetsuits are in the water, one raising their arm, while a person on the boat leans over to assist — Photo: Force Blue

In September 2022, a team of Force Blue Special Operations veterans volunteered to conduct an initial survey of the submerged aquatic vegetation (SAV) in Mallows Bay-Potomac River National Marine Sanctuary. The sanctuary, along with Maryland Department of Natural Resources and other partners, are interested in understanding if SAV abundance within and around the sanctuary is increasing, decreasing, or staying the same. They had conducted aerial imagery that provided detail about the density of the vegetation, but in order to understand which species are found throughout these areas, it was necessary to put divers in the water.

How Is This Data Useful?

A diver is partially submerged in a body of water covered with aquatic vegetation. — The Force Blue team conducted an initial survey of the submerged aquatic vegetation (SAV) in Mallows Bay-Potomac River National Marine Sanctuary. Photo: Force Blue

A woman wearing a life vest holds a handful of aquatic vegetation while on a boat — Brooke Landry, a biologist from Maryland DNR, identifies the species of a specimen of vegetation a Force Blue volunteer found during their survey. Photo: Force Blue

Healthy and dense underwater grasses, also called submerged aquatic vegetation (SAV), act as water purifiers and provide a safe haven, vital food source, and oxygen for blue crabs, young fish, and other ecologically critical bay species. SAV is also an excellent indicator of water quality, responding sensitively to environmental shifts caused by pollution or climate change. The more species that are present in a vegetation bed, the more biologically diverse it is–which typically equates to a healthier ecosystem. The data that the Force Blue Special Operations veterans collected provides much needed information for the sanctuary co-managers on the various species and the health of the sanctuary. Such a comprehensive dataset is a critical component of understanding the relationship between the region's ecology and the sanctuary's maritime heritage resources, which are protected under the National Marine Sanctuaries Act.