There is lots to cover about Barnegat Bay. First we should mention the need to understand how fragile the bay environment is and how many threats it faces. You can go to Save Barnegat Bay to find out more about all of that.
There are three kinds of grasses that dominate, or should dominate, the bottom of the bay.
Eelgrass - The most important organism for a healthy bay.
In the more northernly sections of Barnegat Bay, above the Route 37 bridge that connects Toms River to Seaside Heights, there are some other common grasses. Both of the following are important food resources for ducks and other waterfowl.
Here is an interesting resource about seagrass and what they provide for us around the world.