Wetlands

The Town of Hempstead has approximately 20,000 acres of salt marshes within its boundaries. These marshes provide nesting and feeding habitats for animals such as Diamondback Terrapins, Saltmarsh Sparrows and Black Skimmers, and also protect local communities from wave action and coastal flooding. However, these vital habitats are eroding both at their edges and internally, where ponds form. There are multiple projects going on at the Town to monitor the condition of these marshes and to either protect or restore them.

Monitoring marsh loss is a priority for this department. How much of the marshes have disappeared over time can be tracked by using aerial imagery taken over the past few decades. Pond area and marsh edges can be traced in a Geographic Information System (GIS) software program, which allows for the area of marshes to be calculated over time. This then provides an idea of how much marsh is being lost between years, and which marshes are most at risk. This allows the Town to plan for any potential restoration projects for these at risk marshes. 

The Town is also monitoring how much time the marshes spend underwater.  Specialized waterproof loggers have been placed on several marsh islands to better understand how marsh inundation is changing over time. These loggers use pressure sensors to record when and  how long the marsh is covered by water. By comparing logger data to historical tide data, changes in the flooding patterns of the marsh can be calculated. If marshes are spending more time underwater, this puts foraging and nesting habitat at risk for a variety of wildlife species.

The Town is also working on restoring salt marshes. This will be done using a method called thin layer sediment deposition. Sediment will be sourced from boat channels that need to be dredged. This sediment eroded from marshes originally before filling in the boat channels. It will then be used to fill ponds that are forming on marshes, which should prevent them from eroding further. Once these ponds have been filled, marsh grasses can tap additional sediment on their own, but plantings will also be done to encourage growth of these grasses. This will help restore nesting habitat for local bird species.