Submerged and emergent plants (those below and partially above the waterline) benefit the water quality and biological conditions in the North Fork St. Lucie River (SLR). Aquatic vegetation can reduce shoreline erosion and turbidity by slowing the water down enough to facilitate settlement of suspended sediments. of the settling of these sediments supplies the plants with nutrients needed for growth and improves the water clarity which allows more sunlight, needed for growth, to penetrate the water column. Aquatic plants also provide spawning and nursery habitat for fish and invertebrates.

Resource managers have documented seagrass dynamics in the SLR since the 1940s but little is known about the location, abundance and species of other submerged and emergent vegetation in the North Fork SLR. The following things are known:

• Widgeon grass and shoal grass were once present within the southern portion of the preserve.
• Seagrass was last observed within the preserve in March 2002.

It is expected that the completion of future restoration efforts will promote recolonization and establishment of submerged aquatic vegetation (SAV) in the North Fork SLR.

Emergent vegetation has not been mapped within the preserve. Although mapping all submerged and emergent vegetation within the preserve is a priority, panic grass and smartweed in the upper reaches of the North Fork SLR are especially important because they provide spawning habitat for the opossum pipefish, a federally-listed Species of Special Concern. Locating and mapping these grasses will improve the ability of preserve and regulatory staff to protect opossum pipefish and their habitat when reviewing environmental resource permits within North Fork SLR.

As strategies are implemented to improve the water quality in the preserve, the abundance and health of submerged vegetation is expected to increase. Preserve staff will assist South Florida Water Management District with future North Fork SLR monitoring efforts and seek funding to map emergent vegetation.