Restoring value to wetlands by applying nekton-based measures of habitat quality and restoration success

Historically, the success of habitat restoration has been gauged using estimates of presence/absence and relative abundance. However, habitat quality measures based on relative abundance can be problematic and may provide a misleading indication of success. Metrics based on the biological condition of an organism may more accurately reflect habitat value in terms of foraging success or reproductive potential. To compare restoration success using structural versus functional measures, the densities of two species of resident nekton were compared to two types of mangrove habitat: tidal creek and mosquito-ditched wetland. Sailfin mollies (Poecilia latipinna) did not differ in their abundances between habitats (RMANOVA, p>0.05) suggesting no difference in habitat quality between creek and ditches. Conversely, grass shrimp (Palaemonetes spp.) were more than twice as abundant in the creek (p=0.004) compared to the ditches, suggesting mosquito ditches are better habitat for grass shrimp. Functional data from a small pilot study suggest that reproductive potential is similar between habitats for both species, thus contradicting the measure of habitat quality derived from grass shrimp abundance data. Results of this ongoing study highlight the differences among three nekton-based metrics of habitat quality and emphasize the need for careful selection of metrics for restoration assessment.