A SALT MARSH ECOSYSTEM ALONG A NUTRIENT GRADIENT: TRENDS AND COUNTER-TRENDS IN NUTRIENT EFFECTS

We will discuss some effects along a steep regional nutrient gradient in the New York State coastal marine district that exceeds 4 orders of magnitude. Our most detailed work on salt marshes is within the Hempstead Bay at the western end of the South Shore Estuary lagoon, where time trends in overall marsh loss over an 87 year interval will be compared to current conditions and trends in local nutrient conditions over the past 37 years. These detailed views will be compared to recent and historic results in high nutrient estuaries to the west and low nutrient estuaries to the east to look at the current state of marsh degradation and panne formation. These marshes tend to contain organic material, but some high nutrient locations still seem to have high sedimentation rates while others are loosing to sea-level rise, however lower nutrient locations are loosing vegetation to panne expansion. Some trade-offs between apparently negative observed marsh morphology and long term survival in a rising sea will be discussed. Recent spatial trends and some temporal trends in marsh dwelling birds, along with the implication for the persistence of their prey species and valuable wildlife species within the estuary are also explored.