Water motion has wide-ranging effects on scleractinians, particularly during thermal bleaching when increased flow may aid in resistance to high temperature. Increased flow removes photosynthetically-derived oxygen radicals, causing greater efficiency of PSII and conferring resistance to bleaching. However, enhanced flow can have both positive and negative effects on coral photophysiology (light-adapted yield, QY). Modest increases in flow benefit QY, while larger increases can have detrimental effects, suggesting that there is a threshold effect in QY along a flow continuum.

Freshwater delivery is an important factor determining salinity in the LTER Georgia Coastal Ecosystem (GCE) site. Variability in freshwater delivery was examined in relation to various climate indices: the Southern Oscillation Index (SOI), the North Atlantic Oscillation (NAO) and the Bermuda High Index (BHI). Monthly standardized anomalies of river discharge and climate indices were compared with multi-decadal time series of Altamaha watershed precipitation at 7-13 stations using empirical orthogonal function (EOF) analysis to describe the precipitation patterns.

 The Southern Everglades mangrove ecotone is part of a highly oligotrophic, P-limited estuarine ecosystem. The wetland vegetation in this region is comprised mostly of dwarf red mangrove spanning the oligohaline zone between the freshwater marshes to the north and Florida Bay to the south. The hydrology of the region is wind and runoff-dominated with a small tidal component and is characterized by a strong seasonal pattern in rainfall and discharge from numerous creek systems.

The role abiotic factors play in structuring communities is one of the fundamental questions in ecology. At small spatial and temporal scales, abiotic conditions influence patterns of species movement and habitat use. At larger scales, abiotic factors affect patterns of species abundance and distribution. The structuring effect of abiotic conditions may be particularly important along ecotonal habitats. In the southwestern Everglades, mangrove-lined creeks link freshwater marshes to estuarine habitats.

Palmer LTER has as its focus the marine continental shelf and marginal sea ice zone ecosystems off the west coast of the Antarctic Peninsula. It is a marine pelagic and coastal site strongly influenced by the formation, extent, duration and retreat of sea ice. Over the past several decades sea ice duration has declined by 90 days and no longer persists into the summer period in our study region. At the same time, the mean wintertime (DJF) surface air temperature has increased by 6°C.