Dense monocultures of the grass Spartina alterniflora dominate low marsh in typical New England tidal marshes. These marshes provide a number important ecosystem services; thus, it is to understand factors that influence S. productivity. End season live biomass often used estimate productivity, but this measure fails account for stems lost within growing and may lead significant underestimate. ...

Twenty-eight tidal creeks along the South Carolina coast were sampled during the summer of 1995 to determine the levels of sediment contamination including organic chemicals (i.e., polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], and DDT and its metabolites) associated with different types and varying levels of watershed development (i.e., industrial/urban, suburban, f...

The ability of oysters to remove large quantities of particulates from the water column, thereby potentially improving water quality, has been cited as one of the reasons for oyster reef restoration. However, this ability has not yet been effectively demonstrated in the field. As part of the Alabama Oyster Reef Restoration Project, this study was designed to assess impacts of restored eastern o...

Mangroves grow in the intertidal parts of sheltered tropical coastlines, facilitating coastal stabilization and wave attenuation. Mangroves are widely threatened nowadays, although past studies have indicated their contribution to coastal safety. Most of these studies were based on numerical modeling however and a proper database with field observations is lacking yet. This paper presents part ...

Pyrethroid pesticides have replaced organophosphates for many urban applications, including structural pest control, landscape maintenance, and residential home and garden use. This study was intended to determine if pyrethroids are detectable and widespread in diverse urban systems and if concentrations are high enough to cause associated aquatic toxicity. Urban creeks in California and Tennes...

Trace metals (TMs) are still a serious problem in urban streams because of their toxicity and continuing significant levels in the aquatic environment, especially in bed sediments. Concentrations of Cd, Cr, Cu, Ni, Pb and Zn were monitored in the sediments of several small streams in the Prague area. These streams differ in the main source of pollution (combined sewer overflow CSO, storm water ...

A statewide investigation of urban creek sediment toxicity was conducted in California in recognition of increased incidences of toxicity linked to pyrethroid pesticides. The goals were to examine the spatial occurrence and magnitude of sediment toxicity in California urban creeks, and to examine the role of pyrethroids in toxic urban creek sediment samples. After a preliminary screening of 90 ...

Using a new dataset on household purchases of personal computers (PCs), we document positive correlations between buyers’ incomes and the prices they pay for seemingly identical PCs. These results suggest that firms may be successful at separating the market and charging different prices to consumers with different levels of willingness to pay. We consider the implications of this kind of marke...

Within the framework proposed by Mussa and Rosen (1978) for modelling quality differentiation, we allow consumers to buy simultaneously different variants of the same indivisible good. We call this the ”joint purchase option”. We show that this option dramatically affects price competition: while a unique equilibrium always prevails when consumers are assumed to make mutually exclusive purchase...