Buffer zones promoting oligotrophication in golf course runoffs: fiddler crabs as estuarine health indicators.

Nitrogen pollution above a threshold level induces a eutrophication process in coastal creek ecosystems and consequently impacts on the water quality. The remedy for this scenario is the introduction of methods to enhance oligotrophication by means of constructed wetlands and buffer zones. This paper discusses new data on nitrogen flux and population changes in the primary consumers in the Bradley Creek ecosystem, adjacent to the Duck Haven Golf Course in southeastern North Carolina. In 1998-99, over different seasons, density distribution of the field populations of the fiddler crab Uca minax, was monitored as an indicator of environmental health. A control site at Whiskey Creek, adjacent to the University Center for Marine Sciences, was monitored in the same period since this site is not influenced by any golf course nutrient flux. The results pointed out that threshold level for optimum population density in Spartina grandiflora salt marsh is 0.1 mg/L of nitrates. A dense crab population, adjacent to the golf course with a buffer zone, was indicative of restoration of the estuarine ecosystem. A model, involving the use of constructed wetlands for oligotrophication, is being prepared on the basis of studies conducted by the University of South Alabama for a stormwater wetland constructed adjacent to the university's golf course.

Oxygen and carbon isotopic growth record in a reef coral from the Florida keys and a deep-sea coral from blake plateau.

Carbon and oxygen isotope analysis through a 30-year (1944 to 1974) growth of Montastrea annularis from Hen and Chickens Reef (Florida Keys) shows a strong yearly variation in the abundances of both carbon-13 and oxygen-18 and a broad inverse relationship between the two isotopes. Normal annual dense bands are formed during the summer and are characterized by heavy carbon and light oxygen. "Stress bands" are formed during particularly severe winters and are characterized by heavy carbon and heavy oxygen. The isotopic effect of Zooxanthellae metabolism dominates the temperature effect on the oxygen-18/oxygen-16 ratio. The isotopic results on the deep-sea solitary coral Bathypsammia tintinnabulum, where Zooxanthellae are nonexistent, indicates that the abundance of the heavy isotopes carbon-13 and oxygen-18 is inversely related to the growth rate, with both carbon and oxygen approaching equilibrium values with increasing skeletal age.

Glycogen content in the wood boring isopod, Limnoria lignorum.

The glycogen content of the isopod, Limnoria lignorum, ranges from 2.01 to 3.44 percent of its dry weight. Starvation of the animal for I week results in a decrease of the glycogen content by about 68 percent. Measurements of its oxygen consumption indicate that sufficient carbohydrate, probably its sole source of energy, is oxidized daily to meet the carbon requirements. The infestation zone of Limnoria is restricted to the surface of submerged wood, since this isopod borer, unlike the molluscan borers, does not have a glycogen reserve sufficient to meet prolonged periods of anaerobiosis.