No abstract

A bloom of the macroalga Cladophora prolifera (Chlorophyta, Cladophorales) has recently been reported in Bermuda. The present study summarizes results of experiments conducted in June, 1977, designed to measure rates of primary production and to determine biological, physical and chemical factors controlling the rapid spread of the plant. Productivity was measured using three different methods: 14 C uptake, growth and biomass accumulation. Production values for the alga as estimated by these three methods were 3.1, 2.7 and 0,7 gC/m 2 /day, respectively. Production in June, 1977 was identical to that in December, 1976. Growth of the alga appears to be controlled largely by light intensity and nutrient availability. It is also likely that C prolifera is responding to elevated levels of nutrients in Bermudas' inshore waters. The possible roles of nutrient availability, algal morphology and natural selection in structuring marine benthic macroalgal communities are discussed,

Few studies have been reported of the effects of power-plant discharges on tropical and semi-tropical marine environments where plants and animals in non-stressed conditions live close to their upper lethal thermal limits. This paper describes a multidisciplinary three-years' study made in Card Sound, Florida, before, during, and after, thermal effluents were released from a power-plant. Biomass, growth, and production, of Thalassia and macroalgae, were estimated. Animals were collected by trawl, drop-net, suction dredge, in artifical habitats, and on mesh-panels. Except in an area of 2–3 ha adjacent to the canal mouth, little damage to the benthic community was observed. This was very different from the effect of the first canal emanating from the same power-plant at Turkey Point, where a large area had been affected by heated effluents.