Distribution of the cyanophyte Trichodesmium (Oscillatoriaceae) in the eastern Caribbean Sea: influence of the Orinoco River

Orinoco River influence in the Caribbean Sea, characterized by high nutrient input, causes a decrease of Trichodesmium populations. The Caribbean Time Series (CaTS) station, south of Puerto Rico (17 degrees 36'N 67 degrees 00'W), was monitored for 25 months in order to observe the Trichodesmium abundance pattern and the presence of the river plume. In general, mean Trichodesmium abundance was higher at the surface and decreased with depth. The mean upper water column (surface to 20 m) abundance was 54.1 +/- 32.6 col/m3. Within the sampling period, abundance was highly variable (1-700 col/m3). Correlation between Trichodesmium abundance and wind speed (p=0.002), chlorophyll a concentration (p=0.001), nitrate (p=0.02) and silicate (p=0.003) concentrations were statistically significant. However, Trichodesmium abundance was not correlated with salinity (p=0.70), temperature (p=0.16) and seawater density (p=0.71) variations at CaTS. Eastern Caribbean regions highly influenced by the Orinoco River discharge were devoid of Trichodesmium colonies.

Epidemiological trends of melanoma in Puerto Rico from 1975-1991

The purpose of this study was to determine the crude and age-adjusted incidence rates of melanoma for residents of Puerto Rico from 1975 to 1991. This is part of an ongoing NASA study aimed at estimating whether melanoma and cataracts have increased in Puerto Rico since 1978 because of potential stratospheric ozone depletion and increased ultraviolet-B (UV-B) radiation. Calculating the percent change from their lowest values in 1978 to 1991, the age-adjusted incidence rate of melanoma increased 528% for males and 200% for females in 13 years