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Carpet sea anemones of the genus Palythoa are common inhabitants of reef crest environments in the Florida Keys reef tract. Through a unique assimilation mechanism, Palythoa spp. entomb carbonate sediment within their tissues. The amount of sediment assimilated is significant, averaging almost 45% of wet tissue weight. Palythoa spp. assimilate all available minerals on the reef. Aragonite, magnesium calcite, calcite and minor quantities of siliciclastic components are all assimilated in proportions comparable to their content in adjacent sediment sinks. There is also no preference in terms of skeletal composition; coral grit, coralline red algae, Halimeda and other allochems are all equally assimilated into Palythoa spp. tissue. The only preference is particle size. Sediment extracted from tissue samples is generally ?125 μm in size, far finer than ambient sediment found adjacent to Palythoa spp. colonies (predominantly >500 μm). Much of the finest sediment extracted from Palythoa spp. tissue is composed of elongated crystal aggregates of aragonite. These particles appear to have been produced in situ through biologically influenced mineralization. Aggregates nucleated on exogenous sediment and attained their elongated form as assimilation proceeded. When Palythoa spp. colonies die, the assimilated sediment and the crystal aggregates are released back into the reef environment. The eventual fate of this material has yet to be determined.

This project was undertaken as the initial monitoring program to determine if mosquito adulticides applied along the Florida Keys cause adverse ecological effects in the Florida Keys National Marine Sanctuary (FKNMS). The study monitored the distribution and persistence of two mosquito adulticides, permethrin and dibrom (naled), during three separate routine applications by the Florida Keys Mosquito Control District. The approach was to determine if toxic concentrations of the pesticides entered the FKNMS by aerial drift or tidal transport. The amount of pesticide entering the FKNMS by way of aerial drift was monitored by collection on glass fiber filter pads, set on floats in a grid pattern on either side of the FKNMS. Permethrin was recovered from filter pads on the leeward side for each of the three applications, ranging from 0.5 to 50.1 microg/m(2) throughout the study. Tidal current transport was monitored by collection of surface and subsurface water samples at each grid site. Tidal transport of naled and dichlorvos (naled degradation product) was apparent in the adjacent waters of the FKNMS. These compounds were detected in subsurface, offshore water at 0.1 to 0.6 microg/1, 14 hr after application. Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 microg/l were found in surface water from the canal system adjacent to the application route. Comparison of the observed environmental concentrations with toxicity data (permethrin LC-50, 96 hr for Mysidopsis bahia = 0.02 microg/l) indicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas.

Alfalfa mosaic virus (AMV) infects soybean [Glycine max (L.) Merr.] causing mosaic or mottle patterns on leaves. Resistance to AMV has been identified in soybean, but no AMV resistance genes have been mapped or assigned gene symbols. The objective of this research was to study the genetic basis of resistance to AMV from plant introduction (PI) 153282. This resistance was studied in a population of F 4:7 lines developed from a cross between this PI and the susceptible cultivar Syngenta (NK) S19-90. Results from the F 4:7 population were confirmed in F 2 and F 2:3 populations developed by crossing the same parents. A major AMV resistance gene was mapped as a quantitative trait locus (QTL) near the simple sequence repeat marker Sat_226 in the F 4:7 population. For this QTL, the resistance allele was from PI 153282, the LOD score was 45.5, and the QTL explained 79% of the genotypic variation for resistance in the population. The identification of an AMV resistance gene near Sat_228 was confirmed in the F 2 and F 2:3 populations and the resistance gene showed complete dominance in the F 2 population. This AMV resistance gene identified from PI 153282 is named Rav1 and it should be useful in breeding for resistance to this virus.