Digital library

A PDF Power Point of "Value Added Co-product from Jatropha Biodiesel Production Process".

In the tropics, algal turfs are a key marine community, floristically and ecologically, yet the turf structure and its spatial and temporal variation have seldom been quantitatively assessed. We compared species composition and abundance of turf algae on two shallow subtidal reefs (< 2 m deep) on the island of Hawai‘i from September 2000 to July 2002. Of the 102 species of marine algae identified in the algal turf community, 17 belonged to the Chlorophyta, 9 to the Phaeophyta, and 76 to the Rhodophyta. Red algae dominated the turfs at both sites. Species richness, species diversity, and evenness varied between sites and among sampling dates, perhaps due to differences in substratum, precipitation and wave exposure. The most abundant turf species (Ceramium macilentum J. Agardh, Pterocladiella caerulescens (Kützing) Santelices et Hommersand, Hypnea spinella (C. Agardh) Kützing, Coelothrix irregularis (Harvey) Børgesen, Amansia glomerata C. Agardh and Laurencia brachyclados Pilger) showed very patchy spatial distributions and variable seasonal abundances. 38 new records for the island of Hawai‘i were documented, many of which were common. Although growth form rather than dominant or diagnostic species defines the algal turf community, identification and monitoring of individual species, which have different reproductive and physiological characteristics, are essential to understanding the ecology of the turf.

In what could be the first step toward a new aquaculture sector in Florida, researchers at Florida Atlamtic University (FAU) have succeeded in growing nutritious sea vegetables using aquaculture while minimizing waste and maximizing efficiency and productivity. 

We examined water column temperature time series profiles for several years at two locations in a single kelp (Macrocystis pyrifera) forest to characterize the alongshore variability of the nutrient climate that giant kelp is exposed to and compare it to the response of giant kelp. The differences in nutrient climate are due to differential alongshore vertical variations in temperature, a well-established proxy of nitrate, due to the topographically induced internal wave dynamics within the kelp forest. We observed the greatest temperature variability during summer and most of this variability occurred near the surface. The 14.5 C isotherm, indicating the presence of nitrate, ranged the entire vertical extent of the water column, and was shallowest during the winter and in the southern portion of the kelp forest. Predicted water column integrated nitrate varies from 0 mmol NO3 /m2 to 431 mmol NO3 /m2 yielding a time series daily average of 0.12 gN/m2 day (North La Jolla) and 0.18 gN/m2 day (South La Jolla). Redfield conversion of these values puts the time series daily average for carbon production (upper limit) between 0.8 and 1.2 gC/m2 day for the north and south parts of the bed respectively, and shows considerable variation at several time scales. Giant kelp in the southern portion of the forest exhibited greater stipe densities (a proxy for kelp production) than individuals in the northern portion, corresponding with the alongshore nutrient climate variability. The depth of the nutricline varied by up to 10 m over time scales as short as hours. Variability was greatest at diurnal and semi-diurnal frequencies, with shallower water column depths showing greatest variability. These depth-specific variations in temperature and nutrient exposure may have biologically important consequences for M. pyrifera especially during low nutrient seasons.