Using biopolymers to remove heavy metals from soil and water

Chemical remediation of soil may involve the use of harsh chemicals that generate waste streams, which may adversely affect the soil's integrity and ability to support vegetation. This article reviews the potential use of benign reagents, such as biopolymers, to extract heavy metals. The biopolymers discussed are chitin and chitosan, modified starch, cellulose, and polymer-containing algae.     

Abwasserreinigung Ökologische,technische und ökonomische Aspekte

In order to conserve our waters and water reserves, waste water must be purified before being discharged. Due to the differences in the composition of household and industrial waste, additional physical and chemical purification processes may be required as well as the normal biological purification. Variations in legislation in different countries, the high cost of the necessary technical plant expenditures and continually increasing operating costs make the building and operating of waste-water treatment plants extremely problematic.     

Ecological studies of the coral predator Acanthaster planci in the south pacific

Ecological surveys involving over 500 man-days between 1966 and 1969 indicate that the coral-eating sea star, Acanthaster planci, is a normal component of the coral reef community throughout the tropical Pacific, and that its abundance in the past has probably been underestimated. The sea star is not uncommon in certain environments, particularly back-reef and lagoon slopes. Sheltered, inner reefs are generally preferred over less protected reefs. Recently reported population explosions of A. planci at Guam and on the Great Barrier Reef of Australia appear to be isolated, widely-separated, local infestations of unknown cause. The infestation on the Great Barrier Reef has not spread beyond the area off Cairns and Innisfail. Approximately 40 of the more than 1000 reefs comprising the Great Barrier Reef complex have been infested heavily.     

Coral genera of New Caledonia

Although New Caledonia is surrounded by one of the 3 largest coral reef systems of the world, the published generic records indicate abnormally low coral diversity. Exploration of the reefs in the south-eastern part of the island, largely by means of SCUBA, has yielded specimens which increase the known genera and sub-genera by 50%. New Caledonia now ranks sixth among the coral provinces of the world, with at least 53 genera and sub-genera of reef-building corals. Many of the new records were made in a type of coral environment unlike any previously described. Comparison of the New Caledonia fauna with those of Fiji, the Grett Barrier Reef of Australia, and the Ryukyu Islands reaffirms the remarkable homogeneity of the Indo-Pacific coral faunas.     

The use of genetic markers to estimate the frequency of successful alternative reproductive tactics

Summary This paper outlines a method for estimating rates of successful alternative reproductive tactics from parental exclusions known through the use of genetic markers. We review a method for calculating the probability of excluding a putative father when he is not the actual father. We adapt this method to model two mating tactics of concern to sociobiologists: extrapair copulations (EPCs) and intra-specific egg parasitism (egg-dumping). Four different types of parental exclusions are possible (both male and female, male only, female only, and ambiguous). The two models predict different proportions of each type of exclusion. Models are also generated for the case when the putative mother's or father's genotypes are not available.We used parental exclusions from an electrophoretic study of indigo buntings (Westneat 1987b) to demonstrate these methods. The distribution of parental exclusions in the buntings departed significantly from the predictions of the egg-dumping model, but agreed well with those of the EPC model. The probability of detection for the EPC model (0.401) was then used to estimate the actual rate of extra-pair fertilizations (0.421 of all the young sampled). We present a method for calculating a confidence interval on this estimate, which ranged from 0.247 to 0.659. We concluded that these methods will allow the quantitative study of the success of alternative reproductive tactics in a wide variety of species.