Genetic Diversity of Lepilemur mustelinus ruficaudatus, a Nocturnal Lemur of Madagascar

The genetic polymorphism of natural populations of Lepilemur mustelinus ruficaudatus was studied by protein electrophoresis. We sampled blood from 72 individuals from four populations separated by geographic or anthropogenic barriers from southwestern Madagascar. Six out of 22 enzyme loci showed genetic variation with a degree of polymorphism of 0.273. The expected and observed degree of genetic heterozygosity over all loci is similar to that of other primates (H_e = 0.058, H_o = 0.036). The F-statistics revealed that the four subpopulations were similar with respect to gene structure (F_ST = 0.065, p = 0.016), but the genotypic structures within subpopulations were inconsistent with random mating. For the total of the four subpopulations the proportion of heterozygous individuals was significantly smaller than expected under random mating (F_IS = 0.373, F_IT = 0.414, p < 0.01). These results correspond closely to what is expected considering the low migration ability of individuals of L. m ruficaudatus leading to small and rather isolated inbred populations.     

Information system for monitoring environmental impacts of genetically modified organisms

Background, aim and scope  

European legislation stipulates that genetically modified organisms (GMO) have to be monitored to identify potential adverse environmental effects. A wealth of different types of monitoring data from various sources including existing environmental monitoring programmes is expected to accumulate. This requires an information system to efficiently structure, process and evaluate the monitoring data.     

Temporal and spatial infection dynamics indicate recognition events in the early hours of a dinoflagellate/coral symbiosis

The obligate symbiotic relationship between dinoflagellates, Symbiodinium spp. and reef building corals is re-established each host generation. The solitary coral Fungia scutaria Lamarck 1801 harbors a single algal strain, Symbiodinium ITS2 type C1f (homologous strain) during adulthood. Previous studies have shown that distinct algal ITS2 types in clade C correlate with F. scutaria—Symbiodinium specificity during the onset of symbiosis in the larval stage. The present study examined the early specificity events in the onset of symbiosis between F. scutaria larvae and Symbiodinium spp., by looking at the temporal and spatial infection dynamics of larvae challenged with different symbiont types. The results show that specificity at the onset of symbiosis was mediated by recognition events during the initial symbiont—host physical contact before phagocytosis, and by subsequent cellular events after the symbionts were incorporated into host cells. Moreover, homologous and heterologous Symbiodinium sp. strains did not exhibit the same pattern of localization within larvae. When larvae were infected with homologous symbionts (C1f), ~70% of the total acquired algae were found in the equatorial area of the larvae, between the oral and aboral ends, 21 h after inoculation. In contrast, no spatial difference in algal localization was observed in larvae infected with heterologous symbionts. This result provides evidence of functional differences among gastrodermal cells, during development of the larvae. The cells in the larval equator function as nutritive phagocytes, and also appear to function as a region of enhanced symbiont acquisition in F. scutaria.     

Three party symbiosis: acoelomorph worms,corals and unicellular algal symbionts in Eilat (Red Sea)

Epizoic worms were found to occur on certain coral colonies from reefs off the coast of Eilat (Red Sea). We identified 14 coral species infested by acoelomorph worms at a depth range of 2–50 m. The host corals were all zooxanthellate and included both massive and branching stony corals and a soft coral. Worms from all hosts were identified as belonging to the genus Waminoa and contained two distinct algal symbionts differing in size. The smaller one was identified as Symbiodinium sp. and the larger one is presumed to belong to the genus Amphidinium. Worm-infested colonies of the soft coral, Stereonephthya cundabiluensis, lacked a mucus layer and exhibited distinct cell microvilli, a phenotype not present in colonies lacking Waminoa sp. In most cases, both cnidarian and Acoelomorph hosts displayed high specificity for genetically distinctive Symbiodinium spp. These observations show that the epizoic worms do not acquire their symbionts from the “host” coral.     

Dissolved oxygen and dietary phosphorus modulate utilization and effluent partitioning of phosphorus in rainbow trout (Oncorhynchus mykiss) aquaculture

Phosphorus (P) is the limiting nutrient in freshwater primary production, and excessive levels cause premature eutrophication. P levels in aquaculture effluents are now tightly regulated. Increasing our understanding of waste P partitioning into soluble, particulate, and settleable fractions is important in the management of effluent P. When water supply is limited, dissolved oxygen concentration (DO) decreases below the optimum levels. Therefore, we studied effects of DO (6 and 10mg/L) and dietary P (0.7 and 1.0% P) on rainbow trout growth, P utilization, and effluent P partitioning. Biomass increased by 40% after 3 weeks. DO at 10mg/L significantly increased fish growth and feed efficiency, and increased the amount of P in the soluble fraction of the effluent. Soluble effluent P was greater in fish fed 1.0% P. DO increases fish growth and modulates P partitioning in aquaculture effluent.     

Aspects of population ecology in two populations of fiddler crabs, <Emphasis Type="Italic">Uca pugnax</Emphasis>

Fiddler crabs, Uca pugnax, were collected from a highly contaminated site and a relatively clean site, both in New Jersey to determine if and how environments with varying levels of pollutants may impact aspects of population biology including individual size, morphology (major cheliped size), population density, fecundity, recruitment and survivorship of early benthic phases. Crabs from the highly contaminated site were significantly larger in size, but had lower population density, lower recruitment, reduced reproductive season and lower survivorship of early benthic phases. Our study suggests that contamination may play a role in population ecology of U. pugnax. This study also determined that the reproductive season for U. pugnax in New Jersey is much longer than reported in the literature and could potentially be impacted by global climate change.     

Toxic effects of mercuric chloride on sperm and egg viability of two populations of mummichog, Fundulus heteroclitus

Exposure of mummichog (Fundulus heteroclitus) sperm from polluted Piles Creek (PC) to 0.01 ppm mercuric chloride (Hg) for 2 min caused a significant reduction in fertilization success. However, comparable exposure of sperm of mummichog from a relatively clean area in Long Island (LI) did not effect the fertilization success. Exposure of PC mummichog sperm to 0.05 ppm Hg for 2 min caused significant reduction in sperm motility. On the other hand, comparable exposure of LI mummichog sperm did not have any effect on motility. These data indicate that Hg is more toxic for PC mummichog sperm than LI mummichog sperm. Exposure of both PC and LI sperm either to 15 ppt sea water or to 0.05 ppm Hg for 15 min did not affect the morphology of the sperm, as seen by scanning electron microscopy. Exposure of PC and LI mummichog eggs to 0.05 ppm Hg up to 25 min had no effect on fertilization success, indicating that eggs are more tolerant to Hg than sperm.     

Single-Stage Dewatering of FGD Waste

The Escalante Unit No. 1 flue gas desulfurization (FGD) waste slurry dewatering system represents the first domestic utility to deviate from the typical industry two-stage dewatering system design. Evaluations conducted during the design phase compared three dewatering options: 1) thickener in series with vacuum filters, 2) thickener in series with centrifuges, and 3) centrifuges with no thickener. The evaluation showed that centrifuges with no thickener (one stage) could significantly reduce capital costs. Coupled with capital costs, this option also decreases operation and maintenance costs, reduces the complexity of the system, saves a considerable amount of space, and centralizes the FGD and dewatering systems within one building. This paper describes the evaluation that took place during the design phase of the project comparing the three dewatering options. Operational data for the first year of operation are presented, and operating and maintenance costs are discussed and compared with conventional two-stage dewatering systems.     

Soil metal concentrations and productivity of Betula populifolia (gray birch) as measured by field spectrometry and incremental annual growth in an abandoned urban Brownfield in New Jersey

A forested brownfield within Liberty State Park, Jersey City, New Jersey, USA, has soils with arsenic, chromium, lead, zinc and vanadium at concentrations above those considered ambient for the area. Using both satellite imagery and field spectral measurements, this study examines plant productivity at the assemblage and individual specimen level. Longer term growth trends (basal area increase in tree cores) were also studied. Leaf chlorophyll content within the hardwood assemblage showed a threshold model for metal tolerance, decreasing significantly beyond a soil total metal load (TML) of 3.0. Biomass production (calculated with RG - Red/Green Ratio Index) in Betula populifolia (gray birch), the co-dominant tree species, had an inverse relationship with the Zn concentration in leaf tissue during the growing season. Growth of B. populifolia exhibited a significant relationship with TML. Assemblage level NDVI and individual tree NDVI also had significant decreases with increasing TML. Ecosystem function measured as plant production is impaired at a critical soil metal load.