Characterization of sedimentary phosphorus in Lake Erie and on-site quantification of internal phosphorus loading.

Lake Erie harmful algal blooms and hypoxia are two major environmental problems, and have severe impacts on human health, aquatic ecosystems, and the economy. However, little is known about internal loading of phosphorus (P) from sediments, which pose a challenge for assessing the efficacy of current conservation measures on the improvement of lake water quality. A modified Hedley's extraction procedure was employed to analyze representative sediment samples collected from the Lake Erie basin for assessing sedimentary P stock, potential availability for release into lake water, and internal P loading. Inorganic and organic P in the sediments were characterized by sequential extractions in H2O, 0.5 M NaHCO3, 0.1 M NaOH, and 1.0 M HCl, respectively. In the 0 - 10 cm sediment, total P stock was 172, 191, and 170 metric tons km-2 in the western, central, and eastern basins, respectively. Sedimentary P seems unlikely to contribute to internal P loading in the western basin, while in the eastern basin it can potentially contribute to an internal loading of 359 metric tons P yr-1. In the central basin, 41% of organic P, 15% of non-HCl extractable inorganic P, and 9.7% of residual P in the 0 - 10 cm sediment is potentially available for release into lake water; in the 10 - 20 cm sediment, organic P extracted by NaHCO3 and NaOH is also partially available. The central basin potentially contributes to internal P loading at a total amount of 10,599 metric tons yr-1. Internal P loading may not contribute to HABs in the western basin, but it can cause and maintain hypoxia in the central basin and delay the recovery of lake water quality for a lengthy time period in response to external P reduction measures.

Food web structure in oil sands reclaimed wetlands.

Boreal wetlands play an important role in global carbon balance. However, their ecosystem function is threatened by direct anthropogenic disturbance and climate change. Oil sands surface mining in the boreal regions of Western Canada denudes tracts of land of organic materials, leaves large areas in need of reclamation, and generates considerable quantities of extraction process-affected materials. Knowledge and validation of reclamation techniques that lead to self-sustaining wetlands has lagged behind development of protocols for reclaiming terrestrial systems. It is important to know whether wetlands reclaimed with oil sands process materials can be restored to levels equivalent to their original ecosystem function. We approached this question by assessing carbon flows and food web structure in naturally formed and oil sands-affected wetlands constructed in 1970-2004 in the postmining landscape. We evaluated whether a prescribed reclamation strategy, involving organic matter amendment, accelerated reclaimed wetland development, leading to wetlands that were more similar to their natural marsh counterparts than wetlands that were not supplemented with organic matter. We measured compartment standing stocks for bacterioplankton, microbial biofilm, macrophytes, detritus, and zoobenthos; concentrations of dissolved organic carbon and residual naphthenic acids; and microbial production, gas fluxes, and aquatic-terrestrial exports (i.e., aquatic insect emergence). The total biomass of several biotic compartments differed significantly between oil sands and reference wetlands. Submerged macrophyte biomass, macroinvertebrate trophic diversity, and predator biomass and richness were lower in oil sands-affected wetlands than in reference wetlands. There was insufficient evidence to conclude that wetland age and wetland amendment with peat-mineral mix mitigate effects of oil sands waste materials on the fully aquatic biota. Although high variability was observed within most compartments, our data show that 20-year-old wetlands containing oil sands material have not yet reached the same level of function as their reference counterparts.

The use of stable isotopes ((13)C/(12)C and (15)N/(14)N) to trace exposure to oil sands processed material in the Alberta oil sands region.

Various oil sands reclamation strategies incorporate oil sands processed material (OSPM) such as mature fine tailings (MFT), engineered tailings (consolidated tailings, CT), and tailings pond water (TPW) into reclamation components that need to develop into viable aquatic ecosystems. The OSPM will contain elevated salinity and organics such as naphthenic acids (NA) and polycyclic aromatic compounds (PAC) that can be chronically toxic to aquatic organisms depending upon levels and age. Due to the complexity of the chemical mixtures, analysis of these compounds in exposed organisms can be challenging. In this study, the stable carbon and nitrogen isotope signatures of selected invertebrates from various types of oil sands reclamation sites were analyzed to determine whether stable isotopes can be used to trace the exposure of aquatic organisms to organic constituents of OSPM. In a series of experimental reclamation ponds of similar age and size, there were trends of (13)C depletion and (15)N enrichment for benthic invertebrates along a gradient of increased levels of MFT and/or TPW. A survey of 16 sites revealed high delta(15)N values for invertebrates in aquatic systems containing MFT and CT (gypsum-treated mixes of MFT and tailings sand), which was attributed to the presence of NH(4)(+), a process by-product in OSPM. Findings of this study indicate a potential for the use of stable nitrogen isotopes to define exposure of biota to OSPM during environmental effects monitoring programs both in surface waters and in cases where groundwater seepage containing oil sands processed water enters surface receiving environments in the region.

Long-term ecosystem monitoring and assessment of the Detroit River and Western Lake Erie.

Over 35 years of US and Canadian pollution prevention and control efforts have led to substantial improvements in environmental quality of the Detroit River and western Lake Erie. However, the available information also shows that much remains to be done. Improvements in environmental quality have resulted in significant ecological recovery, including increasing populations of bald eagles (Haliaeetus leucocephalus), peregrine falcons (Falco columbarius), lake sturgeon (Acipenser fulvescens), lake whitefish (Coregonus clupeaformis), walleye (Sander vitreus), and burrowing mayflies (Hexagenia spp.). Although this recovery is remarkable, many challenges remain, including population growth, transportation expansion, and land use changes; nonpoint source pollution; toxic substances contamination; habitat loss and degradation; introduction of exotic species; and greenhouse gases and global warming. Research/monitoring must be sustained for effective management. Priority research and monitoring needs include: demonstrating and quantifying cause-effect relationships; establishing quantitative endpoints and desired future states; determining cumulative impacts and how indicators relate; improving modeling and prediction; prioritizing geographic areas for protection and restoration; and fostering long-term monitoring for adaptive management. Key management agencies, universities, and environmental and conservation organizations should pool resources and undertake comprehensive and integrative assessments of the health of the Detroit River and western Lake Erie at least every 5 years to practice adaptive management for long-term sustainability.

Organochlorine contaminant concentrations in caddisfly adults (Trichoptera) collected from great lakes connecting channels.

Pennsylvania-style light traps were used to capture adult Trichoptera from the St. Marys, St. Clair, Detroit and Niagara rivers, Canada. Adequate biomass was acquired in single, 2-h collections to permit triplicate gas chromatographic analyses of 1-4 g samples for 36 organochlorine contaminants. Contaminant levels varied unpredictably but relatively little among samples taken at monthly intervals over the summer. Samples collected simultaneously from the two sides of the Detroit R. reflected local sediment contaminant patterns, suggesting limited dispersal by adults. Genus-specific differences in contaminant concentrations within the Hydropsychidae and Leptoceridae probably reflect differences in larval habitats and manner of feeding. Contaminant concentrations and relative composition paralleled published reports of contaminants in sediments from collection locations. St. Marys R. caddisflies contained contaminant levels indistinguishable from samples collected at reference sites. St. Clair R. samples contained high levels of compounds associated with petrochemical industries located in the river's upstream reaches. High levels of polychlorinated biphenyls (PCBs) and most other contaminants in Detroit R. samples reflected industrial loadings near Detroit, Michigan. Niagara R. samples contained elevated concentrations of PCBs and pesticides. Cluster analysis grouped samples into five clusters each with unique contaminant composition. These also corresponded to geographic origin: St. Marys, St. Clair, Detroit and upper and lower Niagara rivers. The relative ease of collection and consistent results obtained render adult Trichoptera potentially valuable candidates for surveys of aquatic contamination over a broad range of geographical and ecological conditions.

Correlates of medical compliance among hemophilic boys.

Twenty-nine males with hemophilia completed the Medical Compliance Incomplete Stories Test (M-CIST), and their scores were correlated with health care professionals' ratings of four aspects of medical compliance, along with measures of possible moderating variables. The results indicated that significant associations were found between most of the M-CIST category scores, particularly the Compliance/coping subscale, and the health care specialists' ratings of how well the children exhibited compliant responses to bleeding episodes, and inverse associations with the incidence of monthly bleeding episodes. The findings suggested that the M-CIST continues to demonstrate promise as an instrument to be used in studies of compliance among pediatric chronic illness patients.

School functioning and disease severity in boys with hemophilia.

There have been few recent studies investigating the scholastic progress of children with hemophilia. The advent of PL94-142, which ensures an appropriate educational program based on a child's specific learning disabilities, and home Factor VIII therapy, which increases the hemophiliac's school attendance and sense of freedom and control, might have had a positive impact on the academic performance of these patients. We investigated past and current educational functioning of 26 boys with hemophilia, using both parental and teacher reports. Twenty-two of these children were administered reading and math achievement tests. Results indicate that school absenteeism is a continuing problem for these children, with the average hemophiliac missing 18 school days in an academic year (median = 11 school days missed); one child had missed 77% of the year. Although these boys had normal intelligence and made average grades in school, six of the 22 tested performed more than two grade levels below expectations in reading and 10 performed greater than two grade levels below expectations in math. School underachievement did not necessarily correlate with disease severity (as indicated by serum factor level), school absenteeism, or grade point average. Although eight parents indicated that their children had past or current school problems, and teachers reported that greater than 50% of the group received special tutoring or classes for learning disabled students, six out of 22 (27%) performed below expectations in either math or reading and yet had no current individual educational remediation plan.(ABSTRACT TRUNCATED AT 250 WORDS)