Kym Rouse Campbell

An ecosystem model for assessing ecological risks in Québec rivers, lakes, and reservoirs

Abstract The comprehensive aquatic systems model (CASM) was adapted for estimating ecological risks posed by toxic chemicals in rivers, lakes, and reservoirs in Quebec, Canada. Populations of aquatic plants, invertebrates, and fish characteristic of these aquatic ecosystems were identified and generic food webs were constructed. Bioenergetics parameters that determine the growth dynamics of these populations were derived from published values for these same or similar species. Input values of light, water temperature, concentrations of dissolved nitrogen (N), phosphorus (P), and silica (Si) were constructed from available regional data or data from similar Canadian systems at similar latitudes. The model provides the capability to estimate the probability of changes in the biomass of multiple populations of primary producers and consumers as a function of the concentration of dissolved chemical contaminant. The CASM permits the evaluation of direct toxic effects, as well as indirect toxic effects that result from changes in competitive or predator–prey relations in complex aquatic food webs. Hypothetical risk assessments were constructed for pentachlorophenol, copper, mercury, and diquat dibromide in generalized rivers, lakes, and reservoirs in Quebec. Numerical sensitivity and uncertainty analyses were used to describe the relative contributions of direct and indirect toxic effects on overall ecological risks estimated for functional guilds of producers and consumers in these ecosystems. This aquatic ecosystem model may become one component in a decision support system for assessing ecological risks.

Modeling submersed macrophyte growth in relation to underwater light climate: modeling approaches and application potential

The underwater light climate is one of the most important determinants of submersed aquatic vegetation. Because of the recent, large-scale, declines in aquatic vegetation, largely attributed to deterioration of the underwater light climate, interest in tools to predict the wax and wane of aquatic macrophyte populations has greatly increased. This paper summarizes two modeling approaches that can be applied to assess impacts of changes in underwater light climate on submersed vegetation. The first, stand-alone, model type focuses on metabolism and biomass formation of submersed freshwater macrophytes with difference in phenologies. This type is illustrated by examples from various sites using models developed for the freshwater macrophytes Hydrilla verticillata (L.f.) Royle (HYDRIL) and Myriophyllum spicatum L. (MILFO), and also by an example ecological risk assessment. The models (HYDRIL and MILFO) track carbon flow through the vegetation in meter-squared (m2) water columns. The models include descriptions of various factors that affect biomass dynamics, such as site-characteristic changes in climate, latitude, light attenuation within the water column, carbon assimilation rate at light saturation, temperature, wintering strategies, grazing and mechanical control (removal of shoot biomass). Simulated biomass, net assimilation and maintenance respiration over a relatively short (1–5 year) period agree well with measured values. The models are, therefore, believed to be suitable for predicting plant community production, growth and survival characteristics over relatively short periods over a large range of sites. The feasibility of using a macrophyte growth model of the HYDRIL type for ecological risk assessment is demonstrated. It is used to evaluate the consequences of management changes in large rivers for the survival of submersed vegetation. The current assessment evaluates the potential impact of increased commercial navigation traffic on the growth of Potamogeton pectinatus L. in Pool 4 of the Upper Mississippi River, U.S.A. In this case, navigational traffic scenarios were translated into suspended solids concentrations and underwater light climate, with the latter being used as inputs into the aquatic plant growth model. Model results demonstrate that the scenario increases in commercial traffic cause minimal decreases in growth and vegetative reproduction. Results indicate that this growth model can be a useful tool in ecological risk assessment, since the required stress-response relationships could be established. The second, integrated, model type focuses on the role of seagrass and other primary producers in estuarine littoral zone material cycling (carbon and nitrogen) at the Goodwin Islands, Virginia, U.S.A. The latter model was used to explore the effects of changes

The accumulation and effects of environmental contaminants on snakes: a review.

In any ecological risk assessment, afull complement of the relevant members of theecosystems being studied should be considered. Reptiles in general, and snakes in particular, areimportant although often neglected components ofterrestrial and aquatic ecosystems and should beincluded in any study on environmental contamination. By neglecting reptiles, the risks posed by aparticular contaminant cannot be fully assessed. Since all snakes are secondary, tertiary, and toppredators, they are susceptible to the bioaccumulationof environmental contaminants. Their unique lifehistories make their roles in food webs diverse andimportant, and they are crucial to the properfunctioning of many ecological processes. We reviewand summarize organic and inorganic contaminant andradionuclide/radiation residue and lethal andsublethal effects data for snakes to stress theimportance of snakes and encourage their inclusion inecological risk assessments, to demonstrate thepaucity of available contaminant data on snakes andreveal the main information gaps, to encourage furtherecotoxicological studies on snakes, and to facilitatethe use of existing snake contaminant data inecological risk assessments. This review is the mostcomprehensive review currently available on theeffects on and accumulation of environmentalcontaminants in snakes.

Lizard Contaminant Data for Ecological Risk Assessment

This review is the most comprehensive currently available of the effects and accumulation of environmental contaminants on lizards. The importance of lizards was emphasized in hope that they be included in ecological risk assessments as well as any study on environmental contamination. Some studies presented here indicated that lizards are ideal bioindicators. They are important as a component of biodiversity, and many species are listed as threatened or endangered. In addition, lizards are a significant part of many ecosystems as well as an important link in many food chains. There are large gaps in data for many environmental contaminants, particularly data on lizards. Ecotoxicological studies on a wide variety of lizard species are needed; both laboratory and field studies would provide useful information. Because the majority of lizards are insectivores, studies of the effects and accumulation of pesticides are essential. A few current studies are available from Africa and Australia, but most, especially those conducted in the U.S., were not current. Studies are needed on the effects and accumulation of ubiquitous contaminants, such as heavy metals and PCBs. Because of the many contaminated sites and the significant waste disposal problem, studies are needed on the effects and accumulation of radionuclides on lizards. Furthermore, effects of multiple stressors must be studied. Last, studies are needed linking the effects of contaminants to tissue residues. It is hoped that the convenience of having the vast majority of lizard environmental contaminant data available in one document will encourage its use.

Fishing along the Clinch River arm of Watts Bar Reservoir adjacent to the Oak Ridge Reservation, Tennessee: behavior, knowledge and risk perception

Catching and eating fish is usually viewed as a fun, healthy and safe activity. However, with continuing increases in fish consumption advisories due to the contamination of our environment, anglers have to decide whether or not to eat the fish they catch. The Clinch River arm of Watts Bar Reservoir is under a fish consumption advisory because of elevated PCB concentrations in striped bass (Morone saxatilis), catfish (Ictalurus spp.) and sauger (Stizostedion canadense) due in part from contaminants released from the US Department of Energys (USDOEs) Oak Ridge Reservation (ORR) in East Tennessee. To obtain information about the demographics, fishing behavior, knowledge, fish consumption and risk perception of anglers, a survey was conducted of 202 people actively fishing either on land or by boat along the Clinch River arm of Watts Bar Reservoir adjacent to the ORR from Melton Hill Dam to the Poplar Creek confluence or on Poplar Creek within ORR boundaries from mid-March to early November 2001. Even though 81% of people interviewed knew about the fish consumption advisories for the study area, 48% of them thought the fish were safe to eat, while 38% ate the fish that they caught from the study area. Approximately 36% of anglers who had knowledge of the fish consumption warnings ate fish from the study area. Providing confirmation that people fish for many reasons, 35% of anglers interviewed did not eat fish at all. The majority of anglers interviewed knew about the fish consumption advisories because of the signs posted throughout the study area. However, few people knew the correct fish advisories. Significantly fewer blacks had knowledge of the fish consumption warnings than whites. Information resulting from this study could be used to design a program with the objective of reaching the people who may be most at risk from eating fish caught from the Clinch River arm of Watts Bar Reservoir.

Gender and spatial patterns in metal concentrations in brown anoles (Anolis sagrei) in Southern Florida, USA

Comparatively little is known about heavy metal levels in reptiles, particularly for lizards. Yet lizards often are common predators that could serve as bioindicators of contamination on a small spatial scale. This study examined the differences in metal concentrations of adult brown anoles (Anolis sagrei) for arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in six locations in southern Florida, USA, from Lake Okeechobee (Pahokee) south to Key West. We predicted that levels of contaminants would be higher in the industrialized ports (Port Everglades, Port of Miami) and at a landfill (in Key West) compared to a campground, tropical garden, and marine laboratory. Males were significantly larger than females, as expected. Although there were significant locational differences in metal concentrations, they did not fit a consistent pattern, either among sites or between reference and study sites. However, the lowest levels were generally found at Everglades Marina and Campground (except for selenium) and at Fairchild Tropical Garden (except for manganese). For females, size was significantly correlated with cadmium, lead, and mercury levels, while for males, there were significant correlations between length and arsenic, chromium, and manganese concentrations. Where there were gender differences in metal levels, females had significantly higher levels than males even though they were smaller. We attribute these gender differences to differences in diet due to microhabitat differences in foraging locations. Females spend more time feeding near the ground and males spend more time feeding on tree trunks and branches where they consume more flying insects. This is the first study that examines concentrations of metals in lizards in the United States, and suggests that nonnative lizards may be useful in toxicological studies.

Fishing and consumption patterns of anglers adjacent to the Oak Ridge Reservation, Tennessee: higher income anglers ate more fish and are more at risk

The risks from consuming self‐caught fish are receiving international attention because of high levels of contaminants in some species. The ethnic, income, and educational differences in fishing and fish consumption patterns of 202 anglers fishing along the Clinch River arm of Watts Bar Reservoir adjacent to the US Department of Energys Oak Ridge Reservation (ORR) or along Poplar Creek within ORR boundaries were analyzed to understand how to design a risk communication strategy. Because of elevated PCB concentrations in striped bass (Morone saxatilis), catfish (Ictalurus spp.), and sauger (Stizostedion canadense) due partly from contaminants released from the ORR in East Tennessee, the Clinch River arm of Watts Bar Reservoir is under a fish consumption advisory, while portions of Poplar Creek are under advisories because of mercury. Most studies find that a high proportion of anglers eat their catch, and people with lower incomes and less education generally eat more self‐caught fish than others fishing in the same region. Calculating fish consumption individually for each person indicated that a considerable number of people ate more fish from the study area than the amount used to calculate risks when developing fish consumption advisories, and people who ate fish more often usually ate larger portions. Unlike previous studies of fish consumption, this study indicated that a smaller proportion of anglers ate their fish, and those that ate the most were the high income anglers for this fishing population, rather than those with lower incomes. This suggests that risk communication strategies must include site‐specific information on the population at risk from fish consumption, and that targeting only low income, low education anglers will miss some people who are most at risk.

Assessing ecological risks at US Department of Energy facilities using methods borrowed from landscape ecology and habitat suitability analysis. Part I. Analysis of historical aerial photography and maps

Ecological risks are inherently spatial, and the consideration of scale is critical to all aspects of the ecological risk assessment process. Analysis of alterations in land use and habitat quality and quantity in relation to historical, continuing, and future US Department of Energy (USDOE) operations may be as important as assessing impacts resulting from the release of chemical contaminants into the environment. We examined several contributions from basic research and development in landscape ecology and habitat suitability analysis and their potential application in assessing ecological risks at USDOE facilities. Methods from landscape ecology are presented in this manuscript, while habitat suitability analysis methods and landscape-level ecological models are presented in a second manuscript. The Oak Ridge Reservation (ORR) in eastern Tennessee and the Savannah River Site (SRS) in western South Carolina were selected as representative USDOE facilities for this study. Changes in land use were analysed for sites within the ORR and the SRS using historical aerial photography, which was digitized in order to quantify the change over time using indices that describe landscape structure. A time series of changes in land use and habitat at a larger spatial scale was analysed by digitizing US Geological Survey (USGS) quadrangle maps (124,000) using two scales of resolution for an area of East Tennessee that included the ORR; landscape ecological indices were calculated, and USGS quadrangle maps that included areas inside and outside USDOE boundaries were compared. Historical alterations in land use and habitat type were successfully reconstructed for sites within the USDOE facilities at a small scale using aerial photography and at a large spatial scale for a USDOE facility and the surrounding landscape using a time series of USGS quadrangle maps; both data sources provided useful information. The percentage of the landscape occupied by a particular patch type, the number of patches of a particular type, the total number of patch types, the total number of patches, the total edge, the meanpatch fractal dimesion, and the contagion index were landscape ecological indices that adequately described the change over time that has occurred on the ORR and SRS. The methods presented in this manuscript could effectively be used in ecological risk assessments both at USDOE facilities and non-USDOE lands.

A comparison of landscape structure inside and outside the gates: analysis of the regional landscapes of four US Department of Energy facilities using US Geological Survey quadrangle maps and FRAGSTATS

The US Department of Energy (USDOE) facilities encompass large tracts of land that include important regional ecological resources. The historical development and continued operation of these facilities has changed the structure of regional landscapes. A quantitative analysis was performed to determine if patterns of land use within the boundaries of selected USDOE facilities could be differentiated from regional landscapes. Four USDOE facilities were analysed: the Oak Ridge Reservation (ORR), the Savannah River Site (SRS), Los Alamos National Laboratory (LANL), and Fermi National Accelerator Laboratory (FNAL). Quantitative measures that describe landscape structure were calculated with FRAGSTATS using information obtained from US Geological Survey (USGS) quadrangle maps (1:24,000). The analyses demonstrated that useful descriptions of general land use patterns could be obtained from the quadrangle maps using this simple, coarse and economical approach. However, patterns of land use within the facility boundaries could not be differentiated from those measured for the surrounding regional landscapes using the selected landscape metrics.

The feasibility of using introduced lizards as indicators of environmental contamination

Introduced species can provide valuable opportunities for applied research once they have become established with little possibility of eradication. They have been used as indicators of environmental contamination in aquatic ecosystems for many years. However, in terrestrial ecosystems, introduced species have not been utilized as sentinels of environmental quality. We review the feasibility of using species of lizards that have been introduced, are closely related to species that have been introduced, or have the potential of being introduced to the United States, as indicators of heavy metal contamination. Metal concentrations in lizards were compared from the few available studies, including one recently conducted on the introduced brown anole Anolis sagrei in southern Florida. Brown anoles, tropical house geckos Hemidactylus mabouia, sand lizardsLacerta agilis, common viviparous lizards Lacerta vivipara, common wall lizards Podarcis muralis, and starred agamas Laudakia (Agama) stellio stellio were shown to be suitable indicators of heavy metal pollution because differences were found in metal levels in lizards from different locations within a given region, and lizards from sites presumed to be contaminated by heavy metals contained higher metal concentrations than those from locations that were uncontaminated.