The potential use of Atlantic silverside (Menidia menidia) for monitoring estuarine pollution

Monitoring chronic impacts of nearshore pollution on fish in Atlantic marine systems is challenging due to the mobility and seasonal nature of most habitat use. We evaluated Atlantic silverside (Menidia menidia) as a potential indicator of pollution across a gradient of contaminated sites in the Saint John River Estuary, New Brunswick, Canada. Fish returning from offshore in the spring showed no differences in length, weight, or condition factor between sites, but a graded response in condition factor appeared gradually, consistent with levels of contamination. Gonad size peaked in early June, however no differences in GSI were found among sites. By September, most fish collected were young of the year, with a significant bias towards female juveniles at the exposed site. These results indicate that Atlantic silverside are locally resident during their onshore period, and demonstrates their potential as a sentinel species. Sampling should focus on early June prior to the full moon to ensure maximal exposure periods before spawning, or in late October to evaluate growth as fish grow rapidly prior to offshore movement.     

Reproductive strategies and seasonal changes in the somatic indices of seven small-bodied fishes in Atlantic Canada in relation to study design for environmental effects monitoring

Small-bodied fishes are more commonly being used in environmental effects monitoring (EEM) studies. There is a lack of understanding of the biological characteristics of many small-bodied species, which hinders study designs for monitoring studies. For example, 72 % of fish population surveys in Canada’s EEM program for pulp and paper mills that used small-bodied fishes were conducted outside of the reproductive period of the species. This resulted in an inadequate assessment of the EEM program’s primary effect endpoint (reproduction) for these studies. The present study examined seasonal changes in liver size, gonad size, and condition in seven freshwater and estuarine small-bodied fishes in Atlantic Canada. These data were used to examine differences in reproductive strategies and patterns of energy storage among species. Female gonadal recrudescence in all seven species began primarily in the 2-month period in the spring before spawning. Male gonadal development was concurrent with females in five species; however, gonadal recrudescence began in the fall in male three-spined stickleback (Gasterosteus aculeatus) and slimy sculpin (Cottus cognatus). The spawning period for each species was estimated from the decline in relative ovary size after its seasonal maximum value in spring. The duration of the spawning period reflected the reproductive strategy (single vs multiple spawning) of the species. Optimal sampling periods to assess reproductive impacts in each species were determined based on seasonal changes in ovary size and were identified to be during the prespawning period when gonads are developing and variability in relative gonad size is at a minimum.     

Ecosystem Responses to Extreme Natural Events: Impacts of Three Sequential Hurricanes in Fall 1999 on Sediment Quality and Condition of Benthic Fauna in the Neuse River Estuary, North Carolina

A study was conducted in November 1999 to assess sediment quality and condition of benthic fauna in the Neuse River Estuary (NRE), North Carolina, USA, following the passage of three Atlantic hurricanes during the two months prior. Samples for analysis of macroinfauna (>0.5 mm sieve size), chemical contamination of sediments, and other abiotic environmental variables (salinity, dissolved oxygen, pH, depth, sediment granulometry) were collected at 20 sites from the mouth of the Neuse River at Pamlico Sound to approximately 90 km upstream. Results were compared to those obtained from the same area in July 1998 using similar protocols. Depressed salinity, caused by extreme rainfall and associated high freshwater flow, persisted throughout much of the estuary, which had experienced periods of water-column stratification and hypoxia of underlying waters. Fifteen of the 20 sites, representing 299 km² (76% of the survey area), also showed signs of benthic stress based on a multi-metric benthic index of biotic integrity (B-IBI). Benthic impacts included reductions in the abundance, diversity, and numbers of species and shifts in taxonomic composition, with a notable increase in dominance of the opportunistic polychaete Mediomastus ambiseta as other former dominant species declined. There was no significant increase in the extent of chemical contamination compared to pre-hurricane conditions. Storm-related reductions in dissoved oxygen and salinity were the more likely causes of the observed benthic impacts, though it was not possible, based on these results, to separate storm effects from seasonal changes in the benthos and annual episodes of summer anoxia and hypoxia.     

Can environmental impact assessments alone conserve freshwater fish biota? Review of the Chilean experience

Chile was one of many countries that initiated environmental impact assessments in the 1990s, and has relied on their use for species conservation and territorial planning without the use of larger-scale environmental and ecological planning. The capacity of Chile's environmental impact assessment system (SEIA) to evaluate resident freshwater fishes and the potential impacts of water projects and aquaculture activities – two categories of projects that create direct threats to freshwater fishes – are assessed. Of the 3997 such submissions to the SEIA, only 0.6% conducted any freshwater fish assessment, and only 0.1% conducted any quantitative assessment of expected impacts from the associated project. The small number of assessments was characterized by poor study design, inconsistent sampling methodology, and species misidentification. Traditional assessments failed to include freshwater fish ecology in the general assessment framework. The new strategic environmental evaluation system only underscores the need for vastly improved field sampling protocols and assessment methodologies.     

Community-Based Environmental Management in Atlantic Canada: The Impacts and Spheres of Influence of the Atlantic Coastal Action Program

The Atlantic Coastal Action Program (ACAP) is a unique, community-based program initiated by Environment Canada in 1991 to help Atlantic Canadians restore and sustain watersheds and adjacent coastal areas. ACAP is the eastem-most Environment Canada Ecosystem Initiative. The ACAP family is currently made up of 14 ecosystem-based organizations in the four Atlantic provinces. Each one of these non-profit organizations operates independently, but is formally linked under the umbrella of ACAP to represent a force stronger than the individual parts. In Environment Canada's experience, the program consistently demonstrates the value of a community-based approach and produces results on an ecosystem basis. This paper will examine some of the impacts of ACAP in terms of economics, credible community science, and environmental results which most often align with Environment Canada's objectives. It will explore the influences of the community-based approach to environmental management on multiple scales (local, regional, etc.). Through examples, the paper will demonstrate the effectiveness of ACAP in influencing some of the policies, programs and attitudes of various levels of government and industry in the region, as well as describe how the community-based model has been exported internationally. The paper will conclude with a discussion on a planned path forward for ACAP.     

基于着生硅藻多参数指标评价赤水河生态状况

随着人类活动的加剧,赤水河生态状况受到越来越多的关注,全面了解赤水河的生态状况,识别影响生态状况的主要环境胁迫因子对于赤水河的管理十分重要。笔者分别于2016年春季(4月)和秋季(9月)对赤水河干流着生硅藻及主要环境指标展开系统调查,春季以曲壳藻属相对丰度、高需氧物种、高磷物种、Shannon-Wiener多样性指数为核心参数,秋季以低需氧物种、物种丰富度、高营养物种为核心参数,构建了着生硅藻多参数指标(D-MMIs)。对赤水河干流生态状况进行评估。结果表明:调查期间,赤水河干流中上游样点水体状况优于下游样点,并且春、秋季赤水河生态状况存在差异。D-MMIs与环境因子的回归分析结果显示:影响春季赤水河生态状况的环境因子为COD,影响秋季赤水河生态状况的环境因子为NH4_+~-N。构建的赤水河D-MMIs,能够较好地指示环境胁迫因子对赤水河生态状况的影响,对于指导赤水河的管理实践具有参考价值。     

Incidence of stress in benthic communities along the U.S. Atlantic and Gulf of Mexico coasts within different ranges of sediment contamination from chemical mixtures

Synoptic data on concentrations of sediment-associated chemical contaminants and benthic macroinfaunal community structure were collected from 1,389 stations in estuaries along the U.S. Atlantic and Gulf of Mexico coasts as part of the nationwide Environmental Monitoring and Assessment Program (EMAP). These data were used to develop an empirical framework for evaluating risks of benthic community-level effects within different ranges of sediment contamination from mixtures of multiple chemicals present at varying concentrations. Sediment contamination was expressed as the mean ratio of individual chemical concentrations relative to corresponding sediment quality guidelines (SQGs), including Effects Range-Median (ERM) and Probable Effects Level (PEL) values. Benthic condition was assessed using diagnostic, multi-metric indices developed for each of three EMAP provinces (Virginian, Carolinian, and Louisianian). Cumulative percentages of stations with a degraded benthic community were plotted against ascending values of the mean ERM and PEL quotients. Based on the observed relationships, mean SQG quotients were divided into four ranges corresponding to either a low, moderate, high, or very high incidence of degraded benthic condition. Results showed that condition of the ambient benthic community provides a reliable and sensitive indicator for evaluating the biological significance of sediment-associated stressors. Mean SQG quotients marking the beginning of the contaminant range associated with the highest incidence of benthic impacts (73–100% of samples, depending on the province and type of SQG) were well below those linked to high risks of sediment toxicity as determined by short-term toxicity tests with single species. Measures of the ambient benthic community reflect the sensitivities of multiple species and life stages to persistent exposures under actual field conditions. Similar results were obtained with preliminary data from the west coast (Puget Sound).     

Montane meadows in the Sierra Nevada: comparing terrestrial and aquatic assessment methods

We surveyed montane meadows in the northern Sierra Nevada and southern Cascades for two field seasons to compare commonly used aquatic and terrestrial-based assessments of meadow condition. We surveyed (1) fish, (2) reptiles, (3) amphibians, (4) aquatic macroinvertebrates, (5) stream geomorphology, (6) physical habitat, and (7) terrestrial vegetation in 79 meadows between the elevations of 1,000 and 3,000?m. From the results of those surveys, we calculated five multi-metric indices based on methods commonly used by researchers and land management agencies. The five indices consisted of (1) fish only, (2) native fish and amphibians, (3) macroinvertebrates, (4) physical habitat, and (5) vegetation. We compared the results of the five indices and found that there were significant differences in the outcomes of the five indices. We found positive correlations between the vegetation index and the physical habitat index, the invertebrate index and the physical habitat index, and the two fish-based indices, but there were significant differences between indices in both range and means. We concluded that the five indices provided very different interpretations of the condition in a given meadow. While our assessment of meadow condition changed based on which index was used, each provided an assessment of different components important to the overall condition of a meadow system. Utilizing a multimetric approach that accounts for both terrestrial and aquatic habitats provides the best means to accurately assess meadow condition, particularly given the disproportionate importance of these systems in the Sierra Nevada landscape.     

Biomarkers of environmental contaminants in the coastal waters of Estonia (Baltic Sea): effects on eelpouts (Zoarces viviparus)

The eastern Baltic Sea near the Estonian coast is heavily navigated by numerous cargo ships and oil tankers. Hundreds of accidents and oil spills happen yearly in this area. Yet, there is a lack of data concerning the distribution and effects of the environmental contaminants, especially polycyclic aromatic hydrocarbons (PAHs). Different parts of the Baltic Sea have different levels of contamination; therefore a wide range of monitoring stations in coastal areas in the Gulf of Finland and Gulf of Riga were chosen. The aim of the present research was to document the responses of chosen biomarkers of environmental contaminants in different unstudied areas of the Estonian coastal sea. During 2009 and 2010 we measured PAH metabolites, EROD activities, geno- and cytotoxicity, histology, parasites and other biomarkers from the eelpout (Zoarces viviparus), a resident benthic fish species. The results showed that fish from the Gulf of Riga emitted lower levels of fluorescence in fixed wavelength analyses (representing equivalents of PAH metabolites in bile and urine), and consistently, showed less geno- and cytotoxicity and parasite infection, higher liver somatic index (LSI) and a higher condition factor (CF) than fish inhabiting areas close to the Baltic proper and in the Gulf of Finland. The results point to the effect of long-range contaminant transportation, whether atmospheric or hydrodynamic, and also to the intensive shipping activity in international routes. This study fills the gap of knowledge in this area that has persisted until now. Nevertheless, more studies in this area on the different groups of contaminants are necessary, to specify the factors that are responsible for observed biological effects.     

Heavy metal (As,Cd, Hg,Pb, Cu,Zn, Se) concentrations in muscle and bone of four commercial fish caught in the central Adriatic Sea,Italy

Heavy metal (As, Cd, Cu, Pb, Zn, Hg and Se) concentrations in the muscle and bone of four fish species (Mullus barbatus, Merluccius merluccius, Micromesistius poutassou, and Scomber scombrus) from the central Adriatic Sea were measured and the relationships between fish size (length and weight) and metal concentrations in the tissues were investigated. Samples were analyzed by inductively coupled plasma-atomic emission spectrophotometry with automatic dual viewing. In the muscle, results of linear regression analysis showed that, except for mercury, significant relationships between metal concentrations and fish size were negative. Only mercury levels were positively correlated with Atlantic mackerel size (p?<?0.05). No significant variations of heavy metal concentrations were observed in muscles of the examined species, but a significant difference (p?<?0.01) was found for As, Cd, Pb, and Se concentrations in bone. All the investigated metals showed higher values in the muscle than in bone, except for lead and zinc. Regarding cadmium, lead, and mercury maximum levels, set for the edible portion by European legislation, several samples exceeded these values, confirming the heavy metal presence in species caught near the Jabuka Pit.     

Monitoring mercury in fish in a stream system receiving multiple industrial inputs

Sunfish and a minnow species were used as indicators of anthropogenic mercury contamination in an east Tennessee stream system receiving multiple point and non-point discharges. The monitoring of bluegill (Lepomis macrochirus) and redbreast sunfish (Lepomis auritus) identified bioavailable mercury near three geographically separate industrial facilities, and was able to detect decreases in contamination with distance away from these facilities. In general, total mercury concentrations in the tissue of sunfish in this study were low in comparison to the most commonly cited human health threshold limits, although concentrations at some sites exceeded 1 g/g. Caged blacknose dace (Rhinichthys atratulus) were monitored in conjunction with resident fish as an indicator of more discrete sources in selected headwater streams where fish movement was deemed a potential factor affecting mercury body burdens. Mercury concentrations in muscle tissue of caged dace after 12 weeks exposure were generally low (<0.2 g/g) at all sites but higher than in fish from reference streams. mercury accumulation varied between species (sunfish vs. dace) and monitoring method (caged vs. resident) at the same site, with sunfish tending to accumulate higher concentrations of mercury than resident dace which, in turn, contained about twofold higher concentrations than caged dace. However, the site-to-site pattern of mercury accumulation was similar. This study demonstrates the utility of using small stream dwelling fish with restricted home ranges as a tool for identifying and evaluating the bioavailability of mercury sources in large industrial or urbanized settings.     

Towards generalised reference condition models for environmental assessment: a case study on rivers in Atlantic Canada

Evaluation of the ecological status of river sites in Canada is supported by building models using the reference condition approach. However, geography, data scarcity and inter-operability constraints have frustrated attempts to monitor national-scale status and trends. This issue is particularly true in Atlantic Canada, where no ecological assessment system is currently available. Here, we present a reference condition model based on the River Invertebrate Prediction and Classification System approach with regional-scale applicability. To achieve this, we used biological monitoring data collected from wadeable streams across Atlantic Canada together with freely available, nationally consistent geographic information system (GIS) environmental data layers. For the first time, we demonstrated that it is possible to use data generated from different studies, even when collected using different sampling methods, to generate a robust predictive model. This model was successfully generated and tested using GIS-based rather than local habitat variables and showed improved performance when compared to a null model. In addition, ecological quality ratio data derived from the model responded to observed stressors in a test dataset. Implications for future large-scale implementation of river biomonitoring using a standardised approach with global application are presented.     

Review of the effects of in-stream pipeline crossing construction on aquatic ecosystems and examination of Canadian methodologies for impact assessment

Pipeline crossing construction alters river and stream channels, hence may have detrimental effects on aquatic ecosystems. This review examines the effects of crossing construction on fish and fish habitat in rivers and streams, and recommends an approach to monitoring and assessment of impacts associated with these activities. Pipeline crossing construction is shown to not only compromise the integrity of the physical and chemical nature of fish habitat, but also to affect biological habitat (e.g., benthic invertebrates and invertebrate drift), and fish behavior and physiology. Indicators of effect include: water quality (total suspended solids TSS), physical habitat (substrate particle size, channel morphology), benthic invertebrate community structure and drift (abundance, species composition, diversity, standing crop), and fish behavior and physiology (hierarchy, feeding, respiration rate, loss of equilibrium, blood hematocrit and leukocrit levels, heart rate and stroke volume). The Before-After-Control-Impact (BACI) approach, which is often applied in Environmental Effects Monitoring (EEM), is recommended as a basis for impact assessment, as is consideration of site-specific sensitivities, assessment of significance, and cumulative effects.     

Relationship Between Micro-Invertebrates and Macrophytes in a Wetland: Laguna Iberá (Corrientes, Argentina). Implications for Water Quality Monitoring

From November 2000 to September 2001, eight points in the Iberá lagoon were sampled bimonthly. At each point, pH, temperature and dissolved oxygen were measured and invertebrates were collected from the water around macrophytes by mean of a net of 180 μ m pore size. Four biotic indices were calculated and compared, given similar trends. The total number of taxa shows to be a good and simple indicator of water quality. Averaging indices across points we obtained a good positive correlation between indices and temperature. In this ecosystem, multi-habitat sampling must be used in order to obtain a good estimation of ecological integrity. The total number of taxa can be used for water quality assessment.     

Multimedia environmental monitoring: 50 years at Hanford

Environmental monitoring has been an ongoing activity on the U.S. Department of Energy's Hanford Site in southeastern Washington for almost 50 years. Objectives are to detect and assess potential impacts of Site operations on air, surface and ground waters, foodstuffs, fish, wildlife, soil and vegetation. Data from monitoring effects are used to calculate the overall radiological dose to humans working onsite or residing in nearby communities. In 1989, measured Hanford Site perimeter concentrations of airborne radionuclides were below applicable guidelines. Concentrations of radionuclides and nonradiological water quality in the Columbia River were in compliance with applicable standards. Foodstuffs irrigated with river water taken downstream of the Site showed radionuclide levels that were similar to those found in foodstuffs from control areas. Low levels of ¹³⁷Cs and ⁹⁰Sr in most onsite wildlife samples and concentrations of radionuclides in soils and vegetation from on- and offsite locations were typical of those attributable to worldwide fallout. The calculated dose potentially received by a maximally exposed individual (i.e., based on hypothetical, worst-case assumptions for all routes of exposure) in 1989 (0.05 mrem/yr) was similar to those calculated for 1985 through 1988.In addition to monitoring radioactivity in fish and wildlife, population numbers of key species are determined. Chinook salmon (Oncorhynchus tshawytscha) spawning in the Columbia River at Hanford has increased in recent years with a concomitant increase in winter roosting activity of bald eagles (Haliaeetus leucocephalus). An elk (Cervus elaphus) herd, established by immigration in 1972, is also increasing. The Hanford Site currently serves as a refuge for Canada goose (Branta canadensis), great blue heron (Ardea herodias), and various plants and other animals, e.g., mule deer (Odocoileus hemionus), and coyotes (Canis latrans).     

Characterizing lentic freshwater fish assemblages using multiple sampling methods

Characterizing fish assemblages in lentic ecosystems is difficult, and multiple sampling methods are almost always necessary to gain reliable estimates of indices such as species richness. However, most research focused on lentic fish sampling methodology has targeted recreationally important species, and little to no information is available regarding the influence of multiple methods and timing (i.e., temporal variation) on characterizing entire fish assemblages. Therefore, six lakes and impoundments (48–1,557 ha surface area) were sampled seasonally with seven gear types to evaluate the combined influence of sampling methods and timing on the number of species and individuals sampled. Probabilities of detection for species indicated strong selectivities and seasonal trends that provide guidance on optimal seasons to use gears when targeting multiple species. The evaluation of species richness and number of individuals sampled using multiple gear combinations demonstrated that appreciable benefits over relatively few gears (e.g., to four) used in optimal seasons were not present. Specifically, over 90 % of the species encountered with all gear types and season combinations (N?=?19) from six lakes and reservoirs were sampled with nighttime boat electrofishing in the fall and benthic trawling, modified-fyke, and mini-fyke netting during the summer. Our results indicated that the characterization of lentic fish assemblages was highly influenced by the selection of sampling gears and seasons, but did not appear to be influenced by waterbody type (i.e., natural lake, impoundment). The standardization of data collected with multiple methods and seasons to account for bias is imperative to monitoring of lentic ecosystems and will provide researchers with increased reliability in their interpretations and decisions made using information on lentic fish assemblages.     

Management of invasive populations of the freshwater crayfish <Emphasis Type="Italic">Procambarus clarkii</Emphasis> (Decapoda,Cambaridae): test of a population-control method and proposal of a standard monitoring approach

Invasive species are one of the main threats to biodiversity. When an alien species is introduced into a new environment, fast identification and definition of management strategies may avoid or minimize impacts. When an invasive species is already established, the most adopted approaches are population control and monitoring. In order to perform such strategies, assessment of characteristics of the invasive population is imperative. This study tested a new method of population size estimation and monitoring in an invasive population of crayfish Procambarus clarkii in a conservation area in the Atlantic Rain Forest (Southeastern Brazil). The population dynamics was studied for 1 year to examine the efficacy of the selected method and to evaluate if the population is stable. Later, the effect of periodical removal of animals on the population size was tested. The method of population estimation used in this study proved to be very effective. We recommend using it to monitor invasive populations of P. clarkii. The population size varied discretely over the year with variable but low growth rate, indicating that the population is already established which introduce a notable threat to native species. The continuous removal of specimens proved to be inefficient since the growth rate was higher after the removal. One intensive removal event might be more effective than a continuous moderate removal as the one applied in this study.     

Impact of changed trophic status on the zooplankton composition in six water bodies of Dharwad district, Karnataka state (South India)

Morgan Island, located within the ACE Basin National Estuarine Research Reserve in South Carolina, is home to the only free-ranging colony of rhesus monkeys (Macca mulatta) in the continental United States. The purpose of this study was to assess environmental impacts of the monkey colony on water quality in adjacent tidal creeks and on island vegetation. Three tidal creeks were sampled: Morgan Creek, adjacent to the monkey colony; Back Creek, on Morgan Island not adjacent to the colony; and Rock Creek, on a nearby island unoccupied by monkeys. Temperature, salinity, pH, dissolved oxygen, nutrients and fecal coliform bacteria were measured six times at three sites in each of these creeks, and vegetation change analysis was conducted in a geographic information system using satellite imagery. Results showed elevated fecal coliform concentrations in the Morgan Creek site immediately adjacent to the colony, though no samples exceeded the standard set for recreational water use. Ribotyping reconnaissance matched four Escherichia coli isolates from Morgan and Back Creeks to the monkeys, identifying the colony as one source of fecal coliform bacteria, though relative source loadings could not be quantified. Significant differences were not observed between ammonia or orthophosphate levels in Morgan Creek relative to the other creeks tested; and vegetation change analysis showed a 35% increase in canopy cover between 1979 and 1999. Overall, these results suggest that the rhesus colony’s environmental impacts are localized and minimal. Results from this study provide baseline data on Morgan Island and may be useful in management decisions regarding the future of the monkey colony.     

The value of long-term environmental monitoring programs: an Ohio River case study

As a subset of environmental monitoring, fish sampling programs have been an important part of assessing the potential impacts of water withdrawals and effluent discharges on fish populations for many years. New environmental regulations often require that adverse environmental impacts to fish populations be minimized. Without long-term field data, population evaluations may incorrectly indicate adverse impacts where none exist or no impact where one is likely to occur. Several electric utility companies have funded the Ohio River Ecological Research Program, which has been in existence for over 40 years and consists of fish, habitat, and water quality studies at multiple power plant sites on the mainstem Ohio River. Sampling includes seasonal night-time electrofishing and daytime beach seining at three upstream and three downstream locations near each plant. The long-term nature of the program allows for the establishment of aquatic community indices to support evaluations of technology performance, the collaborative development of compliance metrics, and the assessment of fish population trends. Studies have concluded that the Ohio River fish community has improved in response to better water quality and that power plant fish entrainment and impingement and thermal discharges have had little or no measureable impact. Through collaboration and the use of long-term data, $6.3 million in monitoring costs have been saved during recent fish impingement studies. The ability to access a multiyear fish abundance database, with its associated data on age, growth, and fecundity, improves the quality of such evaluations and reduces the need for extensive field sampling at individual locations.     

Using Baetidae Species as Biological Indicators of Environmental Degradation in a Brazilian River Basin

The Ephemeroptera family Baetidae is one of the most specious families in the Neotropical region and a great effort to improve the taxonomy of this group has been made over the last 10 years in South America. Such studies now enable the development of biomonitoring tools at species-level in the region. A total of 2,199 baetids were collected from seven sampling sites, collected three times (autumn, winter and summer), representing an environmental gradient, draining an area of Atlantic Forest remnants. We describe the mesohabitat of nine Baetidae species and evaluate their responses to environmental degradation and water chemistry by means of biological measures (richness and abundance) and multivariate analysis (Canonical Correspondence Analysis), in order to assess their potential capacity as indicators of these impacts. Most species were found predominantly associated with stony substrates, but some were associated with pool litter, and one species was found predominantly in riffle litter substrate. Species distribution was influenced by the environmental gradient. Based on the CCA ordination, we were able to identify which species were found in pristine versus the most impaired areas, therefore enabling us to establish the sensitivity of each species.