A modified drinking water quality index (DWQI) for assessing drinking source water quality in rural communities of Khuzestan Province,Iran

We reconsidered the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) to achieve an efficient drinking water quality index (DWQI) for assessment of drinking source water quality in rural communities of Khuzestan Province, Iran in 2009–2013. In contribution with a panel of water quality experts, the CCME WQI was mainly modified by four changes: (1 and 2) assigning weight factors for input parameters and index factors, (3) modifying excursion concept for carcinogens and bioaccumulative pollutants and (4) removing effect of unequal measurements of input parameters. The DWQI characterizes the drinking source water quality through comparing the measured values of input parameters with relevant benchmarks. The DWQI score (from 0 to 100) classifies the water quality in five categories as poor (0–54.9), marginal (55.0–69.9), fair (70.0–84.9), good (85.0–94.9) and excellent (95.0–100). Based on the DWQI, the temporal changes of the rural drinking source water quality were not significant; while the spatial variations of the water quality were considerable across the province, so the DWQI scores in the northern counties were higher than that in the southern ones. At the county level, the highest and lowest average scores of the DWQI (±standard deviation: SD) were observed in Izeh and Shadegan to be 90 ± 5 and 69 ± 10, respectively. Based on the DWQI, proportions of the drinking water sources with the excellent, good, fair, marginal and poor qualities were determined to be 6.7, 59.1, 26.2, 7.8 and 0.1%, respectively. Turbidity and Ryznar Index (RI) were introduced respectively as the health-based and esthetic parameters with the most violations (22.7 and 63.2%, respectively). The results of the case study and sensitivity analysis indicated that the DWQI is a simple, flexible, stable and reliable index and could be used as an effective tool to characterize drinking source water quality.     

Evaluation of sediment profile imagery as a tool for assessing water quality in Greenwich Bay,Rhode Island,USA

The Benthic Habitat Quality (BHQ) index was used to assess habitat visible in sediment profile images (SPI) following hypoxia disturbance in a shallow (<10 m) estuarine embayment in Rhode Island, USA. We tested for associations between the BHQ, SPI features and water quality over several assessment windows (1, 3, 7, 14, and 28 days prior to imaging) and at multiple dissolved oxygen (DO) thresholds (2.0 mg l^?1, 2.9 mg l^?1, and 4.8 mg l^?1). Using categorical data analysis, we established empirical relationships between hypoxia prevalence and presence/absence of biogenic features visible in SPI. Fecal pellets, tubes, feeding pits, voids, mounds, and BHQ score were good affirmative features, meaning that their presence (or score greater than 5) indicated a high probability of good water quality. However, low sensitivity to hypoxia precluded their usefulness as indicators, and was attributed to rarity in images and to factors acting on time intervals longer than those examined, e.g. long-term organic enrichment or hypoxia. Burrow structures and the apparent redox potential discontinuity (aRPD), or oxidized layer of surface sediment, were good discriminatory features, with high sensitivity and specificity for both hypoxia and normoxia. Both were strong surrogates for water quality over multiple assessment windows and DO thresholds, and had the highest overall predictive values. We conclude that SPI images can be used to widen the spatial extent of water quality monitoring efforts by utilizing the relationships between aRPD, burrows and hypoxia prevalence.     

Environmental determinants of Gulf Menhaden (Brevoortia patronus) oil content in the northern Gulf of Mexico

Gulf Menhaden (Brevoortia patronus) are a species of commercial and ecological importance in the northern Gulf of Mexico, provisioning the second largest fishery by weight, in the United States, and providing critical ecosystem services in the coastal region. The recruitment and productivity dynamics of the stock are influenced by a suite of environmental factors but an understanding of the factors that determine individual variation in oil content (an indicator of an individual’s commercial value to the fishery and its dietary value to predators) has not been well described. In this work I describe the temporal dynamics of oil content and determine the demographic characteristics that provide predictive power to describe annual contrasts. I relate the predicted patterns in oil yield to a suite of seasonal environmental data series including: the magnitude of spring Mississippi River discharge, spring wind vectors, and the preceding winter El Nino conditions. Two uncorrelated (r = 0.06, p = 0.81) population-level predictor variables were identified that have explanatory power to describe temporal patterns in oil content (L kg⁻¹); a weight-at-length power function parameter (a) and the von Bertalanffy asymptotic fork length (L_∞, mm FL): L kg⁻¹ = − 0.158 − 0.026*a − 0.00163*L_∞ (p < 0.05, R² = 0.42). Analysis of the impacts of environmental variables on the oil content of Gulf Menhaden was evaluated comprehensively in a Bayesian framework by transforming the observed oil content information from two sources to a common scale. Parameters relating oil content to spring Mississippi River discharge and the preceding winter (December–February) El Nino Southern Oscillation index resulted in sample distributions from the posterior where zero was outside the 95% credible interval. This work contributes to the understanding of Gulf Menhaden as a prey species in the Gulf of Mexico and indicates that the value of the species to both the fishery and predators exhibits relatively large inter-annual variability controlled, in part, by seasonal environmental conditions.     

Prioritizing conservation for the reduction of Gulf hypoxia using an environmental performance index

The annual growth of hypoxia in the Gulf of Mexico is largely attributed to agricultural nutrient loadings that originate from the Mississippi/Atchafalaya River Basin (MARB). To effectively target conservation efforts throughout the entire MARB in order to reduce Gulf hypoxia, strategies to rank areas according to their impact on both agricultural production and ecosystem services are extremely important. In this paper, we utilize an Environmental Performance Index (EPI) to rank regions within the MARB according to their environmental performance, that is, their ability to produce agricultural outputs while minimizing nutrient loadings to the Gulf of Mexico. We compare our index rankings to previously used rankings of delivered yields alone and find the spatial distribution of rankings changes considerably when accounting for agricultural productivity. For example, the Corn Belt regions of central Iowa and northern Illinois no longer make up the lowest performing regions of the MARB after accounting for their high levels of agricultural production. Instead, regions along the Missouri river including central Missouri, western Iowa, and southeastern South Dakota as well as areas near the Ohio river including southern Illinois, western Kentucky, and southern Ohio now count among the lowest performing regions using the EPI ranking scheme. We suggest that incorporation of economic production value into large-scale prioritization of agricultural conservation within the MARB is essential to effectively reduce Gulf hypoxia while maintaining food security from efficient farm production.     

Restoration of wetlands in the Mississippi–Ohio–Missouri (MOM) River Basin: Experience and needed research

An ecological and hydrologic restoration of the Mississippi–Ohio–Missouri (MOM) Basin in the United States is proposed as the solution to the reccurring hypoxic conditions in the Gulf of Mexico. Nitrate–nitrogen is the cause of this eutrophication in the Gulf and its source is mainly due to increased fertilizer use in the American Midwest. In that same Midwest, the land has also been artificially drained and 80–90% of the original wetlands have been lost. Our proposed restoration involves the strategic creation and restoration of 2.2 million ha of wetlands in the MOM basin where in-field wetlands intercept agricultural runoff and diversion wetlands are overflowed by flooding river water. Case studies that total 50 wetland-years of data from Illinois, Ohio, and Louisiana are summarized as the basis for the restoration area estimate. Benefits of this restoration, in addition to solving the Gulf hypoxia, include water quality improvement, reduction of public health threats, habitat creation, and flood mitigation that will accrue to the locations in the MOM basin where the restoration occurs. Before the restoration commences, there is a need for formal and rigorous large-scale research in the basin to reduce uncertainties.     

Future changes in summer MODIS-based enhanced vegetation index for the South-Central United States

Evaluating the response of vegetation to climate change is relevant to improving the management of both human and natural systems. Here, we quantify the response of the MODIS-based enhanced vegetation index (EVI) to temperature, precipitation, and large-scale natural variability across the South-Central U.S. for summer (JJA) from 2000 to 2013. We find statistically significant relationships between climate and EVI that vary across the region and are distinct for each land cover type: the mean coefficient of determination (R²) between EVI and climate is greatest for pasture (0.61 ± 0.13) and lowest for forest (0.55 ± 0.14). Among the climate variables, three-month cumulative precipitation has the strongest influence on summer vegetation, particularly in semi-arid west Texas and eastern New Mexico. Summer monthly maximum temperature plays an important role in the eastern half of Texas and Oklahoma, moderated by the influence of both Atlantic and Pacific teleconnection indices over inter-annual time scales. Based on these relationships, we train, cross-validate, and, where statistically significant relationships exist, combine this multivariate predictive model with projected changes in teleconnection indices and statistically-downscaled temperature and precipitation from 16 CMIP5 global climate models to quantify future changes in EVI. As global mean temperature increases, projected EVI decreases, indicative of stressed and dry vegetation, particularly for grasslands as compared to other land types, and in Oklahoma and western, central and Gulf Coast Texas for mid- and end-of-century. These trends have potentially important implications for agriculture and the regional economy, as well as for ecosystems and endemic species that depend on vegetation.     

Summer fish communities in northern Gulf of Mexico estuaries: Indices of ecological condition

We used fish community data from trawl samples collected from >100 estuaries, bayous, and coastal lagoons of the Louisianan Biogeographic Province (Gulf of Mexico) to develop indicators of large-scale ecological condition. One data set, from which we derived reference values for fish community indicators, was based on bottom trawl samples collected from 367 randomly located sites during the summers of 1992–1994. A second trawl data set with similar geographic scope from 2000 to 2004 was used to test the robustness of the indicators derived from the reference data set to new data. We constructed a fish community index (FCI) from three basic indicators: number of species per trawl, total abundance per trawl, and an index of trophic balance among three common feeding guilds. The FCI was not correlated with salinity over a range from freshwater to marine and hypersaline conditions (0–52 psu). Direct correlations between the index and environmental variables generally were weak, although some were significant (p < 0.05). The FCI was negatively correlated with water clarity (secchi depth), water column depth, and sediment toxicity; correlations of the FCI with pH, sediment organic carbon, and sediment silt + clay content were positive. There was a hyperbolic relationship between dissolved oxygen and maximum values of the index, and no significant correlation with watershed land cover at the whole-estuary or estuary-complex scale. Values of all indicators increased between the two time periods. The FCI is a broad indicator of ecological condition for estuaries within the Louisianan Province, with data aggregated at scales ranging from large estuaries to the entire region. Sample density was insufficient to judge performance of the indicators or index at smaller scales.     

Impact of landscape pattern at multiple spatial scales on water quality: A case study in a typical urbanised watershed in China

Buffer zones along rivers and streams can provide water quality services by filtering nutrients, sediment and other contaminants from the surface. Redundancy analysis was used to determine the influence of the landscape pattern at the entire catchment scale and at multiple buffer zone scales (100 m, 300 m, 500 m, 1000 m and 1500 m) on the water quality in a highly urbanised watershed. Change-point analysis was further applied to estimate the specific locations along a gradient of landscape metric that result in a sudden change in the water quality variable. The landscape characteristics for 100 m buffer zones appeared to have a slightly greater influence on the water quality than the entire catchment. The patch density of urban land and the large patch index of water were recognised as the dominant variables influencing the water quality for a 100 m buffer zone. The result of change-point analysis indicated key interval values of the two landscape metrics within the 100 m buffer zone. When the patch density of urban land was >30–40 n/100 ha and the largest patch index of water was >2.5–3.5%, the watershed water quality appeared to be better protected.     

Performance of the Phytoplankton Index for Lakes (IPLAC): A multimetric phytoplankton index to assess the ecological status of water bodies in France

A new phytoplankton-based index was designed to respond to the Water Framework Directive (WFD) requirements concerning the assessment of lake ecological status. The “Indice Phytoplancton Lacustre” (IPLAC) is a multimetric index, taking into account biomass, abundance and species composition of communities. The first metric is based on the total phytoplankton biomass (MBA), the second on the abundance and taxonomic composition (MCS) of 165 indicator taxa. The IPLAC was developed on 2 independent databases, one for the calibration and the second for the validation of the metrics. The calibration dataset was composed of 255 “lake-years” from 214 distinct lakes sampled between 2005 and 2012. The validation dataset included 173 lake-years in order to confirm the response of the index to the trophic gradient and anthropogenic pressure.The results show that the IPLAC correctly highlights chemical pressure (eutrophication). Especially high Pearson correlations are shown with total phosphorus (r = −0.71, p-value <0.001), chlorophyll-a (r = −0.83, p-value <0.001) and water transparency (r = 0.73, p-value <0.001) which are the main proxies for the trophic level. Corine land cover was used as an indication of the anthropogenic pressure and good correlations are also found with the watershed land use, negatively correlated with agricultural area (r = −0.60, p-value <0.001), population density (r = −0.36, p-value <0.001) and positively with forest area (r = 0.57, p-value <0.001).The index is WFD-compliant and is dedicated to natural lakes and artificial water bodies in metropolitan France, and will be routinely used by the French Ministry of the Environment to assess lake ecological status through the phytoplankton community. However, the results must be carefully interpreted in two cases: reservoirs with large water level fluctuations, and samples that include less than 5 indicator species.     

Monitoring,management, and mitigation of Karenia blooms in the eastern Gulf of Mexico

Annual blooms of the toxic dinoflagellate Karenia brevis in the eastern Gulf of Mexico represent one of the most predictable global harmful algal bloom (HAB) events, yet remain amongst the most difficult HABs to effectively monitor for human and environmental health. Monitoring of Karenia blooms is necessary for a variety of precautionary, management and predictive purposes. These include the protection of public health from exposure to aerosolized brevetoxins and the consumption of toxic shellfish, the protection and management of environmental resources, the prevention of bloom associated economic losses, and the evaluation of long term ecosystem trends and for potential future bloom forecasting and prediction purposes. The multipurpose nature of Karenia monitoring, the large areas over which blooms occur, the large range of Karenia cell concentrations (from 5 × 10³ cells L^?1 to >1 × 10⁶ cells L^?1) over which multiple bloom impacts are possible, and limitations in resources and knowledge of bloom ecology have complicated K. brevis monitoring, mitigation and management strategies. Historically, K. brevis blooms were informally and intermittently monitored on an event response basis in Florida, usually in the later bloom stages after impacts (e.g. fish kills, marine mammal mortalities, respiratory irritation) were noted and when resources were available. Monitoring of different K. brevis bloom stages remains the most practical method for predicting human health impacts and is currently accomplished by the state of Florida via direct microscopic counts of water samples from a state coordinated volunteer HAB monitoring program. K. brevis cell concentrations are mapped weekly and disseminated to stakeholders via e-mail, web and toll-free phone numbers and provided to Florida Department of Agriculture and Consumer Services (FDACS) for management of both recreational and commercial shellfish beds in Florida and to the National Oceanic and Atmospheric Administration (NOAA) for validation of the NOAA Gulf of Mexico HAB bulletin for provision to environmental managers. Many challenges remain for effective monitoring and management of Karenia blooms, however, including incorporating impact specific monitoring for the diverse array of potential human and environmental impacts associated with blooms, timely detection of offshore bloom initiation, sampling of the large geographic extent of blooms which often covers multiple state boundaries, and the involvement of multiple Karenia species other than K. brevis (several of which have yet to be isolated and described) with unknown toxin profiles. The implementation and integration of a diverse array of optical, molecular and hybrid Karenia detection technologies currently under development into appropriate regulatory and non-regulatory monitoring formats represents a further unique challenge.     

Vertical migration of Karenia brevis in the northeastern Gulf of Mexico observed from glider measurements

The toxic marine dinoflagellate, Karenia brevis (the species responsible for most of red tides or harmful algal blooms in the Gulf of Mexico), is known to be able to swim vertically to adapt to the light and nutrient environments, nearly all such observations have been made through controlled experiments using cultures. Here, using continuous 3-dimensional measurements by an ocean glider across a K. brevis bloom in the northeastern Gulf of Mexico between 1 and 8 August 2014, we show the vertical migration behavior of K. brevis. Within the bloom where K. brevis concentration is between 100,000 and 1,000,000 cells L⁻¹, the stratified water shows a two-layer system with the depth of pycnocline ranging between 14–20 m and salinity and temperature in the surface layer being <34.8 and >28 °C, respectively. The bottom layer shows the salinity of >36 and temperature of <26 °C. The low salinity is apparently due to coastal runoff, as the top layer also shows high amount of colored dissolved organic matter (CDOM). Within the top layer, chlorophyll-a fluorescence shows clear diel changes in the vertical structure, an indication of K. brevis vertical migration at a mean speed of 0.5–1 m h⁻¹. The upward migration appears to start at sunrise at a depth of 8–10 m, while the downward migration appears to start at sunset (or when surface light approaches 0) at a depth of ∼2 m. These vertical migrations are believed to be a result of the need of K. brevis cells for light and nutrients in a stable, stratified, and CDOM-rich environment.     

A framework to assess the health of rocky reefs linking geomorphology,community assemblage,and fish biomass

The recovery of historic community assemblages on reefs is a primary objective for the management of marine ecosystems. Working under the overall hypothesis that, as fishing pressure increases, the abundance in upper trophic levels decreases followed by intermediate levels, we develop an index that characterizes the comparative health of rocky reefs. Using underwater visual transects to sample rocky reefs in the Gulf of California, Mexico, we sampled 147 reefs across 1200 km to test this reef health index (IRH). Five-indicators described 88% of the variation among the reefs along this fishing-intensity gradient: the biomass of piscivores and carnivores were positively associated with reef health; while the relative abundances of zooplanktivores, sea stars, and sea urchins, were negatively correlated with degraded reefs health. The average size of commercial macro-invertebrates and the absolute fish biomass increased significantly with increasing values of the IRH. Higher total fish biomass was found on reefs with complex geomorphology compared to reefs with simple geomorphology (r² = 0.14, F = 44.05, P < 0.0001) and the trophic biomass pyramid also changed, which supports the evidence of the inversion of biomass pyramids along the gradient of reefs’ health. Our findings introduce a novel approach to classify the health of rocky reefs under different fishing regimes and therefore resultant community structures. Additionally, our IRH provides insight regarding the potential gains in total fish biomass that may result from the conservation and protection of reefs with more complex geomorphology.     

Nitrate-nitrogen retention in wetlands in the Mississippi River Basin

Nitrate-nitrogen retention as a result of river water diversions is compared in experimental wetland basins in Ohio for 18 wetland-years (9 years × 2 wetland basins) and a large wetland complex in Louisiana (1 wetland basin × 4 years). The Ohio wetlands had an average nitrate-nitrogen retention of 39 g-N m⁻² year⁻¹, while the Louisiana wetland had a slightly higher retention of 46 g-N m⁻² year⁻¹ for a similar loading rate area. When annual nitrate retention data from these sites are combined with 26 additional wetland-years of data from other wetland sites in the Basin Mississippi River (Ohio, Illinois, and Louisiana), a robust regression model of nitrate retention versus nitrate loading is developed. The model provides an estimate of 22,000 km² of wetland creation and restoration needed in the Mississippi River Basin to remove 40% of the nitrogen estimated to discharge into the Gulf of Mexico from the river basin. This estimated wetland restoration is 65 times the published net gain of wetlands in the entire USA over the past 10 years as enforced by the Clean Water Act and is four times the cumulative total of the USDA Wetland Reserve Program wetland protection and restoration activity for the entire USA.     

An index approach to assess nitrogen losses to the environment

Nitrogen (N) losses from agriculture are negatively impacting groundwater, air, and surface water quality. New tools are needed to quickly assess these losses and provide nutrient managers and conservationists with effective tools to assess the effects of current and alternative management practices on N loss pathways. A new N-Index tool was developed in spreadsheet format, allowing prompt assessments of management practices on agricultural N losses. The N-Index tool was compared with experimental field data and shown to estimate the effects of management practices on N loss pathways (probability, P < 0.001). The N-Index correctly assessed the nitrate nitrogen (NO₃-N) leaching losses when tested against measured NO₃-N leaching data and atmospheric N losses collected over multiple years (annual basis) and locations. The N-Index tool was developed with international cooperation from several countries and there is potential to use this tool at the international level.     

Decreased lower limb muscle recruitment contributes to the inability of older adults to recover with a single step following a forward loss of balance

In response to a balance disturbance, older individuals often require multiple steps to prevent a fall. Reliance on multiple steps to recover balance is predictive of a future fall, so studies should determine the mechanisms underlying differences between older adults who can and cannot recover balance with a single step. This study compared neural activation parameters of the major leg muscles during balance recovery from a sudden forward loss of balance in older individuals capable of recovering with a single step and those who required multiple steps to regain balance. Eighty-one healthy, community dwelling adults aged 70 ± 3 participated. Loss of balance was induced by releasing participants from a static forward lean. Participants performed four trials at three initial lean magnitudes and were subsequently classified as single or multiple steppers. Although step length was shorter in multiple compared to single steppers (F = 9.64; p = 0.02), no significant differences were found between groups in EMG onset time in the step limb muscles (F = 0.033–0.769; p = 0.478–0.967). However, peak EMG normalised to values obtained during maximal voluntary contraction was significantly higher in single steppers in 6 of the 7 stepping limb muscles (F = 1.054–4.167; p = 0.045–0.024). These data suggest that compared to multiple steppers, single steppers recruit a larger proportion of the available motor unit pool during balance recovery. Thus, modulation of EMG amplitude plays a larger role in balance recovery than EMG timing in this context.     

Comparative study of ecological indices for assessing human-induced disturbance in coastal wetlands of the Laurentian Great Lakes

Several ecological indices have been developed to evaluate the wetland quality in the Laurentian Great Lakes. One index, the water quality index (WQI) can be widely applied to wetlands and produces accurate measurements of wetland condition. The WQI measures the degree of water quality degradation as a result of nutrient enrichment and road runoff. The wetland fish index (WFI), wetland zooplankton index (WZI), and the wetland macrophyte index (WMI), are all derived from the statistical relationships of biotic communities along a gradient of deteriorating water quality. Compared to the WQI, these indices are less labor-intensive, cost less, and have the potential to produce immediate results. We tested the relative sensitivity of each biotic index for 32 Great Lakes wetlands relative to the WQI and to each other. The WMI (r² = 0.84) and WFI (r² = 0.75) had significant positive relationships (P < 0.0001) with the WQI in a linear and polynomial fashion. Slopes of the WMI and WFI were similar when comparing the polynomial regressions (ANCOVA; P = 0.117) but intercepts were significantly different (P = 0.004). The WZI had a positive relationship with the WQI in degraded wetlands and a negative relationship in minimally impacted wetlands. The strengths and weaknesses of each index can be explained by the interactions among fish, zooplankton, aquatic plants and water chemistry. The distribution of different species indicative of low and high quality in each index provides insight into the relative wetland community composition in different parts of the Great Lakes and helps to explain the differences in index scores when different organisms are used. Our findings suggest that the WMI and WFI produce comparable results but the WZI should not be used in the minimally impacted wetlands without further study.     

Dissolved reactive manganese as a new index determining the trophic status of limnic waters

Dissolved reactive manganese seems to be one of the parameters which determines the trophic status of limnic waters, as suggested by its strong correlations with total phosphorus, chlorophyll a, and water pH. The determination of the trophic status involved the application of reactive manganese due to its bioavailability, providing information on the actual, not just the potential (as in the case of total phosphorus or total organic carbon), threat of water eutrophication.The calculation of trophic states index (TSI) based on the reactive manganese concentration, as determined by TSI_DRMn = 20.61 ln (DRMn) − 35.03, permits the rational assessment of the trophic status of lakes. Oligotrophic lakes are distinguished by concentrations of DRMn < 25 μg/L, mesotrophic by 25–60 μg/L, eutrophic by 60–150 μg/L, and hypertrophic by >150 μg/L.The trophic status of 25 lakes located in central Europe in north-eastern Poland was determined based on the proposed “manganese index” and verified by commonly applied indices proposed by Carlson, Kratzer and Brezonik, and Dunalska.     

Lake macroinvertebrate assemblages and relationship with natural environment and tourism stress in Jiuzhaigou Natural Reserve,China

With increasing human population and urbanization, tourism in natural reserves and other protected lands is growing. It is critical to monitor and assess the impacts of tourism on ecosystem health. However, there is a general lack of information on biological communities in natural reserves of developing countries and of tools for assessing human impacts. In the present study, we investigated macroinvertebrate assemblages in nine lakes in Jiuzhaigou Natural Reserve of China. Both benthic (20 dips of D-net) and light-trap samples (2 h) were collected at each lake and all benthic specimens and adults of Ephemeroptera, Plecoptera, and Trichoptera (EPT) were identified and counted. Water temperature and water quality variables were measured on site or in the Lab. Seventy taxa were recorded and dominated by dipterans and caddisflies. Light traps contributed 47% of taxa richness and 66% of EPT richness at the lakes. Detrended Correspondence Analysis showed that water temperature and tourism index were strongly associated with the changes of assemblage composition. Taxa richness and EPT richness calculated for the composite samples (benthic + light trap) were well fit with Poisson generalized linear model (adjusted R² = 0.83 and 0.85, respectively), generally decreasing with increasing elevation, tourism index, and total-N. Tourism index was ranked as the top predictor for EPT richness based on multiple model weights, and elevation for taxa richness. In comparison, when based on benthic samples, neither of the metrics could be fitted with the seven environmental variables selected. These findings highlight the benefit of combined use of the sampling methods for lake monitoring and offered an analytical guide to developing biological indicators of lake ecosystem health in protected areas.