Evaluating ecosystem health of the Seven Maar Lakes of San Pablo City, Philippines using phytoplankton index of biotic integrity (Phyto-IBI)

To investigate the health of the Diannong River water ecosystem, we collected and analyzed phytoplankton, zooplankton, and microorganisms from the Diannong River in April, July, and October 2021. We also analyzed the physical and chemical factors of the water environment and analyzed the habitat quality. The reference points were determined by the habitat composite index and water quality score. Phytoplankton index of biotic integrity (P-IBI), Zooplankton index of biotic integrity (Z-IBI), and microbial index of biotic integrity (M-IBI) which evaluated the health status of Diannong River were constructed by distribution range analysis, discriminatory ability analysis and correlation analysis of candidate biological indicators. Stepwise regression analysis and path coefficient analysis were conducted to determine the environmental factors driving the changes in aquatic IBI. The results showed that the indicators of P-IBI were the number of Cyanobacteria taxonomic units %, the number of Green Algae taxonomic units%, the relative abundance of Euglena, the relative abundance of Green Algae, and the relative abundance of toxic-producing algae. The indicators of Z-IBI were the total number of zooplankton taxonomic units, the relative abundance of Copepods, the relative abundance of the top 3 dominant species, and the Simpson index; the indicators of M-IBI were the Observed species, the relative abundance of Chloroflexi, the relative abundance of Proteobacteria, the relative abundance of the highest dominant taxonomic unit, the relative abundance of the top 5 dominant taxonomic units, the relative abundance of pollution intermediate genus, and the Ace index. The results of the IBI evaluation for three aquatic organisms showed that most of the sites in the upper reaches of the Diannnong River were at healthy or healthier levels; most of the sites in the middle reaches of the Diannnong River and the Yuehai Lake area were at mediocre or poor levels; and most of the sites in the downstream reaches of the Diannong River were average or mediocre levels. the main water environment factors driving the changes in P-IBI were water temperature (WT) and pH. The main water environment factors driving the changes in Z-IBI were total dissolved solids (TDS), WT and total nitrogen (TN); the main water environment factors driving the changes of M-IBI were fluoride ion (F−) and electrical conductivity (EC). This study provides the scientific reference for the application of the index of biotic integrity (IBI) for a variety of aquatic organisms in the river and lake waters and a basis for the management and optimization of the Diannong River aquatic ecosystem.

Nearshore fish community assessment on Lake Ontario and the St. Lawrence River: A trap net-based index of biotic integrity

We evaluated the performance of an index of biotic integrity (IBI) based on 16 fish population metrics of three types: species richness, community assemblage, and trophic composition. Two sets of central Minnesota lakes independent from the original set of lakes used to develop the IBI model were used to validate it. One set of lakes (n = 15) had physical features similar to those used to develop the IBI, while the other set (n = 22) averaged 9 m shallower with 28% more littoral area. We used general linear models to test whether the relationships between IBI or individual metric score and indicators of lake quality (trophic state, floristic quality, or surrounding land use) were the same or differed for the original IBI data set and each new data set. Responses were similar among all data sets, lake IBI scores and individual metrics reflecting differences in land use, trophic state, and aquatic habitat. Sensitivity of individual metrics to different measures of stress varied, supporting the need for a multimetric approach when assessing the biotic integrity of lakes. Index of biotic integrity scores were most highly correlated with trophic state (rho = −0.80). Our results support the validity of the original fish-based IBI as a standardized method for quantitatively measuring the condition of fish assemblages and implied overall biotic integrity of small central Minnesota lakes. As with any model, however, continued evaluation is recommended, especially when applying this IBI to lakes with different physical, chemical, or biological characteristics.

African tropical rainforests, and especially their freshwater biodiversity, are seriously threatened by ongoing industrial deforestation. Sound ecological management is needed to ensure the sustainability of these resources. For this purpose, an index of biotic integrity (IBI), based on fish assemblage characteristics, is developed in this paper. It is used to quantify the impact of industrial deforestation on freshwater biodiversity. Data from 30 non-impacted sites were used to develop a series of compositional, structural and functional metrics that reflect sites with a high biotic integrity, i.e. what a stream-fish community should look like in the absence of human perturbation. These data were compared to data collected from sites subjected to substantial forest watershed loss, in order to identify those IBI metrics that best distinguish streams with high and low biotic integrity. The overall IBI scores reflected the quality of the watershed conditions. In addition, there was a close agreement between an index of environmental quality, based on water and habitat quality and the IBI scores, suggesting that the different biological responses of the fish assemblages (observed differences in the IBI scores) were indicative of differences in physico-chemical quality of the streams. The ability of the proposed IBI to index water resource degradation, due to deforestation, suggests that it can be used as a tool for biological monitoring. However, more consistent and comprehensive data are needed to further refine the IBI, especially the assignment of integrity classes and metric threshold values.

We modified the Index of Biotic Integrity (IBI) to characterize the fish assemblages and evaluate the biotic integrity of four forested streams in the Lower Ouachita Mountains Ecoregion, Arkansas. We related differences in IBI scores with corresponding differences in chemical and physical characteristics of the streams, including the varying intensities of forest management. Analysis of variance and comparison of mean IBI scores among the four streams revealed significant differences between reference and even-aged treatments and between even-aged and uneven-aged treatments (P < 0.05). Turbidity and total suspended solids were inversely related to IBI scores. Further refinement of the IBI should enable its use in the Ouachita Mountains Ecoregion to help assess site impacts, monitor trends in stream biotic integrity, and assess effectiveness of forest best management practices.

Application of neural networks to quantify the utility of indices of biotic integrity for biological monitoring

Anthropogenic activities impacted the ecological health of rivers by altering the physical habitat and water flow as well as by pollution. Monitoring of biotic groups for gauging the river health is a prerequisite for assessing the extent of degradation and formulating management guidelines for river restoration. An assessment using fish-based index of biotic integrity (IBI) was carried out in the Central Indian river, Tapti, for probing its health status. For the multimetric index, twelvemetrics were adopted under five categories: taxonomic richness, habitat composition, tolerance indicators, species resilience, and trophic composition. Among the studied sites, Betul in the upper stretch was selected as the reference site for River Tapti, which almost meets the upper expectation of the metrics explored. Continuous scoring method was applied to evaluate the biotic integrity in the selected sites of the river. The IBI score based on the pooled fish abundance data in River Tapti ranged from 33 to 60. Assessment of the ecological health revealed that three-fourth of the river stretch was moderately impaired (25-50% of impairment) and the most deteriorated site was Kamrej with 45% of impairment which might be due to its location in the urban area with high influx of domestic sewage and industrial effluents. The IBI scores were plotted and compared with an independent estimate of water quality. The CCA with environmental and IBI variables revealed higher correlation with each other and the functional groups such as carnivores, herbivores, and fishes with high population doubling time (PDT) were found in close association with nitrate-N, total alkalinity, and specific conductivity. The study urges the need for the adoption of proper management and mitigation measures to restore the health and wealth of aquatic ecosystem.

Measurement of ecosystem health is a very important but often difficult and sometimes fractious topic for applied ecologists. It is important because it can provide information about effects of various external influences like chemical, nuclear, and physical disturbance, and invasive species. Ecosystem health is also a measure of the rate or trajectory of degradation or recovery of systems that are currently suffering impact or those where restoration or remediation have taken place. Further, ecosystem health is the single best indicator of the quality of long term environmental stewardship because it not only provides a baseline condition, but also the means for future comparison and evaluation. Ecosystem health is difficult to measure because there are a nearly infinite number of variables and uncertainty as to which suites of variables are truly indicative of ecosystem condition. It would be impossible and prohibitively expensive to measure all those variables, or even all the ones that were certain to be valid indicators. Measurement of ecosystem health can also be a fractious topic for applied ecologists because there are a myriad of opinions as to which variables are the most important, most easily measured, most robust, and so forth. What is required is an integrative means of evaluating ecosystem health. All ecosystems are dynamic and undergo change either stochastically, intrinsically, or in response to external influences. The basic assumption about change induced by exogenous antropogenic influences is that it is directional and measurable. Historically measurements of surrogate parameters have been used in an attempt to quantify these changes, for example extensive water chemistry data in aquatic systems. This was the case until the 1980's when the Index of Biotic Integrity (IBI) (Karr et al. 1986), was developed. This system collects an array of metrics and fish community data within a stream ecosystem and develops a score or rating for the relative health of the ecosystem. The IBI, though originally for Midwestern streams, has been successfully adapted to other ecoregions and taxa (macroinvertebrates, Lombard and Goldstein, 2004) and has become an important tool for scientists and regulatory agencies alike in determining health of stream ecosystems. The IBI is a specific type of a larger group of methods and procedures referred to as Rapid Bioassessment (RBA). These protocols have the advantage of directly measuring the organisms affected by system perturbations, thus providing an integrated evaluation of system health because the organisms themselves integrate all aspects of their environment and its condition. In addition to the IBI, the RBA concept has also been applied to seep wetlands (Paller et al. 2005) and terrestrial systems (O'Connell et al. 1998, Kremen et al. 1993, Rodriguez et al. 1998, Rosenberg et al. 1986). Terrestrial RBA methods have lagged somewhat behind those for aquatic systems because terrestrial systems are less distinctly defined and seem to have a less universal distribution of an all-inclusive taxon, such as fish in the IBI, upon which to base an RBA. In the last decade, primarily in Australia, extensive development of an RBA using ant communities has shown great promise. Ants have the same advantage for terrestrial RBAs that fish do for aquatic systems in that they are an essential and ubiquitous component of virtually all terrestrial ecosystems. They occupy a broad range of niches, functional groups, and trophic levels and they possess one very important characteristic that makes them ideal for RBA because, similar to the fishes, there is a wide range of tolerance to conditions within the larger taxa. Within ant communities there are certain groups, genera, or species that may be very robust and abundant under even the harshest impacts. There are also taxa that are very sensitive to disturbance and change and their presence or absence is also indicative of the local conditions. Also, as with the aquatic RBAs using macroinvertebrates, ants have a wide variety of functional foraging or feeding groups, by whose abundance or scarcity an evaluation of the system health may be made. Much of the ground work has been done for useful ant RBAs, but it has primarily been in Australia, Europe, the US desert Southwest, and South America. However, the work already done will transport well to other ecoregions and as has been done with the IBI, it could be adapted with an appropriate investment of time and resources. It would be necessary to establish taxonomic expertise, allocate the local ant fauna to functional groups, and evaluation and modification of metrics and characteristics used to develop indices in the existing methods. Successful adaptation and application of an ant RBA would provide a cost effective, useful, and robust tool for evaluating the health of terrestrial ecosystems anywhere in the region.

The health effect of an aquatic ecosystem on habitat modifications were evaluated in the Keum river watershed, Korea during 1977–1996 using the Index of Biological Integrity (IBI) based on fish assemblages. Values of IBI, based on overall sites, averaged 35 (range: 26–45, n = 38) before dam construction, indicating a “fair health condition” based on the modified criteria of Karr and Chu (Karr, J.R.; Chu, E.W. Restoring Life in Running Waters: Better Biological Monitoring; Inland Press: Washington, DC, 1999; 206pp.), while the values averaged 33 (range: 18–48, n = 15) after dam construction, indicating a similar ecosystem health condition in the IBI between the two periods. Marked modifications in the IBI, however, were partially observed along the longitudinal gradients from the headwaters to downstream along with variations of trophic compositions and habitat guilds. Annual mean of IBI showed significant decreases (p<0.001, t = 10.03) in the mid-reach of 100–240 km location after the construction along with >20% decreases of insectivores and >25% increases of omnivores. Comparisons of habitat guilds indicated that the proportion of riffle benthic species declined linearly from 1977 to 1996 and had inverse relations (r = −0.78, p<0.01) with that of water column species. Such variations were explained by serial discontinuity concept that was developed by Ward and Stanford (Ward, J.V.; Stanford, J.A. The serial discontinuity concept of lotic ecosystems Dynamics of Lotic Ecosystems; Fontaine, J.V., Bartell, S.M., Eds.; Ann Arbor Science: Ann Arbor, Michigan, USA, 1983; 29–42). Chemical data of long-term BOD5 and COD5 indicated that chemical impacts after the dam construction were minor compared to the condition before the construction. Overall variation of IBI was highly accounted (p < 0.001, R 2 = 0.91, n = 38) by the Qualitative Habitat Evaluation Index (QHEI), suggesting that the ecosystem health was mainly affected by the habitat modifications.

The index of biotic integrity (IBI) has been used to assess the biological quality of flowing water systems in areas throughout the United States. Yet, only rarely has biotic integrity been related to independent measures of water or habitat quality. We show that the IBI ranks sites similarly in two Illinois watersheds where conditions remained relatively stable during 3 years of sampling. Further, rankings among sites conform to prior assessments of site quality based on habitat and water quality. Neither a species diversity index (Hˈ) nor any of the individual metrics that constitute IBI performed as consistently at ranking sites as did the IBI. Sampling should be conducted during early summer to reduce variation due to seasonal fish migration and fall recruitment of young-of-the-year fish. In an Indiana watershed subject to extensive conservation planning, the IBI reflects known habitat and water quality perturbations of both natural and anthropogenic origin. Little or no improvement in biotic integrity was detected following implementation of numerous soil and water conservation practices.

Over the last 30 years, the Cerrado has been experiencing various antropic impacts that have brought about alterations to species composition, structure and functioning of aquatic habitats. Therefore, studies on negative impacts are useful to prevent future damage and restore environmental quality. The objectives of our study were: i) to adapt an index of biotic integrity of streams in the Rio Cuiabá Basin and ii) to analyze if the Index of Biotic Integrity (IBI) correlated with the environmental quality measured by the Index of Environmental Quality (IEQ) and with the mesohabitat structure. We sampled 26 streams in sub-basins of the Cuiabá River. In each stream, we closed a stretch of 50 m with blockage nets and used electrofishing to capture fish. To obtain a measure of environmental quality in sampled units, we characterized the stream and its micro basin. For the analyses, we used the Spearman Correlation, Kruskal-Wallis test and Analysis of Multiple Regression. We collected 697 individuals distributed into 6 orders, 15 families and 49 species. The IBI followed changes on environmental quality measured by IEQ when we removed streams that present natural barriers from the analysis (r² = 0.4; r² = 0.58). Types of land use did not affect the biotic integrity (n = 26; df = 4; H = 4,860; p = 0.302), but natural and artificial barriers affected it (n = 26; df = 4; H = 11,027; p = 0.026). The IBI was not sensitive to variations in mesohabitat structure (F₂,₂₃ = 0.373; r² = 0.031; Axe 1 p = 0.620; Axe 2 p = 0.490). The IBI is certainly a reasonable instrument for evaluating changes in the environment, but we cannot ignore the fact that we were able to obtain the same result with any combinations of metrics. This makes its analysis and interpretation difficult.

We describe the successful application of a 4-decade analysis of an Index of Biotic Integrity (IBI) demonstrating its assessment value when applied to the fish community of Lake Chapala. We based our analysis on fish community and fishery composition and on the proportion and density of native and exotic species for each decade. Fisheries landings and IBI values document a long-term downward trend since the 1970s. Data from the 1990s and 2000s reveal a dramatic drop in the IBI score to 20 points (out of a possible 100), a rating of very poor. The fisheries collapse and the loss of 11 native species as a consequence of habitat degradation and invasive species have reduced native fish biomass and richness. Fluctuations in rainfall, principally, and water-extraction related to human activities have had a major impact on the lake. Additionally, water quality deterioration has been caused by a lack of wastewater treatment. The fish community has been further modified by large increases in the number and biomass of exotic fishes. Although the exact degree of decline in biotic integrity is impossible to determine because of uncertainty about the representativeness and accuracy of some historical information, the analysis of the temporal changes in the IBI provides compelling evidence for an accelerating drop in ecosystem health. The application of IBI, which is broad in scope and has flexible data requirements, can serve as a template for assessing trends in other water bodies with a history of fisheries data but limited standardized monitoring of the fish community.

We determined the best predictors of an index of amphibian biotic integrity calculated from 54 shrub and forested wetlands in Ohio, USA using a two-step sequential holdout validation procedure. We considered 13 variables as predictors: four metrics of wetland condition from the Ohio Rapid Assessment Method (ORAM), a wetland vegetation index of biotic integrity, and eight metrics from a landscape disturbance index. For all iterations, the best model included the single ORAM metric that assesses habitat alteration, substrate disturbance, and habitat development within a wetland. Our results align with results of similar studies that have associated high scores for wetland vegetation indices of biotic integrity with low habitat alteration and substrate disturbance within wetlands. Thus, implementing similar management practices (e.g., not removing downed woody debris, retaining natural morphological features, decreasing nutrient input from surrounding agricultural lands) could concurrently increase ecological integrity of both plant and amphibian communities in a wetland. Further, our results have the unexpected effect of making progress toward a more unifying theory of ecological indices.

Biotic indices using fish assemblage characteristics have been applied with great success in river assessments around the world. Internationally the most commonly applied fish index is the Index of Biotic Integrity (IBI), whilst in South Africa the most commonly applied index is the Fish Assemblage Integrity Index (FAII). The Sensitivity-weighted Index of Biotic Integrity (SIBI) was developed as an alternative multimetric fish index, incorporating important principles from both the IBI and FAII. This study indicated that the SIBI was a valuable index which used fish as indicators of biotic integrity in the Klip River. The SIBI was also suited to the analysis of site-specific data and the investigation of specific impacts. It is envisaged that the SIBI concept could be applied to other aquatic systems and could possibly be used as an alternative fish index for South African rivers, especially when investigations necessitate site-specific evaluations. The application of the SIBI and IBI in this study also emphasised the FAII's potential underestimation of biotic integrity. The results obtained from the use of the SIBI indicated that the biotic integrity of the Klip River System is currently moderately to critically modified from its natural condition.

Efforts to halt freshwater ecosystem degradation in central Mexico can benefit from using bio-monitoring tools that reflect the condition of their biotic integrity. We analyzed the applicability of two fish-based indices of biotic integrity using data from lotic and lentic systems in the Angulo River subbasin (Lerma-Chapala basin). Both independent data from our own collections during two consecutive years, and existing information detailing the ecological attributes of each species, were used to calculate indices of biological integrity for 16 sites in lotic and lentic habitats. We assessed environmental quality by combining independent evaluations water and habitat quality for each site. We found sites with poor, regular and good biotic integrity. Our study did not find sites with good environmental quality. Fish-based IBI scores were strongly and significantly correlated with scores from independent environmental assessment techniques. IBI scores were adequate at representing environmental conditions in most study sites. These results expand the area where a lotic system fish-based IBI can be used, and constitute an initial validation of a lentic system fish-based IBI. Our results suggest that these bio-monitoring tools can be used in future conservation efforts in freshwater ecosystems in the Middle Lerma Basin.