Measuring ecosystem health through bioassessment

Measuring the health and conditions of an ecosystem is a complex, involved and daunting task that can be tackled in one of many ways. Bioassessment services have long been utilized for just this purpose, and increased understanding of the structure and function of ecosystems has driven advancement and acumen in the field. That may be why so many ecological research and assessment organizations are turning to bioassessment as a means for determining the integrity of ecosystems and establishing what steps need to be made for preservation purposes.

The basics of bioassessment
Comprehensive techniques for this method of evaluation have been around since the 1980s – while the U.K. implemented the River Invertebrate Prediction and Classification System, the U.S. steered toward the Index of Biotic Integrity. The IBI system assesses ecosystem health through a comparison of observed values along the index. No matter which method of bioassessment, the process requires that health condition be determined from samples collected at appropriate points in the environment being assessed and then evaluated in bioassessment laboratories.

“Bioassessment results are utilized to answer questions about the ecosystem’s ability to support survival and the reproduction of aquatic species.”

As the U.S. Environmental Protection Agency explains, the results from such projects are utilized to answer questions concerning the ecosystem’s ability to support survival and the reproduction of aquatic species. In essence, bioassessment aims to determine how well the ecosystem allows flora and fauna to fulfill their functions and uses in the larger scheme of the biological community.

Exploring different methodologies of bioassessment
Within this field are many different approaches to bioassessment. For example, the number and breadths of sampling sites may vary according to the specific needs of each organization. As the Western Center for Monitoring & Assessment of Freshwater Ecosystems explains, three main decisions must be made when it comes to designing a bioassessment project:

Multivariate versus multi-metric: These are the main approaches to data analysis. Multi-metric analysis techniques involve several measurable characteristics and classifies reference sites (ecoregions) that are predefined according to physical and geographic attributes, such as soils, vegetation and climate. Multivariate, on the other hand, categorizes sites according to taxonomic composition, making no assumptions about ecosystem similarities.

Inclusion versus exclusion of rare taxa: Some projects exclude rare taxa with low abundance or small distribution in order to avoid skewed results and obtain the most overall accurate assessment of biological conditions. However, doing so comes with potential complications. For example, excluding rare taxa from a sample may introduce bias into an assessment by affecting the characterization of the assemblage structure.

Low versus high taxonomic resolution: High taxonomic resolution allows for the most exhaustive and accurate bioassessment of an ecosystem; however, it takes much more time and money to complete than low taxonomic resolution.

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A bioassessment plan is made up of several steps, including the collection of samples and analysis in a laboratory.

Why choose bioassessment?
Determining biological integrity is essential for the development of public policies aimed at maintaining the health and beauty of earth’s natural environments and resources. Bioassessment is a particularly effective assessment tool, as it provides physical, chemical and biological measurements necessary to determine the health of an ecosystem. These measurements can incorporate a wide variety of species, from fish to algae to phytoplankton and other microscopic organisms.

“EcoAnalysts comprises more than one dozen expert taxonomists with nearly 200 years of combined experience.”

Understanding the bioassessment process
Bioassessment projects begin with the design of the study. The aim in this initial phase is to determine precisely what the project should accomplish and clarify those objectives so that researchers know what they’re looking for when they’re out in the field collecting samples.

EcoAnalysts, which comprises more than one dozen expert taxonomists with nearly 200 years of experience, will provide recommendations so that you use the biological indicators that best suit your specific goals and fit within budgetary constraints. Other study components that EcoAnalysts will design include:

  • A strategy for sampling that meets the regulations and requirements specific to the region, implementing protocols for sample collection that are both efficient and scientifically sound
  • Instructions for the proper handling of samples of biological specimens
  • Information regarding raw data requirements and taxonomic effort levels
  • A list of indices and metrics that can help you get the most from the collected data

EcoAnalysts will also execute the final step in the project – the data analysis. The collected information will be thoroughly evaluated by consulting ecologists who have expertise in calculating metrics and indices, quantitative methods and applied ecological theory. Even after providing a detailed report, EcoAnalysts’ experts are available to provide explanations, interpretations and further analysis.