Molecular Biodiversity Monitoring Reaches Critical Implementation Threshold

Human activities are driving rapid biodiversity loss across global ecosystems, creating an urgent need for monitoring tools that can keep pace with the scale and speed of environmental change. Traditional methods, which rely on physical sampling and taxonomic identification, often struggle with limited spatial coverage, high costs, and a scarcity of specialized expertise. In response, molecular monitoring techniques such as environmental DNA (eDNA) and DNA metabarcoding have emerged as promising alternatives. These methods offer high sensitivity, non-invasive sampling, and the ability to detect a broad range of taxa efficiently. However, the question remains whether these technologies are truly ready for routine, large-scale implementation in official biodiversity assessments.

A recent systematic review published in Metabarcoding and Metagenomics provides a comprehensive assessment of the maturity of these molecular methods. The study utilized the Technology Readiness Level (TRL) framework, a standard approach for evaluating the progress of a technology from initial concept to operational use. By analyzing 420 research papers published between 2017 and 2023, the researchers mapped the current state of molecular monitoring and identified key barriers to its widespread adoption. The findings reveal a field that is rapidly growing but still fragmented, with significant gaps between laboratory validation and routine legislative use.

The review highlighted a substantial increase in the number of studies applying molecular methods to biodiversity monitoring. The annual publication count nearly doubled during the study period, rising from 42 papers in 2018 to 80 in 2022. Aquatic environments dominated the research landscape, with freshwater and marine systems accounting for the majority of studies. Terrestrial applications, while present, remained less frequent. Geographically, the United States, China, and Australia led in the number of published studies, though only a small fraction of the research spanned multiple countries. This geographic concentration suggests that while the technology is being developed globally, its integration into national monitoring frameworks is still uneven.

When evaluated against the TRL scale, the majority of studies fell into levels 6 and 7. TRL 6 indicates that the technology has been demonstrated in a relevant environment, often through comparison with traditional methods. TRL 7 signifies that a system prototype has been demonstrated in an operational environment, typically at a medium or large spatial scale. This distribution suggests that molecular methods are broadly validated in small-scale field studies but lack systematic, large-scale demonstrations. Fewer studies reached TRL 8 or 9, which correspond to complete system qualification and actual operational use, respectively. The highest levels of readiness were predominantly found in freshwater studies, particularly those targeting fish species.

The statistical analysis of the 420 papers revealed that the organism group was the only significant factor explaining variation in technology readiness. Studies targeting fish showed higher TRL values compared to those focusing on other taxa, such as invertebrates, plants, or bacteria. This disparity may be attributed to the relative ease of detecting fish DNA in water samples and the established baseline of traditional fish monitoring methods for comparison. In contrast, monitoring complex communities of invertebrates or soil microbes remains more challenging, often due to the difficulty of distinguishing between closely related species or the degradation of DNA in certain environments.

Despite the technical progress, the review identified several critical barriers to the routine implementation of molecular monitoring. The lack of standardization across studies was cited as a major issue, leading to poor comparability between different monitoring programs. Methodological differences in field sampling, laboratory protocols, and bioinformatics analysis can produce inconsistent results, undermining the reliability of the data. Additionally, the need for improved quantitative estimates and comprehensive reference libraries was highlighted. Without robust reference databases, it is difficult to accurately identify all species present in a sample, particularly for understudied or cryptic taxa.

The transition from research validation to routine use is not merely a technical challenge but also a regulatory and social one. The authors noted that the uptake of molecular methods is often limited by issues of legitimacy and legal acceptance rather than technical feasibility. Stakeholders, including policymakers and resource managers, require confidence in the reproducibility and comparability of molecular data before integrating it into legislative frameworks. Building this trust involves establishing common standards, ensuring data transparency, and fostering collaboration between researchers, regulators, and industry. The complexity of innovation processes means that managing stakeholder expectations and facilitating knowledge transfer are crucial steps in this transition.

International cooperation is essential for overcoming these barriers and achieving global comparability in biodiversity monitoring. While national guidelines can be developed more quickly, they risk creating incompatible data sets that cannot be easily combined for international assessments. The review pointed to recent efforts, such as the establishment of the International eDNA Standardisation Task Force and new working groups under ISO, as positive steps toward harmonizing methods. These initiatives aim to define minimum criteria for molecular monitoring, ensuring that data from different regions can be compared and integrated. However, the progress in standardizing methods for marine and terrestrial environments lags behind that of freshwater systems, posing a risk of fragmented global monitoring efforts.

The study concludes that molecular monitoring methods have reached a critical stage of maturity, with significant potential to enhance current biological monitoring in all habitats. However, the field remains fragmented, with a risk of duplicated efforts and incompatible results. To fully realize the benefits of these technologies, coordinated action is needed to establish international standards, improve reference libraries, and facilitate the transfer of knowledge to less advanced regions. By addressing these challenges, the scientific community can expedite the routine use of molecular methods, providing the reliable and comparable data necessary to protect biodiversity and restore ecosystem services in the face of global environmental change.

Subject of Research: Technology Readiness Level of biodiversity monitoring with molecular methods – where are we on the road to routine implementation?

Article Title: Technology Readiness Level of biodiversity monitoring with molecular methods – where are we on the road to routine implementation?

Article References: Laamanen, T., Norros, V., Vihervaara, P., Jerney, J., Kortelainen, P., Kujala, K., Lambert, S., Mäyrä, J., Nikula, L., Palmroos, I., Tolkkinen, M., Vuorio, K., & Meissner, K. (2025). Technology Readiness Level of biodiversity monitoring with molecular methods – where are we on the road to routine implementation?. Metabarcoding and Metagenomics, 9, Article e130834. https://doi.org/10.3897/mbmg.9.130834

Image Credits: AI Generated

DOI: 10.3897/mbmg.9.130834

Keywords: Technology, Readiness, Level, biodiversity, monitoring, molecular, methods, road, routine, implementation, scientific research