Determination of phytoplankton composition using absorption spectra.

Area of Science:

• Marine Biology
• Limnology
• Spectroscopy

Background:

• Phytoplankton community characterization is essential for aquatic ecosystem health assessment.
• Traditional methods like microscopic counts are resource-intensive, requiring significant time, materials, and personnel.
• Developing cost-effective complementary techniques is crucial for efficient ecological monitoring.

Purpose of the Study:

• To assess the feasibility of using absorption spectra measurements for phytoplankton analysis.
• To achieve qualitative determination of phytoplankton by class and quantitative estimation of cell counts.
• To reduce the costs associated with traditional phytoplankton characterization methods.

Main Methods:

• Samples collected from three Spanish Mediterranean coastal estuary systems.
• Absorption spectra (400-750 nm) and phytoplankton classes were determined for each sample.
• Partial Least Squares (PLS) multivariate statistical technique used to build predictive models.

Main Results:

• Successful qualitative and quantitative models were developed using spectrophotometric data.
• Good results were achieved for the identification and quantification of diatoms (Bacillarophyceae), Chlorophyceae, and Cryptophyceae.
• The technique demonstrated potential for complementing traditional phytoplankton counting methods.

Conclusions:

• Spectrophotometric analysis, combined with PLS, provides a viable and cost-effective alternative for phytoplankton assessment.
• This method can significantly reduce the resources needed for monitoring phytoplankton communities.
• Further refinement could expand its application to a wider range of phytoplankton classes.