Comparing structural and functional approaches to distinguish benthic communities from eutrophic and non-eutrophic...

Area of Science:

• Marine Ecology
• Environmental Science
• Benthic Ecology

Background:

• Macrobenthic communities are key indicators of estuarine environmental health.
• Assessing these communities requires robust classification methods sensitive to environmental gradients.
• Existing methods include species-based, tolerance-based (AMBI index), and trait-based approaches.

Purpose of the Study:

• To compare the performance of three macrobenthic classification methods in distinguishing environmental conditions.
• To evaluate the effectiveness of these approaches at different spatial scales.
• To determine their suitability for operational estuarine environmental quality assessment.

Main Methods:

• A hierarchical sampling design was employed across three spatial scales.
• Three classification approaches were compared: species-based, AMBI ecological groups, and biological traits.
• Statistical analysis focused on distinguishing eutrophic from non-eutrophic communities.

Main Results:

• All three classification approaches performed similarly in distinguishing environmental conditions.
• Significant variations were observed at larger spatial scales, corresponding to human-induced environmental changes.
• Eutrophic and non-eutrophic benthic communities were successfully differentiated by all methods.

Conclusions:

• The species-based, AMBI, and trait-based approaches are viable operational criteria for estuarine environmental quality assessment.
• Environmental degradation impacts benthic communities primarily at larger spatial scales.
• Functional approaches may benefit from more detailed data on macrofaunal life-cycles and disturbance tolerance.