Long-term changes in the structure of benthic communities: Revisiting a sampling transect in Crete after 24 years

Area of Science:

• Marine Ecology
• Benthic Ecology
• Environmental Monitoring

Background:

• Long-term ecological studies are crucial for understanding environmental changes.
• Benthic communities are sensitive indicators of marine ecosystem health.
• Coastal zones are particularly vulnerable to anthropogenic impacts.

Purpose of the Study:

• To assess changes in benthic macrofaunal diversity and community composition.
• To compare ecological status over a 24-year period using consistent methodologies.
• To identify drivers of observed changes in the marine environment.

Main Methods:

• A bathymetric transect on the north coast of Crete was revisited after 24 years.
• Identical sampling design, season, techniques, and protocols were maintained.
• Macrofaunal data were collected from 4 stations across 2 sampling seasons with 7 replicates each.

Main Results:

• Benthic diversity and community composition showed significant changes between sampling periods.
• Changes were more pronounced at stations closer to the coast.
• Total benthic abundance decreased, while species distribution became more even, indicating a shift from dominance by a few species.

Conclusions:

• Ecological status remained above good ecological status thresholds despite observed changes.
• Changes in benthic communities were primarily attributed to local anthropogenic factors and natural variability.
• Large-scale factors like Mediterranean-wide nutrient influxes were not identified as primary drivers.