Linking Species Functional Traits to Specific Biogeochemical Processes under Trawling Pressure

Area of Science:

• Marine Ecology
• Benthic Ecology
• Biogeochemistry

Background:

• Otter trawling is a significant disturbance in marine ecosystems.
• Understanding its impact on benthic invertebrates and biogeochemical processes is crucial for effective fisheries management.
• The Cretan Sea, an oligotrophic environment, faces fishing pressure.

Purpose of the Study:

• To investigate the impact of otter trawling on the relationship between functional traits of benthic invertebrates and biogeochemical processes.
• To assess how seasonal fishery closures affect these relationships.
• To identify specific traits and processes affected by trawling.

Main Methods:

• Sampling in trawled and control areas of the Cretan Sea during winter and summer.
• Measurement of environmental parameters: particulate organic carbon, sedimentary organic carbon, bottom water and sedimentary chlorophyll a, phaeopigment, and benthic oxygen consumption.
• Analysis of functional traits of benthic invertebrates and their correlation with biogeochemical data.

Main Results:

• Trawling significantly impacted bottom water chlorophyll and sedimentary organic carbon.
• The relationship between species traits and ecosystem processes was altered by trawling.
• Control sites showed traits related to bioturbation; trawled sites favored opportunistic deposit feeders.

Conclusions:

• Otter trawling decouples species-sediment relationships by altering functional traits.
• This shift impacts nutrient cycling and ecosystem functioning.
• Fisheries management needs to consider the functional consequences of trawling disturbance.