Functionally Rich Fish Assemblages Support Greater Rates of Multiple Ecological Functions in Seagrass Meadows

Area of Science:

• Marine ecology
• Ecosystem functioning
• Seagrass meadow ecology

Background:

• Animal movement between ecosystems is crucial for ecological functions.
• Habitat characteristics influence faunal assemblages and ecosystem resilience.
• Fish functional diversity in seagrass meadows drives energy transfer via carnivory and herbivory.

Purpose of the Study:

• To investigate the relationship between fish functional diversity and ecological functions in Australian seagrass meadows.
• To understand how habitat traits and spatial context affect fish functional diversity and ecosystem functioning.

Main Methods:

• Surveyed fish community structure using underwater video stations (baited and unbaited).
• Assessed carnivory and herbivory rates using in-field assays.
• Quantified seagrass meadow composition across 50 replicates in 10 locations.

Main Results:

• Carnivory and herbivory rates increased with higher fish functional diversity.
• Seagrass cover positively correlated with functional diversity; species diversity showed a negative correlation.
• Meadows with less mangrove influence, greater distance from reefs, and closer proximity to the ocean exhibited higher functional diversity and ecosystem functioning.

Conclusions:

• A functionally diverse fish community and appropriate spatial context are vital for resilient seagrass ecosystems.
• Conservation efforts should prioritize seagrass beds connected to the open ocean.
• Functional diversity metrics are effective for monitoring seagrass ecosystem health and function.