Mechanistic support for increased primary production around artificial reefs

Area of Science:

• Marine Ecology
• Ecosystem Restoration
• Seagrass Ecology
• Artificial Reefs

Background:

• Tropical seagrass ecosystems are highly productive but threatened by human activities.
• Artificial reefs (ARs) are used for fisheries and increasingly for carbon sequestration.
• Fish aggregation on ARs creates nutrient hotspots, enhancing local seagrass production.

Purpose of the Study:

• To model how fish aggregation on ARs impacts seagrass primary production at ecosystem scale.
• To investigate the effects of fish density and nutrient availability on seagrass production.
• To analyze the spatial distribution of seagrass primary production around ARs.

Main Methods:

• Developed a spatially explicit, individual-based simulation model.
• Integrated a single-nutrient primary production model for seagrass.
• Incorporated bioenergetics models for fish to simulate nutrient dynamics.

Main Results:

• Fish aggregation on ARs synergistically enhanced ecosystem-scale seagrass primary production.
• Increased production was linked to nonlinear nutrient uptake and biomass allocation dynamics.
• Seagrass production rose near ARs but decreased away from them, with minor ecosystem biomass reduction.

Conclusions:

• ARs can enhance overall ecosystem production in seagrass systems.
• ARs support fishery restoration by increasing food web energy input.
• ARs promote carbon sequestration through elevated primary production rates.