Foundation Species Modulate Microbial Benthic-Pelagic Coupling in the Rocky Intertidal.

Area of Science:

• Marine ecology
• Microbial oceanography
• Coastal ecosystem dynamics

Background:

• Benthic-pelagic coupling traditionally focuses on pelagic effects on benthos.
• The impact of benthic biological processes on pelagic microbial communities is understudied.
• Foundation species play a key role in structuring coastal ecosystems.

Purpose of the Study:

• To investigate how surfgrass and mussels regulate nitrogen and dissolved organic matter (DOM) cycling.
• To assess the cascading effects of these processes on heterotrophic bacteria in tide pools.
• To understand the influence of foundation species removal on benthic-pelagic coupling.

Main Methods:

• Quantified biogeochemical fluxes (nitrogen, DOM) in Oregon tide pools.
• Monitored heterotrophic bacterial responses.
• Conducted experiments involving foundation species removal under varying upwelling conditions.

Main Results:

• Mussel-dominated pools released high levels of ammonium and nitrate.
• Surfgrass pools transformed DOM, stimulating bacterial growth.
• Foundation species removal weakened nutrient release and reduced DOM-fueled bacterial growth, decoupling benthic and pelagic systems.
• Upwelling intensified benthic-pelagic linkages.

Conclusions:

• Benthic foundation species critically regulate pelagic microbial processes.
• Coastal microbial dynamics are vulnerable to the decline of foundation species.
• Understanding these linkages is vital for coastal ecosystem management and conservation.