Epibiotic pressure contributes to biofouling invader success

Area of Science:

• Marine ecology
• Invasive species biology
• Community ecology

Background:

• Reduced competition is a key factor in introduced species success.
• Benthic marine biofouling communities experience intense overgrowth competition for space.
• Epibiosis, where species use others as substrate, offers a competitive edge.

Purpose of the Study:

• To investigate differences in epibiotic pressure between native and introduced species.
• To determine if introduced species are more likely to be epibionts and less likely to be basibionts.
• To understand the role of larval settlement in invasion success.

Main Methods:

• Ex situ experiments were conducted to compare bryozoan larval settlement.
• Larval settlement preferences on bare, native, and introduced substrates were observed.
• Larval wastage (mortality) was assessed for both native and introduced species.

Main Results:

• Introduced species settled opportunistically on all substrate types.
• Native species preferentially settled on native substrates and avoided introduced species.
• Native larvae exhibited significantly higher mortality rates than introduced larvae.

Conclusions:

• Introduced species possess competitive advantages including opportunistic epibiosis and avoidance of basibiosis.
• Higher native larval wastage further contributes to the success of invasive biofouling species.
• These factors collectively explain the invasion success of introduced biofouling species.