Making marinas bivalve friendly for enhanced biodiversity outcomes

Area of Science:

• Marine biology
• Ecology
• Aquaculture

Background:

• Artificial marine structures like pilings and pontoons are replacing natural coastlines.
• These structures negatively impact marine ecosystems, especially in marinas, by promoting invasive species.

Purpose of the Study:

• To assess the effectiveness of seeding artificial structures with mussels (Mytilus galloprovincialis) to mitigate invasive taxa colonization in a marina.
• To compare different mussel seeding methods and locations for their impact on native and invasive species.

Main Methods:

• Mussel-seeded ropes were deployed on various artificial structures (pilings, pontoons, breakwaters) in a marina.
• Interventions included mussel ropes and droplines under pontoons.
• Data on mussel survival, growth, and species richness (native and invasive) were collected over six months.

Main Results:

• Droplines under pontoons exhibited the highest seeded mussel survival and growth.
• These droplines also showed increased richness of both native and invasive taxa, and a higher proportion of invasive to native taxa.
• Mussel ropes on intertidal structures enhanced native taxa biomass, while those on subtidal structures reduced invasive taxa biomass.

Conclusions:

• Mussel seeding interventions show potential for managing invasive species in marinas.
• Droplines under pontoons were most effective for mussel growth and survival, but also increased overall species richness.
• Further research is needed to determine if these methods can be scaled up to enhance marina biodiversity and ecological function.