Intraspecific variation in a predator changes intertidal community through effects on a foundation species.

Area of Science:

• Ecology
• Marine Biology
• Biodiversity Studies

Background:

• Intraspecific variation, differences within a species, is a key component of biodiversity.
• Predators and foundation species significantly influence community structure.
• The community effects of intraspecific trait variation in predators acting on foundation species remain understudied.

Purpose of the Study:

• To investigate how intraspecific foraging differences in dogwhelk predators (Nucella) affect intertidal mussel bed communities.
• To test the hypothesis that predator intraspecific variation alters communities through impacts on foundational mussels.

Main Methods:

• A 9-month field experiment exposing intertidal mussel beds to three Nucella populations with varying prey selectivity and consumption rates.
• Measurement of mussel bed structure, species diversity, and community composition post-experiment.

Main Results:

• Nucella populations did not significantly alter overall community diversity.
• Differences in Nucella mussel selectivity significantly altered foundational mussel bed structure.
• Altered mussel bed structure impacted the biomass of shore crabs and periwinkle snails.

Conclusions:

• Intraspecific variation in predators of foundation species can significantly alter community structure.
• Predator foraging differences, driven by intraspecific variation, have cascading effects on associated species.
• This study expands the understanding of intraspecific variation's ecological importance to include predator-foundation species interactions.