Managing aquatic habitat structure for resilient trophic interactions.

Area of Science:

• Ecology
• Fisheries Management
• Conservation Biology

Background:

• Aquatic environments are being simplified by human development, threatening biodiversity and ecosystem resilience.
• Increasing structural habitat complexity is a common strategy to conserve aquatic food webs and support fisheries.
• The global effectiveness of structural habitat enhancement for fisheries remains uncertain.

Purpose of the Study:

• To investigate how structural habitat addition affects consumer-resource interactions in aquatic ecosystems.
• To determine if biomass transfer rates (biomass potential) influence the outcome of habitat manipulation.
• To provide a context-dependent framework for managing structural habitat in aquatic systems.

Main Methods:

• Synthesis of existing data and theoretical analyses of consumer-resource interactions.
• Examination of the effects of prey refuge habitat on predatory sportfish and forage fish prey.
• Comparison of outcomes in systems with low versus high rates of biomass transfer.

Main Results:

• Increased prey refuge habitat stabilized systems with high biomass potential, boosting consumer densities.
• In low biomass potential systems, increased refuge habitat reduced energy transfer and led to near extinction of consumers.
• Biomass potential and prey refuge availability can have opposing effects on ecosystem stability and consumer populations.

Conclusions:

• Structural habitat manipulation is not universally beneficial; its impact depends on local system characteristics, particularly biomass potential.
• Effective management requires considering site-specific conditions to avoid negative consequences on aquatic food webs.
• A context-dependent approach is crucial for guiding structural habitat restoration to protect and restore aquatic ecosystems.