Minimising Risks of Reduced Genetic Diversity in Marine Restoration

Area of Science:

• Marine Ecology
• Conservation Genetics
• Aquaculture

Background:

• Global marine habitat restoration increasingly uses aquaculture and hatchery propagation.
• Genetic consequences of large-scale propagation for restoration are poorly understood.
• Lack of genetic guidelines risks bottlenecks, inbreeding, and domestication in restored populations.

Purpose of the Study:

• To assess hatchery impacts on genetic diversity and domestication in kelp (Ecklonia radiata).
• To compare genetic profiles of wild donor populations and their hatchery-bred offspring.

Main Methods:

• Genotyping of wild Ecklonia radiata donor populations.
• Genotyping of hatchery-bred F1 cohorts from these populations.
• Analysis of genetic diversity, inbreeding, effective population size (Ne), and selection.

Main Results:

• Hatchery propagation significantly reduced genetic diversity (20-30% decline in heterozygosity).
• Over 50% of polymorphic loci were lost, indicating genetic drift and loss of adaptive variation.
• Early signs of domestication were detected, with elevated inbreeding and drastically reduced Ne (from ~500 to as low as 21).

Conclusions:

• Unmonitored hatchery propagation rapidly alters the genetic makeup of foundation species.
• This genetic alteration can undermine adaptive capacity and field performance in restoration efforts.
• Integrating genetic guidelines and monitoring is essential for successful, resilient marine restoration.