Bonamia ostreae in New Zealand: Lessons From a Decade-Long Marine Biosecurity Response

Area of Science:

• Marine biology
• Parasitology
• Fisheries management

Background:

• Bonamia ostreae (Haplosporidia) parasite detected in New Zealand flat oysters (Ostrea chilensis) in 2015.
• Threatened Foveaux Strait wild flat oyster fishery and aquaculture sector.
• Parasite spread from Marlborough Sounds to Big Glory Bay, Stewart Island.

Purpose of the Study:

• Describe New Zealand's biosecurity response to Bonamia ostreae since 2015.
• Identify key decisions and surveillance features influencing outcomes.
• Discuss constraints and potential mitigation strategies.

Main Methods:

• Precautionary strategy involving depopulation of farmed Ostrea chilensis.
• Implementation of movement controls and targeted surveillance.
• Analysis of biosecurity response, decision-making, and data systems.

Main Results:

• Depopulation aimed to reduce host density and parasite propagule pressure.
• Key decisions and surveillance design influenced outcomes.
• Fragmented data systems presented a significant constraint.

Conclusions:

• Biosecurity response adapted to parasite spread, prioritizing wild fishery protection.
• Resilience breeding and biosecurity considerations are potential mitigation strategies.
• Effective management requires addressing data system fragmentation.