Freshwater Fish Biosecurity Action Plan for DOC

The northern North Island is home to a number of freshwater sites and ecosystems that are biologically and culturally significant, and nationally and internationally rare. In recent years, freshwater pest species have been spreading further, driven by factors including illegal releases, flooding events, and climate change creating more favourable breeding conditions.

We were engaged to create the Northern North Island Freshwater Fish and Herpetofauna Biosecurity Action Plan 2023, summarising the risks these pest species pose across the northern region, including Koi Carp, Rudd, Orfe, Brown Bullhead Catfish, and Red-eared Slider Turtle.

The challenge

The Department of Conservation (DOC) needed a clear, practical framework to guide freshwater biosecurity work across a large and ecologically significant region. That meant reviewing historical and current records, understanding which species and sites posed the greatest risk, and setting appropriate surveillance methods, all while making sure the plan was genuinely useful for staff planning day-to-day operations.

Our approach

We developed the plan around a solid understanding of the region’s freshwater biosecurity landscape, including:

• Reviewing historical and current records
• Prioritising upcoming freshwater operations
• Reviewing surveillance methodology
• Identifying species of concern
• Setting surveillance and training requirements for incoming staff

The plan identifies known and potential pest species sites, along with the surveillance techniques best suited to each, giving DOC a practical framework for managing workstreams, refining records and reports, and targeting the right geographical areas and species.

Outcomes

The plan now guides DOC Freshwater Biosecurity staff in planning their freshwater biosecurity priorities and netting programmes, helping protect some of the region’s rarest and most significant freshwater ecosystems from further pest species spread.