Seafood monitoring programmes
Monitoring of algal biotoxins, contaminants, and residues in seafood is undertaken through the following:
- shellfish biotoxin monitoring programme for commercial growers and harvesters of bivalve molluscan shellfish (BMS), which is funded by industry
- shellfish biotoxin monitoring programme for recreational gatherers of BMS, which is funded by the New Zealand government
- finfish and farmed salmon monitoring, which is funded by industry.
Purpose and aims
Monitoring for seafood depends on whether the products are intended for commercial or recreational use.
Monitoring of seafood for sale or export
Under the Animal Products Act (APA) 1999, commercially grown or harvested seafood is monitored to ensure that
- it is safe and suitable to eat
- it meets export requirements set by destination countries.
Official assurances (export certificates) are issued to show that seafood products meet relevant regulations.
Monitoring of seafood for non-commercial use or personal consumption
Further monitoring is undertaken to protect people who gather shellfish for recreation. Shellfish and seawater samples around New Zealand are tested each week to check if they are contaminated with biotoxins from toxic algal blooms. The programme is run by MPI. If toxins are detected, MPI issues warnings and the information is provided to district health boards, who may also issue warnings.
History and legislation
New Zealand shellfish have been monitored for the presence of marine biotoxins since January 1993, when shellfish toxicity was first detected in New Zealand.
Monitoring of commercial bivalve molluscan shellfish (BMS) for biotoxins, heavy metals, and toxic substances originating from phytoplankton is carried out under the Regulated Control Scheme for BMS.
Find information about monitoring activities in the Animal Products (Regulated Control Scheme – Bivalve Molluscan Shellfish) Regulations 2006. You can find more information about how the regulations are carried out in the accompanying notice.
Monitoring of commercial finfish and farmed salmon is managed under the following Animal Product Regulations:
- Animal Products (Regulated Control Scheme – Contaminant Monitoring and Surveillance) Regulations 2004
How data is monitored
Seafood contamination is monitored through sampling and surveillance.
Sampling of farmed salmon
Farmed salmon is randomly sampled at the farm and processing premises, and it's tested for a variety of specified contaminants and veterinary medicines. This monitoring is part of the National Chemical Residues Programme (NCRP).
Sampling of finfish
Every year a number of fish species are sampled and tested for contaminants such as mercury.
If contamination or the risk of contamination is identified, then surveillance activities are put in place. These can include a sampling regime and a sampling plan. MPI must keep a list naming sources of the risk and the operators involved. The operators on the list are notified that they are on the surveillance list.
Testing for marine biotoxins
For monitoring purposes, BMS are used because their filter feeding makes them much more susceptible to contamination than non-bivalve species.
Mussels, in particular, accumulate and depurate toxins quickly. For this reason, they are a sentinel species in both New Zealand and international monitoring programmes. They are the preferred species for monitoring for paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), neurotoxic shellfish poisoning (NSP), and diarrhetic shellfish poisoning (DSP).
Phytoplankton monitoring provides an early warning indicator of toxicity in shellfish. In areas where phytoplankton is routinely monitored, immediate action is taken if cell numbers at or above a trigger level are detected. Shellfish flesh is then sampled and analysed for the specific toxin produced by that phytoplankton species.
Testing new marine biotoxins
When new marine biotoxins are discovered in shellfish, MPI develops new methods to detect them, and appropriate guidelines are set. Any new methods of analysis are rigorously tested and validated before they are used for routine regulatory testing.