'Biosecurity' is the protection of New Zealand's economy, environment and people's health from pests and diseases. It includes trying to prevent new pests and diseases arriving, and eradicating or controlling those already present.
Marine borders are hard to manage, as there is no single physical point of arrival. For example, organisms living on a vessel’s hull (‘hull fouling’) can be reproducing and infecting New Zealand’s coastal zone while arriving at port, then continue to infect any area the vessel visits after border clearance.
A range of legislation is used to control the movement of pest species within the country and within our coastal waters; several examples include movement restrictions on marine farming equipment and spat to prevent spread of Undaria seaweed (which has been recorded in the Port but so far not elsewhere); and restrictions on introduction of new species into the coastal marine environment.
Each winter, the Bay is visited by certain species of phytoplankton that are known to produce chemicals causing toxic shellfish poisoning (monitored by Public Health Unit, Hawke’s Bay District Health Board). These chemicals accumulate in the shellfish when they filter feed in waters containing these algae. Worldwide, there are four main types of toxic shellfish poisoning: Paralytic shellfish poisoning (PSP) and Neurotoxic shellfish poisoning (NSP), which attack the nervous system, Diarrhetic shellfish poisoning (DSP) and Amnesic shellfish poisoning (ASP), which mainly cause gastrointestinal symptoms though the latter can sometimes cause memory loss.
Both the presence of the alga Gymnodinium catenatum and unsafe levels of PSP were first recorded in the Hawke’s Bay region in November 2001 and have reoccurred regularly each winter since then. The highest level of PSP toxin recorded in Hawke’s Bay was twenty times the safe health limit and was recorded from the Central Hawke’s Bay coastline in December 2000.