New Zealand has taken its fight against marine pests up a step, formally joining an international agreement on the management of ships' ballast water.
New Zealand's High Commissioner to the United Kingdom, Lockwood Smith has just presented the formal paperwork to the Secretary-General of the International Maritime Organization (IMO), making New Zealand the 54th country to be party to the Ballast Water Management Convention.
Ministry for Primary Industries (MPI) Manager of Border and Biosecurity Systems, Andrew Bell, says the Convention, which enters into force in September this year, will require ships globally to manage their ballast water, helping to prevent the spread of harmful marine species.
Ballast water, which helps ships maintain stability during a voyage, can contain millions of aquatic or marine microbes, plants and animals, which are carried across the globe and can be introduced into new locations when ships discharge their ballast.
"On arrival in port and when taking on cargo, ships discharge ballast water to balance their load. Releasing this water into a new environment can also release unwanted marine species," Dr Bell says.
"These organisms can threaten our marine environment and species and impact those that derive an income from the sea – for example, tourism, marine farming and fishing. Managing established marine pests and diseases can be challenging and costly."
Currently when vessels enter New Zealand, ballast water must have been exchanged with mid-ocean water, or otherwise treated to kill or remove organisms.
Once in force, the Convention will replace New Zealand’s existing ballast water requirements with an international standard, ultimately requiring all vessels to use a ballast water management system to treat their ballast water before discharging it. This will improve global compliance as ballast water management becomes routine for ships.
While ballast water is one means of harmful marine species entering New Zealand waters, the majority of introductions are through biofouling – marine life growing on vessel hulls.
New Zealand has new rules on biofouling, stipulating that all vessels arriving in New Zealand must have a clean hull. These requirements will become mandatory in May 2018.