increase font size
Water hyacinth is a serious water weed and is infamous for its invasive, fast-growing nature.
OPINION: Last summer, a couple out exercising their dog took their usual walk around a local public reserve in Pukekohe.
As they passed a stormwater pond, something caught their eye: a vibrant green plant with purple flowers, floating on the water's surface. It looked healthy, almost ornamental.
Only a few months later, that seemingly innocent plant had exploded across three-quarters of the water's surface, forming an impenetrable mat.
Water hyacinth (Pontederia crassipes) is a serious water weed and is infamous for its invasive, fast-growing nature. Given the right conditions, a single small infestation can double in size in just one to two weeks.
At first glance, water hyacinth may appear too pretty to be a problem with its stunning lilac-coloured flowers from mid-summer to early autumn, each stalk boasting up to 20 delicate blooms. But beneath its beauty lurks an ecological nightmare.
Water hyacinth doesn't just spread outward - it grows downward, with roots extending up to a metre deep. It forms dense mats that can reduce water quality, change water flows and increase sediment, crowdign out native aquatic plants and animals, altering ecosystems, destroying habitats, and blocking irrigation systems.
It is also an expert at long-term survival. Each water hyacinth flower, once fertilised, produces hundreds of tiny seeds that sink to the bottom of waterways where they can remain viable for three decades, waiting for the perfect conditions to sprout.
Water hyacinth is an unwanted organism in New Zealand, meaning it is illegal to sell, grow, display or distribute it. It is also a notifiable organism - so if you do spot it, you must report it immediately to Biosecurity New Zealand.
Thanks to the sharp eyes of the Pukekohe couple, the outbreak in their local park was identified before it could spread further. Biosecurity officers were able to remove the plants, and the pond will be monitored for the next 30 years.
What can you do?
New Zealand's biosecurity depends on all of us.
If you think you've found water hyacinth, report it to Biosecurity New Zealand at 0800 80 99 66 or report.mpi.govt.nz/
John Walsh is director Pest Management at Biosecurity New Zealand.
OPINION: At Fieldays this year, one theme kept surfacing across the sector: global shocks are no longer something that happens “over there”. They are now translating quickly into local, farm-level impacts through increasingly complex and connected channels.
OPINION: The Green Party’s rivers and oceans policy may have a new name but nothing else has changed.
OPINION: Good governance is critical to the primary sector. Whether it is a rural business, a levy-payer organisation or a research body, we need a pipeline of capable directors with a passion for, and knowledge of, the sector.
An industry-wide project led by Ministry for Primary Industries (MPI) is underway to deal with the rising number of feral pests, in particular, browsing pests such as deer and pigs.
OPINION: Dairy farmers are under increasing pressure to safeguard their livestock, equipment and operations from a range of security threats.
Potatoes New Zealand has congratulated Peter Reynolds of TA Reynolds Ltd in Pukekohe on being awarded the Horticulture New Zealand Bledisloe Cup, recognising a lifetime of service and contribution to New Zealand horticulture.
Signing up to a benchmarking tool is not about competition, but about improving collectively, says Ximena Puig and Alvaro Luzardo who are 50-50 sharemilkers at a 164-hectare (effective) dairy farm in Eketāhuna in the Lower North Island.
A leading British farming politician says he's impressed with the positive attitude of New Zealand farmers that he met during his recent trip here.
OPINION: With 10,500 dairy farms, New Zealand continues to punch above its weight around the world.
The Southern Dairy Hub (SDH), which runs a demonstration farm for South Island farmers, has a new general manager.
Esther Guy-Meakin has been announced as the new chief executive of the New Zealand Meat Board (NZMB).
OPINION: The Irish dairy sector is facing a new dilemma - maintaining year-round fresh milk supplies.
OPINION: Could beef cows play an increasingly important role in improving profitability and resilience on hill country farms?
