Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 

Look out for these marine pests

Look out for these marine pests

Every year NIWA carries out numerous marine surveillance missions; surveys at ports and harbours around the country. Their divers are looking for the pests that have hitched a ride to New Zealand waters and are capable of harming our unique ecosystems, fisheries and aquaculture.

Knowing your enemy is crucial. So swot up on six of these beasties if you’re enjoying the ocean this summer. Find out where they are by searching for them online at https://marinebiosecurity.org.nz/. And if you do happen to spot something that shouldn’t be there, you can report 24/7 by calling the Ministry for Primary Industries - Pest-and-disease hotline – 0800 80 99 66

Mediterranean fanworm

The Mediterranean fanworm is a spectacularly large worm with a characteristic whirl of filaments. Its tubes can be over 40cm long and the worm looks like a graceful, golden flower in the water. Populations are increasing, particularly around Auckland. This species can be a major fouling problem on structures and boat hulls, and competes for food with native filter feeders like mussels.
The Mediterranean fanworm can form dense colonies of up to 1000 individuals per square metre that will exclude the settlement of other organisms. The presence of the Mediterranean fanworm in areas where mussels or oysters are located may affect their growth due to competition for food.
Droplet tunicate
The droplet tunicate forms large colonies and is generally found in muddy bottomed tidal habitats and on structures like wharf piles and aquaculture equipment. It is generally submerged just below the waterline, but can often be seen at low tide. Its size is influenced by seawater temperatures, with it decreasing over winter, but rapidly re-growing in summer. It can smother beaches, rocks and tide-pools and displace native species and is becoming more prolific in Northland.

The droplet tunicate looks like clusters of white tubes. Each tube is actually a cylinder containing numerous small individuals. The white tunics can sometimes appear flecked with orange.

Clubbed tunicate

The clubbed tunicate grows on natural and artificial hard marine surfaces. It is most commonly seen on wharf pilings, aquaculture structures, ropes and hulls and may also be found attached to rocks, seaweed and on shellfish. The clubbed tunicate can reach densities of 500-1500 individuals per square metre enabling it to outcompete other species.

The clubbed tunicate has a long, leathery skinned cylindrical form, tapering to a stalk with a disc shaped holdfast that anchors them to hard surfaces. The sea squirt ranges in colour from yellowish to reddish to brownish and can grow up to 160mm in length. It often appears fuzzy underwater.

Asian date mussel

The Asian date mussel, also known as the Asian mussel or bag mussel, is a small saltwater mussel. It inhabits intertidal and subtidal sediments, and produces threads that form extensive mats on the sediment surface. It grows fast, is short-lived and can obtain densities of thousands per square metre.

The Asian date mussel alters seafloor habitats and can also limit the amount of plankton available as food for other species. It is relatively small and has a greenish shell which has zig-zag markings and iridescent radiating bands. The shell is easily crushed and can grow up to 3cm long.

Wakame Undaria

Asian kelp is spread mainly by fouling on vessel hulls and is present in almost all of New Zealand’s international ports and harbours. It grows from the low intertidal area to subtidal depths of around 15 metres on any hard surface and can form dense forests in sheltered reef areas, resulting in competition for light and space which may lead to the exclusion of native plants and animals.

Mature plants are a brown, green or yellow colour and grow up to one to two metres with a visible midrib up the plant. Juvenile Asian kelp have an undivided blade.

Asian paddle crab

The Asian paddle crab is found in the Waitematā, Whangarei and Kaipara harbours and Waikare Inlet in Northland. Adults can produce hundreds of thousands of offspring. It is also aggressive, can inflict a vicious nip with its claws and competes with other species for habitat and food.

It has paddle-like hind legs with adults having a shell width of up to 12cm with six distinct spikes on each side of the eyes. It ranges in colour from pale green through to a deep chestnut brown with purplish markings. Most found in the Waitemata Harbour tend to have brown-orange markings and white tips on the claws.

For more information on identifying our marine pests see:https://marinebiosecurity.org.nz/


© Scoop Media

 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell: On The Tax Working Group’s Road Map

Trying to analyse the interim report on the Tax Working Group (TWG) is like trying to review an entire All Blacks game, but at the half- time mark.

With so much still to be finalised, Sir Michael Cullen and his colleagues are going to need all the All Blacks’ fabled finishing skills to get a coherent, fiscally neutral package together by the February 2019 deadline. More>>

 

Meth Testing Report: Housing NZ "To Right Wrong"

Phil Twyford “Housing NZ acknowledges that around 800 tenants suffered by either losing their tenancies, losing their possessions, being suspended from the public housing waiting list, negative effects on their credit ratings or, in the worst cases, being made homeless.” More>>

ALSO:

No Reshuffle: Meka Whaitiri Removed As A Minister

Meka Whaitiri will be removed as a Minister with immediate effect... The decision was made after receiving a report into an incident that occurred on 27 August in Gisborne, involving Meka Whaitiri and one of her staff. More>>

ALSO:

Pay Equity Bill: Making History For Women’s Pay

The Equal Pay Amendment Bill, introduced to the House today, will make it easier for workers to make a pay equity claim , using a more simple and accessible process within New Zealand’s existing bargaining framework. More>>

ALSO:

Suffrage 125: NZ A Trailblazer For Women

“We acknowledge the work of Kate Sheppard, Meri Te Tai Mangakāhia, and all of the suffragists who tirelessly campaigned for the vote… Today we also need to ask each other: how we can continue to make our country a fairer and better place to continue the legacy of the suffragists.” More>>

ALSO:

Asylum: Refugee Quota Increasing To 1500

“The quota increase will take place from July 2020. In the meantime, we will work to increase the number and spread of refugee resettlement and support services. We need to make sure we’re prepared for this change in policy.” More>>

ALSO:

 
 
 
 
 

LATEST HEADLINES

  • PARLIAMENT
  • POLITICS
  • REGIONAL
 
 

InfoPages News Channels