Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 


Little squirts that hang out around the coast

12 February 2013

Little squirts that hang out around the coast

When you are at the beach or harbours this summer, don’t be surprised if you see sea squirts - marine animals we commonly see attached to rocks and wharf piles that have two siphons on the top of their bodies, one to draw in water and the other to expel it. When disturbed, sea squirts contract their siphons, expelling streams of water—hence their name.

NIWA has created a new, colourful and intuitive guide to sea squirts found around New Zealand coasts and ports. Packed with photographs of 28 species, the guide is geared towards easy identification of sea squirts in the field and is a useful tool for keen underwater observers.

The guide includes some of the recently arrived invasive species of sea squirt that have colonised our ports and harbours, as well as many benign native species. It covers species we’re already aware of, so if you spot what you believe is a new one, please let the Ministry for Primary Industries know on their freephone 0800 80 99 66. Checks can be made to make sure it is not likely to be troublesome.

Sea squirts (ascidians) are amongst the most commonly found fouling animals in ports and harbours around the world, including New Zealand’s. They settle and grow in great abundance on submerged structures such as wharf piles, seawalls, ship hulls and aquaculture structures. In some countries, they are eaten by humans.

The guide gives important information about each species: its appearance, whether it is native, its habitat, how common it is, its distribution around New Zealand, and what threats (if any) it poses to New Zealand ecology and aquaculture.

While most native ascidian species are found in low numbers in intertidal and subtidal environments around New Zealand, non-indigenous species can be highly successful, often reaching densities that preclude other species. The potential impact of some of these sea squirt species on the shellfish aquaculture industry in particular, can be serious.

Sea squirts have abundant, highly mobile larvae that settle and grow quickly into adults, competing with other species for food and space. Some species are able to replicate themselves asexually, which causes very rapid growth of the colony. Rapidly growing sea squirt colonies, such as Didemnum vexillum, can overgrow and smother mussels. Pyura praeputialis forms dense mats that alter natural habitats used by other species.

NIWA scientist Mike Page says, “We designed the guide because people want to know what they are, particularly when they are on the hunt for non-indigenous and invasive organisms. Therefore the guide will be useful for the Ministry for Primary Industries, Department of Conservation, regional councils, district councils, schools, universities and port authorities.”

The guide contains easy-to-follow diagrams of sea squirt biology and flowcharts for species identification. It uses clear and user-friendly icons for each species to show key information about its habits and characteristics.

The sea squirt species are illustrated with high-quality images of the animals in their habitat.

“As far as possible, we have used identifying features that can be seen with the unaided eye or a magnifying glass, and language that is non-technical,” says Page.

The guide is dynamic and new species will be added as they are discovered. The guide will be updated on NIWA’s website.

This research was funded by the Ministry of Business, Innovation and Employment.

ENDS

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Interest Rates: Wheeler Hikes OCR To 3% On Inflationary Pressures, Eyes Kiwi

Reserve Bank governor Graeme Wheeler lifted the official cash rate for the second time in as many months, saying non-tradable inflationary pressures were "becoming apparent" in an economy that’s picking up pace and he's watching the impact of a strong kiwi dollar on import prices. More>>

ALSO:

Scoop Business: Equity Crowd Funding Carries Risks, High Failure Rate

Equity crowd funding, which became legal in New Zealand this month, comes with a high risk of failure based on figures showing existing forays into social capital have a success rate of less than 50 percent, one new entrant says. More>>

ALSO:

Scoop Business: NZ Migration Rises To 11-Year High In March

The country gained a seasonally adjusted 3,800 net new migrants in March, the most since February 2003, said Statistics New Zealand. A net 400 people left for Australia in March, down from 600 in February, according to seasonally adjusted figures. More>>

ALSO:

Hugh Pavletich: New Zealand’s Bubble Economy Is Vulnerable

The recent Forbes e-edition article by Jesse Colombo assesses the New Zealand economy “ 12 Reasons Why New Zealand's Economic Bubble Will End In Disaster ”, seems to have created quite a stir, creating extensive media coverage in New Zealand. More>>

ALSO:

Thursday Market Close: Genesis Debut Sparks Energy Rally

New Zealand stock rose after shares in the partially privatised Genesis Energy soared as much as 18 percent in its debut listing on the NZX, buoying other listed energy companies in the process. Meridian Energy, MightyRiverPower, Contact Energy and TrustPower paced gains. More>>

ALSO:

Power Outages, Roads Close: Easter Storm Moving Down Country

The NZ Transport Agency says storm conditions at the start of the Easter break are making driving hazardous in Auckland and Northland and it advises people extreme care is needed on the regions’ state highways and roads... More>>

ALSO:

Get More From Scoop

 
 
Computer Power Plus
 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news