Waikato weeds assessed
Echinoderms exposed
Fish biodiversity in the EEZ
What Fish is that?
Fish it when it's down?
Sometimes populations of invasive species take a natural downturn. Can selective fishing be used to hasten their demise?
To answer this question, NIWA scientists developed a population model to evaluate the impact of selective fishing on a declining population of the invasive crab Charybdis japonica in Waitemata Harbour.
The model was based on catch data from eight trapping surveys carried out by NIWA and Biosecurity New Zealand in 2002–04.
Dr David Pawson (left) of the Smithsonian Institution demonstrates the finer points of echinoderm identification to NIWA staff Niki Davey, Owen Anderson, and Kate Neill.
NIWA is constantly developing its species identification capabilities, which are fundamental to aquatic biodiversity and biosecurity monitoring.
Last April, NIWA staff Owen Anderson, Kate Neill, and Niki Davey visited the Smithsonian Institution in Washington DC to sharpen their echinoderm ID skills.
New Zealand is home to more than 500 described echinoderm species, including kina and other sea urchins, starfish, sea cucumbe
Predicted fish species richness in the New Zealand EEZ.
Which parts of New Zealand’s EEZ hold the most species of bottom-dwelling fish?
To answer this question, a NIWA-led research team used data from 21 000 MFish research trawls to analyse the relationship between fish species richness and characteristics of the marine environment.
Waikato weeds assessed
NIWA scientist Dr Paul Champion surveys a plot that was smothered with reed canary grass before treatment (inset).
NIWA has recently assessed the impacts and control of three weeds in Waikato wetlands for the Department of Conservation.
Royal fern is well established in the Lower Waikato/Hauraki Plains area, reaching heights of up to 2.5 m, with no current options for eradication. Our control trials found none of the herbicides used gave selective control of this fern, but a range of products could potentially be used where pure stands of this species grow.
DNA sequences of unusual looking bluefin tuna in relation to three known species. All of the suspect specimens appear to be either Pacific or southern bluefin tuna, which are managed under the NZ fisheries quota system.
NIWA is participating in an international research effort to assemble a DNA barcode library for all marine fishes by 2010. The endeavour forms part of the wider Barcode of Life initiative.
DNA barcoding makes it possible to assign unidentified specimens to their correct species when matched against a barcode library.
