6 Jun 2016

Citizen science: large brown seaweeds

From Our Changing World, 9:06 pm on 9 June 2016
Roberta D'Archino, left, and Kate Neill, who are both at NIWA, collecting large seaweeds that have washed ashore on a beach in Lyall Bay, Wellington.

Roberta D'Archino, left, and Kate Neill, who are both at NIWA, collecting large seaweeds that have washed ashore on a beach in Lyall Bay, Wellington. Photo: Veronika Meduna / RNZ

From the top: a bed of large seaweeds, bladder kelp, and Neptune's necklace.

From the top: a bed of large seaweeds, bladder kelp, and Neptune's necklace. Photo: Roberta D'Archino

Marine scientists are calling on the public to help them get a better idea of the distribution of large brown seaweeds along New Zealand's coast.

Brown seaweeds, including the familiar bull and bladder kelps and Neptune's necklace, are an important part of the coastal ecosystem. They provide shelter for other species and buffer the coast from waves and erosion. But little is known about their distribution, and NIWA scientists have launched a NatureWatch citizen science project to encourage people to post images and GPS location data for their local beaches. 

Marine biologist Roberta D'Archino says large brown seaweeds are disappearing from many sites throughout the world, but there is too little data to track their abundance along New Zealand's coastline. Such a baseline is necessary to monitor any changes in the future for any of the 12 species of brown seaweeds found in New Zealand.

Kate Neill, who is also part of NIWA's coast and ocean group, says large brown seaweeds are underrepresented in museum collections because it is difficult to preserve large specimens in a herbarium.

She says the distribution data is only one part of the project. The team also collects the seaweeds to culture them in the laboratory to test them under changing acidity, temperature, light and sedimentation conditions.

They are also developing a camera system to monitor changes in seaweed beds in the shallower waters along the coast. The research is funded by the Ministry for Primary Industries.

You can hear more about New Zealand's seaweeds in this Our Changing World story with NIWA's Wendy Nelson.