The public will be the driving force behind future restoration efforts of seagrass meadows, thanks to an app developed by the Cawthron Institute.
Seagrass meadow, home to cockles and a plethora of sea life, are found in estuaries and harbours such as Nelson Haven and the tidal zone inside Farewell Spit.
However, marine biologist Daniel Crossett says many meadows are in decline. Satellite imagery shows they have declined as much as 60 per cent in Nelson Haven and a massive 90 per cent in the Westhaven Inlet which is surrounded by native bush.
“The meadows are a nursery ground for recreational and commercial fishers. Juveniles will come and hide amongst it, and bigger ones will come and feed there. They trap sediment and it’s a good way to increase water clarity, and there’s evidence of it storing carbon which is a benefit to everything in terms of climate change. And it takes up nutrients off the land.”
Studies show they are rich in biodiversity and Daniel says they can turn into a meadow with their own ecosystem.
Hence the drive to restore declining meadows. The app is part of a multi-year research programme pioneering seagrass restoration techniques in New Zealand and Daniel says the crucial first step is understanding when and where seagrass flowers.
“The app allows the public to find the flowers for a database, and once we know how consistent the flowering is in different regions it helps to know where to collect seeds for restoration.”
All the information collected by communities around the country will be recorded on the Aotearoa Seagrass Flower Survey Database. That will help identify the best times to collect seeds, reveal regional differences in flowering, and guide how many flowers can be sustainably harvested from each meadow. Daniel says the app is also an educational tool to encourage the public to get to know their marine environment which in Nelson and Tasman is often not far from their doorstep.
Beside the Nelson Airport is a sizeable seagrass meadow brimming with life. That tiny – but significant – flower is a tiny strip attached to a blade of seagrass, bristling with stigma that are waiting to capture pollen in the moving water.
The project website is Restore the Meadows and the app is Aotearoa Seagrass Flower Survey within ArcGIS Survey123.
