New and additional species including sponges and seaweeds have been found in Tauranga Harbour and the wider Bay of Plenty following recent biodiversity research.

Sea lettuce was a hot topic at Tauranga's Blue2Green Marine Biotechnology Convention this week.

Speaking at the convention, top Tauranga marine ecologist Professor Chris Battershill said scientists had been working with local iwi to look at the marine diversity in the harbour and wider Bay region.

"There has not been a focus on the biodiversity, the marine diversity, in this region and the little work that we have started doing suggests that it is enormous."

Professor Battershill, chairman of coastal science and head of the Coastal Marine Field Station at University of Waikato, said there were a lot of new and additional species which had been brought to the region on ships.


"It is an exciting scene," Mr Battershill said.

"We know that there are species out here which are generating interesting biologically active chemicals that have applications of medicine.

"But in our case, we are particularly interested in agriculture and horticulture for the region."

Mr Battershill said the new species found in the harbour and wider Bay included sponges and seaweeds.

"The reason they are generating these interesting compounds is because they are all living in a very diverse group and their abilities to maintain themselves and compete are generating exciting biologically reactive chemicals.

"We now know enough from past work to be able to map that into areas that are important."

He said future work would focus on kauri dieback, avocado disease and myrtle rust.

"The reason we are focusing on the agriculture sector is because you can fast-track the commercialisation very well.

"We are still linked internationally to medicinal programmes and they are doing very well as well, that is a longer timeframe however."

Mr Battershill said sea lettuce was an issue most Tauranga residents were worried about.

"It smells, it upsets fishing and there has been a huge public demand for some action," he said.

"Most of this workshop is about that. About half the talks have been on sea lettuce and remediating it or making it better."

He said the way to remediate the sea lettuce issue was to make it a valuable product.

"The interesting thing is sea lettuce is very good at scrubbing out the nutrients because they are in a bit of excess, but if you can make a product out of that, for instance cattle feeds or products you can put into soil to trap the nitrogen, then you win both ways.

"You are getting the nutrients out of the harbour so it clears up and you will able to track the nutrients back on the land again.

"The product that does that, the sea lettuce, is worth money."

He said edible sea lettuce was worth $90 per kg overseas, particularly for food markets in Asia.

"We are thinking about new exports so you can diversify the product base," Mr Battershill said.

"Very soon we will be having sea lettuce reactors here and that is going to help the harbour enormously."