This article was amended on Feb. 29 from a previous version that said Nestle Purina Petcare Europe invested over €1 million in Oyster Heaven. 

Purina Europe has partnered with a conservation startup that aims to produce voluntary marine biodiversity credits from a pilot by creating oyster reefs off the UK coast.

Netherlands-based Oyster Heaven said the partnership will support its mission of boosting underwater life while also generating nutrient credits.

“We have convinced one of the largest food and beverage companies in the world to partner with us on developing an ecosystem services offering from our pilot reefs,” said George Birch, founder and business lead of Oyster Heaven.

“The company is committing to the project to understand the ecosystem benefits that can be generated by the reef, with the intention to expand this significantly across the North Sea if all goes well,” Birch told Carbon Pulse. Oyster reefs are formed from piles of living and dead oyster shells.

Purina also invested undisclosed amounts in three other European marine habitat restoration initiatives as part of its Ocean Restoration Programme, it announced Wednesday.

Collectively, the Purina investments aim to help the four initiatives to restore 1,500 hectares of aquatic environments by 2030, in France, the Netherlands, Norway, Portugal, Germany, and the UK, Purina said in a press release.

Dutch seagrass meadow-planting enterprise Sea Ranger Service, Norwegian excess sea urchin removal company Urchinomics, and Portuguese seaweed restorer SeaForester are also in the programme.

HOW TO MAKE AN OYSTER REEF

Oyster populations have declined by around 85% worldwide, making them one of the most severely affected marine species on the planet, according to a report published by The Nature Conservancy in 2009.

The Hague-based Oyster Heaven aims to capitalise on their ability to filter water, provide food for other species, and protect coastlines.

The company aims to create oyster reefs by embedding them onto biodegradable clay structures, with about 100 oysters per square metre, before dropping them in the sea. About 1,200 square metres of ‘bricks’ of clay, with each chunk weighing about 6 kg, are needed to cover a 5-ha area.

Clay bricks before entering the sea. Source for all images: Oyster Heaven

The bricks come on pallets from a factory before being placed in tanks, where oyster larvae can settle on them for a few weeks.

Members of local communities then drop the bricks off boats into the ocean. Indeed, the model depends on collaboration with fishing groups, Birch said.

“They lead the projects, they put them into the water, they’re getting paid a day rate to deploy these reefs, we’ll train them up in monitoring and repairs. And they’re going to get more crabs and lobsters to fish.”

“What we never want to happen is to squeeze the fishing communities even more, because they’re not having a great time. Yields are going down, fuel prices are going up, and licences are more expensive.”

Oyster Heaven can licence its commercial activity from the Crown Estate, which owns the seabed up to around 12 miles off the coast of the UK.

BABY OYSTERS

Voluntary biodiversity credits, nutrient credits, and biodiversity net gain units offer a “large” profit window for oyster reefs, without the need to consume oysters, Birch said.

Birch could not reveal whether anyone other than Purina has said they will partner with Oyster Heaven, but said he hoped to share commitments soon.

“Whether you’re in the UK, the Netherlands, or the US, there are different flavours of the same kind of regulation.” The company is initially focused on the UK but is considering projects in oceans around the world.

Voluntary biodiversity credits produced by the oyster reefs will use the methodology produced by non-profit Wallacea Trust to measure nature uplift.

The Wallacea Trust defines a credit as a 1% uplift, or avoided loss, in biodiversity per hectare using a location-dependent ‘basket of metrics’. The Biodiversity Futures Initiative (BFI) must independently peer review claims made using the Wallacea framework.

Oyster Heaven has selected credit metrics for its pilot including abundance of fish and surface roughness of the reef. It will gather indicators over a five-year period to allow the baby oysters time to grow before reproducing.

Videos taken by divers hope to see greater numbers of cod, eels, herring, crab, and lobsters. The company collaborates with Newcastle University and the Netherlands Institute of Oceanographic Research on data collection, leasing it out to an independent third party.

Underwater clay reef brimming with young oysters

Purina aims to keep the credits themselves to boost their own biodiversity credibility, rather than selling them, according to Birch.

Another potential source of income from future projects for Oyster Heaven could be generating off-site marine net gain (MNG) units under the UK’s forthcoming legislation, Birch said.

The government is pushing ahead with MNG proposals for requiring developers to leave the marine environment in a measurably better state than before any activities have happened.

The MNG legislation follows the implementation of mandatory biodiversity net gain requirements for developers this month. “If you want to have any sort of development in the water, whether it’s offshore wind [farms], cabling, or a new bridge, you will need to offset the biodiversity damage,” said Birch.

NUTRIENT CREDITS

Oyster Heaven hopes to generate nutrient credits to help nearby developers comply with nitrogen impact requirements. One nutrient credit represents 1 kg of nitrogen or phosphate, usually mitigated through practices such as halting agricultural activities, under English regulations.

“Generally all of our reefs aim to be within 500 m of the coast. We think that one hectare of oyster reef filters out about 500 kg of nitrogen a year. At £2,500 to £3,000 per 1 kg, that’s £1.5 mln worth of nitrogen credits per hectare of oyster reef over a lifetime,” Birch estimated.

The nutrient credits are expensive because they are pegged to pricey English farmland, but Oyster Heaven aims to undercut market prices.

“At the moment, the only way to generate nitrogen credits is by shutting down a local pig or dairy farm. But unless you’re reducing the demand for bacon or milk, a new farm is going to pop up somewhere else – the problem has just migrated,” Birch said.

In addition, it takes about 35 years on average for nitrogen to reach the water from source, so the area would not benefit from the reduced nutrient leakage from a farm for this period, he said.

There should be demand for Oyster Heaven’s nutrient credits from developers in coastal counties operating the scheme, such as Hampshire, if it acquires regulator approval.

“Oysters can’t participate in this regulated system, but Natural England has given us a communication saying it is possible if we provide the right burden of evidence.”

Oyster Heaven will use underwater benthic chambers to measure the amount of nitrogen filtered out of the seawater by oysters, in measurements taken every two years.

LONG-TERM PLANS

The company, linked to oysters’ prolific reproduction rates, sees the reefs covering thousands of hectares under the most ambitious future.

Starting with just five hectares, Oyster Heaven plans to drop enough clay oyster reefs to cover an area of around 150 has in five years.

“Hopefully your 150 has will quickly turn into tens of thousands of hectares. Each mother oyster will have 57,000 children roughly over the course of her life – maybe 10% of them survive to reproducing adults.”

If the company helps embed 100 mln oysters in the ocean by 2027, they could filter 20 billion litres of water a day, managing 200 tonnes of sewage annually, the Oyster Heaven website claimed.

Although oysters are monocultural, 100 mln would not be too many for marine ecosystems, Birch said. “We will not get to a point where we have too many oysters. We’re restoring the same oysters that used to be there 150 years ago.”

There are no plans to farm the oysters yet – but the company would consider sustainable harvesting if numbers are booming in 20 years, he said.

Across several revenue streams, Oyster Heaven seeks to demonstrate how private corporations can profitably invest in natural capital, making conservation less dependent on philanthropy and government grants in a bid to address the biodiversity financing gap.

By Thomas Cox – t.cox@carbon-pulse.com

*** Click here to sign up to our twice-weekly biodiversity newsletter ***