FAQ's - Frequently Asked Questions June 21 2020

Following a few repeat questions we have put together this FAQ page.

Q: Why is a hatchery needed on the Fal Fishery when it has its own wild native oyster population?

A: 85-95% of the world's native oyster populations have been lost to: overfishing, pollution or disease, the Fal Fishery has the smallest 'minimum landing size' (MLS) of 2" 5/8ths (67mm) in the UK and has historically been a juvenile stock supplier to other fisheries in UK and France, where their populations have collapsed. The Fal has possibly the last remaining naturally reproducing native oyster stocks, probably due to the bylaws from 1800's preventing the use of machinery (engines & winches) on licensed vessels, however annual fishery surveys suggest the biomass (population) is in decline here to.

Q: Why is the population declining?

A: Typically a 2 year old native oyster can produce maybe 500,000 larvae but only 1 will probably survive the first 12 months in the wild, a 4 year old 1 million and 2 survivors. Harvesting juveniles for sale to other fisheries mean they are not reproducing on the Fal Fishery, if they were 5 years old before harvesting then they may have left 1+1+2+2 survivors from the 0.0002% wild survival rate. Whereas a 2 year old may not have left 1 survivor!

Q: What is the estimated density of native oysters on the Fal?

A: The Cornwall Inshore Fisheries Conservation Authority (CIFCA) survey of 2019 estimated just 1 oyster per 20m2. Native oysters need to be within 1.5m2 to enable successful reproduction.

Q: How does a native oyster reproduce?

A: Unlike a Pacific oyster, where male emit sperm, females emit eggs and fertilization occurs in the water column, the native oyster is unusually 'in vivo' where sperm must enter the female shell for fertilization, hence the need for a decent biomass in close proximity to each other. Specific environmental conditions are also required, such as sea temperature, but these can be replicated in controlled environments.

Q: How many native oysters will be produced at the new hatchery?

A: Given the fact the new hatchery is a 'micro hatchery' just to carry out various trials, only a small number of +90g brood stock will be used initially. However, if 10 5 year olds can produce 10 million larvae then it is all about the survival rate within the hatchery, which has a capacity to rear 80 million new larvae and 10 million spat. Hatcheries in the USA can have a survival rate of 30-60% when breeding Pacific oyster species. 

Q: Why is the CIC hatchery located within the privately owned purification centre, at Mylor Yacht Harbour, known as Fal Oyster Ltd. t/a Cornish Native Oysters? 

A: The founding director of both the Ltd and the CIC has offered the services to the CIC until such time it has its own hatchery equipment. 

Q: Why is the CIC using public donations to pay the Ltd and what is it actually paying for?

A: The CIC has paid the Ltd. to provide it with hatchery produced native oyster stock.

Q: The fundraising states "to hatch, rear and release 1,000,000 Cornish Native Oysters in to the Fal Fishery" - will oysters actually be 'released' on to the fishery?

A: Yes, we have asked CIFCA to help us deploy the spat (baby oysters) when they have settled on to oyster shell in the hatchery and grown to a size that have a good chance of survival in the wild, probably 5-10mm or larger, so some for the CIC Aquaculture Research Site and some (hopefully 1,000,000 or more) to release on to the public Fal Fishery. BUT remember, even by storing them for research, they will be naturally reproducing for the surrounding Fal Fishery.

Q: Why does the CIC need an Aquaculture Site if oysters are being deployed on the Fal Fishery?

A: The CIC does intend to deploy spat on the public fishery and so far two fishermen have volunteered to distribute hatchery stock (subject to prior approvals from CIFCA). BUT it is also essential that the hatchery born stock is studied and provides ‘scientific evidence’ as to the growth rate, survival rate, maturity, and mortality of native oysters on the Fal Fishery. Simply throwing stock over the side of vessels leaves them open to predators, harvesting by fishermen and does not provide any scientific evidence for future adaptive fishery management.

Q: What is the capacity of the Aquaculture Site and what will happen when the native oysters reach a marketable size?

A: Capacity is 100t roughly, depends on aquatic health stocking densities, the current Fish Health Inspectorate (FHI) recommended stocking density is 2.5 per m2 (linear) due to historical Bonamia ostrea disease studies, the OSPAR recognised density of an oyster bed is 5 per m2 and anything above 10 per m2 is considered a high risk for disease, we shall do some research. BUT no recommendations are available for m3 (cubic) stocking densities, so again we hope to provide that evidence from scientific research by starting with very low density per m3 and gradually increasing it while observing trends, the FHI are keen to work with the project. Once at a marketable size the CIC may invest in its own purification centre in order to generate not for profit income, so it can invest in further research with schools/universities and provide employment to the local community.

Q: What else will the Aquaculture Site be used for and how will it generate income?

A: The CIC intends to provide license holders and approved merchants with a storage facility so they can harvest legal oysters (67mm and probably 50g) and store them until they grow to reach a marketable edible grade with a much higher value (80g and probably 80mm). The CIC must be self sufficient but not for shareholders profits as in Ltd companies, so it will rent out storage at a rate that is viable for both CIC and for fishermen, an example is: wild sailboat native oysters at MLS are worth £3-£4 per kg, but probably grow from 50g to 75/80g in 6-12 months, so some profit gained by fishermen and the increase in weight will be used to pay for the storage facility rented from the CIC. Some fishermen have the limited number of ‘lays’ to store and grow their catch, but these are few and far between, rarely become available and are unpoliced by either harbour or management authorities due to a historical bench mark legal case (Truro Corporation v Rowe 1901 and its appeal in 1902)

Q: Will these oysters be classed as ‘farmed’ and not ‘wild’?

A: While we are essentially hatching (from local indigenous stocks) and storing native oysters (in a biomass that helps natural reproduction of the wild population) I guess some may consider them as ‘farmed’. We are in talks with DEFRA and UK Protected Names Scheme. We don’t really have a problem with ‘farmed’ as we now the only way to improve the survival rate is in a controlled hatchery/growing facility and while we are storing the native oysters in an area surrounded by the wild Fal Fishery they are only feeding on wild plankton and algae. In addition they are massively helping the wild stock population that without this ‘b plan’ the fishery biomass may get to a tipping point of collapse, just as all other fisheries have.

Q: What is the difference between the 17 native oyster restoration projects currently active in UK & Europe and this project on the Fal Fishery?

A: The majority of ‘native oyster restoration projects’ are struggling to source sufficient spat supply and targeting stock from wild oyster beds has huge impacts on those populations, as well as the risk of spreading disease and invasive species. So it is a very fine line between ‘habitat restoration’ lead by scientists and that of ‘fishery management’, which has a commercial interest. BUT as collaborator on both the European Native Oyster Restoration Alliance (NORA) and the UK/Ireland Native Oyster Network (NON), the CIC believes science and responsible fishing for a food resource can work together. ‘Aquaculture’ of shellfish provides our rapidly growing global population with a sustainable food resource when traditional ‘hunting and gathering’ of wild food resources are becoming more and more depleted, with only one likely consequence, so it is important to try to work in harmony with what natural stocks we have left, do some scientific research and prevent a world of only genetically modified food produce, before it is too late.