One of the intentions for my blog was to draw attention to local producers in our food chain.
Why should you care about this? - because in this day an age, our food-supply chain is so long and we are increasingly more removed from the growing, production, processing of our food —Out of sight, out of mind. The danger of this is that as large food industry grows and engulfs local food, we lose the diversity and vibrant communities that surround the social culture of food. We heard a recent talk on BBC Food program that talked about how sustainable oyster cultivation could be; so in light of all this, we went on a wild goose chase … or perhaps better-termed a wild [oyster] chase.
It started on a road trip in the magical West of Ireland with our friends visiting from Canada. It is a scenic, rocky and coastal place that is unlike anywhere on this earth. When I first visited last August for the Dilisk project, I stared through the window in awe and amazement that this place could even exist. The landscape just touched me, the moss, the sporadically placed lakes, winding country road, and romance of the villages. It’s a cold, serene, and contemplative place. I made it to Dingle Peninsula on this road trip and I was wandering the area for photo spots. Just then, I got chatting to one of the locals as he was going off to cut some rope on the pier. He said he was worked for an oyster hatchery and i was intrigued, “this guy can’t get away without telling me where this hatchery is.” He pointed in the distance across the bay and said it was in that direction, past a few houses. I nodded, and dropped a pin on google maps to route the position, which appeared to be an eight minute drive away. It was worth the adventure of eight minutes, ‘sure, what’s the worse that could happen'. So I convinced my friends that we had to go and check out this hatchery.
We followed a narrow road spotted with a holiday homes and no people, mostly roaming herds of cattle and dogs. We pulled up to the small hatchery facility, at the gate a posted sign stated “Business Visits Only”, I told our friend to turn down this road and all the passengers in the car protested, but haven’t you ever wondered how oysters come to be? We rocked up and they were gracious enough to not shoot us with a long-range shot gun. (I do not recommend trying this at home, lads and lasses)
We approached the building and saw the lab full of equipment. Just then, the senior production came out to greet us strangers and after a bit of coaxing and begging they agreed to show us around. What happened next was eye-opening and showed us how oysters come to be.
ALGAE ROOM "Dip your feet into the foot bath,” he said on our way in to a room full of fancy tubes filled with ’HULK’-green liquid bubbling away. It turns out there are two types of algae solution for each part of the oysters’ lifecycle. The bubbling noises were providing the tubes of algae with proper aeration, oxygen and CO2 required for the algae to grow. In production, the manager 'grows-up' the cultures, from 5 L then up to 10 L and the oysters are fed by the algae cultures. The bars of LED light provided the light essential for algae to photosynthesise and grow.
Here is the breakdown of the how oysters procreate ;) I drew a process flow diagram to simplify it
“spat” or “seed" is an old English term applied to the early juvenile stage of bivalves (scallops, oysters, mussels)
"It’s a very tricky task. It's great when all the oysters and algae are doing what they need to be doing but becomes stressful when they're not. Timing and cleanliness is very key to this production."
OYSTERS The production manager showed us a few 'perfect' oysters that displayed the qualities of oysters, the type with no defects and had the best appearance and taste. From these, what they call Broodstock, they are 'conditioned' at a warm and happy temperature about 25ºC to spawn. Once the eggs are fertilised they are put in the rearing tanks. Once the eggs are feritilised, they are transformed into larvae.
Larvae are held in large tanks with filtered, purified water at a constant temperature and fed daily. It is essential to keep the tanks and all steps of the production impeccably clean, so tanks are emptied and washed every few days. The second stage of the process, oysters are fed a different feed that cause them to morph into a cultch, and from there they are able to be put into the nursery system.
Finally, the spat reaches 4-5 mm, continually fed. They are just like real babies, the bigger they get the faster their feed rate and more food they need. Oyster babies at the nursery stage require the most demanding food requirements and space conditions. At the point that they reach this stage, the oysters are ready to go into the ocean. They are then transported to farms that will grow out the oysters until they are market-ready!
Next on the blog, we will visit the next step in the oyster supply chain - get ready for Achill Oysters!
If you enjoy oysters and the people who make it possible to enjoy them, please share this and comment below.
Note: there are several different systems of spawning, growing, and farming oysters. This example is a very self-contained system. Two million mature Pacific oyster larvae it into a ball about 5 cm in diameter when wrapped in mesh.
In general, outside North America, hatcheries set the larvae and grow the oyster seed/spat to size before handing them off to farmers/growers to handle
http://www.fao.org/docrep/003/w3732e/w3732e06.htm#b12-220.127.116.11.%20Light. FAO, Algal Production
http://www.fao.org/docrep/007/y5720e/y5720e0b.htm. FAO, Part 6 Hatchery operation: culture of spat in remote setting site, in the hatchery and in nurseries