The Oyster

Working on the oysters at low tide

The type of oyster grown in Dungarvan is the gigas or pacific oyster, also known as the rock oyster. The industry is now well established here; the first commercial production of oysters started about 25 years ago. From modest beginnings the bay now produces between 2000-2500 tonnes per annum. The entire production for Ireland is approximately 7000 tonnes. Dungarvan is therefore a very significant producer of oysters.

The Bay of Dungarvan is tailor made for oyster growing. The bottom is flat and sandy and all on-growing areas are easily accessible by tractor.

The Gigas or Pacific Oyster

The oysters can only be worked at the low tides with the best working times being the spring low tides. As Dungarvan is an open type of bay there is an excellent water exchange, resulting in strong growth, a clean shell and a good meat content in the oysters, resulting in a wonderfully tasty succulent oyster.

At low water the trestles are clearly visible along low water line, but at high tide there is no sign of them at all.

In a warm Summer the water temperature rises significantly, resulting in spawning of the oysters. This temperature is not sustained long enough for the spat to settle and grow and therefore oyster seed has to be imported to the bay.

A French Buyer Inspecting the Oysters

The seed comes either from a hatchery where the oysters are spawned and reared under controlled conditions, or from a natural settlement site such as Arcachon Bay in France.

On arrival they measure only 4-8mm in length and over their growth period of 2-3 years they attain a weight of 60-120 grams. It is at this size that they are brought in and prepared for market.

The oyster ‘seed’ (juvenile oysters) are first put in small mesh bags where they grow rapidly. In order to attain the desired rounded ‘teardrop’ shape the bags must be shaken and turned regularly. As soon as they are big enough they are graded and put into bigger mesh bags and placed back on the trestles. They need to be turned quite frequently to maintain a good shape and to keep them free in the bags. Eventually they end up in 9mm bags at around 120-140 per bag.

Before grading we bring the oysters in to ‘training parks’ for a few weeks to harden them. Training parks are areas of the beach where the oysters spend a longer time out of water each day at low tide, in order to harden the shell, improve the quality of the meat and most importantly to strengthen the muscle of the oyster to enable them to endure several days in a truck when they eventually go for sale.

We grow ‘natural’ or diploid oysters from spat sourced in Arcachon or Marennes in France, and also triploid oysters (sterile so that they do not become milky during summer months). We produce both regular grade and ‘Special’ oysters, including the ‘Bia Mara Special‘.