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ARCACHON & OYSTER’S
AQUACULTURE AND PEOPLE
COLM POWELL MAY 2016
AQUACULTURE L5 WORK EXPEREIENCE
Arcachon bay is situated in the southwest of France on the Atlantic Ocean. It is situated between the Cote d’Argent and the Cote des Lands, in the region of Aquitaine. The bay covers an area of 150 sq. km at high tide and 40 sq. km at low tide. The bay is surrounded by pine forests and water meadows rich in natural habitat and comprises of ten small towns and fishing villages, home to Arcachons 300 plus oyster enterprises, and The main town is Arcachon.
The entrance to the bay is by a 3km wide inlet surrounded by a narrow strip of land and sandbank to one side and a sandbank in the center of the inlet and on the other side The Great Dune of Pyla the largest of its type in Europe. The oyster park is located in the center of the bay and is only accessible at low tide by flat bottom boats and covers many hundreds of hectares. Oyster parks were introduced in France by Napoleon 3rd, because the gathering of wild oysters was wiping the species out. The first farms began production in the Arcahon area in 1849.
All of the oysters grown and sold here today are the larger Pacific Oyster; the native oysters were rounder and flatter and were totally wiped out in the 1970’s.
The Arcachon basin produces 10,000 tonnes of oysters annually, relatively small in output in comparison to other oyster producing regions. However, 60% of oysters that are eaten in France come from The Arcachon Basin, as the basin is also the principle French supplier of seed oyster for all of Europe.
The Arcachon basin also supports a huge tourism industry with millions of visitors every year and staying in the many camping and caravan sites dotted around the bay. There are many and varied outdoor activities to be availed of in and around the basin.
GUJAN MESTRAS: location for work experience.
The town of Gujan Mestras with its 7 ports and numerous oyster farms and Aquaculture College is considered to be the capital of the oyster industry in the Arcachon Basin.
There is also a thriving boat building industry within the town building leisure craft up to 50 meters long. Every August Gujan Mestras holds its annual oyster festival run over five days with over 100,000 visitors coming for oyster tastings, wine and music.
OYSTER FARM WORKED ON
HUITRES FINES du CAP FERRET Ets SAINT-ORENS Sebastien
PORT de la Barbotiere
This farm is operated by a husband and wife team, and consists of a small intertidal plot, used only for spat collection and 2 hectares spread over five locations within the Park. It is accessed by flat bottomed boats and only workable at low tide, the farm plots are reached before low tide by a series of channels.
The farm plots are fenced in by poles every 8 meters and the oyster bags are laid on trestles and only tied on one side for quick turning.
Once the tide is low enough the working day began, there were lots of jobs to be done. Over the months at sea, the oyster bags upper side would become covered with seaweed so the bags would be turned and the under side would be grazed clean by sea snails and other grazers. The bags are also checked daily for spat and mussel settlement. If these are found to be at high a level the bags are removed from the trestles and moved to another plot and laid directly on to the sand and left for a couple of weeks for the crabs and scrimp to deal with recently settled spat and mussels.
The trestles also attracted a lot of settlement and once the bags are removed they are scraped clean before been reused. The fence poles are removed and replaced as required with the aid of a water pump and a high pressure hose.
Up to five tonne of oysters are loaded on to the boat each day to be moved to other grow out areas within the park and two tonne are transported back to shore to be graded and re-bagged.
After grading the oysters those of market size are stored in sea water aerated holding tanks for up to three days to remove any sand or grit, no UV is used at any stage as the waters of the park are of a A classed water and no depuration is need. The farm produces 50 tonnes of oysters each year which are sold ready for the table to local restaurants and at two weekly markets and the remainder are sold for growing on to other regions of France.
The farm produces five different sizes and two different colours of oysters ready for the table to suit the customer and market requirement.
The oysters are taken out to a sandbank at the mouth of basin to be grown out and take on the white sandy colour of their surroudings and are considered to be sweeter and meatier because the mouth of the basin is flush with nutirents.
The farm doesn’t buy in seed oyster, the spat is collected from the wild in four different ways: Coupelles. Square Loover trays, terracottas tiles and rubber coated pipes
The main season for naturally produced oysters of The Arcachon basin is from September to April when the water begins to get warmer and the oysters begin to spawn. There is still a small amount of business to be done over these four months, in what they call Milky oysters being sold to other regions of France where they like their oysters at this time of the year.
Even at this time of the year the farm has to be farmed, oysters turned regraded and rebagged ready for the start of the new season. It is also at this time that the spat collecters are cleaned and made ready for their return to the water at various locations around the basin.this happens in late July and August where they are left until the following Feburary when the spat collection begins.
The work on the oyster farm is hard and the days can be long. However the farmers have a passion for the oyster business and don’t just treat their product as a commodity. It is a labour of love for these people. The overall business model is sustainible with very little inputs after the setup investment.
Erasmus+ Programme 2014-2016
Students Placement and Workshop 25th April – 8th. May 2016
Lycee de la Mer, Gujan Mestras, Arcachon, France
As part of the Erasmus+ Programme 2014-2016, three mature students from BIM’s FETAC Level 5 Aquaculture course completed work placements in Le Bassin d’Arcachon and attended work shop and site visits in the Marenne-La Rochelle area of France between 25th. April and 8th. May 2016. This visit was facilitated by Denis Guet, aquaculture college – Lycee de la Mer, Gujan Mestras, Arcachon .
The students gained invaluable work experience with local oyster producers in the Gujan Mestras area . Le Bassin d’Arcachon along with the Marennes-Oléron region are France’s primarily bays for the collection of wild pacific oyster seed or spat, known as ‘naissain’. Spat collected from here are supplied to oysters farmers in Brittany and Normandy. Arcachon bay also produces oysters for market from 65 gram to over 150 gram. It is estimated the bay’s 300 oyster farmers produce on average 7000 to 10,000 tonnes per annum.
Oyster farming using ‘parcs’ began in Arcachon in the mid-1800s when the native oyster ‘Ostrea edulis’ and at a later stage the Portuguese oyster ‘Crassostrea angulata’ was collected and farmed. Today it is the pacific oyster ‘Crassostrea gigas’ that is the primarily species farmed in France. In Arcachon Bay each oyster farmer has one to a number of ‘parcs’ (concession – licences) , that are located on major oyster growing sand ‘bancs’, for example , the ‘Grand banc’, Banc d’Arguin’ and ‘Le Cour banc’. Each of producers’ oyster parcs or concessions are marked by poles as shown in below photographs. Licences – concessions are administered by the regional marine department.
The majority of the bay’s oyster production is from farmers who have landbases situated on the southern shore between La Teste de Buch and Gujan-Mestras. These landbases, which consist of grading and packing sheds, and holding tanks are located along channels and ports from which they access their parcs with flat bottom barges – boats.
Many of the oyster producers sell directly to the public from their sheds or have a little cabin selling their oysters and wine such as one of the student placement oyster farmers –
‘La Cabane a Ludo’ , as shown in below photos. Many also travel to local markets at the weekend to sell their oysters. The bulk of the market oysters are sold towards the end of the year near Christmas and New Year.
La Cabane a Ludo, Gujan-Mestras
Oyster spat ‘naissains’ are collected during the summer months using different types of collectors, such as tiles, tubes, coupelles, a new type of collector ‘Pleno’ and rolled up oyster bags. The spat is taken off the collectors the following March-May using a variety of strippers. The spat are then deployed into oyster bags for onglowing by the farmer themselves or sold to oyster farmers in Brittany or Normandy. Some of the northern oyster farmers have partnerships with Archachon farmers for spat collection.
Limed collector tiles Tube collectors with spat
Coupelle collectors Old oyster bags rolled up used for collecting
New type collector ‘ Pleno’
Student assisting with stripping tubes Stripping spat from coupelles
Student assisting with spat into oyster bags Student assisting with deployment of spat bags onto oyster farm
Market oysters in baskets stored in tanks Student sorting oysters for market
Gujan-Mestras Restaurant with local oysters
During the second week of the work palcement , the Irish tutors and students joined tutors and mature students from school Lycee de la Mer on site visits to Marennes and La Rochelle where we visited :
- Irish and French oyster packing and distribution stations –
- Jacques Cocollos – Majestic Oysters Donegal Irleand
- CREAA – Centre régional d’expérimentation et d’application aquacole and
- Grainocean Hatchery and Nursery
Grading Irish oysters for market Oyster tanks – Majestic Oysters
Tasting Irish Majestic oysters with Jacques Cocollos ………..Final package ready for market
Gillardeau braded oyster CREAA visit , Ile d’Oléron
Oyster farm boats – Ile d’Oléron Grainocean Hatchery La Rochelle
Grainocean Hatchery Grainocean landbased oyster nursery Ile de Ré
Grainocean spat being graded after time in sea site nursery.
Grainocean sea site Oyster nursery boat
Packing oyster spat onto Lanterns ready for deployment to seasite lanterns. Longlines.
Counting oyster spat Grainocean spat for market
Grainocean oyster spat
Over the course of these two days there were many discussions and exchange of information between tutors and students of Ireland and France with regard to aquaculture and life in both countries. Lycee de la Mer has landbased finfish tanks for sea bass and sea bream and also has an oyster farm. The mature students have to go though aquaculture school courses and gain qualifications before they can apply for an aquaculture licence.