Grainocean present a comprehensive method of high-end production for oyster farmers


In recent years, the oyster economy has clearly moved towards a rationalised production of high-end oysters. Thanks to the 100% triploid seeds, launched in 1999 by the French family hatchery GRAINOCEAN, which has recently been adding new swing bags equipment, oyster farmers are aiming for a high-end quality product.

GRAINOCEAN, world-renowned for being at the leading edge of technology, and whose core business has always been focused on high-end oysters, bases its genetic selection on shape, growth and fattening capacity, and has devoted three years of research and development to designing its potentially revolutionary autonomous tidal ROLL’BAG® (three patents). The ROLL’BAG® is designed for allowing selected oyster seeds to develop and optimize their full potential across the breeding term, while offering ecological and socioeconomic essential benefits.

After two years of trials on its own oyster beds, and more than 80 growers using the ROLL’BAG® from the Netherlands to Portugal, GRAINOCEAN is finally able to offer oyster farmers a groundbreaking method of high-end production.

Super Spéciales oyster from Grainocean triploid seeds finished over 6 months in ROLL’BAG® on Arcachon coast in France


How does the ROLL’BAG® work?
The ROLL’BAG® is a flat basket whose dimensions are the same as classic bags, with a 3-inch thickness. It is sideways hanging to a trestle via rigid and articulated elements, and naturally set in motion by tides thanks to a lateral inside float – no need for waves or current.

Four times per day oysters will roll down the surface of the ROLL’BAG®, thus ensuring a limitation of the shell growth. This occurs throughout the oyster bed. When it is immersed at high tide, the float rises and the ROLL’BAG® is vertical, which allows the seawater to go through the entire batch of oysters, thus ensuring a uniform feeding pattern.

It is designed for and has proved to withstand the worst climatic conditions, thus perfectly adapted to the Irish winter climate and waves.

Half-grown oysters reared in ROLL’BAG® after a “free movement” step


How does the ROLL’BAG® meet ESG (Environmental, Social, and Governance) expectations?

Environmental gains of the ROLL’BAG®:

• The Robustness of the ROLL’BAG® in extreme conditions, the absence of fragile or consumable elements (plastic mesh, elastics, hooks, collars, etc), the internal float and the locking pins eliminate the risk of plastic waste entering the marine environment.

• The circular movement of the ROLL’BAG® around its holding bar generates a very efficient washing of the ground under the trestle, thus avoiding any accumulation of sediment related to the filtration of oysters.

• The choice of quality over quantity, as well as the spatial occupation related to design, reduces the biomass on the oyster beds and thus allows a better management of the local trophic resource, while improving the profitability per hectare, given the high value of the finished oyster.

• Since the tides are doing all the work, the need for manual intervention on the oyster beds is very restricted, which strongly reduces the greenhouse gas emissions associated with vehicles.

Socio Economic gains of the ROLL’BAG®:

• The elimination of the intense labour involved in working the oyster beds increases the attractiveness of the profession, and makes it possible to move towards an alleviation of current recruitment difficulties.

• Oyster workers, as well as family workers, pay a heavy price in working the oyster beds in terms of MSDs (Musculoskeletal Disorders), especially in the shoulders, the back and knees. Since the tides are operating the ROLL’BAG®, this element of the labour disappears, reducing activity to that carried out at the shed (except for hanging and harvesting the ROLL’BAG®) which also limits the duration of the labour outdoors under tough weather conditions.

• With the ROLL’BAG®, the aim of producing excellent quality oysters and the fulfilment of ESG commitments are in perfect harmony, meeting the expectations of growers and consumers, and promoting the image of the oyster farming profession and its produce. All of this contributes to restoring the attractiveness and image of the oyster farming profession, making it a more appealing proposition to young businessmen and businesswomen.

Homogeneous start of growth on matured Grainocean seeds after 3 months of rearing in classic bags in Co Donegal, Ireland


How does the ROLL’BAG® highlight the quality of the oysters, from seeds to finished oysters?

The benefits of the ROLL’BAG® in terms of high fattening of commercial size oysters while saving labour have been confirmed by all growers who have tried it, especially in bays where it was very difficult to reach such quality in classic bags.

Using the ROLL’BAG® to produce halfgrown oysters is a guarantee of quality of shape throughout the breeding term. The ROLL’BAG® has been designed to allow a “free movement” around the trestle’s bar, or a “limited movement” thanks to a restrictor link. Depending on their rearing cycle and rearing area, farmers use the equipment by switching between the “free movement” to slow the growth of the oysters, to harden the shell and to improve the shape, and “limited movement” to trigger shell growth and gain in size. What’s more, the “free” step makes the oysters able to gather feeding energy without spending it as they are limited in their growth, which generates reserve energy essential for restart and very good growth during the “limited” step.

In 2022, thanks to the ROLL’BAG®, GRAINOCEAN adds a relevant step of “maturation” to its seeds production. By being stored at high density in ROLL’BAG® for several weeks, seeds get used to GRAINOCEAN’s selected oyster seeds and ROLL’BAG® equipment: a comprehensive method of high-end production for oyster farmers the tides while being stopped in their growth, thus passing through pathogens episodes with reduced mortalities. This step takes place right before shipping to oyster farmers in order to make seeds fully adapted to transport and manipulations.
This dynamic storage can also be carried on by oyster farmers to perfectly acclimate the seeds to their own bay.

To follow Grainocean’s innovations, to benefit from technical or zootechnical advice, or to have a look at what oysters farmers using ROLL’BAG® have already shared on social networks, check out Grainocean’s YouTube channel and Instagram.



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