26
J. Haure et al.
(Institut Franc ¸ais de Recherche et d’Exploitation de la Mer) in order to support
research work on toxic algae and their impact on aquaculture. The objective was
to limit economic losses caused by toxic algae in the French shellfish industry.
Several publications resulting from this project, offer more detailed methodological
descriptions (Castaing et al. 2010, 2011; Gueguen et al. 2008, 2011; Le Grel and
Le Bihan 2009; Marcaillou et al. 2010).
Two general scenarios have been observed: (i) sporadic and seasonal toxic
events and (ii) long-term exposures to toxic algae. Implementation of generic
land-based culture was thought to be the most promising solution to maintain
shellfish trade during toxic events. Accordingly, two types of land-based culture
were considered:
– If sporadic toxic blooms occurred, an early preventive storage of uncontaminated
shellfish (either mussels or oysters) was considered as a means of avoiding contamination. Land-based procedures of either wet or dry storage were considered
to be appropriate.
– In cases of long-term exposure of shellfish to toxic algae, industrial-scale detoxification systems were thought to be the best solution for producers, provided that
detoxification was achieved, and that investment costs were exceeded by income
generated from the sale of detoxified shellfish.
Tanks supplied with re-circulated seawater were used, as these are the most
convenient systems for wet storage.
The Research and Development project was based on four workshops: (i) Water
quality (seawater treatment, phycotoxin stability and bioavailability as dissolved
compounds), (ii) Safe storage of non-toxic shellfish (in recirculating seawater),
(iii) Detoxification (improving PSP and DSP detoxification yields using algal feed
or physico-chemical treatments), (iv) economic analysis (regional oyster industry
characterization, market bans, commercial losses and possible counter-measures).
According to the different phycotoxin bioaccumulation patterns described in the
literature (Bricelj and Shumway 1998) some experiments were focused on blue
mussel, Pacific oyster, or the use of both species.
Material and Methods
Biological Materials
Toxic and Non-toxic Bivalves
Non-toxic or toxic market-sized mussels (Mytilus edulis) were collected from
shellfish growers of Vilaine Bay. Market-sized Pacific oysters (Crassostrea gigas)
were obtained from a producer in the Bay of Bourgneuf (French Atlantic coast),
where they had been grown in safe conditions, in an area with no history of paralytic
shellfish poisoning.
J. Haure et al.
(Institut Franc ¸ais de Recherche et d’Exploitation de la Mer) in order to support
research work on toxic algae and their impact on aquaculture. The objective was
to limit economic losses caused by toxic algae in the French shellfish industry.
Several publications resulting from this project, offer more detailed methodological
descriptions (Castaing et al. 2010, 2011; Gueguen et al. 2008, 2011; Le Grel and
Le Bihan 2009; Marcaillou et al. 2010).
Two general scenarios have been observed: (i) sporadic and seasonal toxic
events and (ii) long-term exposures to toxic algae. Implementation of generic
land-based culture was thought to be the most promising solution to maintain
shellfish trade during toxic events. Accordingly, two types of land-based culture
were considered:
– If sporadic toxic blooms occurred, an early preventive storage of uncontaminated
shellfish (either mussels or oysters) was considered as a means of avoiding contamination. Land-based procedures of either wet or dry storage were considered
to be appropriate.
– In cases of long-term exposure of shellfish to toxic algae, industrial-scale detoxification systems were thought to be the best solution for producers, provided that
detoxification was achieved, and that investment costs were exceeded by income
generated from the sale of detoxified shellfish.
Tanks supplied with re-circulated seawater were used, as these are the most
convenient systems for wet storage.
The Research and Development project was based on four workshops: (i) Water
quality (seawater treatment, phycotoxin stability and bioavailability as dissolved
compounds), (ii) Safe storage of non-toxic shellfish (in recirculating seawater),
(iii) Detoxification (improving PSP and DSP detoxification yields using algal feed
or physico-chemical treatments), (iv) economic analysis (regional oyster industry
characterization, market bans, commercial losses and possible counter-measures).
According to the different phycotoxin bioaccumulation patterns described in the
literature (Bricelj and Shumway 1998) some experiments were focused on blue
mussel, Pacific oyster, or the use of both species.
Material and Methods
Biological Materials
Toxic and Non-toxic Bivalves
Non-toxic or toxic market-sized mussels (Mytilus edulis) were collected from
shellfish growers of Vilaine Bay. Market-sized Pacific oysters (Crassostrea gigas)
were obtained from a producer in the Bay of Bourgneuf (French Atlantic coast),
where they had been grown in safe conditions, in an area with no history of paralytic
shellfish poisoning.