Aquaculture and Fisheries News => Aquaculture News => ข้อความที่เริ่มโดย: aranya ที่ กันยายน 01, 2010, 09:52:06 AM

หัวข้อ: Warm water causes spinal disorder in farmed salmon
เริ่มหัวข้อโดย: aranya ที่ กันยายน 01, 2010, 09:52:06 AM
Bone and cartilage deformities in salmon can be reduced by raising it in lower temperatures. (Photo: Terje Engoe)  

Warm water causes spinal disorder in farmed salmon  

Wednesday, September 01, 2010, 04:10 (GMT + 9)

Scientists found that temperatures greater than 16°C can cause skeletal deformities in young salmon. The study’s results were recently published in BMC (BioMed Central) Physiology.

Funded by the European Union (EU), the finding is part of the Reduction of Malformations in Farmed Fish Species (FINE FISH) project. It received EUR 3.02 million under the small and medium-sized enterprise (SME) cross cutting activity of the Sixth Framework Programme (FP6).

Spinal disorder can affect intensively farmed fish relatively often and represents a significant health and productivity challenge for the aquaculture industry. Insufficient knowledge currently exists on the underlying molecular mechanisms involved in bone deformities in farmed fish to help manage the problem.

The team of four Chileans and Norwegians who ran the study wanted to expand this knowledge base by examining the bone metabolism and pathogenesis of vertebral fusions in Atlantic salmon (Salmo salar), reports Research Headlines.

The researchers raised 400 juvenile salmon in 10°C water and another 400 salmon in 16°C water. It is known that salmon farmers often employ warmer water to bolster fish growth rates, and both tanks with the two temperatures were observed over time to note any differences resulting from temperature.

Significantly, bone and cartilage production was found to be disrupted with elevated temperatures, such that there was a higher rate of deformities for the 16°C group. Although this group faster, 28 per cent showed signs of skeletal deformity versus 8 per cent of the fish in the 10°C group.

“[The results] strongly indicate that temperature-induced fast growth is severely affecting gene transcription in osteoblasts and chondrocyte bone cells, leading to a change in the tissue structure and composition,” explained study co-author Dr Harald Takle from the Norwegian University of Life Sciences in Norway and AVS Chile.

The findings complement the FINE FISH project’s new practical knowledge on how to lower the incidence of malformations in the major fish species used in European aquaculture and how to apply this professionally.

Several tools are available on the project's website, such as the FINE FISH diagnostic manuals for individual species -- bass and bream, industrial monitoring, cod, trout and salmon -- and material used in training courses.

The Federation of European Aquaculture Producers (FEAP) estimates that the EU farms 650,000 tonnes of fish annually in contrast with 60,000 tonnes in 1970. Europe as a whole farms more than 1.6 million tonnes a year, with Norway contributing over 860,000 tonnes of salmon and trout.

By Natalia Real