Weekly Overview: Where Have All the Sockeye Gone?

4 October 2016, at 1:00am

ANALYSIS - In fisheries news this week, Tradex Foods celebrated its 300th episode of its 3-Minute Market Insight with a special focus on Frazer river sockeye salmon, asking the question of where has all the salmon gone?

Firstly, the Pacific Salmon Commission noted that higher water temperatures and lower water discharge in the Frazer river due to climate change are challenging the fishery.

Kristi Miller-Saunders, a molecular geneticist at the Canadian Department of Fisheries and Oceans (DFO), added that higher water temperatures can increase stress and mortality in sockeye salmon. However the impacts of high temperatures on juvenile stages is not yet known.

She also said they are looking at how it impacts disease.

However, whilst it is the lowest sockeye return on record, it may not be the lowest spawning. Angela Bates, the Area Director for Fraser and BC Interior at the DFO, noted that fish are coming back look healthy, so hoping they are hoping they will have a good spawn.

Continuing with The Fish Site's coverage of Aquaculture Europe 2016, Dr Andy Shinn, Fish Vet Group Thailand, attempted to work out the economic losses to shrimp farmers resulting from diseases such as acute hepatopancreatic necrosis disease (AHPND) and Enterocytozoon hepatopenaei (EHP).

Through looking at current production and future estimates, Dr Shinn estimates that the economic losses for Thailand due to AHPND from 2011 to now is roughly US$7.38 billion.

As well as the economic losses, it is thought that the disease has also led to the loss of 100,000 jobs.

Losses due to EHP in Thailand is predicted to be around US$76.4 million, although Dr Shinn notes that there is currently little data available. This figure may therefore change as more data becomes available.

Also from the conference, a session on cleaner fish looked at the causes of mortalities and discussed best practice to reduce disease transmission.

Although the use of cleaner fish on salmon farms has grown rapidly in Norway and the UK over the last few years, the fish can be carriers of pathogens and, with high levels of mortality still being reported pre and post deployment, more research is needed into the biology, diagnostics and vaccination of cleaner fish, and, how to reduce mortalities in both cleaner fish and salmon.