All along, fish plant workers at Canada's Newfoundland seacoast thought the massive salmon die-off that occurred in the area was caused by sea lice. But no, the culprit was the warm water that lingered for up to 13 days sometime in September, according to Newfoundland's chief aquaculture veterinarian. The unusually warm water resulted in low supply of oxygen, causing the fishkill.
'Warm water caused salmon die-off in Canada's Newfoundland coast'
Unusually warm water, not sea lice, caused the mass die-off of farmed Atlantic salmon on Canada's Newfoundland south coast recently.
The province's chief aquaculture veterinarian said the warmer-than-usual water over an 11- to 13-day period led to low oxygen levels, causing the fishkill, the Associated Press reported.
Some fish-plant workers and the province's fish harvesters' union earlier speculated that sea lice could have caused thousands of salmon at a Northern Harvest Sea Farms facility to die in September.
"We've done the diagnostics and really, what's occurred is not an infectious process that led them to the mortality," veterinarian Daryl Whelan was quoted as saying. "What's led them to the mortality is the really low oxygen availability to them."
He said water temperatures ranged from 18 C to 21 C throughout the entire water column, which left the fish nowhere to go to cool off.
Meanwhile, Northern Harvest Sea Farms plans to redesign its salmon cages.
"We have to act as though this temperature spike is not an isolated incident. We have to accept it as a new normal so that we are ready to deal with it", said Jason Card, a spokesperson for the company.
"So deeper cages, aeration systems, these are different ways that we can keep the water oxygenated, keep the fish cool and keep a good product going", he added.

US shrimp farmers bat for hike in tariffs on Chinese shrimp imports
US shrimp farmers and processors from eight coastal states have thrown support to President Donald Trump's proposal to increase tariffs on certain Chinese imports, including Chinese shrimp, from 25% to 30%, saying this could further benefit US consumers.
Imports of farmed seafood products from China have been subject to an additional tariff imposed by the US Trade Representative (USTR) since Sept. 24, 2018. Initially set at 10%, these were increased to 25% effective last May 10.
According to timetable, the potential increase in tariffs to 30% was to take effect last Oct. 1, after the administration's request for comments from the public sector.
In comments addressed to USTR Robert Lighthizer, the Southern Shrimp Alliance (SSA) noted that the tariffs have resulted in a significant decline in farmed seafood imports from China and, with it, "questionable seafood products from China".
During the first seven months, US imports of seafood products from China went down by
roughly $150 million to $324 million from $475 million in the same period last year, the SSA said. 
It added that over $100 million of that decline could be attributed to a steep drop in shrimp imports, which fell from $168 million in the first seven months last year to just $65 million this year.
With the decline of Chinese farmed seafood imports, the number of Chinese seafood entry lines refused by the Food and Drug Administration in the first eight months has gone down to 86 from 231 in the same period last year. "While simply one datapoint, this information supports the belief that US seafood importers source questionable seafood products from China because of its availability at low prices", SSA stated.
"The imposition of significant tariffs appears to undermine the appeal of this competitive strategy [selling at low prices] and, in consequence, reduces the pressure on the FDA to prevent unsafe Chinese seafood from reaching American consumers".
In prior comments to the USTR, the SSA claimed that China accounted for 42% (1,310 out of 3,114) of the total amount of seafood entry lines refused by the FDA for veterinary drug residues over a 16-year period (2002-2017).

Another low harvest as Texas shrimp landings drop in August
The US National Oceanic and Atmospheric Administration (NOAA) Fisheries reported that shrimp landings in the Gulf of Mexico in August, at 13.3 million pounds, were the third-lowest reported for any August since 2002, according to the Southern Shrimp Alliance.
Commercial shrimp landings in August were 24.7% below the prior 17-year historic average of 17.7 million pounds for August.
Around half of the shrimp landed in August has historically been in Texas waters. However, this time just 5.2 million pounds of shrimp was landed in Texas. The only previous August where less shrimp was landed in the state took place in 2005.
Throughout the Gulf of Mexico, the numbers reported by NOAA in 2019 have been bleak. For the year, landings of shrimp in Louisiana (17.0 million pounds) are over 50% below the prior 17-year historical average (34.1 million pounds); shrimp landings on the west coast of Florida (2.5 million pounds) are over 44% below the prior 17-year historical average (4.5 million pounds);
Shrimp landings in Mississippi (2.4 million pounds) are over 42% below the prior 17-year historical average (4.2 million pounds); and shrimp landings in Texas (18.8 million pounds) are over 14% below the prior 17-year historical average (21.9 million pounds).

US refusals of antibiotic-laced shrimp imports in September total 6
The US refused a total of 75 seafood entry lines in September, of which six (8%) were of shrimp for reasons related to banned antibiotics, the Southern Shrimp Alliance (SSA) reported.
For the past three quarters, the Food and Drug Administration has now refused a total of 58 entry lines of shrimp for reasons related to veterinary drug residues, exceeding the total annual number of such refusals in 2018 (53) and 2017 (55).
The six shrimp entry lines refused in September for veterinary drug residues were from two different exporters in India and Vietnam. Five refusals came from West Coast Frozen Foods Private Limited of India, while one refusal came from Minh Phu Seafood of Vietnam.
So far this year, the total number of shrimp refusals from India for reasons related to banned antibiotics is 32, accounting for 55.2% of all such shrimp refusals this year.
The shrimp entry lines refused from West Coast Frozen Foods were also found to have salmonella. In addition to those five entry lines, the FDA also refused another seven entry lines of shrimp because of the presence of salmonella: four from Bangladesh (Bright Seafood Ltd.); two more from India (Choice Canning Company); and one from Vietnam's (Khanh Sung Co. Ltd.).
The FDA also refused a shrimp entry line from India (Milesh Marine Exports Private Limited) for the presence of listeria.