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SABRI executive director poses questions about shrimp stocks

SABRI executive director Sam Elliott thinks there may be signs of stability in DFO’s northern shrimp stock assessment.
SABRI executive director Sam Elliott thinks there may be signs of stability in DFO’s northern shrimp stock assessment. - Stephen Roberts

A sign of stability in shrimp?

GREAT NORTHERN PENINSULA, NL – St. Anthony Basin Resources Inc. (SABRI) executive director Sam Elliott thinks the latest assessment of northern shrimp stocks may actually indicate more stability in areas 4, 5 and 6.

In its assessment released Feb. 16 the Department of Fisheries and Oceans (DFO) said the fishable biomass was down 16 per cent to a new low of 87,300 tonnes in shrimp fishing area 6 (SFA6).

It was also down 13 per cent in area 4 and up 31 per cent in area 5.

According to Katharine Skanes, a stock assessment biologist with DFO, the department believes groundfish on northern shrimp is primarily responsible for driving down stock numbers in SFA6.

SABRI. - Stephen Roberts
SABRI. - Stephen Roberts

However, Elliott says if predation is really a huge factor in stock decline, based on the numbers there must be some form of recovery in the northern shrimp stocks.

In 2016, the total fishable biomass in area 6 was determined to be 104,000 tonnes. In 2017, 10 per cent of that was caught, explains Elliott.

Subtracting the 10 per cent caught from 104,000 tonnes, this means 93,600 tonnes were left in the water.

“If nothing changed … you would expect the fishable biomass would go down by 10 per cent anyway, because we took it,” Elliott told the Northern Pen. “We knew it had to go down anyway.”

Therefore, he said, if 10 of the 16 per cent overall decline was due to actual fishing, this means just six per cent (6,300 tonnes) of the decrease can be attributed to other factors, including predation.

From Elliott’s perspective, the number of shrimp that disappeared due to predation would have to be higher to validate DFO’s statement that predation is the biggest factor in the northern shrimp decline – there must have been more shrimp eaten, unaccounted for in DFO’s data.

Elliott’s theory is that there may have been some recovery in the shrimp stocks that was subsequently eliminated by predators.

For example, cod may have eaten an additional 5,000 tonnes of new shrimp.

This amount would not have appeared in DFO’s data, since this new mass of shrimp would have appeared and disappeared within the same year.

In other words, Elliott suggests there may have been some growth in the stock subsequently eliminated by predation.

Elliott also wonders if area 6 shrimp may be moving to area 5, causing higher biomass is in that zone.

“Is there some stabilization there between the three areas?” Elliott asks.

The other possible takeaway from Elliott’s analysis of the data is that predation is not as big a factor in area 6 as DFO is saying.

He wonders how much of DFO’s stock sample was shrimp measuring less than 17 mm.

In its total fishable biomass, DFO only included male and female shrimp larger than 17 mm.

But Elliott points out that smaller shrimp, less than 17 mm, may be fishable in the future as well.

And if the percentage of shrimp less than 17 mm is higher, he says, then this would be another indicator of future stability.

All these questions abound for Elliott and he just hopes the shrimp fishing industry can survive while everyone waits on the answers.

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