Pollock Abundance Up With Strong Six-Year-Old Class

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Jay Barrett/KMXT
Two separate abundance surveys of the Bering Sea are indicating a good number of pollock are coming up. The survey results released by NOAA Fisheries indicate a nearly 60-percent increase in walleye pollock biomass.
Jim Ianelli is chief pollock stock assessment scientist at the Alaska Fisheries Science Center at the National Marine Fisheries Service office in Seattle.
“It’s definitely good news. In 2013 we saw a fair number of five-year-old pollock. And those fish continue to be very productive and abundant in our surveys as six-year-olds this summer. And that’s right about the prime age for fisheries and reproduction. So it’s a good sign for the spawning biomass and the fishery.”
The increase in biomass doesn’t necessarily mean a significant increase in the total allowable catch for 2015, because of the 2-million metric ton cap on all groundfish in the Bering Sea.
“Biologically, the harvest could increase based on the productivity of the stock. (But) due to this overarching ecosystem constraint, they won’t go up much beyond what they are this year. But the conditions for fishing should be quite good, and should generally be no conservation concerns in terms of stock size and sustainability.”
However Ianelli said the abundance of pollock could result in less salmon bycatch:
“It’s a high priority to minimize the bycatch of salmon to the extent practicable, and having good abundances of pollock is certainly helpful in making the fishery profitable and still being able to fish in places where there’s less salmon.”
Each year data is collected through NOAA Fisheries’ crab pot survey, which Ianelli says also works well for gathering information on pollock and other ground fish. This year was one where a second survey is also used, measuring abundance in mid-water.
“Every other year we do a pollock survey that’s focused on mid water abundance of fish. And this was one of the years when we had both surveys operating. And they do transects with echo-sounding equipment and they do tows through echo sign to validate what species and what sizes of fish they saw.”
The bottom-trawl survey index for pollock this year was the second highest biomass since surveys began in 1982, and is 55-per cent higher than average. The 2008 component of the pollock population, as seen last year with near-record five-year-old abundance estimates, was a major component along with the 2006 and 2010 year classes, which Ianelli says bodes well for the ecosystem and fishery.

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