Pacific halibut catches for the next few years are expected to decline in all regions, reversing a three year trend of slight upticks. That was the take home message from the International Pacific Halibut Commission interim meeting going on through Wednesday in Seattle.

Expanded surveys from May through September at nearly 1,500 stations from Oregon to the far reaches of the Bering Sea showed that total setline catches were down 23 percent from last summer, and fish weights dropped 10 percent.

IPHC scientist Ian Stewart says the data were expanded to include more fish ages, weights by port samplers  and  numbers dating  back to 1993. It’s consistent with what’s been seen in surveys for several years.

“The overall spawning biomass appears to have come down from the late 1990s to somewhere around 2010, after which time it been increasing gradually through 2017 and then we see a slight decrease in the time series in 2018.”  

The biggest drop stems from a lack of younger fish entering the halibut fishery.  Stewart says the 9 to 18 year old year ; classes that have been sustaining the recent halibut fishery are not being followed up by strong recruits.

“2018 and especially projecting out to 2019, we are moving out of a fishery that is dominated by those relatively good recruitments starting in 1999 and extending to 2005 and is going to have an increasing number of those relatively poor recruitment through at least 2009 and 2010.” 

Fishing intensity increased slightly from 2016 to 2017 and, based on modifications to the ways the stocks are being assessed, the catch limits for those years were likely set too high.

And although they are not factoring them into their computations, halibut scientists for the first time are considering environmental and habitat conditions, as well as trends in other fisheries.

Stewart says warmer waters starting in 2007 appear to correspond to the lower halibut year classes for which data is just starting to emerge. And as with Pacific cod, most relevant to the drop in halibut  recruitment in recent years is the effects of the blob.

 “Especially through 2015-16 we saw that water extending even to deeper shelf waters in the Gulf of Alaska – we’ve seen a big increase the last several years in pyrosomes , which are these nasty gelatinous zooplankton, well documented sea bird die offs and whale strandings.  So some abnormal things are going on in the Gulf.”

Stewart calls the halibut drop off disappointing, but not surprising as he says they’ve seen it coming.

We’ll have more on the halibut catches in coming days.