Monday, December 21, 2009

Is NMFS science cheating snow crabbers?

Maybe more abundant than we thought. ASMI photo

Some tension always exists between the fishing industry and government scientists over official estimates of just how much fish and shellfish is out there.

The scientists survey the population, then bring the results back to fishermen and processors. Generally, it seems to me the industry has a fairly high degree of trust in the work the scientists do in Alaska, unlike in other parts of the country.

But now comes an apparent admission from the National Marine Fisheries Service in Seattle that surveys for eastern Bering Sea (EBS) snow crab, a multimillion-dollar commercial stock, might be suspect.

The issue is just how good a job the government's survey trawl does in netting snow crab on the seafloor for purposes of estimating abundance. These estimates, of course, have a huge bearing on how many snow crabs the "Deadliest Catch" fleet can harvest.

This past July, according to this brief NMFS report, government scientists and industry players conducted a cooperative experiment on the snow crab grounds to test the standard NMFS survey trawl.

Part of the experiment involved towing two alternative nets, including a modified NMFS trawl and one from an industry organization, the Bering Sea Fisheries Research Foundation. The foundation's trawl is designed for the European Norway lobster fishery.

You can read the NMFS report for full details, but the bottom line is that the foundation's net is a much more effective crab catcher than the NMFS nets, including the one that was modified to improve its catch rate.

Here's the key paragraph from the NMFS write-up:

"Preliminary results show that more escapement of snow crab under the footrope of the EBS survey trawl occurs than previously estimated. Specifically, only 35% of the large males, 27% of the pre-recruit males, 13% of the small males, 25% of the large females, and just 3% of the small female snow crab in the path of the survey trawl are captured."

Deckboss put the following question to Steve Minor, a crab industry lobbyist and chairman of the Pacific Northwest Crab Industry Advisory Committee:

"Is the government short-changing the crab industry because of a flawed stock survey?"

Minor replied: "Let's just say that stock assessment science is evolving."


Anonymous said...

So, How many years has this been going on?....Isn't the private industries' portion of the interest, to aid and insure effective sampling? Who's been running this circus-show?....Why are we using trawls, and not pots to determine biomass?...Seems to me, using pots would be a more condusive method, as that would form the parameters for "real-time" fishing, especially when it comes to assessing areas of mixed classes, sex ratios, and pre-recruits. Or is this something that is out of our governments' effort range?....Want better sampling turn some gear that's focused towards our type of fishing!

Anonymous said...

Why are Pollock/Cod Trawlers doing Surveys for Crab Vessels?....This is a direct conflict of interest!...and they know it...This is B.S....
Put observers on a bunch of pot boats to do surveying during the closure periods....paid for by the government....Where's all the revenue for the government programs going?...From this angle, looks like back into the pockets of those lining the politicians'.


I believe the two anon commenters above are right. Doing a "trawl" survey is just stupid. Use pots!

Anonymous said...

Or better yet start using pots for their pollock survey!

Anonymous said...

I heard that those guys used them exact same trawls year after year in the same place in order that their catch effort would be consistent over time.

JFC what Boneheads!

They need to be using the most state of the art gear (updated every year) and fishing in the nurseries to have the highest possible survey catches and thereby the maximal annual quota.

Anonymous said...

We should impose a federal tax on pollock/cod draggers, and cannery boat owners, to pay for all the crab and groundfish surveys, since they are the ones that have been benefiting the most from these screw ups for the last 30 years. Heck we should just shut em down, before they tear up and rape the rest of the Bering and Pacific waters.It's time to send a message to those that abuse the resources thru the Temptation of back door deals. It's an outdated/expensive, and destructive gear type anyways. It's time to kick these effers in the nuts and then in the pocket books. Hasn't anybody noticed, since the Senior ranking Senator, from Alaska, has lost his coruptive leverage in D.C., their industry just isn't the same? That speaks volumes in what has been happening in the past. I say the new MPA's around the Bering and Alaskan Peninsula should Bar any type of trawl nets, in state waters and Federal. Promote/reward fishing practices that help to rebuild stocks.

Anonymous said...

If they want to catch Pollock....Give them a program to use jigging machines...They do it for Squid in other parts of the world....why not Pollock?

Anonymous said...

I don't see how asking a lobbyist if their industry is getting short-changed is going to get you anything but an answer that promotes that industry's bottom-line interest. That's what lobbyists are paid to do.

Anonymous said...

Umm... isn't the idea of a stock assessment survey to track changes over time? This is old news. They've known about the inefficiencies of trawl surveys for years.

The guys saying they should use pots miss the point. The idea is not to catch crab, but to get an indication of the relative distribution of crab and to feed that number into the statistical models to determine the quotas. Bait skews the survey as it brings crab to the sampling device (i.e. the pot) rather than getting a random sample.

Plus, the important thing is not how much crab the trawl catches. If the survey caught more crab, the statistical model would need to be changed to account for that. The important thing is the change in survey data year after year.

I would be much more alarmed if the research showed that the old trawl survey had wildly fluctuating catch rates rather than consistently low catch rates. If wildly fluctuating, when low catches are encountered it could artificially depress quotas. It could just as easily be the basis for quotas being set too high some years, leading to too much pressure on the stock and subsequent crash. I don't want the scientists to rob me of a fair quota today or to give me too much today at the expense of tomorrow's season.

The big question is not whether the old trawl or the experimental trawl catches more or less crab, but whether it does so with accurate consistency.

Anonymous said...

Apparently the job isn't getting done!...Whether it's limited financial support, not enough diversified experience on survey vessels, to re-structure for efficient methods, or towing methodology, an accurate and calculated biomass is not being met. With a skewed and unproven plan of action, how can a scientist correctly extrapolate abundance, or reduction of stocks? Fish and crustaceans move constantly. How could it ever be possible to gather accurate data, especially without private interest getting in the way. When are we going to see non-partial decision makers in government that can take honest and effective measures to protect all. They move as fast as a slimey fish does, especially when money is involved. Maybe we should start with their pay directly determined by their peers that are affected by their decisions.