FUN WITH NUMBERS: OR HOW TO CREATE ELECTRONIC FISH

Tom Marking Groundfish, Halibut

The previous article on the Groundfish preview was long enough and I didn’t want to clutter it up with too many facts and figures on Pacific halibut, so I’ll tease your scientific curiosity in a brief article on statistical sampling. On several occasions on the HTC site people remark why we can’t get more attention to California and get more sampling down here! I guess the IPHC heard our complaint and they are going to act. Pronto! Here’s what’s in store for us. This is a life lesson in “be careful what you ask for, you might just get it”.

Remember back in 2013 when we finally got them to put 15 sample stations down here in Northern California? Well they did, and “lo and behold” they discovered we still had halibut here. Never mind the Trawl Fleet had been killing them by hundreds of thousands of pounds, but I digress. That would be too obvious and ruin the story.

Anyway, the “Quantitative Specialists” worked their magic with the 1,970 some-odd-pounds of halibut caught in the 2012 survey and determined that we had 100,000 pounds of Pacific halibut that could be caught and used as table fare! Great zukers! We finally had done it…proved to the Royalty that us Peasants actually knew something about our landscape. However, the PFMC folks in OR/WA promptly confiscated the vast majority of those fish, leaving us frustrated once again. So over the years efforts at the Groundfish Subadvisory Meetings at the PFMC yielded a whopping 4% of the 2A non-tribal portion, about 25% of that 100,000 pounds found in the survey. The politics of why that is would fill several pages, and I would lose my readers.

So, bring us to the present, where we (say Treaty Tribes) in the 2A managed to get the IPHC to allot us 1.33 million pounds of halibut for 2017. But, that was under threat of legal action by the Tribes, who have had quite enough of the IPHC and their Statisticians. We were slated to get cut back to 0.75 million pounds again, back to before the 2012 survey in California, clipping us back to a measly 2.2% of the allocation over the entire population. So the clever mathematicians have devised a Time-Space Model and a Hook Competition Correction Factor that reduces by 15% the actual poundage of the fish that were caught in the surveys in 2012 and 2013. This 15% of lost fish are shifted up north into the Gulf of Alaska, since they have a higher Hook Competition Factor. But, to respond to our cries of anguish, they are taking some mercy on us by starting up the 15 surveys again in California from 40d to the 42d line (CA/OR Border). And, just to make us feel better they are re-enacting the 8 surveys from 40d down to the 39d line (of which 0 fish were caught). And if that is not enough to puzzle you, they are going to install 34 more sample stations below the 39d line all the way to Monterey at the 36.5 d line, where most likely 34 more zeros will show up. This should really help us out! So, yours truly appealed and asked for about ten of those 34 proposed survey stations be placed north of Cape Mendocino, where halibut are actually known to exist, and place another dozen or so up in the Tribal Country where lots of halibut are known to exist. The Commission compromised: about a dozen stations will be placed from the Northern tip of Washington down to the Columbia River between 100 and 150 fathoms at 5 nautical mile square grids (the normal is 10 nautical miles squared). Also, somewhere between 17 and 34 sites will be added below the 39d line, down to the San Francisco at the 37.5d line.

Here’s the statistical logic…I say that tongue in cheek! Since with this new Time-Space model, it is already assumed there are no (or a small fraction) of halibut south of the 40 d line, so anything they find will be of benefit to us! And, while it expands the bottom area by another 2,000 square nautical miles, the biomass will stay the same, even if they don’t find anything! So we have nothing to be concerned about they claim. But, here is my dilemma. In the 2012 survey we had a 23 lb/skate average for Weight Per Unit Effort (WPUE), similar to OR and WA. With another 42 sites showing zeros, our WPUE will drop to probably 5 lbs/skate. But, since it’s a smaller WPUE but over a much larger area, the total will be the same biomass (less 15% of course).

Here’s a math problem. The initial survey yielded a 16% increase in 2A harvest biomass. Last year we had 1.02 M lbs recommended by the statisticians, that was cut to 750,000 lbs this year. That 25% loss is a result of the 15% loss to Hook Competition in conjunction with the survey shifting more up north. The expansion in 2013 of eight more sites below 40d yield only a few fish from the off-shore Trawl survey, so we got a 0.02% increase (or 3,000 lb) addition to the CA harvest model. The next 2,000 sq mile expansion down to San Fransisco will probably yield about the same or possibly a bit more, lets says 5,000 lbs. We’ve lost 150,000 lbs of the 1 million pounds (a 15% loss) and we gain a whopping 8,000 lbs from the expanded surveys, and our WPUE drops to something in the area of 5 lbs/skate (a net loss of 142,000 pounds) OUCH! Keep in mind the other Sectors all have 30 to 250 lb/skate by comparison, so where do you thinks that leaves us for a bargaining position? But, statistically its VALID and MEANINGFUL!

One has to wonder why the IPHC is now willing to spend close to $200,000 in cash to sample 42 sites with little expectation of getting anything! I have to ask myself “WHAT ARE THEY TRYING TO PROVE!?” Why, from a statistical point of view are they expending large sums of cash when we are less than 1% of the Pacific halibut population. From a Normal Distribution Curve analysis, this seems puzzling at best and ludicrous in retrospect. After 8 years of being intimately involved with all of this, I am at a loss to understand what is going on, or am I just a slow learner? Two steps forwards, three steps back! Maybe someone smarter can explain all this to me. I realize from a binary world, a 0 is just as important as a 1, but CMON, LET’S BE REAL!
I feel like I’m part of a Carney Act, and I’m being told to “pick a card, any card”!

Editors note: If you are like me then you don’t understand the number game that Tom is ranting about. What should be obvious to everyone is the level of Tom’s frustration. He spends countless hours working the issues and I can’t think of anyone more suited to represent us in this arena. Most of us would be steamrolled into silence.

We have been promised an article for the Spring issue from the CDFW explaining how the dock survey data is used to estimate the total catch. We have been asking for this information for a couple of years. It is likely to be complicated and as difficult to understand as the halibut number game. But we will continue to do our best to provide clarity and reason so everyone will better understand.