Should pinniped predation be included in harvest?

In my view the WDFW ignores pinniped predation by sea lions and seals. When I have asked if it is considered in harvest mortality or in run size estimates I get a vague answer. I do not think WDFW makes any effort to track it even when they have observers on the boats while it is occurring. My Grays Harbor observations of drift nets last fall and set nets recently indicates that from 10% to 50% of the fish that engage a net end up with a sea lion or seal. They do not show up in harvest numbers. Losses happen to recreational fishers as well but I have only lost one fish to a sea lion the past decade so in my view the percentage lost is low in the range of under 2%.

Harvest data in the models now includes 2-3% net drop out and 56% release mortality as part of the allocated harvest mortality. The models do not include pinniped losses which I think are a direct harvest mortality due to the gear type. If these mortalities were considered in the harvest calculations it would more fairly penalize set nets and drift nets for the loss they directly cause. I think there is a need for good loss data and that it should be part of the model harvest calculation for both treaty and non-treaty fishers.

Below is a picture of a typical race to a steelhead in a net. This time the sea lion won.

There was a time when it was included in management. I don't think it is any more.

I believe according to the requirements I saw from previous court cases, the definition of drop out was written so as to include any fish that were in the net and likely died but did not end up in the boat. If I get a chance I will look to see if I can find the exact wording. If someone here has it, that would save me some time, though.

Wouldnt pinniped predation occurring during sport harvest also need to be counted too then? Fish lost to seals while hooked would count the same, right?

Actual wording...IT IS ORDERED that, for the purposes of equitable adjustment, the harvest of net fishermen should include an estimate of the number of fish which come in contact with the net and do not survive but are not actually taken by the fishermen. The net "drop-out" fish estimate for 1982 shall be negotiated by the parties. In order to reach a negotiated estimate, it may be necessary to present this issue to a Joint Technical Committee

Post '82 a figure was added for net dropout (NDO) to all net fisheries. At least through 87. I know of salmon only, as the agencies were separate then. NDO was an add-on that was not included in the data bases. The data bases used at that time included the escapement and documented net catch (for salmon). Adding in NDO, then, provided a buffer that provided some protection for the escapement.

At that time, there was a file of studies (by other entities-including Russia) that had studied the size-selective nature of retention in a gill net and NDO.

From a political point of view, the impact of NDO fell more heavily soon the Tribes as they took essentially significantly more of their share in gill nets while the Cowboys used hook and line and seines.

Note that the order was pre Co-Management.

I think Krijack is right about drop-out. I've heard that term thrown around in meetings about Willapa Bay. The commercials always argued the rates were estimated too high. Almost inconceivably (or predictably), the recs always argued they were too low. Polarizing factors like this, all too often, lead management to treat them as red herrings, for the sake of getting on with the business of dividing the pie.

Pinnipeds and other predators also make a nice scapegoat when escapement comes up short, so it may serve the co-managers better to consider their take AFTER the fact.

Either way, I think this is being considered in allocation, even if it's not being given sufficient impacts.

It should be noted that I have no idea if they are actually following the directive of the court, or, if given the increase in predators the DPO needs to be increased. My only input is that it was included in the original formulas and should be included now.

I believe that it is not being included. Or, if anything is it is applied equally. I know a Tribe that was ordered to develop a seal impact and had, at least as far as folks have told me, never did.

In GH & Willapa the modeled mortality rate includes drop outs and if I recall the tribal % is 4% in the model and Recs are 16% ( ? ) been awhile not being on the model bit. Bottom line is mortalities are modeled in and the drop out is part of it. Now the QIN net actual is running somewhere between 20 and 25% not 4% and frankly you can set on the bank and count how many the sea lions get. The NT Nets with the recovery box bit is a absolute joke as having broodstocked Chinook for many years and damn near did back flips to keep the adults alive. From my experience it is between 50 and 100 % on NT nets releases. Hell the QIN claim 100% on NT releases.

Bottom line for me is the simple fact that mortality on releases be it net or pole are nothing less than a fabricated best guess.

Ya think????

The point I was trying to make is that pinniped harvest from nets is significant now and is not considered in harvest allocation models. (Release mortality is a different subject.)

In my observation of gill nets there is often a problem with fish dropping out as the net leaves the water and rises into the boat. Some fishermen even hold a landing net under these fish for insurance. I assumed that this was what the 2-3% drop out referred to as it would be a reasonable estimate of those losses.

My understanding of the official run size is that it is the summation of harvested fish including NDO plus release mortality plus spawner counts. Net drop out was not accounted for in the models prior to the 2014 model year. In 2014 NDR was added as 2% for coho and 3% for chinook in both Grays Harbor and Willapa. This increased the harvest mortality and caused all the historical run sizes to increase. These values have been used for the past three years as well as a 5% drop off for sport catches. I doubt if any of these include pinniped mortality. When I look at the model for tribal harvest I cannot find any calculation for net drop out. It appears to me that only non-tribal harvests are charged with this loss reducing their allocation.

If I were a modeler trying to model harvest mortality (but not subject to politics) I would consider including pinniped losses to be critical for accurate run management. My first guess at numbers would be 40% of the fish that impact a manned set net are lost to pinnipeds. Unmanned set nets would be much higher. I would consider drift nets to lose 30% of the fish that engage the net and then request a research project be initiated to get better data.

Thanks for the numbers, Rivrguy, which are probably pretty good for the rec dropout, but seem likely to be underestimated a hair on the Tribal dropout. Between predators and release mortality, that figure has GOT to be MUCH higher....

As usual Soft Bite is 100% on the mark. This is WAY more than just simple dropout.

This is a BIG and underappreciated issue that NO ONE in the agency has been willing to tackle head on. Mebbe the new Fish Program Chief at Region 6 is willing to take a crack at it.

We getting close. The drop out rate IS part of the mortality. Just as with a pole that you release with or one hits and gets away to the ones that look OK but in the end fail to spawn successfully. The release moralities and drop outs are part of the same number so in the model it is accounted for. SB the thing I think it is about is simply that the number be it what you call is way underestimating moralities and staff knows it as do the RECS and neters both QIN & NT. Nobody seems to care much outside a few people.

The devil is how you account for them and manage. If all the added mortalities are basically for accounting purposes to figure the split then they don't help the resource.

Say the forecast says that 3,000 fish are coming back and it is divided 1,000 to Indians, 1,000 to non-Indians, and 1,000 to escapement. You do the modeling of the various fisheries and decide that the I's have 200 morts, the NIs have 300. What it should mean is that the I's now take 800, the NI's 700, and escapement gets its 1,000. I suspect that the 2,000 harvestable will all be taken, with adjustments to each share based on mortalities. And the escapement then suffers.

The mortalities have to come off of the forecasted run size in order to put the conservation burden on the fishermen and not the resource.

While we all agree that the current estimates appear low, it's probably further complicated by run size and run timing, not only for the target stock, but also for the non-target (sometimes ESA-listed) stocks. If a run comes in "on schedule" and in something close to forecast numbers, a gillnet fishery can be very efficient and cause little dropout. Of course, if the run arrives early or late, or in smaller than forecast numbers, it requires more fishing time to capture a quota, which likely means more encounters with non-target stocks and, subsequently, higher dropout rates, in a year where the fish can ill afford them.

I don't think this is a reason not to factor dropout, at a standard rate, into quotas, but I imagine a commercial gillnetter might feel differently. Of course, if they went to more selective gear, it would reduce dropout and assure them maximum harvest for their time on the water, which seems like a win-win....

I think one of the problems with at least some of the tangle nets was increased dropout in that fish encountered the gear and weren't retained.

Traps would probably be best, followed by fish wheels although dip netting can probably be selective. When I have seen seines (beach or purse used the problem arises when a modest number of fish are in the bag. Speed sorting is necessary and fish handling skills may give way to speed.

Recreational fishers should care a lot about this intentional oversight by WDFW modelers and managers because we are getting absolutely hosed. For purposes of this thread I am stipulating that pinniped mortality is both significant and unaccounted for in the model. If it was accounted for it would be added to the calculation of the actual run size estimate after the fact. These mortalities would also be counted as harvest by those responsible for the loss. With larger run sizes, each group would be allowed more mortalities. For nets the result would be fewer fish in the boat when they reach their mortality allocation. Pinniped losses to the recreational fisher are relatively small compared to the nets so our increased allocation would result in more actually harvested fish for our share. As the model stands now the tribal fishers are not charged with any drop out losses, the non-tribal commercial fishers are charged with 2% drop out for coho and 3% for chinook. Recreational fishers are charged with drop off losses of 5%. I do not think pinniped losses are any part of these numbers. Release mortalities are an entirely different subject not to be confused with drop out, drop off, and pinniped losses.

Thanks for bringing this to the forefront, Soft bite. I'm curious... if release mortality doesn't factor into dropout, where on Earth are they coming up with sport dropout being higher than either commercial fishery's dropout? What constitutes dropout in a sport fishing context?

You know someone's cooking the books when sport angling accounts for a higher percentage of dropout than gillnets; I'm just wondering what's in the recipe.

One more curiosity: Is the Tribal dropout zero because they are ultra badass conservationists, or is it because they kill everything they catch, thereby leaving nothing to drop?

Dropout occurs, period. Unless one is on the net 60/60/24/7 some fish will drop. Way back when (80s) there were locations where the pinnipeds net fished. They drove fish into the nets and took them out. Even with the netter trying to chase them. I can't imagine in 30 years that seals got dumber.

A gill net has an optimum size of fish it will retain. That is why there are (or should be) sockeye, coho, chum, and chinook nets. A fish that is outside the target range may tangle, snag a tooth, or whatever. Then, die and come un-netted.

Drop-off on rec gear represents all the fish encountered by the gear that did NOT come to hand. There is associated mortality that is not directly appreciated by the angler. Some fish are mortally wounded by the hooking site but subsequently come unbuttoned out of sight. Some are visibly pumping clouds of blood, but throw the hook or break the line. Some may not be mortally wounded by the hook, but are nonetheless mortally stressed out by the fight (think coho that does that signature death roll just before the netshot.... FISH OFF!). These dead fish are accounted for.

Release mortalities are the fish that die post-release as a result of the stress/injury inflicted by the encounter plus the handling after being landed. These dead fish are accounted for.

Pinniped mortality is fish ripped from your hooks during the fight, while netting the fish, or immediately after releasing a fish that now lacks the vigor to swiftly evade a predator. These dead fish are NEVER accounted for.

FF02,
Release mortality is the fraction of fish that are required to be released and subsequently die. For non-tribal commercial fishers with a standard gill net it is typically 56% of released fish. For recreational fishers, it is 10% in fresh water and 14% in marine water. Tribal fishers do not release anything so it does not apply to them. These two numbers have nothing to do with this thread which is about drop out, drop off and pinnipeds.

Recreational anglers also get charged with drop off which is expressed as 5% of the fish you punched. Suppose you lose 50% of your hook-ups and 10% of them die or fail to spawn. Presto, a 5% loss. Your retained fish counts as 1.05 harvested fish. Non-tribal commercial fishers are charged with a net drop out of 2% for coho and 3% for chinook. Harvest is counted as 102% or 103% of the expected fish in the boat. I can easily visualize this as the fish that fall out of a net as it rises from the water to the boat deck. It is unlikely to represent any pinniped harvest which I think would be about ten times this amount. As near as I can determine the tribal harvest model has no drop out for any reason. This significantly understates their harvest mortality and their share of the harvestable fish.
My comments come with the caveat that I have no current or former connection to WDFW. I am simply using my knowledge of arithmetic to examine how things are manipulated in the harvest models. Sometimes it is a leap to say how they got the way they are.

Well thread calmed a bit so to SB question and we all had thoughts. So here is one. Call it what you may hooking / release moralities / drop out and these terms and words have meaning and are woven throughout the model. Then this fact in our terminal area ( all really ) fisheries mortality numbers, you know the total impact of conducting fisheries, are not close to accurate and it is not that it is not known that the error ( and it is sizable ) is present it is rather just accepted by everyone, except SB, as long as seasons move forward. To be honest I doubt that many really would want to know because frankly the disruption in how business is done with seasons would implode.