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Bycatch and Wastage

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Unfinished Surveillance: A Novel of Witness
by Max Ledbetter


Max Ledbetter

Research indicates that purse seiners caught 80%-90% of the vulnerable migrating salmon present in Johnstone Strait during what were commonly 48- or 72-hour fishing openings.

Some might recall Al Meadows's comments (Cockpit Comments. Western Fisheries 102 (August 1981): 28): "I'll be reviewing a study known as the Ledbetter Report in a future comment. This report is about the seine boat fishery in Johnstone Strait and I have heard disturbing news that the Fisheries Service is attempting to water down and suppress it." In the December 1981 issue of Western Fisheries, Mr. Meadows continued, "Max Ledbetter, writing in the guest editorial section of the October issue, is, I feel, pulling some punches and not telling the full story. He is, however, absolutely correct in his summation, where he suggests that fishermen had better develop communication amongst themselves and their various gear types. Recent history has shown us, and the fact that wild chinook and coho are on the verge of extinction further reinforces the realization that we cannot depend on the D.F.O. to do the job" (Cockpit Comments. Western Fisheries 103 (December 1981): 11).

Later, towards the end of the twentieth century, Pascual and Quinn reported, "The best available information about the spatial distribution of sockeye salmon in this area [Johnstone Strait] comes from experimental fishing cruises performed in 1985 and 1986 (Cooke et al. 1987) and surveys of the distribution of fishing effort (Ledbetter 198[6])." (See Pascual, M. A. and T. P. Quinn. 1991. Canadian Journal of Fisheries and Aquatic Sciences 48: 799-810, and my dissertation, Ledbetter, Max. 1986. University of British Columbia.)

The dissertation (Ledbetter, Max. 1986. Competition and information among British Columbia salmon purse seiners. Ph.D. diss., University of British Columbia, Vancouver, B.C.) is available at the University of British Columbia, the National Library of Canada, and UMI (see below). Here is the abstract:

In British Columbia, Canada, salmon purse seiners line up at fishing access points, forming well defined queues (line-ups). These queues were measured from a Cessna airplane, over time, using a one-dimensional recording scale. Sixty-one overflights of Johnstone Strait and Queen Charlotte Strait were attempted; 51 flights were completed.

Two models were presented for exploitation rates in relation to queuing patterns. The overflight model was fit to the line-up distributions. One underlying assumption was that the skippers possessed fairly accurate information regarding the distribution of catches (analysis of variance methods utilizing skippers' logbook data showed that line-up lengths reflected catch rates). The model fit well and the parameter estimates reflected anecdotal and statistical information about fish behavior. The exploitation rates saturated at an effort level of 100 vessels (whereas the maximum effort observed was 363 boats) and indicated that (at saturation) the fleet caught 80% to 90% of the vulnerable migrating salmon present in Johnstone and Queen Charlotte Straits during what were commonly 48- or 72-hour fishing openings. (Note: In addition to vulnerable salmon that survived the fishing openings, salmon that successfully migrated through the strait on days that were closed to seiners and salmon that were not vulnerable to the gear--e.g., below the depth of the nets--also escaped the purse-seine fleet.)

In general, traditional assumptions were rejected. Vessels did not operate independently. Boats were not distributed in a random fashion. The overflight model provided predicted exploitation rates. The exploitation response to effort was qualitatively distinct from the forms incorporated in traditional models.


Ledbetter, Max. 1986. Competition and information among British Columbia salmon purse seiners. Ph.D. diss., University of British Columbia, Vancouver, B.C.

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Hello Max,

Firstly, your thesis is in our collection under ISBN 0-315-34900-X.

To Borrow: It's available from the National Library via Interlibrary Loan. There's no charge for this loan and the format is microfiche only. For anyone contacting you to borrow your thesis, give the person your thesis particulars (including the above ISBN) and have him get in touch with his local library to make the loan arrangements (Interlibrary Loan is indeed just that: a loan between two libraries. Individual clients can't request loans). With this info., our Interlibrary Loan office will retrieve the microfiche copy of your thesis and send it to the originating library (as a reference, you may want to look at our Web site and refer to Interlibrary Loans).

To Buy: It's available on microfiche only from UMI, our filming and sales contractor. Again the format is only microfiche. There are three (3) price ranges for your thesis. An academic client would be charged $36.00U.S.; a non-academic client would be charged $48.00U.S., and an international client would be charged $50.00U.S.

Similar to borrowing, contact UMI quoting the ISBN and your thesis particulars. As mentioned, the notation on UMI's database is incorrect. Please direct those interested in buying your thesis to: Patty Smail, the supervisor of The Customer Support Service. You can reach Patty at or toll-free (Canada and the U.S.) at 1-800-521-3042. (Patti knows the particular problems with the erroneous notation). For further information about UMI, try:

Royalties are paid to qualifying authors, i.e. theses of authors which have sold more than seven (7) copies in a given calendar year. A 10% royalty of theses sales is awarded to an author.

In a nutshell, UMI is part of the Canadian theses picture as many Canadian universities and the National Library of Canada were interested in the services they offer, primarily the high profile of their international databases and the diversity of their coverage (an array of Canadian, American and European theses and dissertations make up UMI's current collection). It was (and is) in the best interests of the Canadian academic community and our Library to bring UMI on board. Thus, an agreement was reached in 1997 to include UMI in the Canadian theses profile.

If I may help further, please let me know.


Mel Simoneau
Canadian Theses Service

(Received, 26 Nov. 2001)

Here are a few e-mail responses (to this Web site and to my message-board postings) and my replies:

Hi Max!
I'm surfing around tonight and I've seen your posts in a few forums. In short your info re: BC Commercial Salmon Fishing is old news and posted in the wrong forums-those FF Guys don't give a s*** either way. Also the info you present is old.
The situation here in BC is that David Anderson-when he was Federal Fisheries Minister- got Sportfishermen priority on the Chinook and Coho stocks with Commercials receiving the majority of Pink, Chum and Sockeye-all of us after Conservation & native AFS Fisheries of course. The seine fishery in Johnstone Straight may look ugly-Hell it is ugly-but it's supported by the best scientific advice-tempered of course by political considerations-that the FOC can find.
Your feeble attempt to tie Pacific and Atlantic Salmon Fisheries together somehow-and after reading your site I'm still not sure how- shows how little you know about the Pacific Salmon situation.
One day you may indeed be "doctor of philosophy of something" but for the moment you need to inform yourself better/present your findings in the proper forum.
Start here if you want some action

(17 Nov. 2001)

My reply follows:

I'm retired from fisheries (thank God) and living in Ontario--last time I was in B.C. was 1987. Furthermore, yours is just one opinion regarding old but, it seems to me, still relevant research: fishing power. In fact, the resource management papers published in the Canadian Journal of Fisheries and Aquatic Sciences have not progressed much since 1986. Same old stuff. I guess some of the jargon is new. . . .

And how does a seine separate the coho from the pinks in Johnstone Strait (etc.)?

Thanks for insulting my Ph.D. status before reading the dissertation: It's in the UBC library. . . . If you have been surfing, you must know that numerous small-boat owners worldwide are virtually up in arms at large fishing boats (i.e., quite concerned about fishing power) and have called for a global strike on World Fisheries Day, 21 Nov. (see the WORLD FORUM OF FISHER PEOPLES:

Max Ledbetter (18 Nov. 2001)

[You, the readers of this Web page, might note that back during 1980-1981, Redden Net Company (Vancouver) and I put together an unsolicited proposal to find the best seine-net design and mesh-size/style combination for reducing the juvenile chinook salmon bycatch. "Although individuals within the Department of Fisheries and Oceans [DFO] encouraged this attempt to obtain funds from the Department of Supply and Services, the DFO opted for an in-house, small-scale survey" (Ledbetter, M. 1981. Guest editorial. Western Fisheries 103 (October 1981): 17).]


Re:-"last time I was in B.C. was 1987"
My point exactly-you are completely out of touch.
"And how does a seine separate the coho from the pinks in Johnstone Strait" Seiners are now are (sic) all required to carry tanks which are used to revive any Coho taken. Coho are brailed-do you know what that means?-out of the seine and placed in the revival tanks-with excellent results. If your info were in any way current you'd know this.
As to "me/mine" I'm a Sportfisherman of 40+ years experience here in BC, Ontario, coastal Oregon, Mexico, Costa Rica, Ecuador and Fiji-I've spent more time in a small boat fishing than many people have at work. Because of my extensive first-hand experience I've seen the battles artesenal fisherman fight against factory-fishing operations. The situation here in Canada is in no way analogous to that in other climes-not even close.
Good Luck with your studies-I can only hope that upon your graduation that you don't end up in the employ of FOC-they have enough bumblers advising them as it is.

(18 Nov. 2001)

My reply follows:

I obtained my Ph.D. in 1986 (I'm 47), and I was both on the boats and in the air. Thirty-five seine skippers provided logbooks. So of course I know what brail means. If the B.C. industry wasn't so overcapitalized, it might not have to waste time brailing injured salmon, if indeed it does on a consistent basis. [The point here is that in response to my rhetorical question, the author of the preceding e-mail admitted that the seine itself (the net) does not separate coho from pinks and sockeye. A brail is a dip net and is sometimes used to haul fish aboard from the seine.]

My research on purse seines is still relevant: fishing power is still fishing power. Like they said on P.E.I., a fleet of purse seiners can wipe out a stock (anywhere in the world).

I doubt that you could understand my dissertation, and I have no intention of re-entering the realms of B.C. fisheries. Mine is simply an attempt to promote my past research.

Time will tell. . . . (Epilogue 20 Years Later: Now see the June 2021 article DFO shuts most B.C. fisheries in desperate effort to save salmon)

Here is response from another reader:

Looks like a serious wrap, not too many places for a fish to high tail it to for survival. That's about as tight a wrap as I've ever seen. There's got to be some limits, has to be . . . Thanks for sharing. The dissertation must have been interesting, heck of a lot more interesting than what I did in school, finance . . .

Great Stuff,

Max Ledbetter (18 Nov. 2001)


Mr. Ledbetter,
I think I see the connection you are making of the two cases [salmon seiners in B.C. and herring seiners in the Gulf of St. Lawrence]. However, are you aware that the Gulf [herring seiners] have access to 23% of the overall quota, they can't fish for roe (no access to spawning grounds), they don't catch immature fish, they have dockside monitoring and at sea observers, etc. . .

On the other hand, the inshore fishermen use gillnets on spawning grounds and have access to 77% of the quota. Knowing the limitation imposed to the seiners, is the fishing power of the seiners still a threat to stock conservation in your view? Thanks for your input.

(19 Nov. 2001)

My reply follows:

I am not, of course, an Atlantic expert. However, I often fail to see how general quotas protect individual stocks. I have seen seiners TARGET river mouths, inlets, rip tides, individual salmon stocks, ocean perch, chinook, squid, etc., and I have observed firsthand the damage the nets inflict on both mature and juvenile fish. From my field experience, which I doubt is now completely "old hat" (given what I read in the Canadian Journal of Fisheries and Aquatic Sciences), I know the general capabilities of the "pirates" within the fishing fleets.


Max Ledbetter, Ph.D. (19 Nov. 2001)


Thanks for your email and site. . . . I work with salmon and bears, especially the significant processes of nutrient transfer to forests which may account for their productivity. I am concerned about the over-mechanization of ocean harvest. What if we harvested mushrooms with bulldozers? I'm for terminal fisheries of salmon using sailboats.

I have flown over Port Hardy [during a commercial fishing opening]. Looks like a Marines invasion.


(5 Dec. 2001)


Dear Dr. Ledbetter,

Many thanks for providing us with the address of your website. We have read the information presented on the site and found it most useful.

The problem with European fleets is also one of over capacity. Many of our fish stocks are below biologically safe limits. The problem of bycatch is a severe one - non target fish species, cetaceans, turtles, seals and sea birds. Decommissioning of vessels does not reduce capacity, as the fishing quotas are sold to other fishermen who own more powerful vessels. At this time of year there are many purse seiners fishing for mackerel, pilchards etc. in the Western Approaches. In the same area are large pair trawlers, other pelagic trawlers, beam trawlers and driftnetters. It is a nightmare.

European politicians seem incapable of taking steps to deal with the fishing industry, effectively. The subsidies provided to the industry encourage over capacity.

We are involved in a campaign which is lobbying to have cetacean bycatch mitigation measures incorporated into the European Common Fisheries Policy. We are lobbying politicians and fishermen's organisations, and are asking our supporters to do likewise; lobbying supermarkets to provide consumers with information regarding the method of capture of their fish products, and to purchase fish caught using handlines and pole and lines; contacting as many artisanal fishermen as possible (those using handlines, and pole and line only), and asking them to provide as much sustainably caught fish as possible, therefore providing the consumer with the ability to buy fish which has been caught in a sustainable way; we then promote the fish caught using the methods mentioned.

Next year, we are planning a "Fish Free Week" throughout Europe, to demonstrate to politicians, the fishermen's organisations, and supermarkets that the public is not prepared to see the fishing industry destroy our seas, and the creatures living in, and dependent on, them.

I hope to contact the World Forum of Fisher People, as perhaps we might be able to help each other.

Thank you again.

I hope we can keep in contact.

Kind regards,


(9 Dec. 2001)


Hi Dr. Ledbetter:

The only substantive comment that I'd make is that while the use of purse seiners may present management challenges in certain fisheries they are generally one of the most energy efficient vessel-based fish catching technologies around. Peter

(10 Dec. 2001)


Max, a few questions come to mind not the least of which are: given the major changes in the dynamics of the fishery caused by BC deforestation, the SEP, the "New" U.S./Canada salmon treaty, and the collapse of BC and Puget Sound salmon stocks (a) are these fisheries still viable; (b) are they still located in these areas; (c) where to from here? I complement you on this innovative measurement technique and wish you the best in future. p

(10 Dec. 2001)


Thanks for this, I will have a look.

Any further info will always be appreciated.


(10 Dec. 2001)


The following was posted on - 01/12/2001 : 10:35:25.

Thanks for the data. As a saltwater guide in 1957/58, it was common knowledge that sportfishing [in British Columbia] was finished for the week after a commercial opening. Things haven't changed. With the private boat licence buy backs it put the Fisheries into the hands of a few owners who will instruct the fleet to fish in the most efficient manner. Only the stragglers in a school of salmon manage to escape the nets. The big schools all get scooped up.


I feel like I am somewhere in between El Nino, Parvicapsula minibicornis, a farm fish and a purse seiner.

Vancouver Island

(13 Jan. 2002)


The following was posted on - 22/03/2002.

Max, I can feel only a tiny bit better about what's happening in Washington (state) and Oregon. Our fish agencies keep very close tabs on the commercial fishery in, say, the Columbia River and Puget Sound, but for obvious reasons, usually don't have a real clue about what's happening before they get here. There are two conditions that have improved: 1) we are making good progress in hatching habitat, but, of course, much more needs to be done; 2) the "war" that goes on between Canadian and US fishers seems to be abating. On a very positive note, we're experiencing for the 2nd consecutive year a large spring and fall run in the Columbia. We trust El Nino will stay away.


My recent comments elsewhere about the BC purse seine fisheries and other topics - 2020.

Regarding The National Post article 'Fishing the hell' out of B.C. sockeye may be best way to preserve stocks:

"I think Justice Cohen was smart to pay attention to what we know about climate changes and maritime conditions rather than to what we might never know about sockeye stock-recruitment.

"I posted [that] comment . . . twice before over the years, but it keeps vanishing. My comment makes sense. In principle, a judge will base his verdict on fact rather than on theory or speculation." [Now see Ottawa to close 60 per cent of commercial salmon fisheries in B.C., Yukon to conserve stocks]

Regarding article about optimism that fishery management can work:

"Other than what I read in the news, I no longer keep up with fisheries management science. Yet I still fail to see that educated readers (those who are familiar with philosophy, statistics, mathematics, computer programming, or simulation modelling) will pay much attention to media reports that do not include discussions about how the so-called indices of fish abundance might fail to reflect changes in fish vulnerability and aggregation. I remember reading on a University of British Columbia webpage that one commentator said that years ago the orange roughy collapse was due to the fact that scientists did not know that orange roughy aggregated. But wouldn't it usually be safe to assume that all life aggregates at one time or another? Right now (during the covid crisis) much of the world has "outlawed" human aggregation. (Is the magnitude of the global covid-19 crisis a function of society's trend toward being overly optimistic when confronted with unknowns?)"

Regarding article about Peruvian investigation:

"I do not know much about Peru, and I do not know if toxic workplace cultures are still prevalent among fisheries scientists, managers, and students today (I saw quite a bit of slander, mobbing, and immaturity during the 70s and 80s, enough to convince me that scientists were perhaps turning a blind eye to dirty tricks), but in 2004 I submitted a comment to the U.S. Commission on Ocean Policy in which I said, 'Obviously, your educational and institutional environments and curricula must include rigorous methods for assessing codes of conduct and ethics.'

"Now I would like to encourage fisheries scientists to continue to develop rigorous methods for assessing the prevalence and effects of perfect crimes."

Regarding Op-Ed:

"I no longer read scientific papers about fisheries science and management, but I wish the scientists and news reporters would make a point of explaining and critiquing the scientists' indices of fish abundance and the scientists' 'independent estimates' of fish abundance. Given changes in technology and climate, how reliable are the indices and the so-called 'independent' estimates of fish abundance?" [Please note that scientists do not know how many fish are in the sea.]

My comment on The Washington Post - Opinion: We're killing off our planet:

"If the entire world population would agree to a one-child policy for the next 5 generations [or even 3 generations], and then to a two-child policy for perpetuity, would we have our environmental problems under better control? Seems like a simpler and more direct solution than cramming billions of cranky people into stuffy rooms . . ."

And regarding

"Our politicians and business leaders are too slow. The bickering democracies and the scientists who hoodwink the people into thinking that policy is science are a danger to life.

"In principle, the simplest way forward is to enforce a one-child birth policy (resulting in one-child families) for the entire world population for 3 generations, followed by a two-child birth policy for perpetuity. People who comply with those policies are rewarded while those who rebel are sanctioned.

"We must quickly reduce our world population so that our leaders and our greed are far less capable of doing global and local harm."

Here is an excerpt from my book Unfinished Surveillance: A Novel of Witness:

"He took the job and practiced karate after work at night—controlled contact to the head and torso, 'red on-off buttons' in the mind ('One moment you're fixing a birdhouse,' his sensei would say, 'and the next you're mauling a mugger'), physical pain culminating prematurely as his theory that coevolution and ecosystem stability were functions not of optimality but of error. Adaptive delusion ensured survival. Subeffective predators did not often starve for lack of prey: they did not overburden their environments; they did not wipe out their food supplies. Mismeasurement, misestimation, and miscalculation blunted overexploitation. Measurement error was inherently adaptive. Yet narcissism and errors of prediction led to disaster, tragedy, because science minimized inaccuracy and imprecision and civilization repressed intuition and prophecy and foresight. Humanity was pivoting away from the domain of survival, toward the edge, toward self-destruction . . ."



In partial summary, the question is one of fishing power--the ability of gear, boats, or fleets, in the B.C. and P.E.I. cases and others, to exploit or overexploit fish stocks. Without a historical perspective based on quantitative (and innovative) field research, we are doomed to repeat our work loads: In the absence of extensive (and often necessarily alternative) time series of fishing effort and effectivity (fishing power), stock assessment and fisheries management become absurd. Like they said on P.E.I., a fleet (or transient cluster) of purse seiners can wipe out a stock (anywhere in the world). Max Ledbetter


Ledbetter, M. 1986. Competition and information among British Columbia salmon purse seiners. Ph.D. diss., Univ. British Columbia, Vancouver, B.C.
Read and Download the Thesis at the University of British Columbia
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Hilborn, R. and M. Ledbetter. 1985. Determinants of catching power in the British Columbia salmon purse-seine fleet. Can. J. Fish. Aquat. Sci. 42: 51-56.

Ledbetter, M. 1981. Guest editorial (re. bycatch and wastage). Western Fisheries 103: 17.
Bycatch and Wastage

Ledbetter, M. and R. Hilborn. 1981. A numerical overview of salmon run timings in British Columbia catch areas. Cooperative Fisheries Research Unit (University of British Columbia), Report Number 1.

Hilborn, R. and M. Ledbetter. 1979. Analysis of the British Columbia salmon purse-seine fleet: dynamics of movement. J. Fish. Res. Board Can. 36: 384-391.

keywords: extinction, catastrophe, purse seine, commercial fishing, area opening, census, creel count, aerial surveillance, reconnaissance, ocean survey, fleet dynamics, human ecology, hunter-gatherer, predator-prey, inshore predation, overfishing, marine biology, zoology, anthropology, fisheries economics, tragedy of the commons, renewable resources, natural resource exploitation, coastal marine environment, purse seiner

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