Pending fisheries collapse? - I pit those who don't see this as a problem

The BBQ Pit
61

[QUOTE=Spectre of Pithecanthropus]
Yes, it’s a problem. Back in the day,

We urged people to have fewer children and they said mind your own goddamn business.

We spoke of the importance of birth control, and whole religions, nay, entire regions of the planet told us it was immoral.
[/QUOTE]

Yeah man, that Malthus totally called it. Mass starvation and extinction by the middle of the 19th century. “Scientists” attempting to predict trends three decades ahead of time have a spot on record for accuracy.

62

[QUOTE=threemae]
Well they aren’t exactly whales, are they?

Whales, definitely, you could hunt them to extinction. Even a “healthy” population of whales might number in the tens of thousands and certainly humans have the ability to hunt them to a level where mating becomes impossible.

And certainly this is true for certain species of fish with low population densities, long reproductive periods, etc.

But for most fish? I really doubt it. Even if the fish become rare enough that they’re economically impossible to harvest, I don’t think that they’ll have trouble finding each other to get it on.
[/quote]

Most fishes are small and not real palatable to humans. We don’t care about them commercially. The fish we like to chomp on are higher up on the food web. They are, by definition, larger-sized, longer-lived, and fewer in number. Because of their place in the trophic web, they also tend to occupy key roles as keystone predators (those that regulate species diversity) or major prey of keystone predators. They look down at the anchovies and laugh.

So no, it is not likely that a hake or manhaden will go extinct. But when was the last time you ate a manhaden sandwich, or ordered grilled hake at a restaurant? On the other hand, we can’t get enough tuna. Do think it’s possible for us to wipe out tuna, based on our consumption rates? (If you aren’t nodding your head, you should be.) Whether or not this is concerning is independent of it being thereotically possible (and it is).

On what basis are you getting your doubts from? Just a gut feeling? Or something a bit more rigorous?

:confused:

There isn’t just one fishing boat. There is never just one fishing boat. And for every boat that’s intentionally killing halibut, there are hundreds more that indirectly kill halibut through by-catch and the like.

One boat can’t wipe out a species, true. But several decades of hundreds of thousands of boats and millions of hauls, covering millions of miles? Are you certain you’re certain?

I’m not the one making a facile statement here. You are. You doubt we could wipe out a fish species…based on what information? Where are your numbers, your evidence? Your training? Are you an ecologist? A fish biologist? Someone familiar with conservation biology? If not, you’re skepticism quite frankly doesn’t impress me, because it seems to be based on feelings rather than facts.

I’m not a doom sayer. I don’t think people should stop eating fish. Hell, I chomp on fish about once a week. So I’m not a weeping tree-hugger type at all. And I’m not saying that humans are close to driving populations to extinction (although I wouldn’t be surprised if we were). But it certainly is possible that we could, threemae. I think it is pragmatic that we consider such a possibility rather than pretend it can’t happen.

(I don’t like to bring my work to the 'Dope, because I don’t want to play expert. But I’m a fish biologist and an ecosystem ecologist by profession. So if you’re tempted to condescend to me again, reconsider. You don’t like my analogies, fine. I’m not the best of teachers, I admit, and sometimes I don’t explain well. If you are really that much of a Doubting Thomas, I recommend following up on the links I posted above and checking out the sources contained therein.)

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[QUOTE=threemae]

So I would encourage you to make your argument from actual numbers and science regarding the ecology of fish as opposed to some far flung metaphor involving alien abduction of humans and discussions of lacking a Starbucks to meet up at. Because frankly we all know that fish hate Frappucinos.
[/QUOTE]
Monstro actually gave you some good links about why you don’t seem to grasp the science behind the possible problem we seem to have gotten ourselves into with regard to big meaty fish, the kind we like to eat and need.

Let me repost them for you.

http://216.109.125.130/search/cache?p=cod+fisheries+trophic+web&ei=UTF-8&fr=yfp-t-405&x=wrt&u=www-unix.oit.umass.edu/~wfcon470/Frank%2520et%2520al%252005.pdf&w=cod+fisheries+trophic&d=XJyyM5IFNhgi&icp=1&.intl=us

Earlier, to another poster you said

.

That’s your problem–you don’t understand the science behind the problem. You just assume that things always come back to equilibrium. But biosystems don’t all react the way you would like them to.

64

**
[QUOTE=Gorsnak]
How the heck does that lead to the market’s invisible hand preventing overfishing? As stocks shrink, prices rise due to decreased supply. The higher prices, far from discouraging overfishing, actually encourage it (until the stocks collapse and the fishery ceases to be feasible). It’s a very straightforward tragedy of the commons.
[/QUOTE]
Never, EVER, doubt the Great Powers of the Invisible Hand.

Many simple humans don’t understand this, but the Market sees all, and the Market knows all. That’s why there is no poverty in the world and all prices are completely fair.

Mere humans with their so-called “brains” should not even DARE to try to alter the course of the All-Powerful Invisble Hand. That inevitably only leads to trouble. Bad, unclean, dangerous trouble like… phamaceutical companies selling drugs at lower than their market value so that poor people can be healthier and live longer!

Or other unholy, unimagininable schemes such as persons with disabilities being given-- GIVEN I say!! FREE MONEY from the Government-- without so much as doing 14 or even 12 hours of honest work. I’m talking healthy, desirable and fulfilling work like rendering dead, putrified cattle, or earning an honest living in an even easier and more rewarding task like happily cleaning out 2 or 3 miles of a feces and disease filled, dark and crumbling sewer tunnel in Calcutta or Lagos.

If it weren’t for the interference of the ignorant heretics, the **Great and Powerful Invisible Hand ** would COMPEL the performance of the above mentioned character-buiding labor so as to give the disabled the honest chance to earn an honest wage of enough pennies (sometimes, even nickels) to afford MORE than enough sawdust gruel to nourish their exhausted bodies to the point where they can feebly crawl or roll on the ground towards their next task. They would even enjoy once daily bathroom breaks (7 times a week!!) during which they have the opportunity to communicate in that wonderful melodic moaning with their fellow gimps. (oh… umm… strike that… I mean cripples… no, no… handicaps! yes that’s it.)

This all illustrates a great example of the Genius of **“The Hand”. ** **The Ultimate Wisdom of the Invisible Hand ** has fashioned the daily bathroom breaks so they are only two minutes and fifteen seconds long for the entire work crew. There is a brilliant economic reason for this (besides maximizing the time labor spends producing). You probably see where this is leading and are already smiling as you meditate once more on the Great Powers of Our Lord Market).

The simple brillance of the **One True Master ** is obvious to all will simply open their eyes and SEE! Consider: when crawing on knee stubs or struggling blindly without guidence towards an overfilled outhouse, only a couple (we find 3 at the most) of subjects will actually sucessfully use the outhouse in the allotted time. The rest of the disabled people are left only with the choice to urinate and deficate in their clothes where they lay.

Obviously this is trickle-down economics at it’s best!! As it actually CREATES more jobs for launderers! and shit shovelers! All Praise the Invisible Hand!!! Just marvel at the simplicity yet effectiveness and profitability that an open and unfettered Invisible Hand Market produces.

And yet, (if one can even believe this,) there are those ignorant, mis-directed, fools who blatently disobey and even seek to take control away from the All Knowing; the Great God of Capitalism– sadly, they actually are so twisted and mentally distressed-- ignorant of the Market’s Grand Love for All that, given the choice, they would have the “persons with disabilties” (“disabilities?” No legs and one arm?? ----Ha! gimme a break!–you can still scrub prison toilets, right? You can still get around on a skateboard or a shopping cart, right?) receive *free money * just so they can live cushy lives full of free hotplates, AM radios, and nice apartments that even allow small 6 legged pets.

I warn you sinners who dare to disregard the Word of the All-Knowing Invisible Hand. You are headed directly for a world with little or no caste system. That’s a world I would call “Hell.”

Don’t try to grow a brain here— don’t tamper with perfection-- there’s nothing to see or do here-- the **All Powerful Invisible Hand’s ** got it ALL under control.

Thank heavens for trickle down-- what human could have thought of that, I ask you? None. Only **Our Master the Invisble Hand ** could have.

THe Hand has the Plan. Very soon, we will all be very rich.

Now stop reading and go buy more useless crap.

65

[QUOTE=samclem]
Monstro actually gave you some good links about why you don’t seem to grasp the science behind the possible problem we seem to have gotten ourselves into with regard to big meaty fish, the kind we like to eat and need.

Let me repost them for you.

http://216.109.125.130/search/cache?p=cod+fisheries+trophic+web&ei=UTF-8&fr=yfp-t-405&x=wrt&u=www-unix.oit.umass.edu/~wfcon470/Frank%2520et%2520al%252005.pdf&w=cod+fisheries+trophic&d=XJyyM5IFNhgi&icp=1&.intl=us

[/QUOTE]

I’ve read the Science article and it doesn’t make the case that monstro is making.

I’ll agree that the article fairly convincingly demonstrates two points:

  1. The North Atlantic Cod fishery is fucked

  2. The changes in cod seem to have far-reaching implications upon the rest of the food web, and the article demonstrates dramatic changes in other trophic levels from phytoplankton to zooplankton to pelagics (crabs) etc.

What the article doesn’t and does not claim to demonstrate is that the reason for the failure of this fishery to recover is due to simply being wiped out by overfishing pressure.

“Whether the recent ecosystem changes are
reversible is an open question. Other factors,
both intrinsic and extrinsic, were associated
with the ecosystem changes. For example, the
expected inverse and reversible relationship
between fishing mortality and cod biomass
(13) that characterized the 1960 to early 1990
period does not hold after 1993 despite the
near-elimination of exploitation (Fig. 2A).
Physical environmental changes may have
contributed to the restructuring of the food
web. During the mid-1980s, the average deepwater
temperatures declined by È1-C. This
decline started about 4 years before the collapse
of cod and other benthic fishes.”

“Stratification has continued to intensify
(Fig. 2B), however, and may be contributing
to diminished energy flux to the
benthic fish community, as revealed by reduced
physiological condition and reproductive
output (19).”

“On
the other hand, the three major cod stocks
resident south of 44- N, though reaching historical
minimum levels at about the same time
as the northerly stocks and experiencing similar
intensive fishing pressure, declined by only
50 to 70%; current biomass has increased from
10 to 44% of historical minimum levels. These
stocks inhabit different oceanographic regimes
with respect to temperature and stratification
and do not show the inverse relationship between
the biomass of macroinvertebrates and
cod found by Worm and Myers (12). These
geographic differences in cod population dynamics
merit additional study.”

Okay, so how does this fit into your argument that it’s simply reaching a critical value of fish from overfishing that suddenly leads to a fish extinction as opposed to some other factor like global climate change?

But enough of this bickering about a single fishery, let’s go back and look at some data as opposed to anecdotes.

If you go to Science online you can work your way towards a PDF of supplementary information. Now look at table S1. It lays out the collapse of these northern cod fisheries (although the Southern heisphere fisheries that never seemed to be beset by the same level of crisis in spite of equally intense fishing pressure are not available in this table).

Okay, let’s start off by doing a graph of the % of recovery by a cod-stock compared to the amount of maximum collapse. I’ve typed these things into Excel and posted .gif’s of the result.

http://img397.imageshack.us/img397/4775/recoveryvsmaxdepletionbk6.gif

Okay, so this one looks good for you. Obviously the fisheries with more depletion have the lowest proportional recovery. But hang on a second. I never said that it was a bad idea to manage fisheries, I said that I doubted that they could be fished to extinction (certainly climate change, pollution, and other systemic factors as pointed out by other posters could do it). So, if your hypothesis is correct, the fisheries with the greatest depletion will actually become entirely extinct unless they just happen to be balancing on some perfect balancing point of maintaining their current levels. :rolleyes:

Okay, so now let’s graph the amount of recovery relative to the minimum, not to the historical maximum:

http://img397.imageshack.us/img397/4122/relativerecoveryvsmaxdewn0.gif

Now what happens? The correlation between relative recovery (current fishery size divided by minimum fishery size) is positively correlated with the amount of depletion.

So, to sum up, I never said that managing fisheries was a bad idea, only that I severely doubted that most commercial fish (like cod) could be fished to extinction. I think that 99.8% is pretty well fucking fished out. From the *Science * article:

“This perturbation has produced a new
fishery regime in which the inflation-adjusted,
monetary value of the combined shrimp and
crab landings alone now far exceed that of the
groundfish fishery it replaced (13). From an
economic perspective, this may be a more attractive
situation.”

And so, are the worst-fished fisheries headed for extinction? No, they’re the ones that are replicated the fastest.

quod erat demonstrandum , motherfuckas’. I hate you all, I just spent 50 minutes on that, I need to go do my biochem homework.

66

Oh, and the point that I intended to make with the last quote: the economic decision to pursue fish lower on the food chain (and monstro you admit are less easily hunted to extinction [I think we can all agree that you can never fish the zooplankton to extinction]) occurred before the extinction of the first commercial fish (cod). Perhaps the decision was made far too late, again this doesn’t disprove the tragedy of the commons, appropriate fish management is still called for, etc., but no, commercial fishing by itself will not drive cod to extinction.

Orange roughy? Who the fuck knows. I’m not going to find out. I’ve already agreed to stop eating the bastards.

Sperm whales. You betcha.

67

A couple of comments on “can we fish them to extinction”. I think you guys are talking at cross purposes here.

As a fisherman, I’d have to agree with threemae, we can’t fish a species to total extinction. When stocks get below a certain point, it’s no longer feasible to fish them at all, and the pressure stops. The main variable in this is fuel costs. When you pay more for fuel than you make for your fish, the game’s over.

However, in functional terms, and these terms are more important, I’d agree with monstro. In biology there’s a very important concept called “functional extinction”. This occurs when the numbers of a species get so low that they no longer perform their function in the local ecosystem web. This function includes who they prey on, who they are a food source for, who eats their excrement and their dead bodies, etc.

Once they are functionally extinct, they may or may not ever recover their original position in the food web. This may or may not be important to humans … but it’s not something we want to do carelessly.

As the sardine example shows, however, we need to be careful about ascribing causes to changes in the ocean. It’s a complex world out there, folks, and humans are not responsible for everything. Having said that, fisheries management is very difficult, with lots of opposing stake-holders and many unknowns. The best policy is to err on the side of caution … within reason.

Not easy …

w.

68

[QUOTE=threemae]
Oh, and the point that I intended to make with the last quote: the economic decision to pursue fish lower on the food chain (and monstro you admit are less easily hunted to extinction [I think we can all agree that you can never fish the zooplankton to extinction]) occurred before the extinction of the first commercial fish (cod). Perhaps the decision was made far too late, again this doesn’t disprove the tragedy of the commons, appropriate fish management is still called for, etc., but no, commercial fishing by itself will not drive cod to extinction.
[/quote]

Again, where are you drawing this statement from? Because one thing (protection of cod) does not follow from the other (the market leaning towards more economically favorable alternatives, like halibut). And you’re arguing a strawman every time you mention the extinction of zooplankton. No one has even mentioned zooplankton going extinct. But I fail to see why this even brightens the picture. Are you planning on eating zooplankton any time soon? Yummy, a copepod salad with a diatomous vinigrette!

It’s not like fishing is the only thing we’re doing to wreak havoc on the ocean. We’ve destroyed many of the vegetated estuarine and subtidal habitats that serve as nursery grounds through pollution and physical disturbance. Our coral reefs are engandered. Global warming is altering upwelling/downwelling cycles. Commercial fishing is really just part of the problem.

[/QUOTE]

69

The market may actually be incapable of managing a sustainable situation; that is: it may be cheaply and efficiently possible to drive a species beyond the point of recovery before costs start to rise significantly enough to limit demand - the capacity for recovery may not (indeed probably does not) enjoy a linear relationship with population size, let alone with the human supply/demand/cost graph.

Humans have harvested species to extinction in the past without market forces intervening to prevent it.

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[QUOTE=Mangetout]
The market may actually be incapable of managing a sustainable situation; that is: it may be cheaply and efficiently possible to drive a species beyond the point of recovery before costs start to rise significantly enough to limit demand - the capacity for recovery may not (indeed probably does not) enjoy a linear relationship with population size, let alone with the human supply/demand/cost graph.

Humans have harvested species to extinction in the past without market forces intervening to prevent it.
[/QUOTE]

As the fate of the Newfoundland fisheries showed.

71

Genetic variation is another critical factor to consider once species’ numbers have been hit hard enough.

Here is an interesting article building towards a retrospective genetic analysis on the sardine fisheries that collapsed off the coast of California in the 1960’s. Unfortunately it isn’t dated, but the url contains “GSsummer96”. It also doesn’t include data to support the hypothesis in the closing paragraph (quoted below) but I’m actively looking for more recent studies published by the same folks.

72

[QUOTE=I Love Me, Vol. I]
**Never, EVER, doubt the Great Powers of the Invisible Hand.

stuff elided here

Now stop reading and go buy more useless crap.
[/QUOTE]

That is sweet. I don’t know how many times I’ve heard free-market fanatics speak about the invisible hand of the marketplace as if it were a fucking benevolent deity. I’ll keep this post in mind for the future.

73

With regard to the collapse of overfished speicies populations; it appears that the ecological niche (vacated by the collapsed species0 is rapidly taken over by other species. Thus we have pollock taking over from cod, and eels taking over from salmon. the problem is: nobody wants ell and salmon. So i argue, aquaculture 9with geneticall modified fish0 is probably the best solution… take tilapia-you can raise tilapia easily, and get mature fish in a few years. Plus, managing a fishpond is a lot easier than going out on the ocean to catch wild fish.

74

I’m not sure if this meets your criteria, but the Longhaw Cisco is an example of a fish driven to extinction (real extinction, not commercial extinction). As with many things, you can’t really say that overfishing is the only thing that wiped it out, but the bottom line is that whether overfishing was the primary factor or not, it was a factor, and the fish is gone.

Arguing about whether predation or overfishing or changing climate patterns is responsible seems moot at this point. You’ll never know the answer, but it’s a tough row to hoe that humans aren’t much better at catching large numbers of fish than natural predators.

You can look for other examples in the IUCN Red List - it’s a pretty good source.

75

Whenever you’ve got people with a commercial interest in continuing an activity without regulation (like fishermen, as a general rule) saying that the activity isn’t doing harm, it’s generally pretty safe to assume that they’re wrong. Or lying. Or both.

76

With respect to the catches constant since 1988 or so, I’d be interested to know how that compares with total fishing effort and technology invested in that catch. It seems to me that with the greater technology and more capital-intensive methods used nowadays, catches should be way up if the number of fish in the ocean were the same.

77

What? How can little old man be driving the passenger pigeon to extinction? That’s ridiculous! Why, there must be millions, no, billions of them! Besides, even if the numbers are going down, I’m sure businesses would stop hunting them and allow them to recover…

78

[QUOTE=mstay]
What? How can little old man be driving the passenger pigeon to extinction? That’s ridiculous! Why, there must be millions, no, billions of them! Besides, even if the numbers are going down, I’m sure businesses would stop hunting them and allow them to recover…
[/QUOTE]

To be fair, the invisible hand was busy somewhere else that day.

79

Can omniscient beings use that excuse?

80

[QUOTE=wevets]
I’m not sure if this meets your criteria, but the Longhaw Cisco is an example of a fish driven to extinction (real extinction, not commercial extinction). As with many things, you can’t really say that overfishing is the only thing that wiped it out, but the bottom line is that whether overfishing was the primary factor or not, it was a factor, and the fish is gone.
[/QUOTE]

It’s not clear whether the “longjaw” Cisco was just a population of regular Ciscos with longer jaws or not. Modern scientists seem to think it was not a separate species. In any case, it was driven extinct by pollution, fishing, and the massive change in the Great Lakes ecology caused by the introduction of the Lamprey Eel.

Predation by introduced species, particularly in restricted habitats (islands, lakes) is the number one cause of extinction around the planet. Fishing seems to have been a minor player in this one.

[QUOTE=Evil Captor]
Whenever you’ve got people with a commercial interest in continuing an activity without regulation (like fishermen, as a general rule) saying that the activity isn’t doing harm, it’s generally pretty safe to assume that they’re wrong. Or lying. Or both.
[/QUOTE]

This is an oversimplification of a complex situation. I don’t know of any fishermen who fish “without regulation”, much less it being a “general rule”. Virtually all fisheries are regulated. The question is always “what regulation, where, and when”. Most fishermen I know are, like myself, interested in the health of the fishery. No fisherman wants to see decreased catches year after year.

Where the disagreement starts always revolves around why the numbers are decreasing, and what we should do about it. Salmon is a good example. The variables regarding whether there’s lots or few fish in a given year are:

  1. Onshore habitat conditions

  2. Sport fishing

  3. Commercial fishing

  4. Dams and in-stream blockages

  5. Native American subsistence fishing

  6. Illegal fishing

  7. Ecosystem changes (salinity, prey species, temperature, etc.)

  8. Natural predators (bears, eagles, rainbow trout)

  9. Size and survival of the birth-year cohort

  10. Hatchery production

  11. Sea lice from farmed fish spreading to wild fish

  12. Underlying natural variability of the system

So every year there’s a huge bun-fight about who is to blame. Sports guys blame the commercial guys, fishermen blame farmers, Native Americans blame everyone else, everyone else blames Native Americans, Canadians blame Americans, and so on down the line.

Now in all of this, who is “lying” as you claim?

[QUOTE=slaphead]
With respect to the catches constant since 1988 or so, I’d be interested to know how that compares with total fishing effort and technology invested in that catch. It seems to me that with the greater technology and more capital-intensive methods used nowadays, catches should be way up if the number of fish in the ocean were the same.
[/QUOTE]

No simple answer to this one. The number you are talking about is called “CPUE”, or “catch per unit effort”. This is measured in different ways in different fisheries (catch per mile of longline per hour, catch per purse-seine net set, catch per boat per day, etc.) Thus, these numbers are not directly comparable.

In addition, CPUE generally decreases from day one of any given fishery — on the first day, the fish stocks are the highest, and catches are the highest and decrease from there.

This is at least theoretically counteracted, as you point out, by increases in technology. With better technology, the CPUE should increase. However, most of the big breakthroughs in fishing technology (long-line hydraulic reels, spotter planes, purse-seine power blocks, herring net shakers, etc.) were in common use by the 1980s.

To answer your underlying question, does the stable yield since 1980 mean that the stocks are not in danger? By no means. Some stocks are in danger, some mortally so. However, it is not a sign of impending doom. At some point or another, it is inevitable that the maximum sustainable yield of any wild population is reached. Our task is to recognize that we have reached that point, and act accordingly.

w.