Massive decline in Atlantic Ocean biomass

[BCO]

Massive decline in North Atlantic Ocean high-trophic level biomass

http://www.seaaroundus.org/Journal/faf103.pdf

Scary paper, this (strangely, it's from 2003, but seems to be making waves on the Interwebz now).

Remember, every time you eat fish you help rape the ocean. Enjoy it while it lasts.

 

[Geriatrix]

It's peak everything over the next couple of years. We live in interesting times.

 

[Ninja'd]

Remember, every time you eat fish you help rape the ocean.

Quit reminding me that vagina smells like fish.

 

[Nick333]

It's peak everything over the next couple of years. We live in interesting times.

Heh! Peak fish.

It's pretty weird that we still have a hunter/ gatherer attitude towards seafood when you think about it.

 

[Geriatrix]

Heh! Peak fish.

It's pretty weird that we still have a hunter/ gatherer attitude towards seafood when you think about it.

We act mostly out of instinct. Won't change any time soon.

 

[ozoned]

The title of this thread could be improved.

"Massive decline in Atlantic Ocean biomass."

The study is reporting a two thirds decline in North Atlantic predatory fish (of a certain size) over a 100 year period.

The actual period reported is from 1950-2000, with single datum from 1900 as an "extreme" base reference.

The actual area of Atlantic ocean under model is 15 segments of the North Atlantic, which also correspond to the most intensive areas of commercial fishing in the NO.

It is incorrect that North Atlantic biomass is declining, let alone Atlantic biomass:
McQuatters et al 2011 Nature

 

[BCO]

Ok, so the study shows that predatory fish are down by anything between 90-60% in areas where commercial fishing happens. On the other hand there's more phytoplankton now. Still not exactly a rosy picture.

 

[ozoned]

The study does not "show" that this fish population is down by "90-60" percent.

The study reports that the stochastic model used predicts, that if you actually counted the fish,
there would be far less than there were estimated to be in 1950. (1950 follows a ten year period in which fishing in the area was greatly suppressed due to the war and it's aftermath)

In addition, the estimation methodology used by the study is now out of date and invalid.

From pg 8:

it is not straightforward to
deduct overall biomass level from total catches. We
expect, however, that the catch composition will
change as a function of the biomass level of the pre-
ferred fishing target, i.e. of the high-trophic level spe-
cies. It is by now well established that fisheries
expansions go hand in hand with the process of fish-
ing down the food web' (Pauly et al. 1998), and we
can therefore use the catch composition by spatial
unit to draw inferences about the overall biomass of
high-trophic level fish species

Two studies, one published in Nature,2010, show that the conclusions reached by Pauly, in this regard, are not valid. see Trophic level entry on WikiPedia (notes 11,12)

Apart from all that, the study selects for fish in the North Atlantic with a trophic level > 3.75 Which for marine life, is very high up the food chain. Which is why I suggested the title is misleading, ie, Atlantic biomass is in fact, not massively down.

This post is now first on google (congrats, BTW ) for the phrase "Massive decline in Atlantic Ocean biomass" simply, because it is spurious, and deeply into long tail territory.

 

[BCO]

Awesome use of condescension quotes You another Phrony account perchance?

Anyway, thanks for providing clarity. The thread title is misleading - it should have read "Massive decline in North Atlantic Ocean high trophic level biomass" (as an aside, isn't it strange that if one types in the exact name of the thread title into google, that the first result is the thread itself? ).

The study reports that the stochastic model used predicts, that if you actually counted the fish, there would be far less than there were estimated to be in 1950. (1950 follows a ten year period in which fishing in the area was greatly suppressed due to the war and it's aftermath)

Where do you draw that conclusion from? The study does not seem to be saying that 1950 estimates were wrong, rather that current numbers are down, hence statements such as:

"The results thus predict that high-trophic level fishes will be all but gone from the North Atlantic region within a few decades if the current trend continues"

or

"The pattern that seems to emerge... is one of massive decline"

I'd be very interested if there were any good optimistic studies regarding marine biodiversity. So far the two you've mentioned simply indicated that lower trophic level biomass may be growing and that the notion o fishing down the food chain is flawed. Looking at the abstract of the latter paper, it seems as if the authors are still cautioning of fishery collapses.

 

[ozoned]

I am not being sarky, not even with condescending quotes

I have some issues with the uncertainty introduced by modeling the biomass predictions using the fish catch as proxy. The authors acknowledge this, and other elements of uncertainty.

I have some issues with the distinctly linear decline they have concluded. I have seen studies on pacific salmon which show a cyclic change over the same period. That is further confused by the modern farming of salmon, but apparently the Japanese records from about the 1600's show the same sort of cyclic change (in fish catch).

I am not arguing or even suggesting this fish biomass is higher than it was, or has not been in decline, I have reservations that it is massively in decline. But that is not relevant, I wanted to clarify that Atlantic biomass as a whole is not the subject of the study.

If you enter "Massive decline in North Atlantic Ocean high trophic level biomass" into google, you wont see this post for pages( even if you were to make that the title of the post. which would make me much happier, and less nitpicky)

 

[BCO]

I am not being sarky, not even with condescending quotes

I have some issues with the uncertainty introduced by modeling the biomass predictions using the fish catch as proxy. The authors acknowledge this, and other elements of uncertainty.

I have some issues with the distinctly linear decline they have concluded. I have seen studies on pacific salmon which show a cyclic change over the same period. That is further confused by the modern farming of salmon, but apparently the Japanese records from about the 1600's show the same sort of cyclic change (in fish catch).

I am not arguing or even suggesting this fish biomass is higher than it was, or has not been in decline, I have reservations that it is massively in decline. But that is not relevant, I wanted to clarify that Atlantic biomass as a whole is not the subject of the study.

Noted

If you enter "Massive decline in North Atlantic Ocean high trophic level biomass" into google, you wont see this post for pages( even if you were to make that the title of the post. which would make me much happier, and less nitpicky)

If I was able to rename the title, I would. Alas, that train has sailed.

*edit* As an aside, you really don't like the common myna, do you?

 

[Palimino]

No-one has considered the obvious. Douglas Adams was wrong about the dolphins (So long, and thanks for all the fish). It is much more than the dolphins that are responsible for this massive decline of biomass.

 

[ozoned]

Noted

If I was able to rename the title, I would. Alas, that train has sailed.

*edit* As an aside, you really don't like the common myna, do you?

You can easily edit your post titles, just select "go advanced" button after clicking on the "edit post" button. You should see your post title in an edit box above the main post text.
(not that I'm insisting you do so, I've been afk for a coupla days and don't feel like picking nits today

Yah, I pretty much regard that bird as a flying cane toad.

 

[BCO]

You can easily edit your post titles, just select "go advanced" button after clicking on the "edit post" button. You should see your post title in an edit box above the main post text.
(not that I'm insisting you do so, I've been afk for a coupla days and don't feel like picking nits today

Cool! Must be a new feature that titles are editable. Done and done.

*edit* Just looked again, the actual post topic is not editable.