World's oceans move into 'extinction phase'

[Rosenrot]

What really hacks me off tho, is the amount of wasted fish, throwbacks etc... the tv series TrawlerMen showed often, tonnes of fish being returned to the sea, mostly dead, as 'wrong size' or wrong type, or 'over quota'.

FISH WASTED. Whats the point of putting dead fish back?

Feed the hungry with them! The poor. I wish folk would eat 'any' fish, instead of a few select species...

Fishermen don't want to waste space on the boats for fish that are undersized or not of a sellable species; they only keep what they can get the most money for (overfishing is driven by greed). In fact, often having fish that are too large or too small on their boats is considered illegal and could cost a boat fines or even its license. Bycatch is a huge problem. There are some fisheries where you get more bycatch than target species. I've always heard some shrimp fisheries as being very notorious for that. Most of the bycatch that is thrown back dies.

If we keep taking fish out at the rate we're going, then we will be eating any fish instead of just the choice ones.

[Guest]

This is the central theme of the prophetic movie Soylent Green.

In the end the only source of protein left on the planet is algae, but as the oceans continue to warm productivity falls off a cliff. Eventually they resort to the end game of all overpopulated human cultures - cannibalism in the form of recycled dead people which is turned into "Soylent Green" food blocks.

The movie ends with the classic and chilling line - "Soylent Green is people".

Br Cornelius

[septic peg]

This is the central theme of the prophetic movie Soylent Green.

In the end the only source of protein left on the planet is algae, but as the oceans continue to warm productivity falls off a cliff. Eventually they resort to the end game of all overpopulated human cultures - cannibalism in the form of recycled dead people which is turned into "Soylent Green" food blocks.

The movie ends with the classic and chilling line - "Soylent Green is people".

Br Cornelius

Cool sounding movie, gonna search for and watch it!!

[Trakyan]

didnt need no experts to tell me the worlds eco system is falling apart

i mean think about the over a hundred species going extinct in a rainforest each day

[Little Fish]

over a hundred species going extinct in a rainforest each day

how do you know this? seems to be a wild claim.

[Doug1029]

how do you know this? seems to be a wild claim.

The background extinction rate, based on fossil evidence is between 10 and 100 species per year. But this is only for species that leave fossil records. The true background rate, is undoubtedly much higher.

The current extinction rate is about 27,000 species per year. That's about 74 species per day. So, you're right: 100 species per day is exaggerated, but is that enough to call it a "wild claim?"

Most of the 27,000 species are tropical insects, particularly in the Amazon Basin. Habitat loss seems to be the major cause.

Marine ecosystems are less well-known, so losses there are difficult to estimate.

Extinction rates follow an exponential decay curve: The probability of an extinction is proportional to the numbers of surviving species. The extinction rate will probably drop as we run out of species to go extinct.

Why be concerned about extinctions? Most of our medicines came originally from plants: quinine and taxol, to name two. A guy I once met makes his living traveling the world and scooping up samples of soil and plants. He sends this material to a lab where they test his samples for biological activity. A wood sample submitted by another biologist proved to have an active, but unidentified anti-HIV component. When he returned to the site to collect more samples for further research, the area had been cleared for farming. So, we lost a possible AIDS cure because of an extinction.

Another reason for concern is that wild species are our emergency backup in case of climate or other disaster. Our current soybean seed supply descends from just three plants. That's a narrow gene pool if there ever was one. One disease could do in the world's soybeans. Wild plants are our backup.

There is great redundancy in the world's ecosystem, but we don't yet know its workings entirely. Consider the role of insect-eating birds in the Douglas-fir forests of the Pacific Northwest: four kilograms of birds eat enough tussock moths to protect between two and three million kilograms of trees. A disaster, let's say human destruction of critical nesting habitat, could threaten those forests.

Imagine the earth's life-support system is an airplane. How many rivets (species) can we knock out of it before it can't fly? Because we don't know the number doesn't mean it doesn't exist.

These are over-simplifications, of course, but they do illustrate the importance of maintaining biodiversity.

Doug

http://www.pbs.org/wgbh/evolution/library/03/2/l_032_04.html

[Little Fish]

The current extinction rate is about 27,000 species per year

how do you know this?

think about how you would even measure this. it would be a huge undertaking to take even one reliable measurement, let alone continous measurements.

given the standard of what gets published these days and the huge rise in retractions of scientific papers, I'd take that figure with a pinch of salt.

[Guest]

how do you know this?

think about how you would even measure this. it would be a huge undertaking to take even one reliable measurement, let alone continous measurements.

given the standard of what gets published these days and the huge rise in retractions of scientific papers, I'd take that figure with a pinch of salt.

Doug explained this. It is an estimate based on the relative proportions of different phyla of species. You are correct in saying that it would be nearly impossible to directly correctly count - but if we have direct observations of the higher phyla we can make a very educated guess based on relative proportions of phyla. Since over 2/3 of all higher species are insects, we can reasonably estimate the loss of those insect species by direct observation of the loss of mammals and birds. These estimates are bolstered by direct measurements of habitat loss (tropical rain forest mainly) and the knowledge that many tropical species are extremely local in range. All these allow reasonable estimates of species loss based on rainforest loss/ coral reef loss / etc.

It is not a precise estimate at all but a very reasonable estimate based on the data we have concerning those more readily measured species. You may not feel this to be a reasonable approach - but the scientific community would disagree with you.

I would not agree with your assertion that an increasing number of scientific papers are been withdrawn. Can you provide any evidence for this wild claim ? It seems like an opinion based purely on your reading of skeptical websites which like to claim that AGW papers are increasingly been found wanting - when infact it is their own misrepresentation of those papers which is at fault.

Br Cornelius

Edited August 19, 2011 by Guest

[Doug1029]

how do you know this?

think about how you would even measure this. it would be a huge undertaking to take even one reliable measurement, let alone continous measurements.

given the standard of what gets published these days and the huge rise in retractions of scientific papers, I'd take that figure with a pinch of salt.

For beetles: Pick 100 overstory trees in the Amazon rain forest. Place cone-shaped collectors in a grid pattern on the ground. Fog the trees with insecticide. Collect the cones and see what beetles/insects you have collected. Wait a few years, then repeat the process. Wait a few more years, then do it again. Then wait a few more years and do it again. Now you have enough data to model some population dynamics of species that show declining numbers. Do any of them fit a decay curve?

Monitor those species using pheromone traps in likely spots. If they come up negative, repeat over larger area, then over entire range. If you don't collect any, the species is probbaly extirpated locally. Wait a few more years, then repeat. Three repetitions is probably enough.

Elapsed time: about twenty years.

Other species require other techniques:

EPA has a plan for the recovery of the Mexican spotted owl in the American southwest. No Mexican spotted owl has been seen in the Front Range since 1947. Do you think it might be extirpated? Populations are monitorred by hiking up the bottoms of local canyons, looking for owl droppings. These usually form a line pointing to a roosting site. Then its just a matter of waiting until you see the owl that roosts there and identifying it.

You can also extrapolate from the phyla you know about: if ten out of 1000 critters (1%) in each of 30 different phyla have gone extinct, then it is fair to assume that the 1% figure applies across the board. Apply this to the phyla you don't know about and you have your estimate.

Doug

[Little Fish]

Species–area relationships always overestimate extinction rates from habitat loss

Extinction from habitat loss is the signature conservation problem of the twenty-first century. Despite its importance, estimating extinction rates is still highly uncertain because no proven direct methods or reliable data exist for verifying extinctions...

http://www.nature.com/nature/journal/v473/n7347/full/nature09985.html

from wikipedia:

[dalia]

If this is similar to every other mass extinction in history, then I would think humans are not responsible.

[WoIverine]

Red Tide, fun times ahead.