November 2, 2006 3:37 p.m. EST
Julie Farby - All Headline News Staff Writer
Washington, D.C. (AHN)-According to a new study published in the latest edition of the journal Science, if current trends in habitat destruction and overfishing continue, the world's fish and seafood populations will collapse by 2048, resulting in less food for humans.
In an analysis of scientific data going back to the 1960s and historical records over a thousand years, the researchers found that marine biodiversity has declined dramatically, with 29 percent of species already in collapse.
Boris Worm, lead author of the study, tells Reuters in a statement, "Whether we looked at tide pools or studies over the entire world's ocean, we saw the same picture emerging. In losing species we lose the productivity and stability of entire ecosystems. I was shocked and disturbed by how consistent these trends are-beyond anything we suspected."
During a phone interview with Reuters, Worm said the decline in marine biodiversity is largely due to over-fishing and destruction of habitat, with the loss of biodiversity making ocean ecosystems less able to recover from the effects of global climate change, pollution and over-exploitation.
The scientists said marine-life reserves and no-fishing zones need to be set up to help depleted areas rebuild, with such measures proven effective in places including the Georges Bank off the U.S. Atlantic coast. [via Buzzflash]
That's a pretty sweeping statement, and definitely sets off my baloney detection alarm. I wish that progressive news sources would post the correct Apocalyptic headlines. What's happening is that species diversity in the oceans is collapsing due to overfishing, not that all life in the oceans will be eradicated.
Yet, anyway.
Here's the key figure of the Science article cited. The correct citation for this is :
Impacts of Biodiversity Loss on Ocean Ecosystem Services
Boris Worm, Edward B. Barbier, Nicola Beaumont, J. Emmett Duffy, Carl Folke, Benjamin S. Halpern, Jeremy B. C. Jackson, Heike K. Lotze, Fiorenza Micheli, Stephen R. Palumbi, Enric Sala,8 Kimberley A. Selkoe, John J. Stachowicz, Reg Watson
Science 3 November 2006:
Vol. 314. no. 5800, pp. 787 - 790
DOI: 10.1126/science.1132294
... At the largest scales, we analyzed relationships between biodiversity and ecosystem services using the global catch database from the United Nations Food and Agriculture Organization (FAO) and other sources (15, 20). We extracted all data on fish and invertebrate catches from 1950 to 2003 within all 64 large marine ecosystems (LMEs) worldwide. LMEs are large (>150,000 km2) ocean regions reaching from estuaries and coastal areas to the seaward boundaries of continental shelves and the outer margins of the major current systems (21). They are characterized by distinct bathymetry, hydrography, productivity, and food webs. Collectively, these areas produced 83% of global fisheries yields over the past 50 years. Fish diversity data for each LME were derived independently from a comprehensive fish taxonomic database (22).
Globally, the rate of fisheries collapses, defined here as catches dropping below 10% of the recorded maximum (23), has been accelerating over time, with 29% of currently fished species considered collapsed in 2003 (Fig. 3A, diamonds). This accelerating trend is best described by a power relation (y = 0.0168x1.8992, r = 0.96, P < 0.0001), which predicts the percentage of currently collapsed taxa as a function of years elapsed since 1950. Cumulative collapses (including recovered species) amounted to 65% of recorded taxa (Fig. 3A, triangles; regression fit: y = 0.0227x2.0035, r = 0.96, P < 0.0001). The data further revealed that despite large increases in global fishing effort, cumulative yields across all species and LMEs had declined by 13% (or 10.6 million metric tons) since passing a maximum in 1994.
Fig. 3. Global loss of species from LMEs. (A) Trajectories of collapsed fish and invertebrate taxa over the past 50 years (diamonds, collapses by year; triangles, cumulative collapses). Data are shown for all (black), species-poor (<500 species, blue), and species-rich (>500 species, red) LMEs. Regression lines are best-fit power models corrected for temporal autocorrelation. (B) Map of all 64 LMEs, color-coded according to their total fish species richness. (C) Proportion of collapsed fish and invertebrate taxa, (D) average productivity of noncollapsed taxa (in percent of maximum catch), and (E) average recovery of catches (in percent of maximum catch) 15 years after a collapse in relation to LME total fish species richness. (F) Number of fished taxa as a function of total species richness. (G) Coefficient of variation in total catch and (H) total catch per year as a function of the number of fished taxa per LME.
Consistent with the results from estuaries and coastal seas (Fig. 2B), we observed that these collapses of LME fisheries occurred at a higher rate in species-poor ecosystems, as compared with species-rich ones (Fig. 3A). Fish diversity varied widely across LMEs, ranging from ~20 to 4000 species (Fig. 3B), and influenced fishery-related services in several ways. First, the proportion of collapsed fisheries decayed exponentially with increasing species richness (Fig. 3C). Furthermore, the average catches of non-collapsed fisheries were higher in species-rich systems (Fig. 3D). Diversity also seemed to increase robustness to overexploitation. Rates of recovery, here defined as any post-collapse increase above the 10% threshold, were positively correlated with fish diversity (Fig. 3E). This positive relationship between diversity and recovery became stronger with time after a collapse (5 years, r = 0.10; 10 years, r = 0.39; 15 years, r = 0.48). Higher taxonomic units (genus and family) produced very similar relationships as species richness in Fig. 3; typically, relationships became stronger with increased taxonomic aggregation. This may suggest that taxonomically related species play complementary functional roles in supporting fisheries productivity and recovery.
A mechanism that may explain enhanced recovery at high diversity is that fishers can switch more readily among target species, potentially providing overfished taxa with a chance to recover. Indeed, the number of fished taxa was a log-linear function of species richness (Fig. 3F). Fished taxa richness was negatively related to the variation in catch from year to year (Fig. 3G) and positively correlated with the total production of catch per year (Fig. 3H). This increased stability and productivity are likely due to the portfolio effect (24, 25), whereby a more diverse array of species provides a larger number of ecological functions and economic opportunities, leading to a more stable trajectory and better performance over time. This portfolio effect has independently been confirmed by economic studies of multispecies harvesting relationships in marine ecosystems (26, 27). Linear (or log-linear) relationships indicate steady increases in services up to the highest levels of biodiversity. This means that proportional species losses are predicted to have similar effects at low and high levels of native biodiversity...
...Our data highlight the societal consequences of an ongoing erosion of diversity that appears to be accelerating on a global scale (Fig. 3A). This trend is of serious concern because it projects the global collapse of all taxa currently fished by the mid–21st century (based on the extrapolation of regression in Fig. 3A to 100% in the year 2048). Our findings further suggest that the elimination of locally adapted populations and species not only impairs the ability of marine ecosystems to feed a growing human population but also sabotages their stability and recovery potential in a rapidly changing marine environment.
We recognize limitations in each of our data sources, particularly the inherent problem of inferring causality from correlation in the larger-scale studies. The strength of these results rests on the consistent agreement of theory, experiments, and observations across widely different scales and ecosystems. Our analysis may provide a wider context for the interpretation of local biodiversity experiments that produced diverging and controversial outcomes (1, 3, 24). It suggests that very general patterns emerge on progressively larger scales. High-diversity systems consistently provided more services with less variability, which has economic and policy implications. First, there is no dichotomy between biodiversity conservation and long-term economic development; they must be viewed as interdependent societal goals. Second, there was no evidence for redundancy at high levels of diversity; the improvement of services was continuous on a log-linear scale (Fig. 3). Third, the buffering impact of species diversity on the resistance and recovery of ecosystem services generates insurance value that must be incorporated into future economic valuations and management decisions. By restoring marine biodiversity through sustainable fisheries management, pollution control, maintenance of essential habitats, and the creation of marine reserves, we can invest in the productivity and reliability of the goods and services that the ocean provides to humanity. Our analyses suggest that business as usual would foreshadow serious threats to global food security, coastal water quality, and ecosystem stability, affecting current and future generations.
References
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# 15. Details on methods and data sources are available as supporting material on Science Online.
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Overfishing won't destroy all life in the oceans, only most of the larger fish.
Some animals, like squid
, that reproduce faster and exhibit complex aviodance behavior may do relatively better in the presence of global warming and an aggressive superpredator like the industrial fishing fleet on the open sea. Which makes me draw some comparisons
because superpredators don't handle environmental stresses famously well 
.[I knew there was a reason why Darth Rumsfeld wanted to militarize space.]
If you wanted to post Apocalyptic headlines, there are other factors besides overfishing that might work better.
Acidifying the ocean is particularly detrimental to organisms that secrete shell material made of CaCO₃, such as coral reefs and a type of phytoplankton called coccolithophorids [Kleypas, J., R.W. Buddemeier, D. Archer, J.-P. Gattuso, C. Langdon, and B. Opdyke (1999) Geochemical consequences of increased atmospheric CO2 on coral reefs. Science 284: 118-120.]. The ocean pH change will persist for thousands of years. Because the fossil fuel CO₂ rise is faster than natural CO₂ increases in the past, the ocean will be acidified to a much greater extent than has occurred naturally in at least the past 800,000 years [Caldeira, K., and Wickett, M.E. Anthropogenic carbon and ocean pH. Nature: 425, 365, 2003.]...
But it turns out this has a much greater effect than just on coral reefs. You see, corals are basically just a sessile form of the base of the oceanic food chain, plankton.
A nice recent more scientific short review of this is found here [Nature 442, 978-980 (31 August 2006) | doi:10.1038/442978a].
Lost protection: making sea water more acidic (centre and right) dissolves the outer casings of coccolithophores, tiny plankton that form the basis of food webs.
The loss of microscopic organisms ubiquitous in the oceans doesn't seem very alarming. After all they're very small. It's just they're the base of the food chain, for everything from salmon to krill to whales to the entire nation of Japan.
Oceanic life is like life everywhere: it's resilient, and if there are mass die-offs, it's likely adaptable species will expand to fill the ecological niches. After all, the world's been warm and full of CO₂before.
But as an aggressive superpredator, you have to realize your limitations, or meet the ends of aggressive superpredators throughout history.
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