Enter the Sea Monster

Dear Friends,

Perhaps you’ve noticed my distraction lately, that I haven’t seemed to pay as much attention to the NP as I used to, perhaps even that the magic seems gone. Well I can’t live the lie any longer–I’ve been cheating on the Natural Patriot, in a manner of speaking. Yes, there is . . . another blog.

It all started so innocently. Being a marine biologist, I’m naturally around the Sea and, well, one thing led to another. And then, well.

The Natural Patriot and I will have to work through this together. But in the meantime, I invite you to check out my new endeavor with my colleague John Bruno, the SeaMonster. Is is now officially live and I would be delighted if some of my faithful readers would stop by, have a look, and leave a comment.

Full speed ahead!

Posted in et cetera, Oceans | Comments Off on Enter the Sea Monster

Safety in numbers . . . of species

[Hot off the presses, from Eurekalert. Also covered in Science Daily and various other venues. ]

Will loss of plant diversity compromise Earth’s life-support systems?

Meta-analysis and reflections on two decades of biodiversity research provide some answers and reveal new questions.

Biodiversity around the world is increasingly threatened by global warming, habitat loss, and other human impacts. But what does this loss of species mean for the functioning of ecosystems that humans depend on for goods and services? Can ecosystems around our planet survive and maintain their primary functions with fewer species in them? After decades of research on many issues pertaining to life on Earth, are scientists any closer to attaining these answers?

In a Biodiversity Special Issue of the American Journal of Botany, to be published in March, many of the world’s experts on biodiversity have come together to present their state-of-the-art analysis of where we stand today regarding the taxonomy, systematics, evolutionary biology, biogeography, ecology, conservation, and restoration of species distributed all over the world.

Understanding the causes and consequences of global loss of biodiversity is the main area of research for Bradley Cardinale, an ecologist from the University of Michigan. In one of the seminal papers in AJB’s Biodiversity Special Issue, Cardinale, along with several international collaborators, explores how changes to primary producers —plants and algae that are the baseline of the biodiversity network—affect ecological processes that are essential to the functioning of ecosystems around the world.

“Nearly every organism on this planet depends on plants for their survival,” Cardinale commented. “If species extinction compromises the process by which plants grow, then it degrades one of the key features required to sustain life on Earth.”

To take on such an enormous question, Cardinale and his co-authors conducted a meta-analysis—this entails finding and sifting through hundreds of published studies for appropriate data that can be used to answer larger-scale questions. In some respects, each paper that met their defined criteria acted as a replicate data set for a particular question, and they were able to use these data sets to then ask if primary producers affected systems in the same way across multiple ecosystems and in multiple parts of the world. This is a very powerful approach because it combines the efforts of researchers all over the world and allows these researchers to zoom out from a small-scale, more traditional, focus on a specific study system or habitat to get a “big picture” perspective.

One of the key questions Cardinale et al. asked was “How does biodiversity of plants influence the productivity and sustainability of ecosystems?” A prevalent idea in the biodiversity scientific community is that species diversity controls how communities capture limited resources—such as nutrients and light—and convert them into new biomass. Using data from almost 400 published experiments in their meta-analysis the authors found overwhelming evidence indicating that the net effect of species loss at the producer level reduces the amount of standing biomass of that community. It also reduces the efficiency by which plants and algae assimilate inorganic resources like nutrients, and reduces rates of primary production (conversion into new biomass).

“This summary provides unequivocal evidence that declining diversity of plants and algae in the world’s ecosystems will decrease the biomass of plants in natural ecosystems, and degrade their ability to use biologically essential nutrients from soil and water,” Cardinale says. “Preliminary evidence also suggests that declining diversity may reduce the ability of natural ecosystems to produce oxygen, and to remove carbon dioxide from the atmosphere.”

While the overwhelming majority of studies in their data set showed that diverse communities of plants and algae are more productive and efficient than their average species, the authors also examined whether a more diverse community is more efficient or productive than the single “best” species in that community. This is a question that agriculturalists and forest managers have had for quite some time. Out of 375 observations, 37% suggested that diverse polycultures ultimately attain more biomass than even their single highest-yielding species (such as a species that would produce the largest crop or the most wood) when grown in a monoculture. This is probably a highly conservative estimate since the analyses also showed that effects of biodiversity tend to grow stronger as studies run for longer periods of time, or as they are performed at larger spatial scales.

The authors explain that there are two reasons why diverse communities are more productive and efficient. Part of the explanation is that diverse communities are more likely to contain “super-species”—that is, species that are highly productive and efficient at regulating ecological processes. But there is even greater evidence that species play unique and complementary roles in their environment. This “division-of-labor” allows diverse communities to be more productive. One of the co-authors of the study, Lars Gamfeldt, illustrates the concept with an analogy: “Plant communities are like a soccer team. To win championships, you need a star striker that can score goals, but you also need a cast of supporting players that can pass, defend, and goal tend. Together, the star players and supporting cast make a highly efficient team.”

So where do scientists go from here? What areas need improvement? How can we develop better, more predictive models detailing the consequences of biodiversity loss?

“Species extinction is happening now, and it’s happening quickly. And unfortunately, our resources are limited,” says Jarrett Byrnes, another co-author of the study. “This means we’re going to have to prioritize our conservation efforts, and to do that, scientists have to start giving us concrete answers about the numbers and types of species that are needed to sustain human life. If we don’t produce these estimates quickly, then we risk crossing a threshold that we can’t come back from.”

Cardinale et al. suggest that future experiments need to manipulate biodiversity at multiple scales and incorporate spatial and temporal heterogeneity; quantify how effects of biodiversity loss compare with those due to other environmental change such as pollution, habitat fragmentation, climate change, etc.; and conduct experiments that manipulate diversity at multiple levels, such as the genetic or landscape level, to see at which level ecological functions are best measured.

“We need to translate the insights gained from simple experiments into the ‘real-world,’ where things get considerably more complex,” Cardinale notes. “But infusing more reality to experiments will greatly enhance our ability to predict the impacts of extinction.”

“We’ll then be in a position to calculate the number of species needed to support the variety of processes that are required to sustain life in real ecosystems,” adds Cardinale. “And we don’t mean “need” in an ethical or an aesthetic way. We mean an actual concrete number of species required to sustain basic life-support processes.”

Finally, Cardinale indicates that we need to know how biodiversity impacts products and processes that are relevant to our daily lives. “For example, how does biodiversity affect the yield of food crops, the control of pests and disease, the purification of water, or the production of wood, fiber and biofuels?”

Emmett Duffy, a co-author, summarizes the paper with an emphatic conclusion: “The idea that declining diversity compromises the functioning of ecosystems was controversial for many years. This paper should be the final nail in the coffin of that controversy. It’s the most rigorous and comprehensive analysis yet, and it clearly shows that extinction of plant species compromises the productivity that supports Earth’s ecosystems.”

CITATION: Cardinale, Bradley J., Kristin L. Matulich, David U. Hooper, Jarrett E. Byrnes, Emmett Duffy, Lars Gamfeldt, Patricia Balvanera, Mary I. O’Connor, and Andrew Gonzalez (2011). The functional role of producer diversity in ecosystems. American Journal of Botany 98(3): 572-592. DOI: 10.3732/ajb.1000364

The full article in the link mentioned is available for no charge for 30 days following the date of this summary here.

Posted in Biodiversity, Science, Sustainability | Tagged , | Comments Off on Safety in numbers . . . of species


[Henceforth, the series formerly know as Friday poetry shall be called Friday Soul, in recognition of the fact that I may at some stage elect to feature something other than poetry. But don’t be alarmed, I don’t see the general theme changing much. Today we have Billy Collins. a uniquely upbeat poet — at last until his last volume — who has the distinction of being the only poet who has ever caused me to actually wake my wife from peaceful slumber because I was shaking with silent laughter while sitting in bed reading. This was not the poem that caused that incident.]

Billy Collins

The way the dog trots out the front door
every morning
without a hat or an umbrella,
without any money
or the keys to her doghouse
never fails to fill the saucer of my heart
with milky admiration.

Who provides a finer example
of a life without encumbrance —
Thoreau in his curtainless hut
with a single plate, a single spoon?
Ghandi with his staff and his holy diapers?

Off she goes into the material world
with nothing but her brown coat
and her modest blue collar,
following only her wet nose,
the twin portals of her steady breathing,
followed only by the plume of her tail.

If only she did not shove the cat aside
every morning
and eat all his food
what a model of self-containment she would be,
what a paragon of earthly detachment.
If only she were not so eager
for a rub behind the ears,
so acrobatic in her welcomes,
if only I were not her god.

Posted in Books and media, Poetry | Tagged | Comments Off on Dharma

How not to end world hunger

Food prices are rising. Again. And the scramble is on to figure out who to blame: climate change?  Biofuels? Good old capitalist greed? Just this morning the New York Times published a discussion panel on the issue: “Is the world producing enough food?”, with all the old familiar arguments and counter-arguments. This perennial debate struck a chord with me, having just completed a discussion of fishery production in my marine ecology class, and having recently reviewed a manuscript searching for solutions to the conflict between fishery production and biodiversity conservation. So here’s my answer to the question posed by the NYT:

No, and it never will.

At least not under the  current, unstated assumptions of modern global society. The reason why requires a bit deeper digging than any of the Times’ panelists was willing to go. I’m haunted in reading these essays, as in so much of the current discussion about sustainability, by what seems to me a fundamental flaw in reasoning. This is the unwillingness to acknowledge the problem at the root of the sustainability challenge, which has long been understood but is rarely explicitly mentioned, and without which all efforts at sustainability (including how to feed the world) will ultimately fail. That problem is the quasi-religion of economic growth, the resultant philosophical blind spot that prevents most of us from appreciating that the earth is finite, and perhaps most important (and certainly least comfortable) of all, the clear implication that the only long-term solution to all of these challenges is to find a humane way to limit the number of humans on earth.

This bears on the various arguments for increasing efficiency in food production–the oft-cited need for a new green revolution (and a “blue” revolution too, if we include as we must the massive juggernaut of growing aquaculture production). Is this not a worthy goal? Of course it is. We’ll never achieve a humane equilibrium on earth without greater efficiency in every sector. Yes, I agree that it’s immoral to take land out of food production to grow biofuel crops for developed-world vehicles. And yes, we need to invest more in agriculture. I’m less convinced that opening trade will solve these problems.

A typical argument one hears, as in this contribution, goes:

“Productivity growth will need to accelerate from historical trends to keep up with F.A.O.’s predictions for population and income growth.”

OK, I get it. But one can’t help but wonder: What happens to the increased food supply resulting from the increased efficiency? Will it not move up the food chain to produce more people with comparable or larger appetites? Is there any evidence in the long history of the human race and our amazing technological advances that increased efficiency has reduced pressure on land and resources for more than a transient period (i.e. for the long run, which is inherent in the definition of the word sustainable)?  I am not being sarcastic or rhetorical here, I’m genuinely curious and can’t think of an example. On the contrary my strong sense is that increased efficiency of food production has in every case flowed efficiently up the food chain to increase efficiency of people production.

And this should be no surprise. Humans are the top predators of planet earth.Technically we are omnivores — indeed the most extreme omnivores around since we can and do consume almost anything of biological origin. But we are top predators in the sense that we can (and generally do) consume any other organism, whereas nothing else eats us. The key point here is that populations of top predators are, by definition, not regulated by their own predators — they don’t have any, and so are, again by definition, regulated by something else. Given that we have largely escaped any significant regulating pressure of disease and natural disasters, the only thing left to limit human population size is food supply. In the parlance of ecological science, the global human population, like that of other top predators, exhibits “bottom-up control”, meaning that our numbers are ultimately regulated by food availability.

What are the implications of this very basic ecological observation? The principal one is that increasing efficiency of food production leads only transiently to greater per capita nutrition, because that better nutrition generally increases reproductive rate, producing more people among which the food needs to be spread, and so on. Admittedly this argument is a bit simplistic, in that transition to a rich economy eventually reduces birthrate, but that tends to occur only after a society reaches a relatively huge per capita consumption rate (the average American has an ecological footprint 20 times that of the average Bangaldeshi). Nevertheless, the general trend is quite clear: more and better food produces more people. I would be very interested to hear a convincing counterexample on  more than a small, transient scale.

So if efficiency will not (by itself) save us, what is the answer? Certainly efficiency is part of the answer. But I think another important part is what Michael Rosenzweig called “reconciliation ecology”, basically designing and managing human-dominated landscapes to be as accommodating as possible to other species. In other words, it seems likely that within this century there will be little if any reserve land (or sea) set aside that is untouched by humans. It’s just hard to imagine how it will survive the press of population and consumption pressure. Therefore, if we are going to save anything, it will have to live in more or less intimate contact with humanity. Then of course there is the elephant in the room: If any significant fraction of the nature that we love and depend on is going to be sustainable (i.e., survive into the long term), we cannot avoid the issue of how to limit the number of humans on earth. Yes, per capita consumption is an even bigger (and growing) problem and increasing efficiency will help on that count. But eventually we as a global society need to be able to have calm, substantive discussions about how to cap human population size.

That is the way to end world hunger, and have a world left to live in as well.

Posted in Politics, Sustainability | Tagged , , , , | 3 Comments

Who pays for overfishing? Poor people in Africa (and elsewhere)

[Based in part on my evaluation for the Faculty of 1000, accessible only by subscription I’m afraid]

The pervasive detrimental impacts of overfishing on marine life and ecosystems have been widely publicized in recent years, ratcheting up calls for stricter regulation and protection. A counter-argument commonly heard in debates on this issue is that fishing (like coal mining, oil drilling, pillaging of old-growth forests, etc.) provides essential jobs, revenue, and food, particularly in poor countries. It’s jobs and food for people versus the environment, you heartless misanthropic tree-huggers.

Or is it?

Answering this question is tricky. For fishing, it requires good estimates of a fish population’s (or community’s) “maximum sustainable yield” (MSY) — the precise quantity  of fish that can be harvested each year while keeping the population healthy and producing at maximal rate for the long haul. Estimating this quantity (and “estimating” is a kind way of saying it, but don’t get me started) requires a lot of data and hard work, which essentially means that it doesn’t happen in most of the world’s fisheries.

In a new paper, Uta Srinivasan and colleagues cleverly sidestepped this problem by first calibrating an empirical relationship between maximum sustainable yield and the maximum recorded catch for those fisheries where such data were available. This is a key step forward because there are lots more data available on recorded catch (since it’s an index of the success and profits of fishers they have some incentive to record it) than there are for MSY. It turns out that the two variables are quite highly correlated (R2=0.84) — as might be expected since there is little incentive to reduce fishing when the population is producing well. In other words, fishers tend instinctively to find the sweet spot (mathematically speaking) and stay there.

So the authors were able to use this general relationship to estimate MSY for fisheries throughout the rest of the world, where MSY data are limited or nonexistent. Then they estimated the difference between MSY and actual yield of overfished stocks, what is in fact brought back to the dock. This difference — between what is and what could be — they term the “overfishing debt”, measured in currencies of biomass, food energy, or revenues. Their analysis found that 16-31% of world fish stocks are overfished, in line with other recent estimates.

But the new — and troubling — finding was that, globally averaged, gross revenue lost to fishing beyond sustainable levels was 6-35% of the landed value of the fisheries, depending on assumptions. Interestingly (indeed perversely), these losses are similar in magnitude to the government subsidies that support excess fishing capacity (again, ironically, largely to support jobs). Most troubling of all, the analysis showed that overfishing debt fell most heavily on poor developing nations: among the 43, mostly African, ‘Low-Income Food-Deficit Countries’ analyzed, losses of potential catch to overfishing averaged a staggering 75% of actual landings. Thus, an estimated 20 million people worldwide were undernourished as a result of unsustainable fishing. And that’s on top of the environmental destruction we already knew about.

In short, this paper shows that global overfishing results not only in the well-known degradation of biodiversity and ecosystems but also in ‘overfishing debt’, a paradoxical — and substantial — loss of revenue and food security, particularly in the nations that can least afford it.

For some possible solutions, see the final paragraphs of this summary.

Original source: Srinivasan et al. 2010. Food security implications of global marine catch losses due to overfishing. Journal of Bioeconomics 12:183-200.

Posted in Biodiversity, Oceans, Science, Sustainability | Tagged , , , , | 2 Comments

Make of yourself a light

[Editor’s note: I can’t get enough of Mary Oliver. There are few poets, writers, or artists of any kind that so consistently make me catch my breath, that give me the sensation of suddenly falling away into a new world.]

The Buddha’s Last Instruction
Mary Oliver

“Make of yourself a light,”
said the Buddha,
before he died.
I think of this every morning
as the east begins
to tear off its many clouds
of darkness, to send up the first
signal–a white fan
streaked with pink and violet
even green.
An old man, he lay down
between the two sala trees,
and he might have said anything,
knowing it was his final hour.
The light burns upward,
it thickens and settles over the fields.
Around him the villagers gathered
and stretched forward to listen.
Even before the sun itself
hangs, disattached, in the blue air,
I am touched everywhere
by its ocean of yellow waves.
No doubt he thought of everything
that had happened in his difficult life.
And then I feel the sun itself
as it blazes over the hills,
like a million flowers on fire–
clearly I’m not needed,
yet I feel myself turning
into something of inexplicable value.
Slowly, beneath the branches,
he raised his head.
He looked into the faces of that frightened crowd.

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Empathy, Enmity, and the Future of Civilization

[The alternate post title that I really wanted to use: “My brief reign as one of the world’s leading intellectuals“]

It smelled a little off from the beginning, I’ll admit. But, as I say, I’m not immune to flattery. So when Jeremy Rifkin invited me to contribute a piece to the Huffington Post sometime ago (OK, the email actually came from his secretary), as one of “30 of the world’s leading intellectuals, scholars, and scientists from a range of academic fields and professional disciplines” (no, I’m not making this up), I deliberated for some minutes and then promptly took the bait. Yes, yes, it was a  transparent advertisement for his new book. But I enjoy a book every now and then — mostly then with my current schedule. And it was free. So I skimmed it. And it was indeed thought-provoking. Alas, my close personal friend Arianna evidently elected not to publish it (she doesn’t call! She doesn’t writeNothing!).

Anyway, since I put an hour or three into writing the thing, I offer it here, belatedly, for your edification:

Empathy, Enmity, and the Future of Civilization
J. Emmett Duffy

Three millennia ago, at the dawn of civilization, an already jaded King Solomon proclaimed that there is nothing new under the Sun. We now know that in an important sense he was wrong—in little more than the last century, surging human population and rapidly evolving technology have profoundly transformed this unique planet, changing even the climate itself, probably irreversibly. After triumphantly capturing fire in the stone age, we’ve lost control of it. Humanity has become not only a force of nature but the force of nature.

This unprecedented boom, which raised human living standards immeasurably, was powered by a one-time inheritance of fossil fuel, the end of which is now looming into view. Yet our numbers, and especially our appetites, continue to grow as the developing world understandably strives to become, in Thomas Friedman’s words, carbon copies of Americans. Reaching that dubious goal, an online calculator tells me, would require the natural resources of 5.8 earths. And we only have one. Civilization as we know it is in for a rude awakening.

Can we yet make a soft landing? Many have argued compellingly that only a revolutionary change in our way of life— something new under the sun—offers any hope. But is humanity capable of such a leap? Jeremy Rifkin thinks so. He sees the answer in a new “Empathic Civilization” that will meld the dizzying power of modern global communications with renewable energy and, more uniquely, the innate power of human empathy.

It is a seductive idea. And a noble one. He is surely right that empathy—for one another and for Nature—must be central if we hope to bequeath a habitable and civilized world to our grandchildren. But properly vetting this grand idea requires focusing clearly on the human nature at its center. Who is this Homo empathicus? And can she really save the world from the profound challenges we face? It’s true that humans are nearly unique among animals in our capacity for altruism beyond our own kin. Rifkin rightly sees this is a bright ray of hope in an often dark prospect. Going farther, he argues that empathy can save the world. I would very much like to believe he’s right.

But any cursory look at the news makes the vision of global empathy seem surreally optimistic. Humanity today, as in every age, is equally prone to monstrous cruelty. The same global nervous system that could link us in a planetary empathic network, for example, has been twisted into a spiderweb for terrorists perpetrating horrific violence on random civilians.

Why is this? Evolutionary research has produced a wealth of evidence, from slime molds through apes, that all societies balance on a narrow ridge between cooperation and conflict. Even the huge colonies of ants and honeybees, those archetypes of cooperation and industry, conceal seething intrigues worthy of any medieval court. And despite our mirror neurons, our inherent sociability, and our highly sophisticated capacity for altruism, humans, alas, are no exception. Just look at the state of American politics.

Empathy and selfishness are the twin poles—the inseparable yin and yang—forming the axis of our social nature. They are clearly manifested in the simplest tribal cultures and remain, despite the veneer of our sophisticated material culture, at the core of our most fundamental institutions, from families to national governments to world religions.

It was ever thus. While Solomon would recognize little of the modern world, he would surely understand that neither empathy nor selfishness are new under the sun. Our common path forward must reckon with the reality that, despite humanity’s impressive societal advances, the tension between selfish conflict and altruism is, literally, a part of our DNA. We ignore that fundamental duality at our peril.

But that need not mean we are prisoners of our history or genes. Humanity has transcended seemingly insurmountable barriers many times, and we are now arguably at the top of our game. The practical challenge in realizing an Empathic Civilization is a re-vision of our concept of community, one that effectively neutralizes our inborn xenophobia and expands our natural empathy to the global tribe gathering as technology relentlessly batters down borders. It won’t be easy, but it is clearly underway as we’ve seen in the outpouring of support for the people of Haiti. Equally importantly, moving forward will also require turning back, to rebuild the community we once shared with the living world, before it was debased into just another consumable commodity. Only now, as they disappear, are we beginning to fully understand how desperately we need our fellow passengers on the ark—materially, psychologically, even spiritually. When we come, as individuals and as a society, to understand this mutual interdependence and put it into practice, the Empathic Civilization will be born. It can’t come too soon.

Posted in Books and media, Politics, Science, Sustainability | Tagged | 5 Comments

Friday poetry: To the New Year

[Editor’s note: Admittedly we’re well into the new year, but it’s a new year for the Natural Patriot. We’ve heard from this volume by W.S. Merwin before, about which a reviewer has commented “Each of the 100-plus poems in Merwin’s meditative, playful, and lithely beautiful collection . . . begins with the word To and directly addresses some aspect of nature or the self, a feeling or an idea, a person, place, or moment.”]

To the New Year
W.S. Merwin

With what stillness at last
you appear in the valley
your first sunlight reaching down
to touch the tips of a few
high leaves that do not stir
as though they had not noticed
and did not know you at all
then the voice of a dove calls
from far away in itself
to the hush of the morning

so this is the sound of you
here and now whether or not
anyone hears it this is
where we have come with our age
our knowledge such as it is
and our hopes such as they are
invisible before us
untouched and still possible

Posted in Biophilia, Poetry | 1 Comment

The future of marine fish

[This article was an invited piece for the American Institute of Biological Sciences’ Action Bioscience online site. I had occasion to mull its content afresh recently after a visit to the University of British Columbia’s Fisheries Centre, whose “Sea Around Us Project” has synthesized a large body of data on global fisheries that have revolutionized our understanding of the state of the oceans.]

Marine fisheries supply a major source of protein to the world’s population, and they support an industry worth over $85 billion annually (1). People have fished since the dawn of human history, and overfishing impacts were apparent even in some primitive societies at relatively low population density (2). It was during the 20th century that fishing expanded rapidly to the global scale as a result of motorized vessels, inexpensive oil, refrigeration, increasingly global commodity markets, and heavy government subsidies to increase fleets (3). Marine fisheries now use 24–35% of primary production on continental shelves and in major upwelling areas, including bycatch (marine animals caught in the nets inadvertently)—a figure similar to the roughly one-fourth of the land’s potential net primary production appropriated by humans (4). Fishing has transformed the world’s oceans (5,6). Humans are now a dominant force of nature in the seas as we are on land.

Status of global marine fisheries

Currently, fishing pressure appears to be near—if not beyond—the ocean’s capacity to provide. Estimates based on fisheries catch data, which were corrected for over-reporting by China, suggest that global fish catch peaked in the late 1980s, and this number has remained flat or begun to decline since (1,9). The Food and Agricultural Organization of the United Nations (FAO) conducts the most comprehensive analysis of global fish stocks every four years, and recently reported that “the maximum wild capture fisheries potential from the world’s oceans has probably been reached” (1). The situation is reminiscent of society’s reaching the point of peak oil—although fishery production is at least partially a renewable resource.

What about individual fish stocks? In 2008, the FAO estimated that roughly half of the world’s 523 assessed fishery stocks are “fully exploited,” meaning that they are harvested at rates near their maximum sustainable limits, while another 28% are “overexploited or depleted,” meaning that they are being harvested at rates not sustainable in the long term (1). Even these numbers are uncertain and possibly conservative since they do not include many small-scale commercial and artisanal tropical fisheries; furthermore, these numbers do not include stocks that have already collapsed and been abandoned.

Fishing impacts have fallen especially hard on slow-growing predators. Typically, deep-sea fisheries, such as those targeting Chilean sea bass (Dissostichus eleginoides) and orange roughy (Hoplostethus atlanticus, right), have undergone an initial boom followed by collapse. In addition, many sharks, which are slow growing and have very low reproductive rates, have been reduced by more than 75% in recent decades (10-13). Impacts are not restricted to such species, nonetheless. At the community level, a wide range of data sources conclude that average abundance, size, and habitat quality have declined substantially in many regions of the world ocean in recent decades (6).

Marine biodiversity and fishery production

Long-simmering controversy about the state of world fisheries came to a head in 2006, when the scientist Boris Worm and colleagues reported the first comprehensive quantitative analysis of links between marine biological diversity and ecosystem services to human society (12). They concluded that disparate sources of data—from theory, controlled experiments, observed historical trends, and fishery catches—show a consistent pattern: marine ecosystems with fewer species, whether naturally or because of human impacts, have lower average productivity and stability. The greater fish productivity in more diverse ecosystems probably results in part from climate or resources that affect both diversity and productivity; however, such effects are less likely to explain the lower frequency of and faster recovery from collapse in diverse ecosystems (12). Although mechanisms remain speculative, the correlations of diversity with productivity and resilience probably result in part from a more efficient use of resources by diverse communities with broader functional capacity, and to the “portfolio effect,” whereby a diverse group of stocks (whether fish or financial instruments) is more stable in the face of environmental fluctuations than any single stock.

The primary message of Worm and his colleagues that links biodiversity to ecosystem services was overshadowed, however, by another point made in the press release associated with the paper’s publication, which was that if current trends continue, all currently fished marine species will have collapsed (fallen below 10% of their maximum historical harvest) by the middle of the 21st century. This claim generated worldwide attention and proved highly controversial. Much of the controversy centered on the use of catch data as a proxy for fish abundance. Critics pointed out, correctly, that catches may fail to track fish abundances because of changing markets, social factors, and management regimes.

While such factors can obscure population trends for individual stocks, however, no compelling evidence has been suggested that globally averaged catch data significantly misrepresent trends in global fish abundances. Indeed, one analysis concluded, “declining catches are an indication of declining stocks. Assuming otherwise would imply that all fishers or regulatory agencies in large marine ecosystems like the Mediterranean drastically reduce fishing of a species without the stock being in decline. Except for the World Wars, we are not aware of any such case” (14). This same analysis showed that the number of new stocks entering global fisheries declined steadily over recent decades and that if current trends continue, the world’s reservoir of unexploited fishable stocks will be exhausted by 2020. This general trend is consistent with the FAO’s conclusion noted above. It seems reasonable, therefore, to conclude that we are at the threshold, or even beyond, the world ocean’s capacity to provide fish and that significant changes are necessary to maintain this service over the long term (15).

What do we want from the oceans?

Different parties can legitimately see statistics on the sizes of fish populations as showing a glass half full versus half empty. Beyond the disagreement about the data, debate involves fundamental values (16): What do we, as a global society, want from the oceans? Are we content to treat them as essentially a planetary factory farm for inexpensive fish fillets (and mines and highways)? Or, do we want something more—a multifunctional, resilient ecosystem that provides a range of ecosystem services, and a stable reservoir of biodiversity, as well as commodities?

The consequences of different values can be seen most clearly by considering how we decide what the optimal abundance of fish in the ocean is (16). Fisheries professionals tend to see the ocean in economic terms as a producer of commodities, proteins, and jobs. They emphasize that fishery management explicitly aims to maximize long-term fish productivity (the amount of fish produced per year), which in theory occurs when a population is reduced to roughly half of its equilibrium biomass. This goal is called the Maximum Sustainable Yield (MSY), and it is the basis of much fishery management legislation. By this view, fishery management has historically aimed to reduce fish populations to somewhat less than half of what they would be without fishing; although more recently, a precautionary approach has begun to advocate less extreme harvest (15).
How do we reconcile economics with ecological diversity?

Critics of this exclusively economic approach, in contrast, tend toward a more holistic view of the oceans, and they emphasize the intrinsic value of biological diversity and its important, albeit poorly quantified, role in producing non-market ecosystem services such as waste processing, climate regulation, and carbon cycling (17). This idea has recently begun to penetrate fishery management in the goal of “ecosystem-based management,” which aims for integrated, place-based approaches to manage the suite of human activities and interrelated ecosystem processes in a given area simultaneously (18,19). By this view, a long-term reduction by half, of multiple fish populations, is likely to have far-reaching consequences for the rest of the ocean ecosystem; although, these consequences are only now becoming well understood (20-23).

The future of marine fisheries

While evaluating the future of fisheries depends in part on what we as a society want from the oceans, several issues complicate the more optimistic predictions:

1. Continued harvest stability is questionable. The theoretical target of MSY is exceeded in fisheries routinely— sometimes severely so (3); yet, it is still poorly understood how such sustained high harvest levels affect stock stability in the face of natural and anthropogenic (i.e., human-derived) disturbances. Increasing evidence shows that both individual fish populations, and the more complex ecosystems in which they are included, can respond in a non-linear fashion to exploitation and other pressures; but these may cross a tipping point into a new stable state that is resistant to attempts to restore it to the original state (24,25).

2. Demand will continue to increase. Global human population is increasing rapidly; it is likely to roughly double before stabilizing at an estimated nine billion. The average per capita resource use is increasing even faster, which means that the human population’s already large demand for fish and other resources will undoubtedly increase a great deal in the coming decades (6,26).

3. Current fishery projections are not all-inclusive. The more optimistic projections of the future of world fisheries are typically based on extrapolating a handful of examples of well-managed fish stocks within the territorial waters of rich, stable, and well-governed western democracies (27). This is a non-representative sample of the world’s fisheries, nonetheless, and there will surely be formidable hurdles to spreading good management models through the rest of the world—particularly in the face of growing human population, per capita resource use, environmental change, and probable political instability resulting from global climate change interacting with these factors.

Indeed, the future of marine fisheries can be seen as a microcosm of the future of human society generally. Some basic questions include:

* How important is abundant and inexpensive food, and the jobs associated with providing this food in the short term—relative to the many other tangible and intangible benefits that we receive from healthy ecosystems over the longer term? It is increasingly clear that many of these benefits cannot be achieved simultaneously.

* How important is the availability of abundant fish now relative to long-term maintenance of a functioning ecosystem that can provide fish (and other ecosystem services) to our grandchildren and beyond?

* What sacrifices, if any, are we willing to make now to ensure the long-term stability of that resource?

A recent consideration of how values influence the conflicting attitudes toward fishery management divided the major stakeholders in ocean ecosystems into consumptive users (i.e., fishers), government, and non-governmental organizations (NGOs) (16); however, they could as reasonably be characterized into present users and future users. When we consider the interests of “users” of the ocean two, three, or four generations down the line, the interests of fishers and governments and others become much more closely aligned. Policies that maximize fish production now—but endanger the production of fish and other important ecosystem services in the next generation—would not benefit tomorrow’s fishers or any of the other citizens represented by governments and NGOs.

Potential solutions

As is true of environmental challenges generally, there is unlikely to be a single solution to making world fisheries sustainable. Effective marine conservation and management will involve several parallel approaches, among which three central proposed solutions should be mentioned.

1. Ecosystem-based management (EBM) recognizes and seeks to incorporate the complex interactions of fish stocks with one another and with the broader ecosystems that support them into fishery management (28). A related, more specific concept is the ecosystem approach to fisheries (EAF)—a form of fisheries governance that draws its conceptual basis and operational approaches from both conventional fisheries management and ecosystem management (29). The basic elements of both approaches involve maintaining single-species exploitation rates lower than would produce MSY and avoiding by-catch of non-target species. Thus, both EBM and EAF depart from traditional fisheries management, which focuses on maximizing productivity of individual stocks in isolation. Because complex indirect interactions are the rule in ecosystem dynamics, and are often unpredictable, EBM ascribes particular importance to precautionary measures that aim to avoid depleting stocks. Ecosystem-based management has been mandated by the Great Barrier Reef Marine Park Act of 1981, in Australia, the Magnuson-Stevens Fishery Conservation and Management Act (1996, reauthorized 2006) in the USA, and the International Convention on the Conservation of Antarctic Marine Living Resources.
Spatial planning focuses on overall human use of marine resources.

2. Marine spatial planning is related to the concept of ecosystem-based management, and focuses specifically on better integrating management of the sundry, and often conflicting, human activities in the sea (30,31). Many of the challenges facing the oceans derive in part from uncoordinated governance. For example, fishing, mining, oil and gas extraction, marine mammal conservation, shipping, and other activities in U.S. territorial waters are regulated by more than 20 separate agencies in isolation from one another. Fixing this situation was a key recommendation of both the U.S. Commission on Ocean Policy and the similar Pew Commission reports in 2004. Zoning has been used routinely on land for many years. Marine spatial planning can strategically site compatible activities together and separate incompatible ones, and it seeks to accommodate the plethora of potentially conflicting human uses such as recreation, fishing, and energy generation in an optimal way. Ultimately, marine spatial management must also coordinate with activities on land to develop adjacent coastal watersheds responsibly; to reduce inputs of toxic contaminants and nutrients; and to mitigate and adapt to human-induced climate change.
Incentive programs involve cooperation.

3. Improved incentive systems for sustainable fishing include, most recently, an exploration of dedicated access such as catch-share programs, as well as more effective governance at national and local levels (32). Fundamentally, managing fisheries involves managing the people that fish, which can involve both sticks (such as the restrictions historically used in management) and carrots (such as financial incentives to switch to less damaging gear). The latter involves appropriate incentive systems for making fishing sustainable (33). One such promising approach that is gaining momentum involves Limited Access Privilege Programs (LAPP’s), also known as “catch shares,” in which a secure share of fish is allocated to an individual fisher, community, or association. The rationale is that because the shares are allocated before the season begins, fishers know how much fish they are allowed to harvest that year, and so there is incentive to do it efficiently, rather than in the counterproductive and expensive race to get the most fish possible that results under the often complicated, historic regulations. On the other hand, LAPPs limit access by definition, and therefore, these entail many difficult decisions about how shares are allocated, as well as the potential impacts of consolidating effort on both the environment and fishing communities.

Finally, no account of the future of fish would be complete without considering the rapidly growing global aquaculture industry, which accounted for more than a third of total global fishery production in 2006 (1). Although aquaculture has been suggested frequently as a solution to the environmental impacts of ocean fishing, and it will surely be part of such a solution, the answer is not simple. Many farmed fish proposed for large-scale ocean ranching—notably salmon and tuna—are carnivorous. These operations can cause even greater harm than wild capture fisheries because such apex predators require large quantities of food, which comes from forage fish harvested from the ocean, and also because of their prodigious waste output, and the risk of disease and parasitism they pose to wild relatives (34,35). Moreover, farmed tuna are taken as juveniles from wild populations but are not recorded as catch in capture fishery statistics.

Thus, if aquaculture is to be part of a sustainable long-term solution, rather than part of the problem, it will need to focus on species low on the food chain such as catfish and tilapia, avoid transmitting diseases and genetic defects to wild fish, and produce minimal waste and habitat destruction. As in wild capture fisheries, achieving these goals requires effective management and policies that can adapt to a rapidly changing world.

Literature Cited

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  3. Pauly, D. et al. 2002. Towards sustainability in world fisheries. Nature 418 (6898): 689.
  4. Pauly, D. and V. Christensen. 1995. Primary Production Required to Sustain Global Fisheries. Nature 374 (6519): 255.
  5. Jackson, J. B. C. et al. 2001. Historical overfishing and the recent collapse of coastal ecosystems. Science 293 (5530): 629.
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  10. Baum, J. K., D. Kehler, and R. A. Myers. 2005. Robust estimates of decline for pelagic shark populations in the northwest Atlantic and Gulf of Mexico. Fisheries 30 (10): 27.
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  14. Froese, R., A. Stern-Pirlot, and K. Kesner-Reyes. 2009. Out of new stocks in 2020: A comment on “Not all fisheries will be collapsed in 2048.” Marine Policy 33 (1): 180.
  15. Worm, B. et al. 2009. Rebuilding Global Fisheries. Science 325 (5940): 578.
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Posted in Biodiversity, Oceans, Sustainability | Tagged , , , , | 1 Comment

Turning pollution into fuel

To ease into the groove of the revived Natural Patriot, I’m starting with the easy stuff: some of the arguably noteworthy developments that transpired during the touch-and-go months of social-networking coma.

First up: the latest on our algal biofuel project, which I have reported on before here and here. Having spent a good part of my adult life pontificating about what’s wrong with the world, I came to the conclusion a few years ago that I couldn’t really look at myself straight in the mirror without trying my hand at actually doing something of substance in an attempt to fix it.  So, long and circuitous story short, I pitched in with a motley group of scientists and entrepeneurs in a project aimed at (here comes my nascent snake-oil salesmen language) putting biodiversity to work.

The project involves harnessing humble wild algae in a natural, low-tech process that couples clean-up of nutrient-polluted water with production of a feedstock potentially useful as biofuel. The operational word here is potentially. We already know that the process, developed >30 years ago by Dr. Walter Adey of the Smithsonian, scrubs nutrients out of water beautifully, efficiently, and pretty cheaply. It’s actually been used in tertiary water treatment plants and in aquaculture operations.

But in the past the heaps of algae produced in the process were simply composted or, in some applications, fed to farmed tilapia (pretty ingenious, that).  The new alchemical angle is to spin them into “green gold” — algal biofuel. “Turning pollution into fuel” is my pitch when I wear a suit and talk to people about this. It’s become my sound bite since it came to me (on a flaming pie, I’m tempted to say) late one night as I was mulling over a presentation to a group of academics and industry people about this stuff.

So last fall a group from the Clean Skies Network got wind of our effort and came to interview us. Here’s the footage — note that you may have to crank the volume a bit to hear the interviewer (Not sure why the Youtube still image makes me look like such a doofus . . .):

Posted in Science, Sustainability | Tagged , , | 5 Comments