Finding 21% of Nemo

Few examples linking the global economy with the global environment are as clear and direct as overfishing. A recent article in the journal Conservation Biology highlights this link: as incomes in mainland China have increased, consumers have exerted a greater demand for live fish from tropical coral reefs.  

The study focuses on declines in spawning aggregations, which are critical because they are large gatherings of many fish in a small area – ideal for successful reproduction, but also easy pickings for harvest.  And unlike North American salmon, whose harvest is heavily regulated or restricted as they gather to spawn, many of these spawning fish are going to feed the growing demand for them in restaurants.

The authors were able to collect the most data for Nassau grouper, a large fish that takes years to reach sexual maturity and a popular dish in some parts of the world.  Spawning aggregations of this species were reduced to the point that it is now classified as threatened.

More broadly, the authors found declines in 79% of the aggregations for which there were sufficient data.  The declines noted in the study are an example of what fish biologists call recruitment overfishing: taking so many fish that the population cannot replace itself.  Combined with the growing trend of harvesting fish before they are sexually mature, these practices destroy the natural capacity of reef fish to provide enduring, sustainable harvests.

Click here to read an abstract of the article.

Ocean acidification’s newest foe: fish poop?

Another reason to appreciate marine fish: they produce carbonates within their intestines, and these carbonates are vital for marine life but disappearing through global warming.  

One of the by-products of global warming is ocean acidification, or the decrease in pH throughout the sea. This acidification harms the ability of organisms as diverse as algae, corals, and shellfish to form calcium carbonate skeletons.

In the latest issue of the journal Science, researchers report that 3 to 15 percent of all carbonate in the oceans is produced in the intestines of bony fish and then excreted.  Additionally, the carbonate excreted by fish dissolves in the water more readily than other sources.  Another major source of carbonates comes from the shells of dead organisms, but these tend to dissolve in the depths of the oceans, while fish-produced carbonates dissolve in the upper layer.

So as increased carbon dioxide makes oceans more acidic, marine life has a new ally in the form of fish feces. (In the interest of complete accuracy, the carbonates are formed in fish intestines but are not actually feces – only roommates with feces.)

An abstract of the article is available here.

Sustainably delicious

Taking a page from farmers, American fishermen are offering their local communities shares in their catch through community supported fisheries.  By purchasing a share at the beginning of the season, consumers get an allotment of fresh seafood each week directly from the folks on the boat.  It’s a promising example of how sustainability, buying locally, and supporting small businesses can interact.

While less widespread than community supported agriculture, coastal communities like those in  North Carolina and Maine can enjoy the benefits of tremendously fresh seafood while also doing something good.  Here’s a quick run-down of the benefits this model has over more traditional seafood harvest and distribution:

First, it’s a good way for small-scale fishermen to have a more reliable and more livable income.  As fish stocks worldwide are declining, smaller operations in traditional fishing towns have suffered; most of the growth in the industry comes from huge ships operating in remote and dangerous seas.  Community supported fisheries provide local boats money at a critical time and can provide fishermen with a higher price for their catch than merchants.

Second, the structure promotes sustainability – to an extent.  The history of commercial fishing has largely failed to ensure fish harvests in a given area remain abundant from one generation to the next.  But community supported fisheries promotes a greater bond between consumers and local fishermen, and also gives fishermen a greater sense of economic security – both good steps to prevent overharvest.  While there’s no guarantee all such operations will be sustainable, it at least provides the right kind of environment for it to succeed.

Lastly, community supported fisheries are changing the way people view seafood.  It’s much easier to be disconnected from ocean life because it’s often out of sight, miles from shore and yards beneath the surface.  Connecting consumers with the changes in seafood with seasons, weather and climate emphasizes the importance of maintaining healthy oceans in the same way gardening helps people realize how the natural world affects their plants.  Out of sight usually means out of mind – and for the oceans, that’s usually bad news.

It’s good for fishermen, better for the sea and good news for those who like their seafood as fresh as can be.

Predicting climate change’s impact on agriculture

At a global scale, a warmer climate does not provide better growing conditions for food crops.  In a study published in the current issue of the journal Science, the IPCC’s climate projections for the 21st century are compared with historical examples of warm summers to show the destructive impact of high temperatures.

The authors (an atmospheric scientist and an economist) show the IPCC’s models indicate a strong likelihood that by 2100, the median summer temperatures in many areas will be equal to or higher than the warmest summers during the past century. Essentially, what was an exceptionally hot summer in the 20th century will be standard at the end of the 21st.

The authors discuss warm years in the past 100 years as an example of agriculture’s general response: in 2003, a heat wave in Europe sent production of key grains down by double digits in France and Italy, and 1972 saw a general failure of the wheat harvest in Russia.

Additionally, it’s important to realize a warmer summer isn’t just a gentle increase in temperature – it’s often the result of periods of intense heat which can kill crops before they’re mature.  Perhaps more important is the relationship between warm weather and precipitation, since drought and heat waves are a fatal combination. Precipitation patterns also change as temperatures increase, often resulting in hotter temperatures with more sporadic rainfall.

On the whole, the study’s outcome is bleak, particularly for tropical regions already stressed by increasing populations and degraded land.  Here, as for most of the rest of the world, a warmer planet is more likely to produce scarcer harvests than abundant harvests.

To read the abstract of the article, click here.

Evolving against our best interests

Call it survival of the littlest.  A new study published in the Proceedings of the National Academy of Sciences provides evidence that harvesting wild populations of fish and wildlife can be counterproductive – for the animals and the people who hunt them.

The study is troubling because it shows how harvesting the biggest individuals in a population can lead to future generations that are smaller.  It’s also a reversal of the normal selection pressure – predation – in which the youngest (and sometimes oldest) members are eaten most often.  When human pressure is intense, it creates an evolutionary force producing the opposite of what we want: smaller populations less capable of replenishing themselves.

For instance, many game species like bighorn sheep have a minimum size restriction, so only the largest individuals can be taken.  The same pattern is often found in commercial and recreational fisheries, where fish have to be a certain minimum length to be legally harvested.  When this pressure is high enough, it has the effect of selecting against larger (and typically older) individuals, leaving the smaller and younger individuals to survive and reproduce.

Commercial fishing usually harvests the larger members of a population.  This type of pressure favors fish that grow to a smaller size, because smaller fish aren’t harvested as much – so they survive and reproduce.  But in many fish species, smaller females produce far fewer offspring than their larger and older counterparts.  So harvesting the biggest individuals, while productive in the short term, can lead to future harvests with smaller and fewer individuals.

While these trends have been noted before (particularly for fish, as noted in an earlier post), the study examines a wide range of organisms in which the negative impacts are occurring.

The article’s abstract is available on the journal’s website.

Greening the stimulus

There are two things the proposed economic stimulus package should do, in the very broadest sense:

1) foster economic growth

2) foster lasting economic growth

Sound obvious?  Not necessarily, and that’s where a healthy dose of ecology and science can be valuable.  

American prosperity in the last decade and the American recession of the past year seem to hinge on the rapid increase of real estate and complex, poorly-regulated financial arrangements based on homeowner debt.  In other words, there was a great deal of wealth created without any tangible goods, services, or knowledge behind them.

During the same decade of sky-rocketing American home prices, the rest of the world was entering a period where the competition for limited resources (oil, natural gas) and the effects of using those resources (climate change, pollution) became the greatest threats to the well-being of humanity as a whole.  So as American politicians consider the best way to stimulate the economy, creating economic growth based on tangible goods and services that increase our quality of life seems a sensible solution.

What does this have to do with science and ecology?  First, we need a solid grasp on ecology to understand how our choices impact things like the climate, our agricultural lands, and the oceans.  This doesn’t mean the stimulus should include gobs of earmarks for ecological studies; instead, we should view the stimulus package through an ecological lens to make sure it helps get us closer to a sustainable future.

Secondly, none of the natural resources on earth offers the same riches as our scientific potential.  And if Americans are going to produce some sort of goods and services they can sell abroad, the smart money says it will be the result of accumulated knowledge based in the minds of its scientists and entrepreneurs.  

Making the stimulus more green isn’t just a hip idea – it might be the smartest way to create growth and to begin tackling the biggest challenges we face in the 21st century.

A farmer, a biologist, and the future of civilization

Our ability to feed ourselves rests on the ability to nourish the soils that provide the plants that we and our food animals eat.  While many other issues are important, there are probably none as immediately linked to our survival as this.

For this reason, a recent op-ed discussing soil and agriculture by a farmer and a plant biologist was much more interesting than it might sound.  Along with supplying clean freshwater, managing soil and agricultural land is the bedrock of our civilization – and their viewpoint is well worth the time it takes to read.

It’s also a good illustration of the importance of ecology in our daily lives.  By understanding how plants, soil, and erosion are related, we can better protect the precious soil that nourishes us.  Crafting smart policies in farm bills to help this process are an important part of this, and ecologists and farmers have a large role to play.

President Bush, conservationist

Give credit where it’s due: in the last days in office, President Bush has cemented his legacy of marine conservation.  In designating nearly 200,000 square miles of Pacific Ocean and islands a marine national monument, Mr. Bush has preserved a massive, vibrant chunk of one of the world’s most overlooked and threatened ecosystems.

Globally, oceans are being pushed to the brink by overfishing, which is changing the way these ecosystems function.  The announcement of the monument is a bright spot, for several reasons:

- Marine conservation has lagged behind terrestrial conservation.  By preserving such a wide swath of habitat, the United States has taken an important step to increase the amount of oceans protected globally.

- The monument fosters species threatened elsewhere and preserves intact populations of large predators.  In degraded areas, most of the large, predatory species have been severely depleted.  Sharks and other vital species are present in good numbers; it’s critical to preserve such areas where the natural balance of species is intact.

- The area protected includes some of the most productive spots in the Pacific.  Though immense, large portions of the Pacific Ocean have low densities of marine life.  The monument preserves a bountiful area.

It’s not the first time Mr. Bush has acted with foresight: in 2006, he created the slightly smaller Papahānaumokuākea Marine National Monument.  Together, the two monuments are probably the most important contribution any president has made to oceans and marine life.  Environmental organizations like the Pew Environmental Group were quick to praise the action.  

Click here to read the account in the New York Times.

When mundane becomes exciting: Dr. Lubchenco goes to Washington

Like an iPod hidden in a pair of socks, sometimes exciting news comes wrapped in a less-than-exhilarating package.  An incoming president’s selection of a person to run the National Oceanic and Atmospheric Association (NOAA) usually garners the same amount of excitement as, say, a pair of tube socks.  But when Jane Lubchenco was announced as the new administration’s pick for the job, it caused a stir.

Lubchenco, a professor at Oregon State University, has an impressive background: former president of the American Association for the Advancement of Science, a 1993 MacArthur fellow, and a highly cited scientist.  But it’s more than just a matter of appointing another brilliant mind to a government post.  

It’s the combination of Lubchenco’s knowledge, policy chops, awareness of global issues, and symbolic change the selection represents that makes this otherwise bland announcement newsworthy.  

As a scientist, Lubchenco has been heavily involved with helping scientists become important contributors to public affairs.  As the person tapped to look after oceans and the atmosphere, two tremendously vital realms of our existence that get scant public attention, the ability to communicate science to lawmakers and the public is a useful skill.  

At a time when global issues like climate change and depleted fisheries are reaching a critical point for billions of people, scientists are going to play a large role.  Since America is home to the best universities and many of the world’s best scientific minds, Lubchenco’s selection also sends the message that America is going to be an active player in this struggle.

NOAA is part of the Department of Commerce, which has helped to create the impression that marine life is merely something to be bought and sold.  This ignores the ecological complexity of oceans – and without knowledge of how the ecology of marine life operates, there’s no way to preserve the sources of seafood upon which hundreds of millions of people (and huge parts of the global economy) depend.  Lubchenco’s nomination means America is starting to take a long-term perspective on the increasingly diminishing capacity of the oceans to feed us.

A great scientist with a solid grasp of communicating with the public and running the world’s largest scientific organization – you don’t need to be a scientist or a policy wonk to appreciate a smart choice like that.

Farming biodiversity

We use vast swaths of our planet to grow the food we eat.  What impact does that have on the species in and around that land?

It’s a simple question with huge implications for biodiversity.  In South Asia and Southeast Asia, it’s also an urgent question, as increasing agricultural demands make the tropical forests there among the most threatened in the world.  Are the species there doomed, or is there hope for balancing biodiversity and increased agriculture?

A study in the Proceedings of the National Academy of Sciences suggests there’s hope.  The study’s authors examined bird diversity in southwestern India, a region with high biodiversity and an extensive history of agriculture.  Where arecanut palm is grown,  90% of the bird species found in neighboring intact forests were also present.  In contrast, peanut fields and rice paddies have essentially no native birds or other wildlife during parts of the year.

Beyond showing the coexistence of birds and food plants, the study is important because it helps to identify the factors that help to promote this coexistence.  The authors point to the vertical structure arecanut palms provide, but which rice paddies and peanut fields do not.  (In other words, rice paddies are essentially two-dimensional, whereas acrenut palms are much more three-dimensional, like native forests.)  Additionally, farmers rely on bordering forests to provide mulch for their crops.  There’s an incentive to preserve these forests, and native species use this habitat.

The article also highlights critical ecological issues that aren’t explicitly tied to global warming.  If we manage to tackle climate change, there are many other problems facing a planet with a population of six billion.  Understanding how we can produce the resources we need to survive without destroying everything else is one of those big problems.  This paper provides a step in the right direction.

Click here to read the open access article.