Baltimore: Poster Child for the Tigris and Euphrates?

Following is repeated with minor edits from this week's lesson for one of my classes.


In the 1980s, I spent a year investigating aquatic ecosystems of small streams in watersheds occupied by the city of Baltimore, Maryland. The study was a sort of scoping effort designed to help identify urban ecosystem indicators of impairment and restoration potential. We measured the abundance and diversity of sediment-dwelling invertebrate and finfish communities, and characterized associated habitat quality at each study site along a gradient of urban development intensity, from very rural to inner city.


Among our findings was a tidbit relevant to our lesson this week. Throughout the various sub watersheds and tributary stream networks, there were population remnants of many surprisingly sensitive species. In other words, where habitat patches remained, biodiversity reflected same, even when the chunks of quality habitat were small and very isolated. To me, this indicated surprisingly high potential for restoring healthier ecosystem structures and processes. There is nothing inherent about the watershed or the landscape excluding most species. The provision of appropriate habitat will bring them back. In my career since, which has been largely devote to the assessment and restoration of urban ecosystems, I have tested this hypothesis and it generally holds true. [While the technical details of the Baltimore work are not particularly relevant here, in case you have a more-than-casual interest you can find a couple of reports from the same program a decade later when the investigators had a rigorous grasp of methods and data analysis at http://www.dnr.state.md.us/irc/docs/00007773.pdf and
http://www.dnr.state.md.us/irc/docs/00008954.pdf .  One report is for the more intensely urbanized waterways within Baltimore City, one is for the suburban-to-rural surrounding county. If you examine the tables listing fish species and their frequency in the samples, you will see my point. A number of species are represented very infrequently. But they do exist, and where habitat is appropriate they cannot only survive, they can thrive.]


The Shatt-al Arab marshes at the Arabian Gulf delta of the Tigris and Euphrates rivers is by light years the largest and most important wetland in the arid Middle East. The extensive reed marshes have existed for millennia, and many animal species evolved in-place and are characteristic. In addition, the marshes are crucial for feeding and resting during the enormous bird migrations that move from Africa to Europe and central Asia via Arabia and the Middle East. Furthermore, the energy fixed in the biomass of the reeds is broken down as detritus and the nutrients and energy passed along in turn to the marine ecosystems of the Gulf. In other words, the high levels of fish and shellfish production, and the reef life and rich fauna of mud and sand shallows throughout the Gulf, depend on the Shat-al Arab for trophic support. [Years ago in a souk in Kuwait I found a food shop selling fist-sized chunks of a hard, crumbly, yellow material. The texture was dry and chalky, but the flavor was oddly rich and slightly sweet. My Arabic being abysmal, and the shopkeeper’s English little better, I could not gain any traction on identifying the stuff. In typical fashion, when it became apparent that something interesting was happening, other shopkeepers, bystanders, and shoppers joined us, some whose English was excellent. I was able to establish that the material was used in soups, and often as a restorative for sickness or fatigue. It also devolved that it was a rustically old-fashioned ingredient—younger people in the market had never eaten it. But nobody could explain what it was or where it came from. I bought a chunk and took it to show the students in the class I was teaching at the Kuwait Foundation for the Advancement of Science. They gave me the same info—soup, sick—but also didn’t know what it was. A couple of them called their grandmothers overnight and the next day revealed that it was pollen collected from the Shatt-Al Arab reed marshes. I later found it to be generally available at at least a shop or two in any market, usually being purveyed alongside a similarly shaped and textured bone-dry chalky residue made from camel’s milk cheese or yogurt.]


For various political and military reasons the marshes, at the apex of the Gulf where Iran, Iraq, and Kuwait converge, are in a strategically vulnerable location. A useful history of the regional environment and its strategic importance is available at


 http://www1.american.edu/ted/ice/iraniraq.htm . 


Note that the material at the ICE web site, which is based on events of the Iran-Iraq war of the 1980s and published in 1998 according to the text, has, of course, been overtaken by more recent events. A thorough and up-to-date summary of the region, its environmental issues, and their relationships to various military conflicts written by Steven Lee Meyers was published last summer by the New York Times. It is available at: 


http://www.nytimes.com/2010/06/13/science/earth/13shatt.html


and is the most objective [if you punch “Shatt-al Arab” into a browser, a substantive proportion of the hits will involve organizations with specific, not necessarily scientific, perspectives] and current summary I’ve been able to locate. 


In brief, the waterways and wetlands of Shatt-Al Arab have been in gradual decline for a long time. Upstream waters were being committed, saline waters were intruding, pesticides and industrial chemical inputs were at risk levels in at least some locations, and some of the resources were being overharvested. However, during the Iran-Iraq war, things took an acute turn. Iraq re-engineered the hydrologic system to deliberately dry most of the area. The wetland character immediately altered, and most of the region shifted from an aquatic to an incipient and developing terrestrial system. Reedbeds declined, water disappeared, mud dried. It was a wide-scale environmental change of enormous consequences, affecting European songbird populations, Gulf fisheries, and most painfully, perhaps, the indigenous people whose culture was closely attuned to the big wetland.


The regional hydrology was re-plumbed following Saddam Hussein’s ouster to attempt to convert it back to wetland. But ecosystem recovery has lagged. Pre-war constraints—lack of fresh water flow, salt water encroachment, agriculture, and possibly transport of chemicals and sediments into the area from upstream—not only continue, the magnitude of some has increased. In addition, changes in landform occurring while the water was cut off may take a long time to re-equilibrate to the regional wetland character. 


But restoration has at least begun. And the message from Baltimore’s intensely urbanized ecosystems is encouraging. As habitat quality recovers, much of the biota has the potential to follow suit. It will take time, there will be difficulties, and if regional constraints (such as low fresh water throughput) are not released, ultimate conditions may be far from ideal. But to the extent that hydrology and other physical and chemical conditions are restored, the ecological services flowing from the biology will again accrue. 

Rails on the Ropes--From Today's Lesson in one of my Classes

Rails are small quail- or chicken-like birds evolved primarily for stealthy stalking on muddy sediments in grassy wetlands. They have sharp bills and sharper eyes that can spot movement of the small invertebrates—amphipods, crabs, insects—that are their preferred food from meters away. It takes just a moment for them to be in position to pluck the meal from silt or stem.

Above is an image of a clapper rail, a rather typical species that lives in North American coastal marshes [slurped from the web, credited to the New York Public Library, I believe].

Most rails look hopeless in flight. They vastly prefer to run, but if pressed they clatter up out of the grass, thrashing noisily at the air, make headway for a few meters, and drop gratefully back to the mud to dash away. Despite their inefficient aerial skills, many species make long migrations. One can only speculate that they are exhausted at the end of the trip and need to bulk up on extra helpings of seafood to recover.

Many bird species, when they reach new habitat where large, active predators are absent or rare, lose the power of flight. Rails seem to do so with particular aplomb. As rails populated successive islands and atolls across the Pacific where the only predatory threat was the occasional overflight by a frigatebird, they settled in, became flightless, and went to work gobbling shrimp and fiddler crabs.

Flightlessness has its drawbacks. If conditions change—i.e., predators suddenly show up—you may be in trouble. Poster child, of course, is the Mauritius dodo [Raphus cucullatus], large, flightless, and clumsy. Its flesh was tough and didn’t taste very good, and wasn’t favored for ship’s provisions. However, between the occasional sailor’s meal [perhaps when they couldn’t hunt down more edible components of the avifauna] and the rats, cats and pigs that showed up with the vessels, it only took a few decades to go extinct [the Wikipedia entry is complete and well-referenced, see http://en.wikipedia.org/wiki/Dodo ].

The Laysan Rail [Porzanula palmeri] was native to its namesake island and one or two associated atolls in the northern Hawaiian islands. Discovered [by westerners] and described in the late 1800s, it went extinct on Laysan a few decades later after rabbits liberated by the guano diggers who lived on-island decimated the vegetation the birds depended on for shade and cover.

Laysan Rail. Also slurped from the web. 

However. In a move anticipating modern methods of threatened species management, a colony of Laysan Rails had been established on Midway Island, another on nearby Pearl and Hermes Reef. The latter was decimated by a series of typhoons in the 1930s. That left the Midway population, by all accounts thriving, as the basis for the future of the species.

Bummer. By the time the runways were constructed and fought over and combat finally ended, the Laysan Rail was gone. Likely no single factor took the last survivors. Rats, cats, habitat destruction, possibly the occasional cantonment meal. There was a lot of pressure on the little guys. There was hope well into the 20^th century that there might be remnant populations, if not on Midway, then elsewhere in the leeward Hawaiian Islands. I believe that hope is mostly dissipated, and the Laysan Rail has taken its place with the dodo as a cautionary tale for those of us concerned with biodiversity in the 21^st century.


If you got a few moments on your hands, please surf on over to:
http://docviper.livejournal.com/
http://endoftheworldpartdeux.blogspot.com/
http://theresaturtleinmysoup.blogspot.com/


And thanks for stoppin' by!

Sustainable Consumption

Many people think [without actually “thinking”, near as I can tell] that easy paths to sustainability run down the Vegetarian Road and the Local Produce Highway. Seems like a no-brainer, no? You don’t feed produce to animals, you eat it instead and you save something like 75% to 90% of the calories that would otherwise vaporize metabolically. You grow your food locally, you save all the fuel, infrastructure, and carbon footprint invested in getting it your store from Chile or Mexico or Morocco or wherever.

Milkweed bug nymphs. These

babies (literally babies) suck

liquid from the plant without

doing it any real injury.

Like most easy answers, a lot of this is complete bullshit. If you’ve ever been to arid parts of the Middle East, eastern Asia, or North America, or alpine territory anywhere, you’re looking at a lot of real estate that ain’t growing edible plants at all, much less at a scale that would help support human life. But it CAN grow goats, sheep, cattle, hares, rabbits, camels (including Andean species like lama, alpaca, etc.), cui (cavy or guinea pig, eaten spiced and deep fried in the Andes), swine, armadillos, poultry…oh hell, you can grow all sorts of animal biomass on such ground. Converting otherwise unproductive land into a real contributor.

Short-horned grasshopper. The

quintessential chewing herbivore.

These do indeed cause overt damage

to the plants, but the plants don’t

necessarily mind.

Similarly, the belief that local production nets sustainability is simply wacky until you account for differences in the inputs of time, matter and energy needed to produce in different areas. In other words, if you are going to grow meaningful quantities of wheat in Switzerland, or grapefruit in New Jersey, or rice in England, you’re going to have to input a SHITLOAD of matter and energy to get it done. I’m guessing, in these cases and others, that you’re going to have to input more time, matter and energy than the total needed to Indonesia plus ship it. Sustainable? I don’t think so. Net sustainable? No smeggin’ way.

Here’s a cool one. These are the

tracks of leaf miners. Mostly these are

moth and fly larvae that burrow through

the leaf tissue, feeding (and defecating)

as they go.

Anyway. Back in the days when Ecologists were Systems Ecologists, we tended to discount herbivory. Except for the grassland steppe ecosystems of central Asia and North America and the open oceans, most of the energy action—from half to over 90%--went down via decomposer food webs.

Some insect—I have no idea

beyond that—set up this nifty

little rolled up ball of Christmas

fern fronds and defecated all

the hell inside it. And kept it

rolled up in there until I

split it and photographed it.

Cool!

All that structural material in forests (tough, leathery oak leaves, stiff, spiky bark, hard and mostly hollow wood) had to be processed through invertebrate guts and slathered with extracellular digestive enzymes by microbes to make it amenable.  

Nectar-feeding butterfly. No

nutrition problems here, at least once you find the sugary stuff and get your mouthparts into it. Easy to digest, massive energy content? Recipe for trophic success!

It’s not completely clear to me why more energy isn’t shunted down the road of liquid-feeders. It really is on the order of 10% or so. Not much more even under the best circumstances. I’ve seen people claiming that it’s an evolutionary problem—too much water and not enough physiological adaptation. But I’m not sure that makes sense Hell, if a few organisms can adapt to do it, more could. I must be missing something.

Oh. Here’s the real key to the

herbivory shunt on the food web. This katydid turned up dead under the porch light one afternoon. Note

it’s intact and complete.

The late Richard G. Wiegert, guy who had life licked and spent summers in Yellowstone, spring and autumn on Sapelo Island, and winters (only) teaching in Athens, Georgia, had a problem. His energy flux models of Sapelo tidal marshes couldn’t account for 19 grams of carbon per square meter per year. This was a hell of an issue for Dick. Pissed him off for his entire career.

And the next morning? This katydid carcass was sliced and diced. Carved, sauced and served. Now THAT is a food

web in action!!!

Bill and I found the answer. One warm afternoon on Sapelo, we were out in the marsh for some reason, just kind of enjoying the sun and the smell of the grass and the mud and the water. It was quiet. Too quiet. And along with the sound of the breeze and the scent of the air moving gently up from the sediment surface, there was a clearly audible “Crunch. Crunch. Crunch.” We looked around to investigate.

One last photo. A monarch

butterfly larva chomping 

away in an Eastern Shore

garden in late summer. All is

good in the food web!

And were shocked. This was the second place we found where big legless lizards—genus Ophisaurus—seemed to be ecologically important (the other was the pine scrub behind the dunes on the Outer Banks). The lizards were out on the warm mud at low tide in the Sapelo marsh, wolfing down fiddler crabs, crunching them noisily at a great rate. I’m pretty sure at just about 19 grams of carbon per square meter per year.

Wiegert never did buy our thinking on this point. Let the record show that he died still missing 19 grams of carbon. And that Bill and I know where it goes!