Animal Earth

gastrotich, from University of Washington web pages

For the past several weeks, I've been deeply engaged in reading Animal Earth, a fine book by Ross Piper. Very highly recommend; Piper writes lucidly and with a sense of humor, and the photographic illustrations are, to understate the case, superior.

The book brings home the extraordinary diversity of life at the microscopic level, calling attention to overlooked yet essential animal phyla such as Loricifera, ancient lineages of animals which the general public completely overlooks and is probably even entirely unaware of. Yet we share our planet with tens of thousands of such species, which easily outnumber us both in numerical terms and that of sheer biomass.

No one—even specialized biologists—knows much about these creatures, yet they form the essential underpinnings of life on the planet. Marine plankton—the larval stages of a staggering variety of arthropods, as well as other animals—are one of the planet's great microbiological reservoirs, creating the invisible understory of all—yes, all— marine life. Yet damage to plankton populations is difficult, if not impossible, to gauge, and methods for assessing the overall health of plankton populations present challenges of scale and complexity it is nearly impossible to evaluate, let alone overcome.

Large scale activities that result in gross, easily visible habitat destruction and the extermination of larger animal species generate the overwhelming majority of concerns about ecosystem damage. These are often the result of mechanical processes such as strip mining, deforestation, and overfishing. Yet the chemical pollution of biological microsystems may well turn out to be the greatest long-term threat to ecosystem health. Physical damage can, after all, be overcome; but if the foundational microbiology of a system is disrupted, any short-term recovery may turn out to be impossible.

The fossil record, especially the Burgess shale and other benthic (sea-floor) lagerstätten, demonstrate just how long many of these species have been with us; 500 million years and more. Their durability testifies not only to their resilience, but also how essential to ecosystems they are. No organism can persist in a habitat or body shape for that long unless it is performing essential roles for which it is, for all intents and purposes, perfectly adapted. Many of the smallest life forms we encounter in the world of microbiology fall into this category. These small life forms are the ones most likely to be compromised or destroyed by trace chemicals in their environment; amounts that seem insignificant to larger creatures represent massive doses on a microbial scale.

It's unlikely that the world will see a rush to the serious study of such tiny creatures any time soon; and while we continue to ignore them, the destruction of their populations seems assured.

The situation presents powerful arguments in favor of the most conservative approach possible to the introduction of new chemicals intended for widespread use and distribution, and stricter controls on the emission and control of all chemical waste processes of any kind, not only industrial, but also household wastes.

A sense of touch

This article on the ability of bacteria to detect form through a sense of touch is very interesting.

As with other cases across the biological spectrum, we're continually astonished when "lower" organisms display the ability to do things we thought were unique to higher ones... especially humans. Yet in this case, we can safely say that all of the macroscopic sensory abilities and behaviors we see have their roots, as well as their parallels, in the microbial kingdoms. Macroscopic behavior is a reflection of microscopic behavior; big things reflect little things.

This fractal arrangement is consistent throughout nature, so much so that it gets glossed over. But even the smallest creatures are not, in the end, so much unlike us. The same, or at least similar, sensory tools are needed to orient, to taste, to "see," on every level.

Microbes, which perhaps seem to be alien creatures, as small as they are, thus share an oft-unrecognized kinship with us. Not only do they colonize us, parasitize us, and coexist with us; each microbe is a legitimate, unseen life carried forth and lived out according to imperatives that, to it, are just as compelling as our own. There is a sensory and molecular awareness within these creatures; and it's to be appreciated, not dismissed.

 

Nanoplastic and Other Micropollutants

In the world of the unseen, the law of unintended consequences dominates.

Our pervasive use of plastics... which don't biodegrade well, if at all... has inundated the environment with plastic waste. It's unsightly... and when we see it we're sometimes dismayed, even though by now the sight of it is so common that we've developed a sort of visual immunity, whereby we edit it out of our vision. This enables the vast majority of people to walk right past most plastic waste without picking it up. 

It's always someone else's responsibility.

What most of us don't understand in the least is that plastic, like all other materials in the environment, is subject to mechanical forces that steadily erode it. Abrasion takes place as plastic is transported by wind or water; it rubs against branches, grinds against sand and stones, and creates smaller and smaller particles... which, as it happens, aren't really much more biodegradable than the larger pieces the plastic first came from.

The net effect, over the past city or more years, has been the creation of a steadily increasing sand-like substrate of plastic nano particles, tiny little bits of plastic that are so small as to be nearly invisible to the naked eye.

No big deal, you might think; but it IS a big deal, as scientists at Plymouth University reveal in the link. Plastics assist in the transfer of toxic chemicals into small marine organisms who ingest them; and these small, uninteresting organisms form some of the foundational elements in the food chain on shorelines—and, of course, in many other cases.

Not only are plastic nano particles present on shorelines, they are becoming increasingly abundant in suspension in water, where they affect aquatic food chains all over the world. Imagine living in a world where you began to have to inadvertently eat pieces of plastic with your spaghetti, your hamburgers, your bagel; these tiny organisms are already in that world. they can't escape the consequences of our polluting activity and they aren't able, as we are, to discriminate between plastic particles and food particles. It's absolutely certain that because of this, nanoplastic pollution is already wreaking havoc on food chains and biodiversity in the microsphere; and it's all taking place out of sight. the long term effects are likely to be severe, but the phenomenon is drastically understudied and the public is (as usual) not just uninformed, but completely ignorant—and, let's admit it, probably won't care anyway, at least not until it impacts their lifestyle.

Treating issues of this kind with a shrug of the shoulders and a "who cares" is not good enough. Much stronger environmental controls need to be placed on the production and use of plastics, which will take a major rethinking on the part of both producers and consumers.

Microbes and population balances

Readers will perhaps recall that in the last post, I explained that the application of fertilizers and mechanized agriculture have vastly expanded human populations... well, I didn't say that specifically, but we all know it's true. The sheer number of human beings on the planet has exploded; and the balances and population levels of countless different organisms have consequentially suffered or benefited.

One of the well-known situations in ecological analysis of the biosphere is that species maintain balances relative to one another — that is to say, they are not exactly "balanced," but the density of various  species is directly related. If one species becomes more dense, another one become will be less so, and so on.  There are winners and losers not only in the primary species, but in all of their accessory companions.

Dependencies change. One of the recent cover articles in Scientific American (see King of Beasts, in the November 2013 issue) explains that it's quite likely that the rise of human predators on the great plains of Africa led to a notable reduction in the diversity of carnivores who competed with them.

What I suspect is true — although I don't have any proof for it — is that the expansion of human population has had, and is having, similar impacts on the microbial world. That is to say, microbes exist in specific balances with one another and with the macroscopic species that they interact with. Drastic changes in the macro environment that affect microbes will ultimately have effects similar to the ones hypothesized by Lars Werdelin.

For example, wherever there are a lot more human beings, there's a proliferation of the specific bacterial species associated with human activity. This is self-evident. A second self-evident consequence is that these bacteria compete with other bacteria; and since, even on the bacterial scale, resources are limited, if bacteria and other microbes associated with human activity get a leg up because of all the humans they have to interact with and colonize, they are able to reproduce and spread at the expense of other bacterial species that would find other, different conditions more favorable.

This may not seem like it means a lot; but it what it means is that environmental holocausts, in which huge populations of important species are eventually lost (again, see Werdelin's article), can take place on the microbial as well as the macroscopic scale. The microsphere functions in essentially the same way the macrosphere does; and our manipulation of the environment may have the result of completely overwhelming important microbiological communities we haven't studied or looked at. This can lead to a wide range of malaises that affect the health of species such as, for example, bees.

 Let's think about that one for a minute. It's well-known that bee populations have been collapsing all over the world. Everyone assumes that this must be because of either a pesticide, a group of pesticides, a pathogen (infectious disease, whether viral or bacterial) or a new kind of parasite — although they haven't been able to identify any special new parasites, just lots of the old ones in weak hives. But what if it has something to do not with what the bees have — that is, pesticide or disease affecting them — but with something they don't have? What if we have inadvertently wiped out bacterial species that they need for their survival, which now can't populate their bodies and their hives properly? This "subtractive effect" — whereby a missing microbe is what causes weakness in a population — is much more difficult to measure, but it almost certainly exists.

 I haven't seen much discussion of this particular issue in scientific journals, but it strikes me that biologists ought to take a closer look at it.

Runoff

Agriculture has many unintended consequences. It has impacted the global carbon footprint for thousands of years; scientists at Lamont-Doherty (which is in my immediate neighborhood) discovered some ten years ago that evidence suggests this effect began as much as 5,000 years ago, as soon as mankind began clear-cutting large tracts of land for cultivation in Asia Minor. Interestingly, studies of arctic ice cores suggest that the carbon emissions produced by agriculture underwent significant dips during successive episodes of bubonic plague in Europe and the Middle East—plagues which substantially reduced populations and took large areas of agricultural land out of production, returning it (however temporarily) to forest.

One of the most dangerous and pernicious effects of agriculture, however, has relatively little to do with its very serious impact on atmospheric carbon levels; and that is the application of fertilizers.

Fertilizers, which dramatically increase the available amount of nitrogen and phosphorus in soil, work hand-in-hand with fossil fuel (mechanized) agricultural production methods to magically boost soil productivity. As we have explained in earlier posts, this boost in soil productivity comes directly at the long-term expense of microbial populations; and the detrimental effects of that soil quality depreciation have only recently begun to be understood, because most of the negative effects are both long-term, and invisible. 

Today, when we see vast desert areas that used to be rich, fertile agricultural land (much of Asia Minor, for example, falls into that category) we assume it's because of climate change; but the first and foremost cause of the decline of the land into unusable desert began with the destruction of its microbial communities, a long-term degradation that was unseen and beyond the ability of the cultures causing it to understand or measure. We are now at a point where some few scientists do understand this problem; yet it is receiving little or no attention in the press, because it lacks glamor, and is difficult to solve. Nonetheless, it represents one of the greatest long term threats to human populations. Continued destruction of the microsphere (my own newly coined term for the microbial communities we rely on for survival) will eventually do society as we now know it in if it isn't halted.

This recent article about the effects of fertilizer runoff on coral reefs underscores the unseen effect of agriculture on ecosystems. Although the scientists involved had their attention drawn to the situation because of the damage being done to coral reefs—which are glamorous, touristy, and thus deemed worthy of consideration by the public—what the article does not make clear is that the damage extends to a wide range of other creatures which cannot be so easily seen. The damage cited here is, after all, damage specifically inflicted on very tiny creatures—coral polyps. The only reason we notice it is because these nearly microscopic creatures secrete exotic skeletal structures—corals—which we find aesthetically appealing. There are a host of other microscopic creatures around them, both in their immediate vicinity and all the way down to the reefs through the waterways that carry the pollutants—which are also affected. 

The damage to the coral reefs, which is grave, is thus only the last damaging effect we can see; the end result, so to speak, of a pollution event that has damaged ecological infrastructure all the way down the line from the place where it was originally applied to the soil. The soils have been negatively affected; the streams that carry the runoff from the agricultural areas are affected; the rivers the streams feed into are affected; and the estuaries the rivers run into are affected.

After running this damaging course which leads all the way to the sea, the runoff finally wipes out corals, and suddenly we are alarmed and take notice. It's kind of like having a cancer that has spread through the entire body but only gets noticed once it has erupted on the skin. There is widespread, systemic damage; but our assessment of that damage is crudely limited to the areas where it's most visible.

The coral reefs are indeed telling us we're in trouble; but what they are telling us is that the trouble is everywhere. Not just on the coral reefs.

Intelligent, long-term solutions to the problem of agricultural runoff are thus vital to the future of both agriculture and the ecosystems that support it. Mankind's future well being depends on understanding this properly.