Words and Pelagic and benthic and abyssal and OED and 6000 meters

My exploration of the "depths" in the previous three mini-essays has made me want to clarify one last term, pelagic, derived from the Greek word for sea. My primary interest is in determing if this word has a determinate meaning and, if so, what that meaning is. I think we will get confused again, however, and have to be saved by Pelagius. However, that causes a problem, too, since the theological system spawned by Pelagius, called Pelagianism, would be denounced as heretical by Augustine in the second half of his career and branded as such by Pope Zosimus in 418. It seems, then, that nothing will save me. I guess we should just get back to work.

Pelagic

So, it is simple enough to say that pelagic is taken from "pelagos," the Greek word for "sea." But, let's start with the OED definition. "Of our pertaining to the open or high sea, as distinguished from the shallow water near the coast; oceanic." This is not the only definition, but it gets us started. So, maybe we can divide the world as follows. Something living near the coast would be littoral; something in the high seas would be pelagic. Ok. This is clear enough. But once you get out in the high seas, you have a sea that is of various depths. What might the relationship be between pelagic and depth? Or, will pelagic just simply mind its manners and confine itself to "oceanic," leaving the various "depth terms" to fight out who gets which depths of the ocean?Let's look at the usages. From 1882 is an article that is very sure of itself. "Used technically by naturalists, the term pelagic ...denotes those animals and plants which inhabit the surface waters of the seas and oceans." Phew. That is absolutely great. Pelagic creatures swim along on the surface of the open seas. Then, the article goes on to say: "I have spoken of pelagic life as belonging to the surface waters of the ocean....but, ...it is impossible as yet to limit definitely the range of pelagic forms in depth, and we shall even have to refer to some connections of the fauna of the deep ocean bottom with that of the surface." If that isn't confusing enough, now comes the zinger sentence.

"Pelagic life then includes the inhabitants of the whole ocean waters, excluding those belonging to the bottom and shores."

Ok. Now I think I get it. You start at the ocean surface, not by the shore, and then start going down. It is all pelagic until you get to the ocean bottom, where, presumably, abyssal takes over. But what do you think abyssal thinks about this, much less benthic? Don't you think they want to go up from the bottom as close to the surface as they can, thus leaving only the surface for pelagic? Maybe not, but pelagic is showing itself quite the expansionist.

The Systematizers

Ah, wherever you have Western male thinkers, you will have guys who want to categorize. So, a few years later another writer says this. "We would suggest that the term oceanic Plankton be subdivided into pelagic Plankton...from the surface to 100 fathoms, zonary Plankton for those living in the intermediate zones between 100 fathoms from the surface and 100 fathoms from the bottom...and abyssal Plankton for those living within 100 fathoms from the bottom." It seems like zonary never took hold, for in 1912 an author talked about "the main characteristic of pelagic life is its independence from the bottom." Then, finally in 1957, someone said the obvious, "The distinction between pelagic and benthic (what happened to abyssal?) species....depends on how far from the bottom a species must live in order to be considered pelagic." Yes, that is precisely what I have been trying to figure out since I began to write this essay. But then the author goes on to say, "As yet nothing is known about pelagic animals from depths greater than 6000 meters--i.e., from the trenches."Yikes. Now we have 6,000 meters, almost 20,000 feet in depth. This is a far cry from the 100 fathoms of about 100 years ago. Indeed, the pelagics have given the extreme bottom ("the trenches") to the benthics or abyssals, but they seem to have nearly taken over everything else. Watch out when the pelagics start flexing their muscles; they will want everything except the ocean bottom.

Conclusion

Just when I thought it was safe, then, to conclude this essay with the understanding that pelagic referred to everything except the creatures of the deepest ocean, my eye fell upon the next clause in the OED dictionary. "now spec. living on or near the surface of the open sea or ocean, as distinguished from the depths." But that isn't what the quotations say. I am so confused. It will take more than Pelagian theology to save me.

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