The things we don't know

I called up an old friend of mine, a marine biologist with long experience on the Texas coast and asked him: "Hey, you know all those critters that live in Sargassum weed? What happens when the stuff washes ashore?"

Because it does, in heaps and piles, early in the summer.

Sargassum is a macroalgae and can be found drifting in the Gulf of Mexico in large rafts. Small, air-filled bladders on the plant keep it afloat.

Savvy nearshore anglers have long known to target mats of sargassum, which provide shade and shelter for numerous small organisms, which in turn draw gamefish including ling (cobia) and dolphin (dorado).

A surprising number of organisms live under and in bunches of Sargassum, and many are cleverly disguised to resemble their surroundings. Highly specialized pipefish, shrimp, crabs -- and one very odd (and some think ugly) fish call Sargassum -- and nothing else -- home.

In fact, these animals are so highly specialized, it's difficult to imagine them living anywhere else. Thus, my question.

My friend's answer: "Hmmm .... that's a really good question ... I don't know."

I ticked-off the options: 1. the Sargassum critters bail-out at some point, maybe at about the third sandbar, and swim, scuttle or leap seaward to the next big drift of Sargassum. Only, after that happens a few times, wouldn't those bunches of algae get a bit crowded?

Or, how about this: 2. all those creatures wash ashore and die with the plants they've bound their lives to ... well, surely some do. Just watch the gulls turning over freshly arrived clumps of Gulfweed; clearly they see it as a snack bar.

And pick up a handful right at the surf line sometime -- if you sift through it carefully enough, you'll find some of the critters yourself. Still, most of the weed washes ashore under light occupancy at best.

Maybe 3. the Sargassum-adapted organisms give up on their foundering homes and just find another habitat, for however long they'll last.

Nah ... I don't like that one.

I'm sure there are other possibilities, but the fact remains: so far as I can tell, nobody knows what really happens. I checked, not just with one marine biologist, not just with two, but with half a dozen. All agreed it was an intriguing question, but nobody had an answer.

I asked my buddy another question -- one pertaining to a species in which he has a special interest: "Why do you suppose snook have that snazzy black racing stripe down their sides?"

Granted, it's a pretty off-the-wall question, but he's a smart guy with lots of education and a great sense of curiosity.

Only, he didn't know.

So I asked my girlfriend ... and how cool is it that I actually thought she might know the answer? Well ... she is a marine biologist. But it's still awesome she knows this stuff. Or ... a lot of this stuff, anyhow.

Her answer? "Huh. I don't know."

I don't have a theory, but I figure that -- when it comes to fish -- everything is for a reason. Most of those reasons, in the end, come down to just a couple of things: eating, not being eaten, and reproducing.

A pinfish's pincushion of spiny rays sometimes discourages predators; a tarpon's bony mouth allows it to crush and swallow crabs and other prey; a drum vibrates that thin muscle over its air bladder to get a date; a lionfish's showy display is a warning ... so why the snook's stripe?

Here's something, from a post I saw the other day on a coastal fishing message board: Humans cause red tide (the periodic karenia brevis algae blooms in the Gulf of Mexico). Well ... probably not. You can pin plenty of other algal blooms on H. sapiens, but in the matter of red tide we're probably innocent.

The red tide organism appears to always be present in Gulf waters in low concentrations, and when it goes into reproductive overdrive and blooms into a fish-killing, throat-irritating red tide, that usually starts offshore. Wind and current bring it to our bays and beaches.

But as I tried to answer the question of what does cause the toxic algae to go nuts and become such a bother, I found out that ... you guessed it: we don't know.

That is to say, the experts don't know.

Turns out there's a lot we don't know, and even some of the things we think we do know are as we know them only some of the time ... or to paraphrase my uncle, another one of those scientist-types: that's the way things usually are, except when they're not.

All in all, I find that kind of comforting.

In a world where it's easy to believe nearly everything has been answered, measured, named, quantified and catalogued ... it's kind of neat to think there are still things to find out.