You’re calling me a . . . WHAT?

In the midst of a pandemic, climate change, and the resurgence of fascism, it wouldn’t seem that a warning about a fish from the Virginia Department of Wildlife Resources (DWR) could be that big a deal.

According to the DWR, the Alabama bass has invaded some of Virginia’s big impoundments, and it continues to move north. I checked in with Maryland and West Virginia, and they’re bracing for the new fish as well. 

As I dug deeper, I began to realize that the DWR threat alert has less to do with any objective reality about the world out there, but a lot to do with the subjective reality in people minds. It’s mostly about us, and about what we think and do. It’s a complex story, full of twists and turns, sometimes funny and ironic, but other times disturbing.

A brand called “bass.” Let’s begin with a paradox: How could anybody have a problem with a fish called a “bass?”

Some of us even honor the bass with a place on the Christmas tree.

“Bass” is the most iconic name in America’s ichthylogical lexicon. It’s a familiar, friendly word. When you say it, your mouth opens into a relaxed smile. The word is a seal of approval that signals “good to catch,” “good to eat,” “good to think.”

As a brand name, we pin the label “bass” onto a lot of fish that are not really bass at all, just because we like them or because we want others to like them (see A Name by Many Other Fish). We don’t care that that the Alabama bass and the other dozen or so black bass species in North America are actually kinds of sunfish.

As a small boy I caught many sunfish (my mom called them “round fish”), but the fish I proudly brought home to show my parents was a largemouth bass (a “long fish”), all smelling of muck and algae from the little farm pond where I caught it. Today, my fish of choice is the smallmouth bass, the star of the Potomac River.  

Motor roaring, gelcoat gleaming, a bass avatar races to some secrete cove.

Aggressive and hard-fighting, bass rank number one with anglers, according to a US Fish and Wildlife study. They swim at the center of a sport fishing subculture that accounts for a large share of the $70 billion generated annually by freshwater fishing. The avatars of the sport zip around reservoirs in metal-flaked gel coat speedboats that can cost $50,000.  

The bass is also a handsome creature, with the classic lines of what we think a fish should look like. If a child draws a fish, chances are it will look like a bass. Among the various black basses, the Alabama bass stands out, its golden green flanks punctuated by a row of dark spots.

Fighting words. So again, how could the Alabama bass ever be a problem? I went back to the Virginia DWR website to search for clues. As expected, I found the usual Ecology 101 explanation of how a species entering a new ecosystem can sometimes overwhelm and outcompete native species. If they succeed, they’re invasives. If they don’t, they’re just fish.

But the DWR had a far more potent argument for why this native of the Mobile River watershed poses a threat to Virginia than the quantitative evidence of population biology. The really powerful pitch comes from the qualitative power of words.

It turns out that the DWR had put the Alabama bass on its Predatory and Undesirable Species List. If you want to vilify a fish or anything else, you can’t do much better than label it a “predator” and “undesirable.”

Let’s take a closer look at these two words, starting with “predatory.” The term conjures up the media-stoked imagery of ferocity, viciousness, stiletto teeth dripping blood, a threat to suburbia, dogs and small children, God and country.   

But in the real world of biology, a predator is simply a creature that makes its living eating other creatures. It’s not a word meant to condemn or to pass judgment. It simply describes the place a creature occupies on the food web. Of course bass are predators, along with trout, tuna, perch, and most of the other fish that we esteem. Take a look in your fishing tackle box at all of those lures that resemble minnows, crayfish, worms, and bugs, all designed to attract the kinds of fish we like the most, all predators. I’ll bet you don’t have anything in there that imitates algae, duckweed, or bladderwort. I’ll bet you can’t even name a fish that is strictly herbivorous.

A predator is no more loathsome than an omnivore or an herbivore. Either out of ignorance, carelessness, or craft, the DWR is simply weaponizing an otherwise perfectly useful word.  

An “undesirable.” But the second epithet in the title of the DWR’s list gets us into dangerous terrain. “Undesirable” is not merely a descriptive term, such as “predatory,” but judgmental. It doesn’t describe a creature—even misleadingly so—but rather how we should feel about it. It is a word that takes us into a dark realm of human psychology, where it has helped drive some of the most shameful events in our country’s history. It’s a word that conjures up the “other,” the unknown, the treacherous, the unclean. It’s not a word of science, but of nativism and of hate-mongering mythologies.

An “undesirable” gets an unequivocal “no” from a representative of America’s Great Race in a cartoon from the turn of the last century.

I’m particularly thinking of our country’s history of immigration. The Immigration Act of 1882 identified foreigners deemed “undesirable” for entry into the US, a category that would be broadened in succeeding years to keep out poor people generally. In 1903, the Immigration Restriction League, alarmed at the influx of peoples from Southern and Eastern Europe, issued a report that identified those immigrants it deemed “undesirable.” The Undesirable Aliens Act of 1929 Act criminalized crossings on the southern border as a way of barring Mexican immigrants. 

Great Race under siege. This was a period in US history when the country’s scientific and political elites promoted the hollow concept of race and the misguided theory of eugenics. They insisted that human races and ethnic groups are non-equal and must be kept separate. Immigrants, they warned, were inferior, both mentally and morally, to the native descendants of Northern and Western Europe, which a leading public intellectual of the time called the Great Race. In only one way were the immigrants superior: producing large numbers of children. Even worse, immigrants were interbreeding with the native (white) existing population. If left unchecked, undesirable immigrants would turn America into a land of imbeciles and degenerates.

In much the same way, the Alabama bass can  “genetically pollute” the “native” bass population as it creeps northward from its original range, states the website of Maryland’s Department of Natural Resources. Particularly at risk are America’s “Great Races” of fish, the largemouth bass and smallmouth bass.

“They’re not sending us their best.”

Starting to sound familiar? Let’s imagine that there is such a thing as a Mexican bass (Micropterus mexicano), and that its population is expanding north, crossing the Rio Grande and into Texas and beyond. “They’re not sending their best,” Donald Trump would have thundered in the 2015 speech in which he announced his candidacy. “They’re sending fish that have lots of problems, and they’re bringing those problems with them. They’re bringing crime. They’re bringing murder. They’re rapists.”

Change denial. The idea of keeping races pure depends on how we think about change in the natural world. Before I saw the DWR website, I might have regarded the expanding range of the Alabama bass as another example of the mixings and migrations and emergences and extinctions of life on earth that have been going on since life began. But most people take a more immediate view of nature. For them, nature operates in a time frame defined by human life spans or stories in the Bible. They seek safety in the bubble called the status quo, like residents of a gated community with a 24-hour security guard.  

The idea of an ever-mutating natural world also runs counter to the mission of a state wildlife agency. The mission of the agency is to protect the environment. But which environment? The concrete, objective environment that you can see and touch and feel? Or the one that the agency’s constituents regard as normal? 

As stamp collectors collect stamps Linnaeus (aka Linné) collected plants and animals, gave them Latin names, and organized them according to his revolutionary system.

Even up two a couple of centuries ago, the intellectual elite assumed that we live in a static world: After the Biblical flood, nothing much changed of any consequence. Carl Linnaeus, the founder of modern taxonomy and also a highly religious man, summed up his faith and his work in the phrase, “Deus creavit, Linnaeus disposuit” (God created, Linnaeus organized). Each species inhabits its own box, sturdy and impenetrable.  Largemouth bass have always been largemouths, and must remain so. Lions are lions, and could never share genes with tigers (in fact, they can).

People still believe in this view of natural history, and I found many of them at the Creation Museum in northern Kentucky a few years ago. Sneer as you want at this temple of Biblical literalism, but I genuinely enjoyed spending three days there exploring a view of science embraced by millions of believers. I saw dioramas where humans mingle with dinosaurs. I spoke with interpretive guides who were unquestioning in their Bible-based view of the creation. I attended lectures given by PhD “scientists” who could overwhelm skeptics with rapid-fire facts and Biblical references.  

But facts don’t add up to science. In many cases, they’re rooted in anecdotal and myth-based assumptions that can ensnare long-ago taxonomists and present-day creationists, as well as the folks at state fish and wildlife agencies. If the Creator had anything to do with laying these traps He must have had a sense of humor, just like my own Patowmack the Trickster, the guiding spirit behind this website.

Taxonomic tempest. One such clever trap has to do with boxes, a standard prop of magic shows and pop-up toys for small children. Recall that Linnaeus created taxonomic boxes, each of which contained one species, as it always had and always will. The box occupied by the Alabama bass today carries the label Micropterus henshalli, the fish’s scientific name.

When people think about taxonomy, if they think about it at all, they conjure up notions of anonymous toilers in the vineyard of science, their eyes bleary from hours bent over microscopes. But not when it came to writing the taxonomic history of the black basses. Here we find a tale of buffoonery, comical errors, twists and turns, and ultimately, findings that pull the rug of scientific gospel out from under the dire warnings about the Alabama bass.

Briefly, the tale goes as follows. All black bass are members of the genus Micropterus, a name that was created by French naturalist Bernard Germain de Lacépède in 1801, when he received a smallmouth bass specimen for study. He noted its diminutive (micro) dorsal fin (pterus), the inspiration for the name. Unfortunately, Lacépède didn’t realize that the fin was small because several of its rays apparently had been bitten off when it was young.

Along with black bass taxonomy, Henshall offers practical advice to the angler, such as the proper form for casting to the left.

The species name, henshalli, honors Dr. James A. Henshall, revered by the literary subset of the angling fraternity (there are some!) as author of the 1881 classic Book of the Black Bass. In a prose both dry and sly, Henshall recounts the deliberations, disputes, and missteps of scientists―mostly French―who gave the different bass species their scientific names. It could only have been described as a farce. In one instance, a haughty Professor Rafinesque proposed different names for the same bass species, each name corresponding to a different size fish. For the largemouth bass alone, these learned men of science delivered up some 57 judgments and a minor lexicon of Latin names, according to Henshall. “The scientific history of the Black Bass is a most unsatisfactory one,” he concludes.

In the end, Henshall explained this comedie taxonomique as an example of Gallic people “indulging their national love of novelty.” But, as we’ll see, later scientists, politicians, and bureaucrats solemnly used these same taxonomic distinctions as criteria for formulating environmental policies.

A leaky box. Let’s take another look at the taxonomic box that contains the Alabama bass and see how sturdy it really is. Is it a box for eternity, or for some lesser span?

We first see that the box containing the Alabama bass is still shiny and pristine. And no wonder, since it’s practically brand new, dating back to only 2010. Before then, it was safely stuck inside another box containing the very similar-looking spotted bass, since it was regarded as a spotted bass subspecies. (For its part, the spotted bass was described scientifically only in 1940.)

The Alabama bass shed its subordinate rank thanks to the development of conceptual tools that would give biologists a far more detailed and accurate understanding of the evolutionary  relationships among living things. By using these new methods, called phylogenetics, biologists came to the agreement that the Alabama bass was a separate species. In 2010 it was officially recognized as such.  

And so, for some 70 years, the fish we now call the Alabama bass was considered a kind of spotted bass, which is a proud native of southwest Virginia, and not an alien and certainly not an undesirable. But when scientists found the Alabama bass to be a separate species, it lost its Virginia residency status. One stroke on a biologist’s return key turned what had been a native fish into a non-native, an esteemed bass into an invader.   

More leaks. But although the taxonomic box containing the Alabama bass is phylogenetically valid, it is itself full of holes. As with other species of black bass, the Alabama bass can freely hybridize with other members of the larger bass community, notably with the largemouth and especially the smallmouth.  

It reminded me of the fears the eugenicists had over the impact of immigrants on the Great Race. It was bad enough that they were arriving on our shores and packing into crowded tenements—boxes for undesirables—in the big cities. Even worse was the threat that they and their genes would leak out of these boxes and into the general population.  

Ironies of invasion. Into this muddle steps another reality, further complicating the meaning of native/non-native and desirable/undesirable. It turns out that the Alabama bass is no less “native” to Virginia and Maryland than the “native” largemouth and smallmouth bass it presumably threatens.

The largemouth’s original range (at least back when people started recording such things) encompassed the Mississippi River basin, the southern Atlantic seaboard, and a few other places. People liked it, and so government agencies teamed up with eager fishermen and landowners to release it into lakes and farm ponds throughout much of the US. No worries that the newcomers reduced or eliminated existing populations of many native fish and amphibian species.

From there the largemouth spread around the world. In some places, the people welcomed the new fish. I once was proudly served largemouth bass on the shore of Lake Yojoam in Honduras. The whole fish came to the table deep fried to a golden brown, flanked by black beans and tortillas. On the other hand, the Japanese consider it a threat to their own native species.  

The same goes for the smallmouth bass. Its original range included the St. Lawrence River, the Great Lakes, and part of the Mississippi River basin. It’s now established throughout much of the US and elsewhere around the world. One of the earliest introductions was carried out by a General William Schriver (he wasn’t really a general, like a bass is not really a bass), who used the newly completed railroad connection to the Ohio River town of Wheeling to ship smallmouth fry over the continental divide to the Potomac. Despite the explosive impact the smallmouth surely must have had on the Potomac’s native fish populations, the general’s act was widely praised.

For its part, introduced smallmouth have decimated populations of native fish and amphibians. In the Pacific Northwest, smallmouths consume up to 35 percent of outmigrating salmon, a fish which is already in a very precarious situation due to dams and development. In the Potomac River, the introduction of smallmouths may have lead to the demise of a population of trout-perch, an elegant little fish with spotted sides.

Plastic bags and tiny fish. As we’ve done for thousands of years, when we come across a plant or animal we like in our travels, we bring it home. Sometime the outcomes are good, sometimes not.

Fishermen mostly like the Alabama bass. Many call it the ‘bama bass. Imagine a couple of buddies in a pickup driving from Virginia drive down to Alabama to visit kinfolk. They do some fishing and manage to net some Alabama bass fingerlings, which they stick in a plastic bag full of water. Hopefully they’ll survive the trip home where the fishermen will dump them into a local lake.  

It would seem like an innocent act, even rising to a First Amendment right protecting a person’s esteem for the fish of their choice. But not in the eyes of government fish and wildlife agencies, which condemn such acts as forms of environmental vandalism.

“Anglers are the primary vector for the spread of Alabama Bass in Virginia,” according to the DWR. “Current populations are the results of angler introductions that have occurred over the last ten years.” Fishermen as vectors? Here we go again with the loaded words. In epidemiology, a vector is an organism that does not cause disease itself but which spreads infection by conveying pathogens from one host to another. Think mosquitoes, bats, ticks, snails, fleas. And if fishermen are the vectors, the fish are the disease.

Oops, never mind. When it comes to introducing new species, the bad guy is the one with the bag; the good guy is the one with the badge. One gets a fine and the other works for a government agency that issues a celebratory press release when it introduces a new species. The press release touts the admirable qualities of the creature and describes how its introduction will “expand recreational opportunities.”

Jonah’s whale didn’t have much over the formidable vacuum cleaner state biologists released into Virginia.

No surprise that the state biologists don’t always get things right, such as when Virginia introduced the blue catfish into Chesapeake Bay tributaries in the 1970s. A native of the Mississippi River drainage system, this monster grows to well over 100 pounds, fights like a bulldozer, and is good to eat. But it’s also an aquatic vacuum cleaner that consumes most anything it can get its mouth around, which is just about everything. Today, it continues to increase its numbers, and in some places accounts for 75 percent of fish biomass. The losers in this game of species roulette are the native fish and crabs that the state agency is supposed to protect. Oops.

In other cases, government support for introduced species creates scenarios that could be written by the Jokester Creator or my Patowmack the Trickster. For example, Maryland’s Department of Natural Resources monthly report touts the risk assessment it’s preparing for the “potentially invasive” Alabama, and then goes right on to highlight its work in promoting other non-native species: brown trout (from Europe), rainbow trout (from the North American west), tiger muskellunge (cross between muskellunge and northern pike, upper Midwest and Canada), northern pike, smallmouth bass (upper Mississippi basin), and the walleye pike (Canada and northern US).

The bottom line. Just when it looks like the Alabama bass issue has devolved into a game of leaky taxonomy and fuzzy thinking, along come some actual facts that may or may not concern fishermen.   

As the state agencies say, the Alabama bass has sharp elbows. It rapidly expands its population and outcompetes native species, at least for a while. In North Carolina’s Lake Norman, for example, numbers of largemouth bass dropped to less than 8 percent of their former abundance after the new bass’s introduction.

At first the Alabama bass grow big in their new homes, but then their average size falls as they eat their way through the prey species. A lake formerly holding 2-3 lb largemouth or smallmouth bass will end up being dominated by 1 lb Alabama bass, according to Virginia’s Department of Wildlife Resources. Fishermen want big fish, and particularly so if they bought a $50,000 bass boat to catch 3-lb fish. If they’re now catching 1-lb fish, it’s like their boat lost 2/3s of its value (of course, I’m no economist).

In any event, the stakes can be high. The Virginia DWR estimates that 60 percent of fisherman target largemouth and smallmouth bass during the course of a season, and spend “millions of dollars” in the process. “Declines in either population will result in not only the loss of sportfishing opportunities, but in economic harm to the region,” according to the agency.

Of course, nature doesn’t care about such things as fisherman satisfaction and economic benefits, but they matter to anglers and to the businesses that supply them with rods, reels, boats, plastic rubber baits, beer, guide services, and everything else 21st century Americans need to catch a fish.

In this sense, the problem with Alabama bass comes down to what fishermen are presumed to want, what government fisheries managers are able to do about it, and the complete lack of interest the fish themselves have in these issues.

As they always have been, the black bass tribe and their environment are works in progress, shape-shifting and boundary crossing without regard to the policies of government biologists or the whims of their angler admirers.

A name by many other fish

Will the real bass wave your pectoral fin!

The fish—scores of them, all vaguely similar in appearance—didn’t move except for the rhythmic opening and closing of their gill covers. They knew what most people don’t know: The term “bass” is an artifice of the human imagination, not a real thing. Except in Germany where it’s spelled “barsch” and means “perch.”

Behold the elegant simplicity of ichthys, the Christian bass.

The fish we Americans call “bass” do not fall into any kind of biologically cohesive group, except that most of them follow the general architectural plan of ichthys, the Christian symbol of bumper sticker notoriety. Its regular and symmetrical shape are what first come to mind when we think “fish.”

When the first Europeans arriving in America encountered these ichthys-shaped fishes, they liked what they saw and often named them “bass.” One of the few positive things Capt. John Smith wrote in his otherwise downbeat account New England was, “[T]here hath beene taken one thousand Bases at a draught. . .” What were these “Bases?” There’s no way of knowing, although the name he chose for them at least tells us they weren’t eels.

Giant of the bass world.
The might-have-been Manchurian bass.

How about the Manchurian bass (Channidae)? Unfortunately it doesn’t exist, because by the time fishermen saw through the vilification campaign waged against it by government wildlife agencies and the media, the name “snakehead” was already well established.

So if you see a fish that you like, and you don’t know what it is, just call it a bass. Who’s to say you’re wrong?

Return of the sponges

It was a bad afternoon for a river expedition. A light rain had started to fall, pushed by a gusty breeze. But this was about sponges, and it couldn’t wait. By tomorrow morning, the remnants of Hurricane Ida would sweep into Potomac country. Heavy rains would flood the river, producing swift currents that would scour away anything not firmly anchored to the bottom.This would be my last chance this year—perhaps forever—to see my delicate and enigmatic creatures.

The thrill of discovery. I call them “my sponges” because I had found them in 2011, the first sighting of sponges in the main stem of the upper Potomac River. I also call them “creatures,” because a lot of people don’t realize that they are animals, not plants, and are moreover the first animal to emerge on earth, possibly an astonishing 890 million years ago.

The most lively thing about D. radiospiculata are its jumping jack-like spicules. Otherwise it just sits there like a head of cauliflower.

I was thrilled by that discovery 10 years ago, and even more so when the sponge expert at the Smithsonian Institution identified the sponge as a species rarely found along the eastern seaboard. Its scientific name was Dosilia radiospiculata for the delicate radial structure of its skeletal parts. I proudly signed a release to donate my specimen to the Smithsonian collection.

I felt a kinship with the legendary naturalist explorers of former times, whose exploits I so admired. Now I had exploits of my own. But I quickly I learned that not all scientific discoveries are equal. A person can live their entire life without thinking even once about a freshwater sponge. When I told one person about my sponges, her response was, “Let’s go see what’s on the buffet table.”

Then the sponges disappeared, also after a flood, like the one that was threatening to hit now. In the following years I searched for them, all up and down the river, but found no trace.

But even though my discovery was perhaps not very interesting, it was significant. Look at Darwin and his earthworms! As it turned out, my discovery and the events that followed would transcend the subject of sponges, and help me to better understand the world and our place in it.

Here my guide would be Potowmack the Trickster, the spirit of the river, who excelled in exposing our foibles and puncturing our pride, particularly as regards our place in the natural world.

A nice afternoon for my son and his family of mucking around in the river turned into another chapter in the sponge saga.

Sponges redux. And now, after 10 years of absence, the sponges reappeared. I had taken my son Matt and his young family out for a Potomac afternoon of getting wet and muddy. As we were preparing to leave, Matt casually remarked, “Hey Dad, isn’t that one of those sponges you told me about”? I was astounded.

We were in a little cove, its water murky from the silt we kicked up boarding the canoe. But we could still make out the bottom and its tufts of algae, dead leaves, and smoothed river stones. And the sponges, a whole colony of them.

By now everyone was settled in the canoe and clearly anxious to be on their way. I snapped off a couple of more photos, and off we went. I would return as soon as I could to spend some quality time with these long lost creatures.

One last encounter. Now here I was by myself, paddling hard through the rain and the weeds and around the rock ledges. I heard some distant rumbling to the west, imagining that Hurricane Ida was already arriving. It turned out to be aircraft making their approach to Dulles Airport, some of them probably carrying Afgan refugees. Most of the world was focused on the Afgan evacuations, or the hurricane, or covid-19. My mind was on sponges.

I angled across the river heading for a gravel bar, a spot where you can still find remnants of the canal that George Washington built to skirt the rapids. I wondered if Washington also saw the sponges. Would he have cared?

The gravel bar was already occupied by an increasingly agitated flock of Canada geese. They bobbed their heads and honked and cackled and pooped and then took to the air, flying low over the water, still honking and pooping.

I pulled my kayak up on the shore, picking my way around the piles of goose droppings. The water was a little discolored, but clear enough to see.

Crushed and confused, I search the little cove for any sign of sponges.

The trickster returns. But there was nothing to see. The sponges had vanished, once again gone without a trace.

I was disappointed, but at the same time intrigued. No doubt about it. Here was Patowmack the Trickster at work once more.

What happened? I had read somewhere that ducks will eat sponges. I’d guess that geese eat a lot of the same things as ducks. I imagined a flock of geese coming upon a colony of sponges, and in no time devouring them all—but with an exception. For along with the sponges the geese also pick up the sponges’ gemmules, those tiny spherical reproductive bodies. The geese fly off and land somewhere else, always honking and pooping, and depositing the gemmules. If the current is swift, the gemmules just become part of the organic soup that washes downstream to who knows where. But if the geese land in some protected cove or back water, the gemmules could produce a new colony of sponges come next season.

I later asked my son Matt what he thought of my scenario. After all, he was the one who found the sponges. He also has a doctorate in ecology, so he should know about such things.

Matt listened politely to me, and then came up with a more prosaic explanation. The sponges looked pretty shopworn, he remembered, and they smelled bad. Later he had to wash his hands over and over to get out the stink. Probably the sponges were just dying, he said. Their season had come to an end, like the leaves starting to fall from the trees or mushrooms turning black and slimy. The bits and pieces of their bodies—including the gemmules—those tiny time capsules—probably lay  among the algae and dead leaves in that same little cove. With any luck, the gemmules could produce another colony when the conditions are right. I later learned that scientists describe this stage in the sponge’s life cycle as “gemmulation and degeneration.”

River keeps its secret. I like both explanations. I like mine because it illustrates the lengths the human imagination will go in finding a cause for anything and everything, even in the absence of any real evidence. The more complex the cause, even if it enters the realm of the conspiratorial, the greater its allure. Taken to the extreme, a search for causes could inspire elaborate myths and liturgies and the creation of priestly hierarchies. (If it seems like I’m straying a little far from a pooping goose, blame Potowmack the Trickster.)

In contrast, Matt’s explanation looked at the disappearance of the sponge from the standpoint of the sponge. The life cycles of natural creatures operate independently of our assumptions and expectations. It’s the creatures that are calling the shots, whether we like it or not.

Whatever actually happened in that little cove is the river’s secret, at least for now. I don’t have the persistence to figure it out, and Matt is mainly focused on getting tenure.

Let’s just call it a thought experiment. We can name it Schrödinger’s Sponges. It’s as if the sponges were locked away in a box, just like the famous physicist’s imaginary cat. Is the cat dead or alive? Unless we open the box to see, it occupies both states at the same time. The same goes for the fate of the sponges. Until we have data based on observation, all explanations are valid.

I think this would be good problem to leave to some graduate student with a lot of time for research and little interest in public recognition. 

Peaceful and easily overlooked, a little cove branching off from the river probably holds the answer to the mystery of the sponges.