CONCRETE PROOF THAT OYSTERS ARE RESOURCEFUL HOMESTEADERS, FITTED TO FILL DIVERSE HABITATS
Dr. James J. S. Johnson
And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good. And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth. (Genesis 1:21-22)
Chesapeake Bay oysters (photo credit: Emaze.com)
Chesapeake Bay oysters are ecologically resourceful, especially when it comes to homesteading underwater – and we should not be surprised.
But why? God prioritized animals, all over the world, to “be fruitful”, to “multiply”, and to “fill the earth”.
God chose to fill the earth with different kinds of life. All over the world, we see His providence demonstrated in ecological systems. Different creatures live in a variety of habitats, interacting with one another and a mix of geophysical factors—like rain, rocks, soil, wind, and sunlight.
[Quoting James J. S. Johnson, “God Fitted Habitats for Biodiversity”, ACTS & FACTS, 42(3):10-12 (March 2013).]
Because God loves variety, the earth itself has a diversity of habitats that can provide niches for animals to live in.
Accordingly, God “fitted” (i.e., designed and bioengineered) the internal programming of diverse animals to creatively adjust to miscellaneous habitats. In other words, diverse animals are “fitted to fill” different geophysical environments, which are themselves dominated by different types of plants, and the results are interactive and changing communities of lifeforms, adjusted to living in ecologically diverse “neighborhoods”.
Chesapeake Bay oyster-bed (photo credit: Chesapeake Bay Foundation)
To illustrate, check out what is happening with Chesapeake Bay oysters, especially those which are “homesteading” on artificial “reef” platform-beds.
An unremarkable thing happened in a remarkable way during the recently ended oyster season in the Chesapeake Bay. Some Virginia watermen harvested bivalves from public oyster grounds in the Rappahannock River. There’s nothing unusual about that, of course, but these shellfish had settled as baby “spat” and grown to harvestable size on a thick bed of gravel-sized stones that had been put on the river bottom to provide an unconventional home for them.
Typically, shells of other oysters are the natural landing pads for recently hatched bivalve larvae, which need to attach to something hard as they begin sedentary lives of filtering algae from the water. But the Chesapeake is running short on [bivalve] shells; there aren’t enough to go around to sustain the traditional wild [oyster or clam] fishery — to say nothing of the growing aquaculture industry and an ambitious effort to restore the Bay’s depleted oyster [and clam] population.
Some watermen, particularly those in Maryland, remain leery of using anything other than oyster shells to provide habitat for bivalves.
But the shell squeeze is prompting some oyster growers and fishery managers to try alternative “substrate,” the hard [platform-like] material on which baby bivalves live and grow. Working with the Virginia Marine Resources Commission, W. E. Kellum Seafood, one of the state’s oldest and largest oyster businesses, has in the last few years tested the suitability of crushed concrete from a demolished bridge and ground-down stones taken from a dam on the James River.
“This past season, the oysters we harvested were from 2-year-old granite we planted,” said Tommy Kellum, the company president. “That worked extremely well. We got a terrific spat set on it, and it grew well.”
In the right conditions, oysters will settle and grow on practically any hard surface, not just other oyster shells. Bivalves can be found clinging to wooden docks, concrete bridge piers and riprap, the big granite rocks lining the shore to prevent erosion.
[Quoting Timothy B. Wheeler, “Oysters Making Themselves at Home on Reefs with Alternative Substrate”, CHESAPEAKE BAY JOURNAL, 27(4):12 (June 2017).]
Does that mean that artificial oysterbed planting is “better” than the “natural” habit these bivalves have, of attaching themselves to oyster shells produced by prior generations?
Probably not, but (as Francis Schaeffer repeatedly reminded us) we live in a “fallen world” — so we need to “make the best of what we have”, in order to be good stewards of God’s creation. And that stewardship can apply to oyster-bed aquaculture resourcefulness. (Just as careful ranchers can raise healthy cattle or sheep, careful aquaculture “farmers” can raise healthy bivalves.)
Some watermen, particularly those in Maryland, remain leery of using anything other than oyster shells to provide habitat for bivalves. Maryland watermen and their supporters have protested the use of crushed granite, fossil shell from Florida and clam shells from New Jersey in oyster restoration projects . . . [and their] protests landed on sympathetic ears at the Maryland Department of Natural Resources, which blocked the further use of such materials in the Tred Avon [River, a tributary of the Choptank River, which is the Chesapeake Bay’s largest tributary on the Delmarva Peninsula]. The watermen argued that the rocks interfere with crabbing and fishing. Based on their experience, they say, oysters will not settle and grow nearly as well on substitute materials as they will on shells. Some also noted that the Florida fossil shell used in Harris Creek and the Little Choptank was full of water-fouling silt. “I think you should use the natural stuff that the good Lord put there,” said Ron Fithian, a Kent County commissioner and former waterman who is a member of Maryland’s Oyster Advisory Commission. “Nothing works better, and they shouldn’t substitute anything, especially stone. …You don’t get the concentration of spat on stones you do on oyster shell.”
Scientists and other proponents of the rock and concrete alternatives acknowledge that oyster shells are optimal, but they insist there’s just not enough fresh shell to go around — thanks to the decades-long slump in the oyster industry, which rebounded a bit several years ago. To make up for the shortage of fresh shells from harvested oysters, many watermen are pressing for the U.S. Army Corps of Engineers to permit the [Maryland Department of Natural Resources] to dredge 5 million bushels of fossil shell from an inactive oyster reef near the mouth of the Patapsco River called Man O’War Shoal. The proposal is opposed, though, by conservationists, recreational fishermen and even some watermen, who fear dredging up the old shell will ruin the shoal’s value as habitat for striped bass and other species. . . . [Balancing an ecosystem is tricky, of course – it’s really hard to please everybody!] Watermen have also pushed for the state to resume the taxpayer-subsidized “shell repletion” program it ran from the early 1960s until 2006, planting shell on the bottom and “seeding” it with juvenile oysters transplanted from areas getting good natural spat set.
[Quoting Timothy B. Wheeler, “Oysters Making Themselves at Home on Reefs with Alternative Substrate”, CHESAPEAKE BAY JOURNAL, 27(4):12 (June 2017), with emphases added.]
Scattering oyster shells, for reuse by oyster larvae (photo credit: PBS)
Ironically, the concrete and gravel “reef” platform-beds are working out quite well, which proves the resourcefulness of the juvenile oysters that attach there.
“Just about anything that is hard would work,” . . . said [said Andrew Button, head of the Virginia Marine Resources Commission’s shellfish conservation and replenishment department]. “Everything, from shredded tires to ‘recycled bathroom fixtures’, has been tried, with some success, by someone at some point.” Watermen and others have expressed concern that concrete from roads and other demolished structures might be contaminated with oil and other hazardous substances, which could be picked up by oysters and other marine life.
But in one recent study, Morgan State University researchers found no cause for concern. The Maryland State Highway Administration, looking for alternatives to landfilling old pavement, contracted with Morgan a few years ago to evaluate the feasibility and safety of using it in building oyster reefs. Morgan scientists placed chunks of recycled concrete aggregate in tanks of Bay water at the university’s Patuxent Environmental & Aquatic Research Laboratory in Calvert County. They compared oyster spat survival on both concrete and shells and found no difference. They also tested for chemicals that might leach into the water — and subjected it to even more rigorous analysis with a mass spectrometer. “There was less [pollution] in it than the EPA required of drinking water — orders of magnitude less,” said Kelton Clark, director of the Patuxent lab.
The researchers also set up demonstration reefs using the recycled highway concrete in two locations with different water salinity — one in the Patuxent River near the laboratory and the other in Fishing Bay on the Eastern Shore — to see if oysters on rubble would be any more vulnerable to predators.
Again, no difference. There was one test that the highway debris flunked, when compared to shells: the hand-tonging test. Clark said researchers invited a hand-tonger to try harvesting the oysters growing on the concrete. The fist-sized chunks of rubble proved too heavy to lift using the tongs.
But for building oyster habitat in sanctuaries not open to harvest, Clark said, it’s just as good as the scarce shell. “It may not be acceptable to you or me, but the Chesapeake Bay doesn’t care what we like,” Clark said. “There’s no scientific reason not to use this material.”
In another study, the U.S. Army Corps of Engineers and the University of Maryland teamed up to see how alternative substrate performs in the Bay. In 2011, the Corps built seven reefs out of granite in the Cook Point sanctuary in the Choptank River, where the bottom consisted of sand, an area of flat shell and some large mounds of shells. The granite reefs placed nearby ranged in height from 1–3 feet off the bottom; some were covered with a layer of shells, while others were not. The artificial reefs were planted with oyster spat produced by the University of Maryland Center for Environmental Science hatchery at Horn Point. After three years, UM researchers analyzed the growth, survival and reproduction of the oyster populations in the area, and also checked for other organisms living on or around the reefs. They found more oysters on reefs made of both granite and shell than on those built of granite only, but both types had relatively healthy densities, averaging 91 oysters per square meter and 49 oysters per square meter, respectively. The granite-only reefs did have thicker populations of organisms such as anemones, which researchers suggested could be competing with oysters for space on the rocks.
Most of the artificial reefs built in Harris Creek and the Little Choptank River as part of those sanctuary restoration projects are too new yet to evaluate their performance as hosts for oysters, but preliminary analysis of reefs finished three years ago in Harris Creek shows that those with a stone base have nearly three times the density of oysters, on average, as those with a base made up of clam shells. All were planted with spat on shell produced by the UM hatchery.
Scientists say the shape and size of the materials used can matter in determining how well oyster spat settle and survive on artificial reefs. The granite stones used to build reefs in Harris Creek, for instance, have more than three times as much surface area as do the reefs made of clam shells. That’s important, according to Jay Lazar, field operations coordinator for NOAA’s Chesapeake Bay office, because it gives oyster spat more places to latch onto as they settle to the bottom. The spaces between rocks also offer more protection from predators.
[Quoting Timothy B. Wheeler, “Oysters Making Themselves at Home on Reefs with Alternative Substrate”, CHESAPEAKE BAY JOURNAL, 27(4):13 (June 2017).]
This successful conservation aquaculture practice did not “work out” by random accidents. Rather, a lot of careful thinking was necessarily involved, especially God’s creative thoughts (and deeds) that provided both humans and oysters with multi-generational life and abilities needed to live their respective life cycles – even down to the super-small level of biochemical details that include interactive nuclear DNA, mitochondrial DNA, various RNAs, and the teleological functioning of gazillions of highly specialized protein molecules.
Who devised all of that to work?
The necessary details – of both human life and oyster life – required God to think through a lot of specifications, which themselves represent bioengineering programming to achieve God’s intended purposes (for humans and oysters).
Man-made items are constructed following directions called plans and specifications. Specifications are a unique kind of writing designed to convey intent. They are written instructions that set advance constraints on precisely what, how, and when particular materials will be used. Plans show geometric details of where materials are placed (though there is overlap between the two). Together, they must be detailed and selective enough to accurately and unambiguously communicate intended fabrication information to obtain all the product’s features.
Writing specifications and drawing plans can be difficult work. Designers are forced to initially build the project in their minds. They must visualize numerous details, and then clearly represent everything in that mental picture in words and drawings–a daunting task at any time, but especially for situations where no prototype even exists.
It is important to highlight two points about specifications. First, they are as close of a representation of the designer’s thoughts as possible–but they are not the thoughts themselves. Thoughts exist independently of the paper or programs which convey them. Second, when plans or specifications exist for something, they are–without exception–a sign of conscious design. Why? They reveal an intentional state that is characteristically restrictive. It selects in advance particular attributes for an intended purpose–which is the exact opposite of blind natural processes that yield random, ill-defined, piecemeal conglomerations of whatever is available.
So the secret to great architecture [or to building great human beings, or to building great Chesapeake Bay oysters!] is not in the drawings, but in the mind of the architect [i.e., the mind who creates the ideas about what should be built].
When evolutionary biologists determine the structure or sequence of DNA, they believe they uncover the secret of life.2 Disregarding the fact that information is immaterial, they fixate on the material of DNA. But they are incorrect. Functioning just like specifications, DNA is manipulated by specialized proteins that enable it to transfer, transcribe, store, and recall information for building a living thing–but it is not the information.
The real secret of life is the [purposeful] information.
[Quoting Randy J. Guliuzza, “Natural Selection is Not ‘Nature’s Design Process’”, ACTS & FACTS, 39(6):10-11 (June 2010).]
In other words, by promoting both conservation and aquaculture, human experts are showing resourcefulness, by facilitating juvenile oysters to display their own resourcefulness! And both kinds of resourcefulness interactively display God’s own resourceful imagination – because it was God Who gave resourceful thinking to humans, and it was God Who preprogrammed and bioengineered resourceful instincts into homesteading oysters.
(PowerPoint slide credit: Joe Reiger’s Oyster Restoration Workshop)
So, what is the bottom line on this? God fitted oysters to fill many underwater habitats, not just oysterbed reefs composed of preëxisting oyster shells.
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