Nature Does It Best

In fact, the mangroves on Big Edwards are greener and taller than those growing a few feet away on an oyster “spit” that has NO PINES AT ALL. Permit me to say that again (I said it about four times to Doug Sword, but it was Not Mentioned In His Article –“NMIHA,” let’s call it, to save repetition below). On Big Edwards, the mangroves are taller than the island nearby where there are NO pines or other trees of any kind.

With oysters and a swarm of other creatures nestled in their roots, the mangroves are helping to build and protect a tidal shallows that slopes gradually away from most of Big Edwards’ shoreline. It’s called “inter-tidal habitat,” and it’s the nursery and supermarket for a vast bounty of marine life. In only a few spots do easily-trimmed tree branches come anywhere near Big Edwards’ mangroves. Pines can’t be bad for mangroves, I thought a year ago, as I looked at both growing on the island. Mangroves and pines co-exist there, and they have flourished together for decades.

Why do both species get along? The pines grow “upland,” on higher ground, not in the water. Mangroves grow with their roots in the water, some distance away from the pine canopy. It’s because mangrove roots are in the water that the plants can stabilize shorelines, shelter creatures and remove some excess nitrogen from the water.

I double-checked with Professor Langeland and other FLEPPC biologists recently (the leading critics of the pines). There’s no doubt about it: according to the experts, what one sees on Big Edwards is not a fluke or a mirage: the mangroves grow with their roots in the water. The pines grow “upland, “ away from the water, and, generally, as on Big Edwards Island, well away from the mangroves.

That a former Vice-chairman of the Pest Plant Council advocates removal of invasive plants, the Herald-Tribune found the space to report. But that the state’s top critics of Australian Pines say that the critique of the pines is not about water quality, and that mangroves commonly can (as on Big Edwards Island) co-exist with Australian Pines—this, the Herald-Tribune did not report.

Some say they favor scooping out land from portions of Big Edwards Island to create “inside” shoreline and watery pools where additional mangroves could grow. There’s no actual plan, and the article didn’t describe one, but using old diagrams, my measurements, discussed with Doug Sword (but NMIHA--not mentioned in his article), suggest that after cutting new channels through the mangrove shallows for water to flow into the new holes, there wouldn’t be enough room remaining to add back enough mangroves to make a meaningful difference to water quality in Roberts Bay. At 1,700 acres, it’s not a tiny waterbody.

If the plan were to add two big holes in the interior of the small island, the costs are expected to include sacrificing a popular beach, and scraping and barging enough sand and dirt to fill at least four football fields three feet high—while trampling all over the second largest mangrove island in the Bay. It’s an even bigger project if such “island-top-destruction” is attempted over the entire island. So much earth-moving appears quite extravagant when measured against the present need and promised benefits (just about none, to water quality, we’ll get to “habitat” shortly). All that barging, trampling, channeling and diverting of the current poses a risk to the existing mangroves on Big Edwards, to the inter-tidal habitat that nature has been building there for more than 50 years, and to the remaining seagrass in the north end of Roberts Bay (the Bird Rookery islands are close by). [NMIHA]

(Curiously, in 2,800 words promoting “restoration” and completely ignoring any suggestion that the Bay is better served by safer, proven efforts addressed to more pressing needs, the paper did not tell readers, including many who have played, hiked or rested there, that removing some—or all—of the island above the waterline was among the restorations that officials had pondered).

Various hole-punching plans were proposed by the Army Corps of Engineers 10 years ago, but resoundingly rejected then because they destroyed the beach and boater recreation, in addition to killing the unusual and spectacular look and feel of Roberts Bay. The key point to remember: such a “restoration” will chop up Big Edwards Island, and cut channels through mangroves and inter-tidal habitat that nature has been building there. By ripping away some of nature’s habitat on the outside of the oval-shaped island, one could put some additional human-planted mangroves into newly designed holes inside, but even that won’t matter to water quality in the Bay--or its main fresh-water tributary, Phillippi Creek, which flows into Roberts Bay two miles south of the island.

Take the extreme case: barge away the ENTIRE island and replace the entire six acres with new mangroves. By how much could that reduce the level of nitrogen in the Bay’s waters? By virtually nothing. Those added mangroves would occupy a volume of water amounting to less than two-one-hundredths of one percent of the water in the Bay—and none of that water goes upstream to the fresh-water portions of Phillippi Creek, the area of water quality concern.

This may sound technical, but the point is clear: To claim water quality as the goal of cutting down the pines or “restoring” the mangrove island is to mislead the public, shift attention (and resources) away from more urgent measures that DO make a difference to water quality, and make a false claim about the results to be obtained by using public funds--a deplorable tactic made worse when you consider that “restoration” experts believe the results are better when nature does the mangrove planting, not restorers.

Trout, Oysters, Crabs, Mullet, Snook...

Spurred on by the tangle of mangrove roots washed over by the tides, the fertile shallows building out from Big Edwards Island show that Sarasota’s ancient estuary is doing its job. With oysters, sea trout, crabs, mullet, snook and an amazing array of other marine creatures finding their way to the Island’s coves and meanders, Mother Nature’s supermarket is open for business. (Local fishermen get excited when they recall the action this year around Big Edwards Island before the cold spell hit. As one supplier to Walt’s fish market puts it: “The Bay was on fire!”) A swarm of nine-armed starfish (numbering about 80) burrowed in the sand last spring, near one of the sandy beaches. Three kinds of seagrass hold fast to the bottom in various spots around the island, while dolphins splash past the tiny spiral shells of snails. The intertidal zone abuilding around Big Edwards fascinates, because it is the living Bay at work doing its own restoration. It shows that the Bay can respond naturally even to the assault of careless dredging and dumping that created the island in the 1950’s, given half a chance and 50 years of time.

What then, of other reasons sometimes offered for cutting down the pines? For example, the birds. I love to see them on Big Edwards Island—in the pines and wading in the shallows, and I could list many. But why bother—it’s beside the point. It would be like talking up the junior college football team when the Super Bowl is right next door. About a block southeast of Big Edwards as the osprey flies are those bird rookery islands, termed “the most important bird sanctuary in Sarasota Bay” by Audubon of Florida’s Ann Hodgson.

Like the VIP floor at nature’s own Ritz-Carlton, the bird rookery islands serve their guests by teaming up with Big Edwards. The steep-sided bird islands offer protected suites to the avian guests. The gently sloping shores of Big Edwards are a dining room, offering marine meals to wading birds at low tide. (For birds like ospreys who don’t wade to breakfast, meals are on offer all day long in Roberts Bay). Those with other lifestyle preferences have a broad choice of accommodations and menus nearby on the mainland and Siesta Key. No doubt it’s possible for designers to imagine changes they might wish for, but it’s hard to actually look at Roberts Bay’s super bowl and dining service for birds and see a priority need—or any significant need--for another artificial intervention.