Let’s go time-traveling. We don’t need to go absurdly far — just back to 1870, the year my great-great grandfather was born. We’re not going to Indiana to visit him. Instead, we’re going for a boat ride in Charlotte Harbor. Being thoroughly modern, we’ll take a modern vessel with us.
We jump out of the space-time vortex right in the middle of the Harbor. Let’s choose a course. Why not head down to Boca Grande Pass and see what that looks like? As we fly along, we notice several things: First, the water clarity is crazy good. Second, there are fish everywhere. Third — CRUNCH!
What happened? We ran into an oyster reef. In 10 feet of water. Any idea how long until someone starts SeaTow?
In today’s Charlotte Harbor, there are a few scattered areas where you need to watch out for oyster bars. But a few generations back, there were towering oyster reefs here — big enough to be hazards to navigation in otherwise open waters. There were billions upon billions of oysters, so many that their filter-feeding kept the Harbor much clearer.
An average-sized oyster pumps about 50 gallons of water every day, scouring it for edible particles. The Charlotte Harbor estuary covers 270 square miles at an average depth of about 10 feet. According to math, that’s about 560 billion gallons of water.
In Chesapeake Bay, it’s estimated the historical oyster population could filter the entire bay’s volume once a week. In much shallower Charlotte Harbor, it was probably more like once every other day.
That means we once had about 5.5 billion oysters. Now we have roughly 5 percent of that, and so huge amounts of water that once were filtered through Mother Nature’s Brita now go uncleaned. Massive amounts of sediment containing nitrogen and phosphorus, once captured by the mucous membranes of oysters and deposited on the bottom with their droppings, now drifts free and feeds algae instead.
Where did they go? Once the railroads came to Southwest Florida, some were harvested and sent to the Northeast, where oyster reefs were already depleted by seafood-hungry city dwellers. Oysters ship very well. Reefs were dynamited to allow safer boat passage, mined for road-building materials, covered with sediment by canal and channel dredging projects, and suffocated by phosphate mine spills.
The bigger question is, can we get them back? Maybe, partially. Baby oysters prefer to settle on the shells of other oysters, so putting oyster shells in the water encourages live oysters to build there. Oyster restoration projects are currently underway in estuaries from New York to Texas. In Charlotte Harbor, we face a particular challenge in that the multiple state and federal agencies charged with ensuring the health of local waters are much more focused on protecting what’s left rather than restoring what was.
Thus, projects that would be clearly beneficial, such as oyster reef restoration, are met with the same level of official skepticism as dredging or other destructive practices. This regulatory logjam will have to be broken somehow if we’re ever going to have enough oysters to improve Charlotte Harbor’s water quality.
Capt. Josh Olive is a fifth-generation native Florida Cracker and a Florida Master Naturalist, and has been fascinated by all sorts of wild things and places since he was able to walk. If you have questions about living with wildlife, email him at Publisher@WaterLineWeekly.com. You can also follow him on Instagram @florida_is_wild.