The effect on fish life has been devastating. Many species, such as tarpon and snook, spawn only in brackish water. Among most species common in the area, juvenile fish can tolerate "sweeter" water than can adults. And because most fish are cannibalistic, the brackish estuaries provide a haven for the young, keeping out older fish that would gobble up even their own young.
The National Park Service recognizes the water-shortage problem. In reply to a letter from U.S. Representative Dante B. Fascell of Miami last February, the Park Service's Southeast regional director, Joe Brown, wrote, "Changes in the management of fresh water in southern Florida over the past 20 years apparently have destroyed the low-salinity estuarine nurseries that once supported local fisheries. These areas are now yielding fewer—but generally larger—game fish." Clearly, the big fish have invaded the once sacrosanct nurseries, and are consuming more offspring than they did in the past.
Another factor pointed out by Davis is that South Florida is long overdue for a hurricane. "This region usually gets hit by a tropical storm or hurricane once every five to seven years," he says. "The last big blow we had here was Betsy, in 1965." A hurricane flushes the system in a somewhat heavy-handed way. A great volume of rain falls, replenishing the marl and, to some degree, the aquifer. The nutrients that have been locked in place on the bottom and in the mudbanks are washed out, mixed and recycled throughout the system. Still, a hurricane is a high
price to pay for what would only be temporary relief.
One measure that should help reduce some of the park's salinity is already in the works. Next year the Army Corps of Engineers will plug the Buttonwood Canal, a cut made in 1922 to join the saline waters of Florida Bay with the brackish-to-fresh waters of Coot Bay and Whitewater Bay, two inland bodies of water near the west coast. The result of hacking this six-foot-deep-by-80-foot-wide shortcut has been high salinity in Coot Bay and lesser but substantial salinity in the vast reach of Whitewater Bay. In the 1979 federal budget $1.3 million has been allocated for the plugging operation.
"Plugging the Buttonwood should restore Coot Bay and Whitewater as nurseries," says Ruoff, "but the main benefit will be in the waters west of Cape Sable, out in the Gulf, which doesn't do too much good. It's the areas east of the cape that are suffering most from excess salinity. There's been talk of putting in a pumping station at Taylor Slough, east of the bad area, and shunting excess fresh water into Florida Bay rather than dumping it into the Atlantic. But that's still in the talking stages."
A storm cloud was now building to the west, growing larger, blacker and more ominous by the minute. That stifling, dead-quiet heat that precedes rain in the tropics was nearing a climax. "We've got an hour or two before it hits," said Hank Brown, squinting to the westward. "Then she'll cut loose—blessed sweet rainwater. Let's head on into Madeira Bay and see what we can hook up with." The guides fired up their motors and we skimmed into a shallow cut that allows access to the nearly perfect oval of Madeira Bay, an inlet of Florida Bay. Inside, the water went from gin-clear to mocha-brown in a skiff length, the indication of streams feeding into the Bay from the mainland. It is the food from these streams—microorganisms that draw mullet, crustaceans that attract baitfish, tarpon and other game fish—that still makes Madeira productive for the angler.
Mullet were mudding in a vast, beige fan near the outlet of one of the streams. Bottom feeders, they stir the muck to suck up microorganisms. In the process they frighten shrimp, crabs and other bottom dwellers on which red drum, sea trout, sheepshead, bonefish and channel bass like to feed. The mullet in this part of Florida Bay are primarily of the silver variety, a smaller species than the black mullet, which go up to two pounds. Because of their small size (three-quarters of a pound is average) and inferior eating quality, silver mullet are sold mainly for bait, while the black mullet, most common on Florida's west coast, are used for food.
"Apart from the salinity problem." said Brown, "there's the question of the commercial netters. When the park opened back in 1947, there were only about 15 or 20 men fishing this area commercially. They were tough old back-country guys whose families had been hacking a living out of the Glades since the days of the Seminole Wars. I've been told that the first park superintendent promised to let them keep fishing but that no new permits would be issued. We've checked all the records for that time but we can't find such a promise in writing.
"Anyway, what's happened is that the park is still issuing permits—more and more of them in the past two years. Right now we figure there are 181 commercial netters working the park waters under permit. In the two years since John Good was made superintendent, netting permits for the park have gone up by 67.6%. At the same time, the mullet catch is taking a nose dive—from 1,436,500 pounds in 1975 to 387,000 pounds last year.
"Sport fishing has fallen off, in our experience, by the same degree. I've worked these flats and banks all day, looking for mullet mud and the fish that will feed in it along with the mullet. Then when I finally find them, a commercial boat wheels up and sets its net—bang, just like that. You can bet your boots that plenty of redfish. snook, bonefish and the young of many species get taken in that gill net, all of them gilled out, killed, along with the mullet."