TEEN ANGLERS ONLINE CLASSROOM

RECREATION AND EDUCATION FOR THE NEXT GENERATION

LESSON 7

THE MAGICAL POWERS OF THE ESTUARIES

Insults

Now that we have looked at some of the magic of estuaries, it's time to look at one final piece of magic. Recall that the "Magical Power of Estuaries" revolves around at least three, maybe four, different communities of producers: emergent, submerged and floating plants, and that the floaters come in two basic sizes: the microscopic plant plankton and the macroscopic (that is, visible to the naked eye) algae the drift in and out of seagrass beds. Remember also that estuaries have two completely different sources of power, and that estuaries also receive nutrients from two different sources: runoff from the land and incoming tides from the ocean. Now for the last bit of magic. But first, a little history. Until very recently, say the past several hundred years, we lived on and around estuaries without causing any lasting damage. The shoreline of Florida is littered with the mounds of native American peoples who lived here as much as 12,000 years ago -- yet these folks did no damage to the life of an estuary that we can see. And they lived along those estuaries for nearly all that 12,000 years. Then the invasion began, starting in the early 1500s. By the 1800s, most of the major coastal cities of the USA were already teeming with people, and with industry. After all, if you wanted to move cattle, or lumber, or tea, or anything else measured in tons, the easy way was by water. By the mid-1800s, Boston, New York, Philadelphia, Baltimore, Washington, Charleston, Savannah, Jacksonville, Mobile, New Orleans were all thriving port cities. On the west coast at the same time, San Francisco was leading the way. And all were built on estuaries. Where did the trash from all these millions of people and thousands of ships go? Overboard, into the estuary. And where did all the sewage go? Into the estuary. At that time, and even today in much of the world, estuaries were and still are considered buggy, bad-smelling swamps that made great places to dump garbage. Many, perhaps most, of the world's estuaries have been degraded by poisons, landfills, loss of habitat, overfishing and other of man's activities to the point that most if not all their magical productivity has been lost. In 1974 I wrote a series of articles for the Palm Beach Post about the importance of mangroves (our estuarine emergents) and seagrass beds. One of my interviewees was a former commercial fisherman who now owned a large seafood house. As we talked about the roles of mangroves and seagrasses in the productivity of estuaries, he suddenly leaned forward in his chair, took the cigar out of his month, and looked at me wide-eyed. "Do you know," he said, "my condo is built right on top of the grassbed where I used to catch all my bait shrimp!" That's called "loss of habitat." Now that I come to think of it, our president, Al Bernetti, and wife/webmaster Suzanne live in a condo on the water -- which was built on top of a grassflat I used to wade-fish 50+ years ago! Let's look more closely at some of the insults we humans heap on estuaries. We'll start with pollution. We can break pollutants down into two big categories: poisons and excess nutrients. The poisons can be further broken down into two big categories: pesticides and metals. Pesticides are used on lawns, farms, golf courses and lots of other places. We generally use more pesticides than necessary, and the excess then runs off into canals or rivers which feed estuaries. A moment ago I picked on our president. Well, he is definitely not alone. I am for sure an environmental criminal. And some of the stuff I did back in the early '60s will be around to haunt you-all throughout your lives. At that time, I worked in mosquito control for our county. And I put out probably 100 pounds of a pesticide called DDT; we used it to kill mosquito larvae in ponds, ditches, canals - wherever. Now DDT has a half-life in the environment of 20 years; that means that every 20 years, half of it is gone, but the other half is still out there killing all kinds of things. So if I put out 100 pounds by 1965, 50 pounds was still killing things in 1985. And in 2005, 25 pounds was still out there killing. And in 2025, 12 1/2 pounds will still be killing stuff. And in 2045? 2065? We biologists figure ten half-lives must pass before the stuff is diluted enough not to matter. For DDT, that's 200 years! Metals are generally poisonous at some concentration. Living things must have tiny amounts of some metals; iron, for example, is at the heart of the hemoglobin molecule, and if you, like me, don't process iron well or get enough, you are anemic. Magnesium, of all things, is at the heart of the chlorophyll molecule. But metals in overdose are highly poisonous, and some of the amounts involved are so tiny they are hard to believe. Some of the common metals seen in waterways include copper, zinc, lead and others. These metals get into our waters from the wearing of tires on pavement, the gases coming from the tailpipe on your car, burning coal to generate electricity, and multiple other sources. Now to excess nutrients. They come from two main sources: agriculture and sewage. The nutrients we worry about mostly are nitrogen and phosphorus, in the form of nitrates (or ammonia) and phosphates. Sewage is the easy one to control, but we don't do a super job of it. Yeah, we treat our sewage to remove bad bacteria and viruses - but most treatment plants don't touch nutrients in the effluent from the plant. A few, known as advanced wastewater treatment plants, do remove excess nitrates and phosphates from sewage effluent, usually by allowing the effluent to sit for a while in a marsh or pond, where plants grow and take up those excess nutrients. Agriculture - and suburban lawns and golf courses - are harder to work with. A sewage treatment plant is known as a "point source discharge," which means the nutrient-laden effluent leaves the plant through a pipe (a "point source"). Agriculture and suburbia are harder to work with; their excess nutrients and poisons just run off the land all over the place. But always downhill, and usually into a ditch, canal, river, lake, pond - or estuary. A town I lived in a few years ago (Jupiter, FL) is actually collecting that overland runoff and treating it as sewage. It ends up going through an advanced wastewater treatment plant - and it costs money to do it. Agricultural runoff can also be collected and treated (usually by giving it time in a marsh or pond) to allow plants to remove excess nutrients from the fertilizer used on the farm. Question: where does your milk come from? Cows, of course. And cows give more milk if they feed on rich grasses, made rich in nutrients by artificial fertilizers. Question: how many cow splats does a cow produce in a day? These are loaded with the nutrients the cow didn't utilize - and the average cow produces 80 pounds per day! So a pasture with 100 head of dairy cattle produces 4 tons of sewage a day. Where does it all go? Worse still, how about pigs? We raise lots of pigs, and their feces are especially noxious - and loaded with nutrients. Talk to the folks who live in North Carolina about the effects of a hurricane which flooded pig sewage ponds; the rivers carried the "stuff" into Pamlico Sound, and created two dead zones in the Sound. Or talk to commercial fishermen in Louisiana, where the Mississippi River has created a dead zone of thousands of square miles in the Gulf of Mexico - from excess nutrients carried downstream from the farms of the midwest. So we have horror stories. What can we do about them? We've already done the easy stuff. Point sources of pollution, easy to identify and act on, are by and large under decent control. Nonpoint sources are the hard part. And that's where the effort is going today. What can you, as an individual, do? You've already started, by joining Teen Anglers. A next step, if you wish, is to do volunteer work. Talk to your state and local parks people, see if there are any stream or pond rehabilitation projects you can work on, find out about your local government to see if they have any projects that might use you as a volunteer -- things like planting trees, water quality sampling and so on. Another direction where you can make a difference is to join an organization which promotes conservation. Ducks Unlimited, Trout Unlimited, Audubon, the Coastal Conservation Association -- there are many organizations looking for members to help on their projects. Maybe even get a group of you together to do something. One person CAN make a difference! Good fishing, tight lines, and may the wind always be at your back. Test Lesson 7  HOME PAGE OF THE TEEN ANGLER WEB SITE       Can you figure it out before next month?  Bob Bergen, Professor of Science, Retired. Teen Angler Mentor Copyright © 2008[National Teen Anglers]. All rights reserved. Revised: February 10, 2010   HOME PAGE