Can Manatees and Humans Coexist, And Why Do I Care?

I grew up in Florida, in central Florida to be exact. As a kid we went to Blue Springs and other manatee havens on field trips, to observe these gentle and curious animals. They are huge, and as they tend to inhabit shallow areas of the Florida coastal waterways its easy to see them in the clear springs of Florida, and even swim with them in some cases (not recommended, as you may inadvertently injure them). In the 1980s and 1990s, when i lived there (before I went back for undergrad) manatee conservation was forefront. They were nearly gone; hunted to the brink of extinction in the earlier part of the century, with the remaining population falling prey to the razor-sharp propellers of fast-moving boats. During one field trip, we noticed that every single manatee had scars on its back. Yeah, every one. In fact, the conservationist leading the trip told us that that was how researchers told individual manatees apart in most cases. Because the scar patterns were unique, and manatees without scars were that rare. That made me incredibly sad.

Florida is a land of rich natural ecological beauty and diversity. When Europeans landed there hundreds of years ago, hundreds of times more manatees lived in Florida and were a vital part of the ecosystem of its waterways. Slow-moving and curious manatees were quickly hunted to low numbers for their meat and blubber until a very small population was left, quite similar to the plight of the slow and defenseless Dodo. As I look back, I feel very grateful that the elementary and middle-school teachers I had imparted to me a sense of wonder (rather than utility) in regards to the wildlife of Florida. Ecotourism is a huge part of what makes Florida special. If legislators and residents aren't convinced that saving the manatee is important per se, they better look to their property values. Manatees eat aquatic plants which clog Florida's waterways. When there are too few manatees (like now) these plants must be artificially cleared from the waterways else they clog boats and prevent safe (and fast) passage. This clearing sans manatees takes place at a cost to taxpayers and to boaters, therefore the presence of manatees actually makes boating better and easier. Eliminating this natural clearing system is downright stupid, if only from a fiscal perspective.

Given that Florida is reconsidering whether manatees are actually endangered, I thought I'd take a look myself and what seems to be the problem with these creatures: why do they keep getting run over by boats? Well part of the problem is that the number of boats in Florida has skyrocketed in the past 50 years. There are currently more than 900,000 boats registered in Florida and another 350,000 which are registered in other states by used in Florida. Thats a *lot* of boats in the water at any given time, and prime boating season coincides with manatee migration and high activity (they move when the water gets colder, which is when the snowbirds come to Florida to spend the winter). Below is a graph that charts the percentage of manatee deaths which are attributed to boating as well as how many manatees have been killed over the past few decades.

i-73b8febb04aa59b289a985cea61e1975-mantee figure.jpg

The other part of the problem, as detailed in studies by Ed Gerstein and colleagues, is that manatees live in an environment full of ambient noise and cannot reliably detect the sounds of boats. Therefore an on-board signaling device which is tailored to manatees (ie, a warning device) could prevent unnecessary deaths.

Manatees and whales may be well adapted to hear and detect significant biological sounds in their environments; however, boats, ships and barges were never part of their evolutionary histories. Thus these animals are faced with modern ecological challenges for which they are at a sensory disadvantage. In light of the psychoacoustic measurements described above, the known acoustical characteristics of shallow-water habitats, the spectra of boat noise and the dangerous, deceptive problem of acoustical shadowing, it is apparent that manatees, and perhaps other passive-listening marine mammals, could benefit from an acoustic warning device designed to fit on the front of boats, ships and barges.

However, the lobby group that is attempting to kick manatees off the endangered species list is twisting this research for their purposes: well, if manatees can't hear the boats anyway, why make them slow down?

Thing is, the story of the manatees is not a new one. Human development hits an environmental snag. Said snag is preventing well-funded, well-connected interests from making money or enjoying themselves the way they deem fit. Guess what? In pretty much all situations its the environment that absorbs the damage, NOT the interested-party's bottom line. Manatees will become extinct, because the number of boats isn't going down, neither is the number of tourists and residents using the waterways, anytime soon. The reduction of protection for manatees isn't done in the dark: ALL interested parties, and ALL governmental institutions know exactly what they are doing. They just don't care.

Thats where the common citizen comes in. Only public outrage and outcry will change the minds of Florida legislators in regards to manatees and their protection. Florida should take up the flag themselves, and fight the good fight. It breaks my heart that that isn't happening. Truth is, people are going to have to yell long and loud to counteract lobbyists who want to boat where-ever they please. Are conservationists up to the task? Where is the coverage, the blog posts, the opinion pieces, the stories in response?

If you are a blogger, or if you have a voice, please consider examining the issue. At risk of sounding like LeVar Burton, don't take my word for it. Examine the issue yourself. Start here, and check out the link to the report in that post. And if you can do something, please do.


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Uh oh, looks like I hit a nerve. Well Steven, I'm certainly interested in your point of view but I don't appreciate your tone. If you want to continue commenting here, please note my commenting policy to the left which is basically, please be respectful. Else your comments will be deleted.

One thing I've always wondered, (as a paraoid kid going fishing on my Grandfather's boat off the Jersey shore who was always scared I'd fall off the back and get mauled to death) is what prevents some sort of cage (similar to what protects a fan) from being around a motor? Wouldn't this help reduce the manatee injuries?

As Patrick Henry (curse his theocratic soul) once said, "Give me manatee or give me death!"

By Mustafa Mond, FCD (not verified) on 11 Apr 2007 #permalink

what prevents some sort of cage (similar to what protects a fan) from being around a motor? Wouldn't this help reduce the manatee injuries?

Yeah, that might work. A propellor shroud might increase susceptibility to clogging with seaweed or rope, and any damage to the shroud might prevent the prop from turning, so there's a downside to be weighed.

By Mustafa Mond, FCD (not verified) on 11 Apr 2007 #permalink

Its manatees that eat up those clogging aquatic plants, so if there were more manatees saved by housed propellers, there'd be less plants to clog up the housing.

The prop cage and the signalling device are both great ideas, but unfortunately they cost money. I have a feeling that the types of people who consider just slowing down their boats to be an unacceptable inconvenience won't be quite so receptive.

I also have a feeling that the vast majority of the citizens who support these lobbying groups can't really be convinced to support conservation instead unless it is framed in terms of economic good or their own self-interest. They've already made their list of priorities (of which conservation is very far down), and I think that these sorts of things are very hard to change.

Shelley was on track with her piece, then got lost in conspiracy tales. Look, I'm the Exec Director of Florida Marine Contractors Association, folks who build docks and seawalls. A few years ago, the whole industry was shut down -- shut down.

You could not legally build a dock in Florida because various lawyers were fighting about how much manatee "protection" is enough. "Protection" was defined as slow speed zones, and cops to police those zones. Seriously, you'd have more cops on the water watching for boats going 6MPH (too fast!), then on I-95. Seriously.
If the lawyers (and lawyers and science do NOT go together) thought an area was "inadequately protected," then you couldn't build a dock, the logic being it might add a boat to the inadequately protected waterway.
While the legal fight went on, thousands of people whose only "crime" was to build a dock were put out of work. Oh, yeah, huzzah for manatee protection.
When we sued the Feds to say their work stoppage was illegal, we were able to raise a whopping $80,000 from across the state for the case. Big money rolling, to be sure. (When the Manatee Club filed its suits that caused this mess, their attorneys pocketed some quarter of a million in "fees," which the judge said was the value of their effort/
We won, but the BS you go through to permit a dock means that most people -- over half -- don't bother at all. Our lawyers received no "fees," either, despite prevaiing. Long story why. But during the earlier lawsuits, because our organization couldn't raise the money to participate, my predecessor as Exec Director had to cool his heels in a hallway outside a judge's chamber, where the folks with the bucks (the Manatee Club and 17 other groups), wrote the terms of the settlement. Yeah, transparent government and democracy.

I realize that the manatee becomes more 'endangered' the farther you get from Florida. Folks, it's not endangered. Moreover, those speed zone "protections" have had damn little to do with its "recovery." There's no evidence they work -- and there's not even a method to measure effectiveness. No kidding. People just wanted to believe that speed-happy drunk boaters were out to chop some manatee bacon for brunch. And a Washington Federal Judge readily bought the BS.

Yes, please, check out this issue -- but you're gonna be very surprised when you read the current peer-review literature. You'll also be -- I hope -- embarrassed by conspiracy theories that doubt the integrity of the science community that's been working on both the manatee's "status", and a host of related issues.

People like Perran Ross, Elsa Haubold, Chris Fonnesbeck, Richard Flamm and Mike Runge are -- well, they're a lot brighter than me and I bet brighter than you, too.

I also know that manatees really aren't that important to people who don't live around them, like me. You'll post your baloney about how Bush is wrecking the ESA (actually, all the "protections" we're talking about happened during his terms -- ouch), you'll demean people you don't know and talk trash about Florida. But, you'll maybe take the time to learn the facts -- note I did not say truth, which is subjective -- or you'll probably say it ain't no thing for you, and move on to the next "outrage". Which is the most over-used word in the language these days.

Sorry to be grumpy and long-winded.

Uh oh, looks like I hit a nerve. Well Steven, I'm certainly interested in your point of view but I don't appreciate your tone. If you want to continue commenting here, please note my commenting policy to the left which is basically, please be respectful. Else your comments will be deleted.

No one here is out to get all the dock-builders fired, or to even reduce the number of boats/docks. My point is to attempt to find ways that manatees and boats can coexist. I don't want the industry of which you are a part of "shut down," and its unfair to blame people who are concerned with the status of the manatee for the red tape that is the result of mismanaged laws and court cases. Yours is not the only industry to be affected by species protection laws and I guarantee it will not be the last. Wherever people and the environment collide will be messy and painful, it inevitable. The trick is being able to reconcile the two. Please remember that your livlihood also depends on there being functional and beautiful waterways, the manatee is part of that ecosystem.

I am not far from the issue, as you suggest. As I mentioned in my piece, I've spent nearly my whole life in Florida. I went to undergrad in Manatee County and directly studied manatees at Mote Marine Observatory in Sarasota. As for the scientific literature, please direct me to papers in addition to what I've discussed here, which I'd be happy to take a look at if you think it supports your point.