Beaches and their place in nature
By John Potter
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Do you enjoy going to the beach, communing with nature and knowing that you are enjoying the beach just as ancient peoples of the region once did? If you want to keep that feeling more than you want to know the truth don’t read any more of this page.
The National Oceanic and Atmospheric Association defines a beach as “A deposit of non-cohesive material (e.g. sand, GRAVEL) situated on the interface between dry land and the sea (or other large expanse of water) and actively “worked” by present-day hydrodynamics processes (i.e. waves, tides and CURRENTS) and sometimes by winds”. “
Beaches are somewhat like organisms. They grow and shrink, move, change shape and can repair themselves. They are affected by factors including wind, waves, sand supply balancing each other….if we’re lucky.
Beaches naturally erode and recede. Of course this isn’t good for tourism or local folks who like to visit the beach. In most places with beaches they constitute a significant economic contribution to the community and losing them to erosion is not an option most communities would willingly accept. So, if a community decides to fight erosion what options do they have?
There are basically three options to battling beach erosion:
- Structural: Build things to stop the erosion.
- Retreat: Keep moving structures away from the beach as it recedes.
- Nourishment: Replace the sand that’s been washed away.
Structural solutions were used for a long time, but now nourishment is the favored method. The drawback to nourishment is that it has a limited lifespan and will have to be done again and again. You can see photos and read complete explanations on NOAA’s site at NOAA PAGE
Retreat is the most natural method of course, but since people like to build roads, houses and hotels along the beach it is seldom used.
Keeping beaches from washing away is so common that there is an industry built around it called Coastal Engineering. Coastal engineering is the study of the processes ongoing at the shoreline and construction within the coastal zone.
In order to nourish a beach the sand has to come from somewhere. Usually it is dredged from as close offshore as possible to reduce costs. This has become a problem in South Florida where dredges now have to venture all the way to the Bahamas. The solution for Miami is to dig a giant underwater hole offshore to try to capture the receding sand, and for Fort Lauderdale using ground up glass bottles for beach sand. Does that sound crazy? Listen to the story on NPR… NPR STORY
My opinion…
Beaches are the cornerstone of many local economies, South Florida’s certainly are, and we cannot afford to loss them even if the methods we use to preserve (or more accurately replace) them are grossly unnatural and probably having a negative impact on the environment.
I haven’t found many (but some pretty strong ones) negative comments on beach nourishment other than that it’s expensive and doesn’t last long, but I can tell you from personal experience that it has a negative impact on the environment. Dive off of Fort Lauderdale Beach and observe half buried dead coral heads for yourself. All of that sand they cannot retrieve has to go somewhere and I think it’s burying coral reefs and other ecosystems.
We’re a long way from having tourists who can appreciate a nice estuarine tidal marsh as much as a beach, so I think we must reluctantly accept present circumstances and continue to shoot ourselves in the foot.
It would be really nice if an education campaign could be stared to try to wean tourists of their obsession with beaches and get them interested in other qualities of natural coastal areas. Any businessman will tell you that the risk of just chasing the tourists away is too high.
Another option would be to place building moratoriums on land close to the beach. This sounds reasonable to me, but I doubt many people would agree with me.
These decisions that we are making now will come back to haunt us. Under the circumstances we are using up our coastline in an unsustainable manor. Either we change or in a generation or two the beach will have be so fake it will be like a ride at Disney World. Unfortunately I don’t think many tourists will mind.
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“Beach Renourishment at Cape San Blas” clip from Youtube (not an Escape Key Graphics product) |
