Sunday, March 7, 2010

7 Weeks Left to Earth Day! Week 10: Manatees!

It’s been a lengthy, cold winter in Florida this year and an unprecedented number of manatees have died.   Manatees are not able to tolerate water temperatures below 65 degrees and die slowly as their immune systems fail.  A record number (5000) of Sea Turtles have also been affected by the cold, stunned into a coma-like state that would have killed them if not for being rescued by state and federal Wildlife Workers .  While humans continue to debate the ins and outs of climate change, or climatic instability as I prefer to call it, the planet’s flora and fauna are struggling to adapt, and so are we!

Manatees have long fascinated humans, in fact long ago, sailors thought that they were a kind of mermaid, hence their Latin name Sirenia.   West Indian manatees (Trichechus manatus), sometimes referred to as sea cows, live in shallow coastal waters, estuaries, rivers and canals.  These gentle giants can be found in  Florida during the winter months but migrate as far north as Virginia or west to Louisiana during the summer.  This species of manatee ranges into the Caribbean and down as far south as Brazil.

Primarily nocturnal, they can be seen resting close to the surface both day and night and though mostly solitary, they do interact with other manatees, especially when the weather is cold.  Here in Southwest Florida large groups can be spotted near the Florida Power and Light, warm-water discharge on the Orange River in Lee County. where they huddle to try and keep warm!  They can also be seen at  Manatee Park
Manatees move in and out of salt water and fresh water habitats following the food trail for the most part!  They are herbivores, feeding mostly on sea greases, but will eat most aquatic plants.  Despite their vegetarian diet, manatees grow very large and can weigh between 800 and 3,300 lbs (400-1,500 kgs)!  They move easily through the water, propelling themselves forward with their tails.
The split upper lip of the manatee allows them to pass food easily into their mouths while they feed and they use their flippers to dig up plant roots.  Chewing sea grass wears out their teeth and so they grow new ones which slowly move forward as the old ones wear out!!
Manatees are listed as endangered and sadly this year’s record cold has hurt their numbers even more.  Mostly they are harmed by boat propellers; some folks do not adhere to the speed limits in shallow water zones and the propellers cut into them.  You can learn more about manatees at this Website . 

Lesson Plans:
1.  Introduce children to manatees; if you live in a region where manatees live then perhaps they will have see some; if not, then they’re an interesting species to learn about and quite different from other mammals.  This Video shows them in their water world and here are some helpful ideas from National Geographic to get you started.
2.  Geography: Explore some of the places where manatees and dugongs live.  In North America  manatees migrate north during the summer months; follow their journey and discover where they go.  Do they visit the same places every year?  How long does it take them to reach their destinations?
3.    Manatees’ primary diet is aquatic plants including sea grass, an important component of estuarine ecosystems.  Seagrass beds stabilize the sea floor with their roots; help to filter water by trapping particles in their leaves; slow down wave action during intense storms and provide a nursery habitat for a wide variety of marine species.  Unfortunately speeding boats can significantly harm these underwater meadows.  Learn more about Seagrass  and explore other species live in seagrass beds.
4. World Water Day  is coming up; plan some activities related to water.  Is there a creek near you that needs protecting?  Do you live up-river or down-river?  Here are some Resources related to Water that might be helpful to you.  Also, there is a campaign called Walking for Water– perhaps you can get your school involved.

Manatees help to control the overgrowth of seagrass beds and they benefit seagrass growth by dispersing the seeds around the sea floor.  Because manatees also graze in freshwater habitats, they help to control the growth of nuisance and invasive plants such as water hyacinth.

I couldn't find any stories about manatees, so, since they were often thought to be mermaids here are some stories that you might find enjoyable: The Fisherman and his Soul (quite long)  Here is a Collection of Mermaid Tales
Song  Well, the Manatee Song seems to be the obvious choice here! 

Green Action of the Week!
We are all interconnected, so even if we live far from the ocean, we can still make a difference and help to protect it.  Working together for the manatees is a National Geographic Lesson Plan that can help you kick start a program to lend your voices to the protection of these gentle marine species. 
Enjoy your week and please let me know if you have any special projects so that I can share them with readers.
With gratitude for life and this beautiful Earth!

Extra Resources:
Manatee  Lesson Plans Grades 1-5
Lesson Planet: A Collection of Lesson Plans on Manatees: 

Manatee Photos: USGS and NOAA
Labels: manatee, water

No comments:

Post a Comment