The Wonders of a Seahorse

Early Thanksgiving morning, a group of intrepid adventurers set out on the East End for a Sanibel Sea School early morning beach walk. One of the great things about a beach walk is that the rewards are directly related to the effort – the more you look, the more you find. And let’s face it, these days, few things in life are so simple and so direct.

And so we set forth, sleepy and cold to discover what the sea held for us. It was an unusually low tide and many sand dollars were evident just beneath the sand on the outer bar and there were other fascinating things, but mostly everyday stuff. When all of sudden, the kids let forth shrill, brilliant screams of delight. There amongst the red algae, in the moat between sandbars, they found a seahorse. A spectacular specimen – beautiful brown with long stripes – appropriately enough, a Lined Seahorse; this one was nearly five inches long.

Seahorses are fabulous animals. They, of course, are fish and while mostly overlooked, they are not really all that uncommon on Sanibel. They prefer seagrass meadows and mangrove habitats. There are about 50 species worldwide; we have two. And as a whole, they are not well known to science, but what we do know is that they are pretty amazing.

Most fish are broadcast spawners. They release eggs and sperm into the water to be fertilized, and the fry to fend for themselves, from the moment of conception, with no parental care. Some fish make nests and tend their eggs, and others actually carry developing eggs in their mouths. But in seahorses, the male literally becomes pregnant - a female deposits her eggs in a special pouch on the abdomen of the male. He fertilizes the eggs and seals the pouch until the eggs hatch and the young swim away. As they develop, the male provides nutrition and oxygen to the embryos, and he regulates the salinity of the pouch. The eggs mature in two to four weeks, and then the father goes into labor and squeezes out the 100 or so young. At that point, they are on their own.

And, most seahorses appear to be monogamous; they become pair-bonded and repeatedly mate with the same mate; some for a season, and some perhaps for life. The female comes around once or so a day and checks in with her mate. They dance for a few minutes and then go their separate ways until the next day. And usually within hours of the male releasing his brood, they undergo ritualistic mating dances lasting up to eight or nine hours. Their gyrating dances culminate with the female depositing more eggs to start the cycle again.

Fascinating stuff, but, early that blustery November morning, all these facts are lost; as well they should be, to the sheer joy of discovery of a great big old seahorse alive and well, in the moat between the sandbars, in the shadow of the Sanibel Lighthouse. One of the many things to be thankful for on our Sanctuary Island.

A litte coconut husk hat fun at lunch. A great way to have a little fun.

A Roseate Spoonbill glides over Ding Darling National Wildlife Refuge

A Great Day for Learning, Fish and Fun

Today was one of those perfect days to be in the field in SW Florida. This Little Blue Heron posed for us on Wildlife Drive in Ding Darling National Wildlife Refuge. Then we saw a large group of White Pelicans. White Pelicans winter here and spend their summers in the Rocky Mountains. It is great to see old friends return to the Refuge. White Pelicans are much different than our beloved residents, the Brown Pelican. It is nice to see them side-by-side. We also got a peak of a nice little American Alligator.

Then we were off to the beach for some beach ecology lessons. We were had a nice day of seining at the beach. Katie Schroll, of Medina, OH is shown here showing off some of the many fish we were able to seine off the beach. The weather here was a little warmer than back in Ohio.

Our Gulf waters are alive with baitfish this time of year and it is great to see these little creatures first-hand. We were also able to catch a large number of sand fleas in our seines.

And, of course, what would a field trip be without a little plain old fun?

Living on an Island in an Estuary

Most of us love living on an island, but let’s not kid ourselves, we really live in an estuary. Yes, on an island, but an island in an estuary. We are not a sentinel island standing alone in the sea. We are part of a magical place where continents, and the fresh water draining them meet the ocean. Estuaries are places of transition from one world to another, a cauldron of admixture, and in many ways a place of birth, reunion and rejuvenation. The most powerful forces on Earth, colliding.

If you’re like me, you feel a release, the moment you hit that bridge – west bound and home – to our little island. I’ve noticed the release comes when I first hit the bridge (the estuary), not always crossing to the island.

Estuaries are among the richest environments on Earth and oddly this richness blooms amidst eternal change. The fresh water brings with it a rich mixture of nutrients and materials from the continents – nutrients for marine plants to grow and flourish, which in turn provide the energy for vast and far-reaching ocean food webs.

Estuaries change – they vary in temperature, salinity, depth, nutrient levels, and the amount of sediment in the water. And, the pace of their change is rapid. They change with the tide, they change with the seasons, they change with the weather, and even the arc of the sun. To record environmental conditions of estuaries, scientists take measurements on a scale of minutes. Longer intervals allow changing conditions to go unnoticed. Electronic instruments that record various environmental parameters every several minutes are allowing us to better understand estuaries.

We are facing tough environmental challenges on our island. And rightly, many of us are at best, bewildered about our future. How we can help and what we can do to make things better – these issues perplex us. Often we are inundated by the onslaught of problems we face – what can we do? A first step is to recognize that our Sanctuary Island is not just an island, but part of an extensive estuary system. A system reaching from Gasparilla Island to our home here on Sanibel, and eastward into the middle regions of Florida. Estuaries are where rivers meet the ocean. The entire land region drained by a river is known as its watershed. So, really we are a part of the watersheds that are drained by the rivers that feed our estuary. Watershed management influences our environmental harmony.

A sanctuary island in an estuary that drains a watershed. Great, so how does this help us face our problems? We need to remember that we are not alone; we are a part of a system with shared problems and we will find shared solutions. It also helps me to realize our environmental problems are not acute, but chronic ones – we’re not running a short dash, but a marathon. We need to pace ourselves and make the appropriate choices to help conserve our island sanctuary in an estuary.

Most importantly, remember that we can solve our problems. If in doubt, just go to the beach and count the number of Brown Pelicans and compare that to what we saw thirty years ago. Once we recognize a problem and become dedicated to solving it, we can.

Over the coming weeks, I’ll be discussing our estuaries and small things you can do that make a cumulative difference. Until then, start to look at the big picture of estuaries. Find leaders who share your concerns and support them. Let’s walk through our environmental challenges with a clear eye and the faith that a positive outcome is possible.

It's Not Always a Photo Op Day

Field biology is often full of great photo moments. On other days, it is a lot of hard, uncomfortable work. Today was one of those 'work' days. We spent the better part of the day installing drift fences on the Ding Darling National Wildlife Refuge. Drift fences are a sampling device used to sample terrestrial vertebrates. The one we installed today is a series of sediment fences that have conical traps at the terminal ends. The idea is that small animals encounter the 'wall' and turn to travel parallel to it until they walk or crawl into the trap at the end. The traps are monitored two times a day to see what has been caught; it is identified and then released unharmed. Drift fence sampling is a way to accurately describe and monitor small vertebrate populations in terrestrial environments. We were creating these sampling devices to monitor populations of Indigo Snakes, and endangered species on Sanibel Island. So, today it was a lot of sweat, blisters, thorns and poison ivy...just another day at the office. The best job in the world.

A Crocky Day in Paradise

Team crocodile endured a long, hot 3-mile hike today on the Indigo Trail of Ding Darling National Wildlife Refuge. We were rewarded by a close up look at a 12-foot American Crocodile. The photo above is not her, but an alligator we saw on our way to see her. Read more about it below. Wow, what a great way to start off the week!

We also saw Anhingas, a Bald Eagle, a 5-foot yellow rat snake, and a close-up look at a 9-foot Alligator. The alligator was missing it's right front forelimb. Check out the photo we got of it. In this photo you can see that none of its bottom teeth protrude above the upper teeth - one of the ways to tell crocs from alligators.

It was a giant relief to wade into the estuary, cool off and find oysters, horshoe crabs, and a young starfish after that long hike. Wading, and the "ice in the back of the shirt trick" was the perfect end to a long, hot, animal-packed hike.

Here's to you Stevie, and the crocs we all love. Another Day in Paradise.

Time Flies

"Another day in paradise" is a popular expression for the consistency of island life. In tropic and subtropical environments, time progresses but seasonal transitions aren't always so obvious. Sure, at some point it is cold here in SW Florida, the days get shorter and the rains taper off, but those crisp chilly mornings that remind so many folks of the waning of summer are not a part of our transition. Here on Sanibel, we are reminded of the passage of time by the composition of our birds. Wading birds aggregate in shallows, and small confusing warblers flock to our mangrove trees. In the photo above, an endangered Wood Stork arrives to the flats of Ding Darling National Wildlife Refuge as Double-Crested Cormorants take a break on an exposed bar. Not a bad deal, marking the passage of seasons by the 'bird calendar'; of course if you're not watching birds, watching the Gators on Saturday afternoons might just remind you that somewhere the mornings are crisp and the leaves are turning colors.

Where the forest meets the sea.

Habitats that lie within the intertidal zone are tough places to make a living. They are constantly changing. An environment that embodies that adage that nothing is consisten, but change. In the intertidal, water levels change, the salinity of the water changes, the presence of high energy waves, variable temperatures and with it, changing amounts of oxygen. All of these variables present special challenges to living things. In the face of such adversity, a group of woody plants has evolutionary risen to these challenges and marked sandy tropical and subtropical intertidal zones as their home turf. We call these spectacular woody trees and shrubs occupying the zone ever shifting between land and sea, mangroves. That habitat they dominate, we call mangals. There are approximately 54 species of mangrove trees throughout the world which belong to 16 different plant families. On Sanibel, there are technically four species of mangrove. We most commonly think of three species, the Red Mangrove, Black Mangrove and White Mangrove. And although not commonly thought of as such, the Buttonwood Tree is also classified as a mangrove.

This photograph is a red mangrove (Rhizophora mangal). This species is characterized by its highly developed system of aerial roots. These roots provide stability for the tree while allowing the roots to not penetrate deeply into the oxygen-depleted muds in which the tree grows. The labyrinth root system provides a structural platform for a myraid of sea life. Coon oysters (Isognomon alatus) commonly grow on aerial roots, and are thickly covering the roots in this picture. Lore has it that these little oysters are so named, because racoons can easily eat them at low tide. In addition to oysters, numerous other species of invertebrate live on and among the roots, including sponges, tunicates, and many crustaceans. Thanks to this structure and many invertebrates, small and/or juvenile fishes are also common in mangal communities... and where there are small fishes, big ones are surely close by, waiting to step up and do their part in the intricate food chain of the inetrtidal.

How lucky that woody trees have been able to slove the problems of living in tropical inertidal zones. They are the foundation of a series of food webs that create the magnificent ecosystems of near-shore marine environments. So, the next time you get a crunchy fried grouper sandwich take a moment to thank a mangrove.

Sea Hares

Amongst large rafts of red algae, we have recently found many sea hares washing up on Sanibel shores. The algae that has been washing up is considered by most to be an unpleasant addition to our shores, but it does make its own contributions. Among the algal mats tiny shrimp swim and crawl around, and there are a large number of sea slugs washed ashore that seem to be correlated to the presence of this algae. These interesting little gastropod molluscs are called Aplysia brasiliana, commonly known as sea hares. They are a type of sea slug that normally inhabits sea grass beds, are herbivores and graze on benthic algae. They have been extensively studied by neurophysiologists (scientists that study how nerve cells work) beacuse they have very large nerve cells (10-50 times larger than mammal nerve cells) that are orange in color. For more information about sea hares, visit http://www.seaslugforum.net/factsheet.cfm?base=aplybras. And the next time you see a green-brown blob on the beach, that exudes a purple ink when touched, check it out and introduce yourself to a sea hare. If you can return it to the water on an outgoing tide you might keep it from being stranded.

The Last Moments of the Longest Day

On June 21, we noted the Summer Solstice. The Summer Solstice is one of the two days during the year when day and night are at their longest and shortest periods, depending upon where you are on Earth. Because of the tilt of the Earth on its axis, in the Northern Hemisphere the Summer Solstice is the longest day of the year, and in the Southern Hemishphere, the shortest. Because we are north of the equator on Sanibel (26.45271 N) we enjoy our longest day of the year, and this year we had about 13 hours and 48 minutes of daylight. Now the days get shorter and the nights longer until the Winter Solstice. For more information on the Solstice, see http://www.windows.ucar.edu/tour/link=/the_universe/uts/summer.html. Yesterday, we found numerous sea hares - a type of sea slug washed up on the beaches....today there were none. With each new tide, the sea brings us new surprises. More about sea hares tomorrow - the nights are short here this time of the year. Until then, enjoy the long days of summer. And use those daylight hours to sneak in some exploration the natural world that surrounds us.

The Sanibel Light - About the Only Thing that Happens on Sanibel After Dark

The Sanibel Lighthouse is an historic landmark located on the eastern edge of the island - for you gps buffs, that's 26.45271 x -82.0141. It was first illuminated in August of 1884 and was designed as a navigational aide to mark the mouth of San Carlos Bay. Its light is 98 feet above the ground and was created by a beautiful and very functionally complex, third order fresnel lens. Punta Rassa, on the mainland side of San Carlos Bay - across from Sanibel - near the current causeway is at the mouth of the Caloosahatchee River and was at the time, a thriving port that among other cargos loaded many cattle to be shipped to Havana. The lighthouse was one of two identical lighhouses, the other was placed at Cape San Blas, on the Florida Panhandle. While en-route to Sanibel, the ship carrying pieces for both lighhouses sank, divers were dispatched and sucessfully recovered the lighhouses. The Sanibel lighthouse sits on the eastern edge of Sanibel, and although it is not open to public tours, visitors may walk around the base of it and enjoy the shelling on nearby beaches and views of North Fort Meyers and on clear days of Naples to the southwest. Also check out the Sanibel fishing pier just west of the lighthouse - 'cause you never know, it might just be your lucky day. For a detailed discussion of fresnel lenses, visit http://www.michiganlights.com/fresnel.htm.

Snowy Plover Chicks

This is a Snowy Plover chick that hatched on the east end of Sanibel in early May. Snowy Plovers regularly nest on Sanibel and their chicks run about mostly unnoticed by the humans that pass within five feet of them

From NY to Sanibel

Today we are still in New York saying goodbye to all our good friends at Fieldston and Pennington and Chapel School and Sarah Lawrence Early Childhood Center and the American Museum of Natural History. We're saying to everyone, "come on down and visit us! Come to Sanibel Sea School! Come to our home! You can rent a few bikes and explore our island with us.

The movers come next week to pack up all those shells and egg cases and sea urchin tests and fish bones and turtle bones to move them back to the ocean!! What would an anthropologist make of Dr. Bruce Neill - carting bags of detritis home on a plane for years and years and then paying a moving company good hard-earned money to bring it all back, carefully wrapped in boxes (re-useable boxes)! We humans are splendid.

(Speaking of splendid, our friend Jamie, took this great photo of a scorpionfish. How do you like that camouflage. I bet his prey never know what hit them.)

I'll leave you all with something to ponder. All those handheld device chargers we leave plugged into outlets still use a little energy. In fact, chargers use about 5 watts an hour when nothing is plugged in to them!!! So, when you plug your device into to you, unplug your charger from the wall. Over and out, EV

Our New Blog Site

Welcome to Sanibel Sea School. We are develpoing a blog site to better share information about the natural world around southwest Florida. If you want more infromation about Sanibel Sea School, please visit us at sanibelseaschool.org, or just click on the link to your right.