Video Summary of our Class in the Keys

A while back I put together an 8 minute video of photos and videos from previous classes we've taken to the keys. The video was made to explain to students considering whether or not to go what the class is all about. It should give all of you a nice idea of where we go and what we do. You can also go to my facebook page and see underwater photos taken by one of the students here. In this photo album, I label many of the common plants and animals as seen on the locations we dive.
More, mostly above water photos of previous trips can be found here, here, and here. Enjoy!

A Beautiful Slug?

As I mentioned last time, the Craig Key Channel swim offers an opportunity to float on your stomach and let the currents drift you over top of some pretty impressive, large sea creatures out in the middle of the channel. But even more fun for me is to go inch by inch over the rocks and mangroves along the shore. The mangrove roots seem to be a nursery for many juvenile fish. Angelfish, parrotfish, groupers, puddingwives, scorpionfish, the invasive lionfish, green morays, and especially species of colorfully decorated damselfish all hide among the roots and rocks and young fish seem especially prevalent here. More fascinating still are the array of invertebrates that live in the channel. Shrimp, sea cucumbers, sea stars, brittle stars, sponges, hard & soft corals, anemones, zoanthids, tunicates, feather duster worms, and many molluscs including the beautiful conchs and cowries are just a few of the fascinating invertebrates regularly seen on the Craig Key Channel dive.

Atlantic Deer Cowrie

Cushion Sea Star (genus Oreaster)

Every dive we record all the species of plants and animals we are able to identify and the list from a Craig Key Channel Dive is always long and interesting.
But there is one unique animal we always make a special effort to see every time we swim the channel. It is a species we see almost no place else. It is called the Lettuce Sea Slug, or Elysia crispata (formally Tridachia crispata) It is usually not much more than an inch long and usually shows some combination of green, yellow, and purple hues. It loves to hide on the large, crunchy Halimeda algae beds where it is almost impossible to find due to it's nearly foolproof camouflage. Some of the slugs however crawl onto the rocks and mangrove roots where they are easier to spot and when they are found, they quickly become one of the favorites of most students.
The first thing that catches a diver's eye is the slug's frilly design on it's back. These fancy ruffles which look a bit like a head of lettuce and give the slug it's name, are actually folds of tissue called parapodia. These skin folds provide two key life functions for Elysia, one which is a particularly fascinating handiwork of the Creator.
The thoughtful observer would quickly guess that the design of these parapodia is likely increasing the surface area for some reason and this is the case. The ruffles function much like gills, taking in oxygen and releasing carbon dioxide so the design aids in gas transfer.
More fascinating still, these parapodia function in providing the animal food. The lettuce slug feeds by sucking the cytoplasm out of cells of algae. Not all the cytoplasm, however, is digested. The slugs are able to keep the chloroplasts intact. The chloroplasts are the structures within the algal cells that carry out photosynthesis.

chloroplasts

Elysia then stores the intact, stolen chloroplasts in it's frilly parapodia and there, incredibly, the chloroplasts continue to function, gathering sunlight and converting it to food which, rather than feeding the algal cells, instead feeds the crafty slug. So incredibly, this creature can feed by sticking food in it's mouth like an animal AND it can feed by gathering sunlight like a plant! In fact, some have called Elysia a fusion of plant and animal. That's pretty cool! Actually, the Lettuce Sea Slug is a mollusc, particularly from the Class Gastropoda. It is basically a snail without a shell. Whatever you call it though, the Lettuce Sea Slug is one of those creatures that we find that is incredibly beautiful, but when you learn a bit more about it, you discover it is as interesting as it is sweet to look at.

Channel Surfing

One of the underestimated benefits (if I may say so) of taking Marine Biology with Lake Center is that you get to dive with guides that have years and years of exploring the near shore waters close to Layton. Obviously, there is water everywhere in the Florida Keys so discovering the most interesting places to snorkel only comes by jumping in at many, many places through the years and finding the best spots.
We still do an occasional exploration of a new dive location but most of the places we go are time-tested favorites.
One such favorite is shown in the satellite photo above. We call it the Craig Key Channel Swim and as you can see, it is situated right up against US Rt 1. Hundreds of cars speed right past this wonderful spot every day not knowing what they are missing just a few yards from their vehicle. If you look at the bottom half of the photo you see a large, grayish area. This is an expansive turtle grass bed. This is a very shallow flat where at low tide, the water barely rises above the tops of the grass. The bottom on the flat is quite muddy and not firm so even though there are some interesting things that can be found here, we generally stay away from this very shallow area.
Ah, but that narrow blue-green area right below the road that looks about as wide as the road, that is another habitat altogether. This is a classic channel. The ocean seeks to find the path of least resistance as it cuts it's way through the shallows of the keys and back out into the ocean depths and through the years, these cuts create channels where the water is deeper, cooler, and moving faster as the ocean squeezes, if you will, through these channels.
As a result, larger sea creatures you would never find in the shallow flats can be found cruising from one deep area to the next via these channels. And that is exactly what we see during this swim. Goliath Grouper, Spotted Eagle Ray, Tarpon, Barracuda, Snook, & Southern Blue Sting Ray are all seen out in the deep portion of the channel which can be 15' deep during high tide.

Spotted Eagle Ray

Goliath Grouper

It is while searching the deep center of the channel that the term "channel surfing" can be applied. If you have avoided the slack period (the time when the tide is changing from coming in to going out or vice versa--at this time there is almost no current here) you will get to experience a fairly strong current pulling you through the channel. It is a new feeling for most Ohioans to swim out to the middle of the channel and then to surf, or drift at a surprising speed down through the channel, watching for the large sea creatures below you. The only problem you must adjust to is that if there is something interesting you want to dive down to investigate you must see it far enough ahead of you and compensate for the speed you are traveling horizontally and start your dive down well ahead of your target. Channel surfing is a very cool sensation!
To enjoy the channel surfing, your guides must always first determine the direction of the current because, again, depending on the tide, the current may be ripping east to west or west to east. Usually we look first for the brown algae of the genus Sargassum. This is an abundant algae that has air bladders as part of its structure so when boats or other things tear it from the bottom, it floats in the water. By looking to see which way the Sargassum is floating through the channel, we can usually determine the direction of the current. Sometimes by looking down from the road, we will see schools of tarpon and they usually will be swimming with the current. Always though, the leader will get into the water to be sure we are 100% certain about the direction.
Then we simply walk along the shore and enter the water at a point where channel surfing the current will take us right back to the car.
But channel surfing is not the end of the Craig Key Channel Swim story. There are shallow edges to the channel that are full of smaller, fascinating things that I enjoy even more than the large things cruising the deep. But we'll leave the story of the Craig Key shallows for next time.
So the next time you're using the remote to power through all the stations, remember there is a far more enjoyable channel surfing waiting for you in the fabulous Florida Keys.

Warm Thoughts on a Cold Day

What better day to write about the Florida Keys than a day when my home weather station keeps hitting minus 15 wind chill even at mid-afternoon. Usually the temperature in Layton is right around 90 at this time of the day when we are down there in the middle of June. The water temperature is usually in the low to mid 80s by then allowing even those who get cold very easily to be very comfortable for long stays in the water.
Water temperature is a crucial factor in the growth of the animals which build the reefs we love so much: the hard corals. These corals grow well in the Keys because the water temperature there stays from the mid 60's in winter to the mid 80's in summer. If the water rises to 90 degrees or dips down below 60, the coral can bleach and die within days.
This was exactly the case in January of 2010 when a serious cold spell caused the ocean temps to stay in the low to mid 50's around the Keys for at least a week.
One of our favorite dives is at a wonderful place called Indian Key. This spot is delightful for a number of reasons but one of the more special features has been the very large Starlet Coral mounds.

These coral heads are interesting animals in and of themselves but what makes them such an attraction at Indian Key is the array of animals that live on and around them: Neon Gobies sitting on the top. Christmas Tree worms sticking out all over. Slate-pencil urchins hiding underneath and even an occasional octopus is found hiding in the crevices.

Christmas Tree Worm

Neon Goby

However, the coral heads of Indian Key took a hard hit in January of 2010. By June of 2010, many of the formations were partially or completely bleached white from the freeze. By June of 2011, a number of the formations had disappeared completely. 

Slate-pencil Urchin

Encouragingly, a number of the larger formations that had survived were showing new areas of growth and many, many tiny new formations were littering the ground. The new growth in the larger formations gave us hope to search for perhaps our favorite resident of Indian Key's coral heads, the Green Moray. This eel loves to hide on the sandy bottom under the overhangs of of the coral heads and the snorkeler willing to dive down and search the holes and underneath these coral formations at Indian Key was almost always certain to find 3 or 4 of these interesting animals. A Green Moray can reach 6 feet long and appears to be one huge muscle. The eel is actually gray colored but is entirely covered by a bright green mucous. Often called a sea serpent, the Green Moray is actually a sleek fish with no scales. Not uncommonly, an investigating diver will come face to face with these unique fish which can be a bit unnerving because invariably their mouths are open revealing an impressive set of teeth. But morays are very non-aggressive animals and what often looks like a move to bite someone is just the moray sucking water into it's mouth which passes over it's gills and allows the fish to breath.

In 2010, for the first time in many years, we found no Green Morays at Indian Key and despite much looking in 2011, we again found none (although we had great looks at them on other dives).

However, one student who was constantly diving and looking carefully for morays did make an exciting discovery. He found an eel doing what they love to do: sticking his head out of a hole in the bottom of the Starlet Coral.

Only this was no Green Moray. This was the much more uncommon Goldentail Moray.

The Goldentail is not as massive a fish as the Green Moray. It grows to little more than 2 feet long. But what it lacks in size it more than makes up for with it's fine, golden markings and it's rarity. Yet another animal finding its home in the wonderful hard coral formations of Indian Key.

I could enjoy some 85 degree water at Indian Key right about now...

The Thrill of Discovery

Each year that we take another group of students to Layton for a week of Marine Biology, I create a "Most Wanted List". This list is made up of species which are known to live in the surrounding waters, but that I have never yet seen or at least have not seen in many years. Usually a reward of ice cream or some similar fare is offered to the underwater sleuth that discovers any of the organisms on my list. 

Perhaps at the very top of my list during our last trip was a seahorse. Our favorites tend to be invertebrates but the seahorse's rare status along with it's unique beauty placed this charming creature very high among the things I longed to see.
Half way through the week, our group was doing our annual night dive. This is where we all snorkel out from shore after it is completely dark with only small, underwater flashlights in hand.
Due to new diver's anxieties of being in the ocean in pitch blackness, we always stay in very close-knit groups with each group staying near to the others.
It is always a little touch and go as to what you can hear while you are snorkeling but this night, the stillness was broken by a very clear, very loud sentence not 15 yards from me. The voice belonged to Charles McMullen and the sentence was, "I found a seahorse!" Needless to say, this leader made a very abrupt turn towards Charles and covered the 15 yards in a time that would've made Michael Phelps proud. Sure enough, there was the first live seahorse I had ever laid eyes on, slowly waving his tiny dorsal fin to maintain it's balance against the light current while holding on to a purple pterogorgia coral with it's tail.
Soon everyone from all of the small groups were floating in a circle around the searhorse and it's coral anchor and you could literally hear "oohs" and "aahs" coming through snorkel tubes all around. Because of their tiny fins, seahorses are pretty lame when it comes to swimming. Though they can straighten out and swim horizontally like a regular fish (which this one eventually did) they still can barely make headway, even though their little dorsal fin can be wiggled 35 times per second. As a result, they must rely completely on camouflage for defense.

As an example, here is a photo taken last year by one of Central Christian's student's, Hannah Horner on a dive where we amazingly found 3 or 4 seahorses. Can you pick it out?
Anyway, back to our story of discovering our very first seahorse. After everyone had oohed and aahed for several minutes, it appeared to me that this fish was quite tame, it showed no reaction to the 10 shark-like things floating in a circle around it so I reached down and gently lifted it off the coral and placed the seahorse standing on it's curled tail in the palm of my hand under water. We were then able to carefully pass the seahorse around the circle under water to each person in the group. It would either rest upright in our palms or curl it's tail around our fingers. Finally, we placed it back near it's home soft coral where it straightened out and swam like it's close relatives, the pipefish, and reattached to the coral, blending in like it had before.
In addition to being such calm, gentle, beautiful creations, the seahorses are amazing in several other regards. These little guys have very healthy appetites. Though they are restricted to catching only what floats by as they hang on to a coral or blade of grass, a single seahorse has been observed catching and eating 3000 brine shrimp in a single day!
More uniquely the seahorses are one of the very few animals where the male carries their unborn young. The males possess a brood pouch on their ventral side. The female deposits her eggs into the male's pouch where they are internally fertilized and carried until he releases the fully-formed young into the water 20-21 days after the eggs were deposited.
All 5 seahorses that we have now found in the last two years have been the species Hippocampus Erectus, the Lined Seahorse. Though this species can be gray, red, green, or orange, all 5 we have found have been primarily black and all 5 have appeared to be the larger males all nearing 6" in length.
But though I have now layed eyes on 5 different seahorses, I will never forgot the thrill of the first one; the joy of discovery.
Thanks Charles. I hope you enjoyed your ice cream cone in Key West.

Can't We All Just Get Along?

Because the seas are "teeming with life", the marine environment is unusually full of animals sharing space in a variety of symbiotic relationships. Many of these are visible to the naked eye and a delight to observe.
"Finding Nemo" is one of my all time favorite movies and though the setting is Australia instead of the Florida Keys, much of what is depicted in the cartoon quite accurately represents what is found in reefs around the world, including the Keys.
In the beginning of the movie, Marlin and his family are living in the safety of a large anemone and in the Florida reefs we find a variety of similar symbiotic relationships happening with anemones.

One of the largest and most common anemones in Florida is the Giant Caribbean Sea Anemone, Condylactis gigantea . Usually we will find 1-5 of these beautiful animals on a typical dive at the work site. These creatures' tentacles come in a variety of colors: all purple, green, brown, orange or blue. Most often they are cream-colored with pink or purple tips. Usually hidden is their stocky, fleshy body column which is usually attached to a rock, coral, or some other hard surface on the bottom.
Anemones belong to the phylum Cnidaria which includes the corals and jellyfish. These animals all possess a unique type of cell called nematocysts which enable the animals to defend or feed themselves by the harpooning action of these stinging cells. These nematocysts are lethal to many small marine animals but the callouses of most snorkeler's fingers are thick enough so that no sting is felt if you touch their tentacles. Usually there is just a sticky sensation when the tentacles stick to your skin as the animal attempts to inject its mini harpoons into your finger.

This stinging characteristic of Condylactis makes it all the more interesting as to how creatures come to live among the nematocyst-loaded tentacles and yet there is exactly where other species live. If the snorkeler waits patiently and looks closely at the tentacles of any Condylactis they find, they will almost always be rewarded with a small (1/2 inch long) but BEAUTIFUL shrimp, most often a Spotted Cleaner Shrimp like the one in the macro photo above. The pictured shrimp is shown standing on the tentacles of a Condylactis. You can see the white spots on the tentacles which are the stinging cells.
For about 2 1/2 hours after a shrimp first moves into an anemone, the anemone makes aggressive actions and the shrimp defensive actions towards each other. But then anemone relaxes and the shrimp appears to develop a membrane which protects it from the sting. Shrimp that have been removed and washed off in studies need another 2 1/2 hour acclimation period to re-develop this protection.
After the adjustment hours are over, the anemone provides protected shelter for the tiny shrimp and the shrimp appears to clean the anemone as well as foster the growth of another organism which shares a vital symbiosis with the anemone, zooxanthellae, a tiny type of algae crucial to the anemone's survival and also often providing the pigment which colors the anemone. 
Those of us created in the image of God could take a few cues from these two invertebrates, very different from each other yet living together in a way that both are blessed by the actions of the other. And once again, the blue waters of the Keys reveal two fascinating creatures waiting to delight the observant diver and testify of a very creative Creator.

A Spectacular Worm

Trying to decide which creature or place from the waters around Long Key to share about first is a challenging task so I'm choosing what will probably be the first animal you will see in the first location we dive at each year during mini-term. The dive site we simply call the worksite. It is an easy place to get in the water for the first time and students have been studying marine life here for years.
The sattelite image pictured above gives an overview of our home base for the week. On the right side is a yellow marker pointing to the roof of the Goshen College Facility where we live for the week. You can see that it boarders the Zane Gray creek or channel that cuts through Long Key. Turtles, sharks, Goliath Groupers and many other interesting things swim right under our dock which overlooks this channel.
On the left side of the image you see the yellow marker which marks the worksite. To reach it we take a 10 minute walk up South Layton Drive, left along Rt 1, and then turn right on a path that cuts through the mangroves to the bayside waters of the ocean. You can see the dark areas under the clear blue water that provide structure (coral, rocks, sponges, grasses) that many of the interesting animals we study live in.
As I mentioned, the last couple years at least, the first animal you are likely to notice as you put your mask under the water is, of all things, a worm. Now that may not sound very exciting to you as your mind pictures the earthworms all over your driveway after a heavy rain here in Ohio but marine worms are an altogether different sort. We see many worms that have appendeges that come off their heads that look look like Christmas trees, others that can be 6 feet long, some that sting like fire, and some that are all the colors of the rainbow. These are from the phylum Annelida and most worms that we  see are segmented worms from the class Polychaeta.
The worm that comes to view very quickly at the worksite is called the Medusa Worm. More often we simply call it Loimia. It's full scientific name is Loimia medusa. Medusa you may recall was the beautiful lady from Greek mythology whose pride in her beauty eventually caused Athena to turn Medusa's lovely long hair into snakes.
It is the extremely long, snake-like "hair" from Loimia's head that gives it the name Medusa.

Of course a worm has no hair but what the diver is seeing are bluish, translucent tentacles that can be as long as 2 feet. To the delight of the student snorkeling in the shallow waters (perhaps 3' deep) at the worksite, not only are Loimia's tentacles interesting to see but if you give any one of the tentacles the slightest touch, they immediately begin to be retracted back into the worms hideout. And a hideout it is. You will likely never lay eyes on the actual Medusa Worm. These worms live in self-constructed tubes which they build out of sand and their own mucus. This tube-building only takes about a half an hour where the young worm grabs sand particles with it's tentacles, brings them back to it's mouth, smears its gooey mucus on the sand, and then builds the tube around itself about twice as long as it's young body so that it can continue to grow inside the tube it has built. They must not be claustrophobic because they live the rest of their lives inside this tube with only their long tentacles reaching out into the ocean searching for it's food which is usually tiny pieces of waste matter or small, decomposing animals. When it finds a tasty morsel, if it is small enough, it slides the food down it's U-shaped tentacle back into it's mouth near the top of it's sandy tube. If the food is too large for this, it will drag the food back to it's mouth by retracting that tentacle.

So the next time you wade into the water off of Long Key, before you go chasing one of the flashy, brightly colored fish, look down and enjoy the amazing Medusa Worm, Loimia medusa.

Why a Marine Biology Mini-term Class?

"What comes into our minds when we think about God is the most important thing about us." So wrote A.W. Tozer. There are many things that affect what comes into our minds when we think about God. For me, carefully observing what God has created is one of the most effective ways of helping me think appropriately about Him.
Romans 1:25 speaks of an error very prevalent in our day; of people having a love of nature to an unbalanced degree,  "They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator." NIV
On the other end of the spectrum, many of us think less highly of our Creator than we should because we fail to stop and smell the roses if you will. That is, we don't take the time to notice the magnificence of creation and what it tells us of the Creator. A few verses earlier in Romans 1:20, we are told that "His invisible nature and attributes, that is, His eternal power and divinity, have been made intelligible and clearly discernible in and through the things that have been made (His handiworks)". AMP
This is why I love to study and teach Marine Biology. Under the sea, I see some of God's most magnificent handiwork and I grow to love and appreciate Him more.
It is my prayer that each student that travels to the Florida Keys with us will join me in growing in their love of God as we together observe and marvel at His magnificent handiwork in the aqua blue waters surrounding the islands that make up the Florida Keys.
In this blog we will be looking at some of the plants and animals that live in the ocean surrounding the Florida Keys and we will share some of the unique places we experience together during our one week class based in Layton, Florida on Long Key. I hope we learn together to be more amazed about God through seeing His underwater handiwork.
In the very beginning of the Bible in the middle of the creation story, we hear God speak the words, "Let the water teem with living creatures." Let the oceans swarm with living things. This is exactly what we experience when we put our masks under the water in the keys. It is a privilege to be able to share some of what He has done with you.