Our Conservation of Marine Resources Creative Inquiry Team created this informational video highlighting student research being conducted in the Florida Keys National Marine Sanctuary.  In this first episode of Bottoms Up in the FKNMS Kylie Smith from Clemson University describes her ongoing research project.

Childress Lab Summer 2013

The Childress lab spent this past summer back in the middle Florida Keys. We started the summer out with a new course in Marine Ecology, where 6 undergraduate students from Clemson made the long drive to the Keys while towing our 18’ Parker. Each day in the field the class set out on the water to learn about a new ecosystem.

 

We started out with a snorkeling journey through the mangroves where we identified algae, sponges, fish, and other organisms. We also did plankton tows from the Everglades National Park in the Florida Bay across to the Atlantic Ocean. Along the way we took water samples, visibility information and substrate composition data. From the data collected, we tracked changes in water quality, plankton abundance and substrate composition over several miles.

During this course, the undergraduate students picked a topic to study as an independent project. Sarah and Katherine decide to study the distribution of queen conch off Indian Key State Park. With the help of the class, they set up transects in the water and marked the location of each conch. They also noted the substrate composition near each conch. Their results showed that conch distribution is best predicted by the presence of other conch.

 
While snorkeling off Indian Key, I looked out of the corner of my eye and saw a large, dark object coming towards me. Panic filled me as I thought of bull sharks but once I focused, my fear became joy as the manatee swam past me. The animal glided past not being slowed by the presence of observers. 

For the next project we rented kayaks from the Long Key State Park and paddled our way around Long Key Lake. We stopped at different stations to take water quality data and estimate the abundance of upside down jellyfish at each station. Teams of two paddled their way down a 25 M transect line, attempting to keep the kayak straight. Rachel and Justyn found that upside down jelly fish distribution can be predicted by higher salinity and lower pH.

The third project for the Marine Ecology class was studying lobster behavior in a salinity gradient. Juvenile lobsters collected from sites in Florida Bay were used to determine the salinity preferences and tolerances of the Caribbean spiny lobsters. Kelsey and Alex found that juvenile lobsters preferred the higher salinity water no matter the gender or presence of another lobster.

 

During the Marine Ecology class we found time to play hard as well as work hard. We took a day off the water and toured the Turtle Hospital in Marathon. We learned about how they take turtles in, provide treatment and homes for them, and how they release the turtles back to the wild.  After the tour, we headed to Key West to show the class members the Key West aquarium, historic restaurants, and even stopped at Margaritaville for dinner. At sunset, we made our way to Mallory Square to watch street performers, a Key West tradition.

We wrapped up the Marine Ecology course by celebrating with another Keys tradition, the Full Moon Party at Morada Bay. Great food, music and dancers filled the evening followed by fireworks. At the end of June, the Marine Ecology course traveled back to Clemson with Dr. Childress. I stayed behind with two undergrad assistants, Brandt and Sarah, to conduct my own research.

This summer marked the second field season for a new project in the Childress Lab. We are observing parrotfish grazing behavior to study their impacts on coral species in the Florida Keys. We started the month of July off by conducting surveys of patch reefs to collect data on parrotfish abundance, parrotfish behavior, and substrate composition. Each reef was swarming with colorful reef fish, barracuda, turtles, and even sharks. Brandt and even saw a pod of dolphins swim past. Every day we got in the water, we never knew what we would see.

Just like the Marine Ecology class, not every day was all work. We headed to Key West for a day of fun diving, sightseeing and shopping! We also took a day to visit The Theatre of the Sea to watch the dolphin and sea lion shows.

In July, Dr. Childress came back to the Keys to help us install cages on the reef. These cages will allow us to monitor the impacts of parrotfish grazing on specific coral fragments that we transplanted. They will also allow us to monitor the impacts of macroalgae competition on coral growth. Every day we loaded the boat down with cages, diving equipment, and hammers to install the cages. Dr. Childress hammered in four rebar stakes for each cage and I affixed the coral fragments to the reef. Brandt and Sarah, an extremely helpful part of our team, came behind to install the cages made of vexar mesh and PVC pipe to the rebar. We photographed the corals once they were installed in the cages to monitor the condition of each fragment. It is our hope to visit the cages in October to collect additional data.

 

The summer was an incredibly productive field season and I owe it to the many assistants that helped. The members of the Childress lab and Marine Ecology course were an incredible asset in the field helping to collect algae, build cages, swim cages to divers, install the cages, and many other tasks.  We look forward to returning back to the Keys in October. 

 

After a week of checking our field site, our first batch of lobsters is no where to be found! Although none of our experimental lobsters were located, we did have three resident lobsters stay on the site for the entire week. We tracked each resident lobster by a unique color combination of antennae tags. We also determined the sex and carapace length of each resident lobster.


Today we released our second batch of lobsters at a new site. Our second site contains no artificial shelters unlike our first site (which contained artificial shelters). We will continue to monitor our first site along with our second site. It is important to continue checking our first site in case our experimental lobsters return. This will help us determine whether we should check sites for more than one week after an experimental release.

As promised here are some pictures of our first site release. The first step was to catch all the lobsters out of our mesocosm using hand nets and tickle sticks. The tickle sticks are a great tool that we use to help walk our lobsters into our nets.













Then, the lobsters were loaded into a cooler and placed on the Parker. We drove out to our first experimental site, which was where we set up our transect the previous day. Each lobster was removed from the boat and gently placed into or near a shelter. Both artificial and natural shelters were used. To observe the denning behavior and dispersal of resident lobsters, we also tagged lobsters that were already on the site. These were lobsters that were not used previously in our experiment, but happened to be utilizing shelters within our site. During the next week, we will be checking the site daily to see where our lobsters are!

Field Release Tomorrow!

For the past week, we have been examining the denning behavior of 20 spiny lobsters in an enclosed area (mesocosm) that contains ten artificial shelters. Each morning, we snorkeled the mesocosm and recorded where the animals are. We can tell each animal apart because they have a unique combination of colored antennae tags. After four days, we reduced the number of artificial shelters in the mesocosm to five to examine whether habitat loss will result in a change in denning behavior.

Now that we know the dominance status of each individual and have examined their denning behavior in an enclosed area, we are ready for the final stage of our experiment. Tomorrow we will be releasing our first set of 20 spiny lobsters onto a field site to examine their denning behavior and dispersal in the natural environment. To prepare for our first release, we placed weighted transect lines along our sites. Using transect lines allows us to locate specific structures and to easily navigate our sites. Some great pictures of this process will be posted soon!

The many sizes and shapes of lobsters

Spiny lobsters have a complex life cycle. It begins when females travel to deeper, colder waters to release their young. The females fan their telson (or tail), and the larvae drift off into ocean currents without any parental care! At this stage, the transparent lobsters are referred to as phyllosome larvae.


As they complete all eleven stages of their development, spiny lobsters begin to look more like adult lobsters and are called puerulus larvae. It is a long journey (6-12 months), and as the surviving larvae grow, they begin to settle on hard bottom habitats. At this stage, spiny lobsters are solitary and have banded legs which aid in camouflage (see picture above). Spiny lobsters become social when they grow larger and migrate out of algal habitats.

Tracking juvenile lobsters using acoustic tags

Have you ever wondered where lobsters go when they leave their homes? Lobsters like all animals have to go find food, avoid scary predators, and make it home safely each day. What makes this particularly difficult to study is the fact that lobsters are nocturnal (active at night). That means while we're asleep in our beds, these lobsters are just waking up to go exploring. So how do marine biologists study the behavior of lobsters at night?

One way is to use acoustic tags. The small transmitter attached to the back of the lobster above sends out a signal a regular intervals (every 90 seconds). With the proper receivers set in the water, it is possible to track the movements of a tagged lobster without even being there. Here's how it works...


First, you need a set of acoustic tag receivers. Think of these as small radio receivers that operate on batteries and are water-tight. Here we have 10 radio receivers mounted in stands and ready to be placed underwater. Once in the water the receivers can keep track of many different lobsters at the same time.


Our experiment relies on the expertise of our friend and senior research biologist Dr. Rodney Bertelsen of the Florida Fish and Wildlife Research Institute. Dr. Rod is an expert at tracking marine animals using acoustic tags. He usually tracks the big adult lobsters out along the coral reef, but for this experiment, he is helping us to track our juvenile lobsters in Florida Bay.


The first step is careful placement of the receivers in a pattern on the ocean floor. On our study site this is shallow water, only about 2 meters deep and the receivers are placed about 20 meters apart. Dr. Mike drives the boat very carefully checking his GPS to find the exact spot for Dr. Rod to release the receiver.


Next, it is time to catch some juvenile lobsters to participate in our experiment. Here Dr. Mike dives down with a hand net to collect a juvenile lobster. The water is a little murky today because the wind has mixed up the sediment making it hard to see very far. A total of three lobsters are collected and returned to the boat.


Dr. Rod carefully attaches the acoustic tag to the shell of the lobster using Super Glue. This sounds painful (and should not be tried at home) but it is harmless to the lobster because their shell is hard. The glue will keep the tag attached for a week or two until the lobster has its next molt. Then as the lobster crawls out of its old skin it will leave the tag behind. Dr. Rod also places a bright yellow tag on the base of the antennae. Can you see the yellow tag in the picture? This helps the divers to recognize a tagged lobster once released.


Now the time has come to release the tagged lobster. Dr. Mike carefully swims the animal back to the same shelter where it was collected. It is not known if lobsters keep the same shelter night after night, but we hope to find out from this experiment. By the end of the day we release three tagged lobsters known by their tag colors as RY, LY, and YY.


Here is lobster RY in his home shelter, an concrete block. This is where he was released on Day 0. We note this on a map printed on waterproof paper. We carry this map on a clipboard underwater each day when we search for our tagged lobsters.


Meanwhile, our acoustic receivers are listening for the 'ping' of each acoustic tag. When a 'ping' is heard it is recorded along with the time of day. Later when we recover the receivers and download the data to a computer, we will know which receivers heard from each lobster. As the lobsters move around, they will only be received by the closest receivers. That way we can estimate their location at all hours of the day and night.


Today is Day 5 and we checked on the location of the lobsters on Days 2 and 4. Lobster RY was found in a hole about 2 meters from it's original release point on both Days 2 & 4. Lobster YY was found 1 meter from it's release point on Day 2 and then 8 meters away on Day 4. Lobster LY was not found on either Day 2 or Day 4, but that doesn't mean its left the site. We'll have to wait until we check the data from the receivers to know if and when it left the area. Check back soon to see what happened to our tagged lobsters.