Thursday, October 24, 2013
Tuesday, September 3, 2013
I had the opportunity to spend my summer down in the Middle Florida Keys with the Childress lab this summer. I went down to assist Kylie with her data collection, but I also got the opportunity to learn about the diverse community of the Keys with the Marine Ecology class that Dr. Childress taught in June. During the class most days were spent in class, luckily for us this meant being on the boat or in the water. Snorkeling through the mangroves and on the reefs allowed us to get familiar with many of the species commonly seen. Other days were spent carrying out different techniques to sample a site for diversity, or honing our lobster wrangling skills as well. After we had explored different aspects of the Keys, independent projects were conducted using the techniques learned in the previous weeks. This allowed the teams to choose a topic in the Keys that interested them.
When the class ended I stayed for the month of July to assist Kylie in the field. Kylie’s project examines the effects that competition from macroalgae and corallivory from parrotfish have on coral health. In the past year I have been helping Kylie analyze photos, videos and data from her trip down to the Keys during the summer of 2012. I was extremely excited to get out of the lab and get into the water, where I could see first hand the images I had only viewed from a computer screen.
We began by taking survey data on 14 sites along Long Key. The survey methods consisted of two divers swimming along a transect doing fish counts and behavioral observations on parrotfish. There were also two other divers who swam down the transect and took video footage as well as pictures for later analysis of the reef’s composition. Once we completed the surveys we began to put out cages to monitoring the effects of macroalgae and parrotfish on coral fragments. This was a huge task we completed this summer. 12 cages were placed on 7 of the sites. 6 cages were left open, allowing parrotfish in, and 6 were closed, preventing anything from entering. Each cage had coral transplant in it and either no algae, medium algae, or high algae. These cages are to be monitored several times throughout this upcoming year in order to see the impact the level of algae and the presence of parrotfish have on the health of the coral fragments.
Putting the cages out was no small feat. But through the wind and the rain we managed to secure 84 cages in the water. One of the many things I took away from this summer was how valuable it is to be able to adapt to your environment. We had to re-attempt our ideas numerous times before we achieved an effective method. For example, many of our first cages ended up detaching from the substrate. We had to attempt to change our original plans to try and secure them more effectively. You never know what things can end up being helpful in the field. Who would have thought a salad spinner would be a staple in preparing the algae for the cages? Many times we struggled to come up with the best thing to do but once we finally got it the victory was so much sweeter. The experiences I got this summer only added to my passion to continue in my path towards graduate school.
Monday, September 2, 2013
One of the classes I took focused on the life history strategies of reef corals and included a field trip to beautiful Orpheus Island National Park to observe and study corals. We were each assigned a coral species (mine was Lobophyllia hemprichii) and instructed to observe the distribution, competitive interactions, and the size of the colonies. We also had to design an independent project based of what we noticed about our coral.
To determine the distribution and density of the coral, we laid three 10 x 2 meter transects and counted the colonies within the space. Competitive interactions were noted by simply swimming around and noting how the coral interacted with surrounding colonies. For the independent study, my partner and I decided to look at the distribution of Lobophyllia versus Symphyllia, a similar coral in the same family. We laid six 10 x 2 m transects, three shallow and three deep, and counted in the number of Lobophyllia and Symphyllia colonies along each one. We noticed in our observations that Symphyllia seemed to be more abundant in the shallower areas of the reef while Lobophyllia prevailed in the deeper areas. We hypothesized that Symphyllia may be able to tolerate the stresses of shallower areas while Lobophyllia outcompeted it for the deeper areas.
Thursday, August 29, 2013
This past spring semester I spent 90 days on a 112ft Schooner called the S/Y Argo. 25 Shipmates and I sailed from Tortolla, BVI to Tahiti via the Panama Canal and the Galapagos. We covered 6804 nautical miles and passed through the furthest point on Earth away from land. Life on board ship was organized by watch team and much of the day was taken up by cleaning, sitting in lectures, and cooking meals. However, the tasks always seemed to be put on hold for the frequent, but always exciting, visits from dolphins swimming at the bow or whales spotted off in the distance.
One stop we made was to the island of Dominica in the Caribbean. There we went on an all day hike to the second largest boiling lake in the world. Our fearless guide, Pancho, walked the whole thing barefoot. He brought a carton of eggs to show us just how hot the water was, and 8 minutes later we were snacking on hard boiled eggs cooked right in the stream. We also filled our water bottle with water from a fresh spring. Dominica's mountainous landscape was described by Christopher Columbus as a crumbled up piece of parchment paper. On the hike we learned a lot about the island's history and culture. We also got to see some of the places where the second Pirates of the Caribbean movie was filmed.
We did some diving and saw first hand how abundant the lion fish are on the Caribbean reefs. Our guide killed 8 of them on just one dive. Similarly, on Bonaire, the lion fish have become a problem. They have lion fish festivals where people can cook and taste the fish prepared in different ways in an effort to promote fishing for the fish. Along the entire caribbean lion fish have become a problem and many of the islands are trying to battle the issue. In Dominica they would try to feed the dead lion fish to eels in an effort to create predators for this otherwise unchallenged species.
Another unique experience we had was going though the Panama Canal. The Canal is set up with 3 locks on the Atlantic side, followed by a 50 mile long lake, and 3 locks on the Pacific side. For my research project we looked at the change in salinity going through the canal. There was a drastic change going through the locks because the lake is freshwater in contrast to the saltwater oceans. The range of the pH values went from 32-34 ppt at the entrances of the canal to less than 1 ppt in the lake. Through our data we were able to confirm the idea of the canal acting as a biological barrier due to pH that could prevent species from crossing from one ocean to the other.
One stop on our trip was to the Galapagos Islands. Because of a rather unfortunate mix up with the Ecuadorian Government and our permit we only got to spend three days on Santa Cruz. However, we were able to go diving and do some land tours. We saw giant tortoises, sea lions, hammerheads, Galapagos sharks, white tip sharks, eels, an electric ray, spotted eagle rays and even two orcas. We learned that sailors would stop in the Galapagos and pick up tortoises to keep in the hold of the boat for long passages across the Pacific. Because they could go for several months without food or water, they were a source of fresh meat for the sailors on the long passage across the Pacific.
Overall this trip was unforgettable. We were lucky enough to dive and visit some of the most amazing places in the world. It was an experience of a lifetime.
Every summer, my dad and I go on a dive trip to a different location. This year it was Cozumel, Mexico. It was such a beautiful place; the water was crystal clear every day we dove. Out of all the things we saw, my favorite was all of the sea turtles. There were a bunch of Loggerheads, and a few smaller green turtles. I think we even saw eight of them on one dive. The currents can be a bit strong, so it takes a lot of fighting to stay in one place and watch them. We always have a lot of fun swimming along, pretending to be one of the fish. I particularly enjoy diving more now that I’ve learned to identify many of the species that I see, including all of the different species of parrotfish.
Over the summer, I went down to the Key Marine Lab with Dr. Childress’ Marine Ecology class. My personal project was to count the number of Cassiopea jellyfish along transects, and compare the density to factors such as salinity and nutrients in the water. As the water was so shallow, we weren’t able to snorkel above the transects, as we’d just be kicking all the jellyfish and getting stung. So instead, we canoed down the line, counting the jellyfish on either side. This was tricky, because if you went too slowly, the canoe would shift around and float off course, but too fast, and you would zoom by and be unable to count all the jellyfish. I’m not sure how accurate our count was, because there were hundreds. The whole bottom was a carpet of jellyfish in some areas. Despite the difficulties, it was a fun day of data collection.
After we counted the jellyfish, and took water samples at each site, we were left with the task of analyzing each water sample for nitrates, and using the YSI to take the salinity, pH and dissolved oxygen. All of the tests behaved as they should, with the exception of dissolved oxygen. I’m not entirely sure what the issue was, but we ended up waiting a long time on each sample, but the reading would not settle out at any reasonable number. Eventually we just surrendered, and stuck to pH and salinity. If there’s one thing I learned from this project, it’s to never expect things to go according to plan. We ended up finding that as salinity increased, so did the jellyfish density. pH, on the other hand, had a negative correlation with jellyfish density. Interestingly, we also found that the higher the salinity was, the lower the pH, which was opposite from what we expected.
I spent the beginning part of my summer studying abroad in Panama and Costa Rica. For most of the month of May, I joined 36 pre-med and pre-dental students from Clemson University to set up clinics in less fortunate parts of the countries. We assisted local doctors and dentists in providing free medical and dental care. Over the seven days of clinics, we saw hundreds of patients and learned so much about the careers we are hoping to pursue.
As part of the dental team, I was given many incredible opportunities to perform dental procedures, like routine cleanings, fillings, and tooth extractions. This was an experience that definitely solidified my decision to pursue dentistry as a career. I also enjoyed getting to experience the cultures of Panama and Costa Rica. I met so many new people from Clemson, Panama, and Costa Rica, and my experience abroad is something I will always remember.
The rest of the summer was spent studying for the Dental Admissions Test, applying to schools, and working at a restaurant in my hometown. Though these past few months have been memorable, I am so excited to be back at Clemson for the start of a new school year and to once again be a part of the Childress Lab!
This summer I spent time living on Long Key, FL as a part of the inaugural Marine Ecology class of Clemson University. After a three week lecture portion of the course, covering subjects from physical oceanography to a more in depth study of the harmful algal blooms occurring in the Keys, the class headed south to experience the Keys in person. We lived in the city of Layton and worked out the Keys Marine Lab, often out on the water snorkeling a number of Florida Bay sites as well as venturing Oceanside into the warm waters of the Atlantic.
In the lab portion of this class we learned various techniques for collecting and analyzing data. For example, we did plankton tows at a number a sites through the Florida Bay as well as Oceanside. In addition to plankton tows, we took YSI readings and collected water samples, performing tests such as pH, ammonia concentration, nitrate concentration and alkalinity in order to observe a trend in the overall water quality. In analyzing this data, we were able to form some hypotheses about the trend in water quality moving throughout various portions of the Bay into Oceanside.
In addition to the exercises completed in Lab, we were also tasked with designing and completing an independent research project. For this portion of the lab I chose to look at the distribution of Queen Conch in relation to the distance from shore as well as the substrate composition. We sampled these variables by laying out a 25 M x 25M grid at two sites and snorkeled them, measure population density and substrate composition at 5M intervals in 25M columns. Although we found no significant data comparing the population density to the substrate composition or distance from shore, we did find a significant difference between the two sites we sampled. We found that in these sites, identical in substrate composition and distance from shore, one had a very high population density and one had a very low population density. We can most likely attribute this to the congregating behavior of Queen Conch. Because movement is limited in this species, it is beneficial for Queen Conch to congregate in order to successfully find a mate and reproduce.
In my time in the Keys, I found one overlying theme to be true and that is the need for close monitoring of trends in the marine environment. From events such as Global Warming to an increase in boat traffic and pollution, it is our responsibility to help manage and preserve marine species and habitats in order to maintain a healthy, functioning ecosystem.
Sunday, August 4, 2013
|Scott Miller completed his Calhoun Honors College BS Thesis|
Katherine Heldt completed her Biological Sciences MS Thesis
Effects of disease and ocean acidification on the den sharing behavior of juvenile Caribbean spiny lobster, Panulirus argus
Scott Donald Miller
Calhoun Honors Undergraduate ThesisDepartment of Biological Sciences
Dr. Michael ChildressThesis Advisor
Chemical cues play important roles throughout marine ecosystems, and different factors can alter the way that organisms detect or interpret these cues. Diseases in populations and global water quality changes, such as ocean acidification, can greatly alter the behavior associated with information gathered from olfaction. The Caribbean spiny lobster, Panulirus argus, is an organism that relies on chemical cues to find protective shelters and to mediate social behavior, and both disease and ocean acidification have the potential to impact its ability to rely on these cues for these behaviors. Our study sought to see how disease would influence lobsters’ ability to compete for shelters and how ocean acidification impacts den sharing and social behavior in these lobsters. This study comprised of three parts.
The first portion of the study examined the interactions between diseased and healthy lobsters in a shelter-limited environment. A healthy lobster was placed inside of the only den in an experimental aquarium, a diseased lobster was introduced, and physical interactions were observed. This was repeated with the same lobster inside the den, but with a healthy lobster as the intruder. We found that the presence of a diseased lobster lowered the aggression of both healthy and diseased lobsters and that in diseased trials, the healthy lobster spent more time in the den compared to the diseased individual.
In the second part of the study, the effects of ocean acidification on lobsters’ den sharing and aggressive behavior were examined. Lobsters were housed in pairs and observed nightly for a week in both normal and lowered pH, where aggressive acts, den sharing, and olfactory sampling behaviors were measured. Y-maze odor preference trials were run simultaneously to determine lobsters’ odor preferences. The Y-maze trials were conducted in three rounds. During the first round, lobsters were kept in normal pH water and the Y-maze contained normal pH water. In the second round, home aquaria were kept the same, but the Y-maze contained lowered pH water. For the third round, both home aquaria and the Y-maze pH were lowered. During behavioral observations, we found lobsters to show less aggressive acts, less den sharing, less antennule flicks, and more antennule wipes after prolonged exposure to depressed pH. Lobsters showed some evidence of altered odor preference when the Y-maze pH was reduced.
In the final portion of the study, scanning electron microscopy was used to determine if exposure to pH damages the sensory organs of the lobsters. At the completion of the study, lobsters’ antennules were removed, fixed, and observed under SEM. We found similar counts of setae in both groups. There was evidence of damage in the group exposed to lower pH, but due to a small sample size, this was inconclusive. This study provides evidence for significantly altered den sharing and social behavior in P. argus when exposed to various stressors that are projected to continue to be an issue in the future.
Individual behavioral variation of juvenile spiny lobster (Panulirus argus) denning behaviors and the role it plays in shelter competition during habitat loss
A Thesis Presented to the Graduate School of Clemson UniversityIn Partial Fulfillment of the Requirements for the Degree Master of Science In Biological Sciences
Katherine A Heldt
Michael J. Childress, Committee Chair
Variation in juvenile spiny lobster (Panulirus argus) aggressive and gregarious behaviors may play an important role in structuring population level interactions. Since aggressive and gregarious behaviors were not repeatable and were found to be highly correlated with size, these behaviors were found to be largely driven by a combination of behavioral plasticity and ontogeny. Although larger individuals were found to be the most aggressive individuals, least gregarious and often occupied crevice shelters by themselves, they did not exclude smaller, less aggressive lobsters from crevice shelters. Surprisingly, in shelter limited situations, small, less aggressive individuals were more likely to use dens and remain in dens, while large, more aggressive individuals were more likely to remain outside of dens and disperse. In general, larger individuals are able to walk longer distances in less time and are less likely to be preyed upon while away from shelter, suggesting that vulnerability may play an important role in the decision to share dens or disperse. Effects of prior experiences in natural shelter-rich or natural shelter-poor habitats were also found to influence denning behaviors with individuals from natural shelter-poor habitats better responding to sudden shelter loss. Therefore, prior experiences may also play an important role in denning behavior. This thesis provides evidence for behavioral ontogeny and plasticity in juvenile spiny lobster social behavior and is an important first step in understanding the role of individual behavioral variation in den competition and behavioral mitigation of habitat loss.
|Congratulations to the Childress and Ptacek lab graduations for 2013!|
|Scott Miller, Eric Rice, Tyler Collins, Larissa Clarke, Kelsey McClellan|
|With their official B.E.E.R. mugs!|
(Behavioral Ecology and Evolution Research)
Poster # 85
Personality in Lobsters: Do Juvenile Spiny Lobsters Show Repeatability in Their Social and Anti-social Behaviors?
Mentor: Dr. Michael Childress, Biological Sciences
Students: Larissa Clarke, Katie Cunningham, Katherine Heldt
Caribbean spiny lobsters are attracted to conspecific odor cues which lead to den cohabitation. However, recent studies have found that den sharing is also influenced by aggression toward conspecifics. Since aggression differences among individuals are often a result of distinct behavioral phenotypes, we wanted to test if such phenotypes occur in juvenile lobsters. Our study investigates whether gregarious and/or aggressive behaviors are repeatable for juvenile lobsters. We measured aggression by observing the number of aggressive acts (antennae flicks/pushes and body pushes) exhibited for 7 nights. We measured gregariousness by observing conspecific odor preferences in y-maze choice tests. These behaviors were measured one week after capture (time 1) and again after three months in captivity (time 2). Repeatability was determined by comparing the change in behaviors from time 1 to time 2. A significant correlation between the expression of these behaviors is evidence for repeatability and potentially fixed behavioral phenotypes. This project was partially supported by the Creative Inquiry Program.
Poster # 148
Who says Intermediacy is a Bad Thing? Influences of Community Factors on Coral Diversity in the Florida Keys
Mentor: Dr. Michael Childress, Biological Sciences
Students: Kelsey McClellan, Brandt Quirk-Royal, Kylie Smith
The patch reefs of the Florida Keys contain a diversity of coral species, which provide a foundation for a community of organisms. The intermediate disturbance hypothesis is an ecological model that suggests intermediate levels of disturbance allow for high species diversity. Based on this hypothesis, we examined if coral species diversity was related to various community factors on 14 patch reefs throughout the Florida Keys National Marine Sanctuary. Survey data of the reef was used to evaluate the complexity and species composition. We found coral species diversity was unrelated to depth or topographic complexity. Coral species diversity was negatively related to macroalgal cover. Additionally, coral species diversity was highest for intermediate levels of parrotfish abundance and parrotfish species diversity. These results suggest that parrotfish may play an important role in coral ecosystems. This project was partially supported by the Creative Inquiry program.
Poster # 73
Effects of Ocean Acidification on Aggression and Den Sharing Behavior of Juvenile Caribbean Spiny Lobsters, Panulirus argus.
Mentor: Dr. Michael Childress, Biological Sciences
Students: Scott Miller, Katherine Heldt
Acidification of seawater has been shown to impair chemoreception ability in marine crustaceans, yet no work has been done on how this may affect social behavior. We examined the effects of lowered pH on aggression, cleaning, and den sharing behavior in social, juvenile Caribbean spiny lobsters, Panulirus argus. Lobsters were observed to determine the number of aggressive acts, antennule wipes (cleaning behavior), and antennule flicks (“sniffing” behavior) in normal and acidified conditions. Y-maze trials were conducted in normal and acidified environments to determine if acidification impacts lobster activity levels and attraction to conspecific odors. We found that lobsters performed fewer aggressive acts and shared dens less frequently in the acidified environment. Decreased antennule flicks and increased antennule wipes were also observed in lower pH. Our study suggests that ocean acidification impairs lobster aggression, den sharing, and cleaning behaviors, which could have wide-ranging impacts on this ecologically and commercially important species. This project was partially supported by the Creative Inquiry program.
Paid a visit to Paula Deen's restaurant and had a great meal.
Enjoyed seeing the sights and sounds of Savannah.
Even the strange guitar bar the Wormhole.
Everyone seemed to be relieved to have their presentations finished. Good work team!