Parasite Hunting browsing by category

Tracking the exploits of Katrina Lohan and Kristy Hill, two marine biologists scouting for microscopic oyster parasites from Chesapeake Bay to Panama.


From the Field: The Language Barrier

Monday, February 25th, 2013

by Katrina Lohan

We were able to find a final location for Ostrea sp. in Bocas del Toro, which wrapped up our sampling there. So it was time to return to Panama City to complete our sampling on the Atlantic side of the Panama Canal.

Now I have been trying to learn and remember some Spanish phrases. There were times when my lack of fluency was awkward, and other times when it is more problematic. Our return trip to Panama City was one of the problematic occasions!

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From the Field: An “Unglamorous” Sampling Site

Thursday, February 21st, 2013

by Katrina Lohan

Life underwater. Fire coral, anemones, sponges and a diverse group of oysters cling to a dock at the Smithsonian's Bocas del Toro Marine Station. (Kristina Hill)

Life underwater. Fire coral, anemones, sponges and a diverse group of oysters cling to a dock at the Smithsonian's Bocas del Toro Marine Station.
(Kristina Hill)

To satisfy our sampling scheme, we needed one more location with all three genera present. The dock at Bocas del Toro wasn’t the most glamorous location to sample, but it was an amazing place to snorkel around. There were many bivalve species and an abundance of individuals for each species located on the pilings. There were lots of different fish, coral, hydroids and sponges. It was beautiful! We decided to make this our third sampling location as it was easily accessible and had all three species–or so we thought.

We know oysters are tricky to morphologically identify, as they have such a wide range of growth patterns. It wasn’t until we were back in the lab and had shucked a few of the oysters open that we realized what we thought was Ostrea sp. in the field was actually a different species, Dendostrea frons. Oops…

From the Field: More Oysters, Please!

Wednesday, February 20th, 2013

by Katrina Lohan

Katrina Lohan attempts to scrape Striostrea oysters off rocks in a tidal pool at Bique, Panama. (Kristina Hill)

For the second oyster sampling excursion, we headed out to Bastimentos and Solarte to try to find another site where the same three oyster species co-occur. Unfortunately, Kristy was out of commission at the time due to illness (though I’m happy to report that she has made a full recovery).

Mark, Greg and I had scouted out a few potential locations the night before. While we had no trouble finding Isognomon sp. and Crassostrea sp. on the mangroves in multiple locations, we struggled to find a location where Ostrea sp. occurred with them. So, when we ventured out to collect in the morning, we decided to scout out a few more locations that might have all three species. At Solarte, we found just the right spot! Collecting all the oysters we needed didn’t take long at all, so I suggested that perhaps we do a little snorkeling while on our way back to the field station. Mark knew just where to go. We ended up snorkeling at a place called Hospital Point, where I saw a spiny lobster (Panulirus argus). Then we stopped at another snorkeling spot with huge sea stars, cute sandy gobies, sea cucumbers and beautiful coral!

The extra time spent in the water was just what I needed to motivate myself to get into the lab and process some oysters, as I knew that any data I helped generate would add to the ever-growing body of knowledge about the world beneath the waves!

From the Field: Punta Caracol

Wednesday, February 6th, 2013

by Katrina Lohan

Mark Torchin collects oysters off mangrove roots, while Greg Ruiz and Kristina Hill sort and count the different oyster species. (Katrina Lohan)

Our first sampling site was Punta Caracol. We were able to find three oyster species attached to the mangrove roots at this site, including Ostrea sp., Crassostrea sp. and Isognomon sp. The salinity was about 30 parts per thousand, so well within the acceptable range for the three protozoan parasites that we are hoping to find.

I spent some time on the boat, but I desperately wanted to get in the water. Thus, when we had trouble finding Ostrea sp., I eagerly offered to jump in and snorkel around in the mangrove roots to look for more individuals. While I wasn’t too successful finding that species in the areas I was looking, I greatly enjoyed getting into the mangrove trees to search for them! I saw xanthid crabs, sponges and lots and lots of barnacles! We did eventually find enough individuals from all three species, at which point we headed back to the lab to process all the oysters.

Being in the water was definitely the best part of the day!

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From the Field: Scouting in Bocas del Toro

Tuesday, February 5th, 2013

by Katrina Lohan

After spending less than a week at the Naos Laboratory, Kristy and I headed to Bocas del Toro with collaborator Mark Torchin from STRI and my advisor, Greg Ruiz from SERC. The flight from Panama City to Bocas del Toro is only about an hour, so we left on the first flight out in the morning and arrived at the station in plenty of time to put in a full day’s work. Though tired from getting up early to make the flight, there is nothing that wakes me up faster than a chance to get in the water!

Reconnaissance cruise in Bocas del Toro, on the Atlantic side of Panama. Since the canal opened almost 100 years ago, species as well as cargo have been able to cross the waterway between oceans. (Kristina Hill)

The majority of our first day was spent settling in. We had a safety orientation with Plinio Gondola, the Deputy Scientific Coordinator at the field station. We then unpacked the gear and quickly took over our assigned space in Laboratory 100. Next it was time to settle into onsite accommodations. The Bocas del Toro field station has dormitories as well as houses for visitors. We are staying in one of the houses, the Casa Hoch, which has two rooms, a dining room, lounge area and full kitchen. Excellent accommodations!

After settling in, we decided to do some reconnaissance in hopes of determining at least one potential sampling location. Kristy, Greg, Mark and I headed out on one of the marine station’s boats to find oysters. We spent most of the time searching mangrove roots attempting to determine what species were present in the different locations we were surveying. While driving around the mangroves is nice, I particularly enjoyed the reconnaissance that involved snorkeling. While snorkeling, I was able to check out potential pathogen reservoirs in addition to noting the bivalve species in the area. So many research options and so little time!

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From the Field: Disease Reservoirs

Friday, February 1st, 2013

by Katrina Lohan

Katrina Lohan scrapes mud and algae off a rock at Punta Culebra. Later, Lohan will use genetic tools to see what protozoan parasites are inside that sample.
(Kristina Hill)

During the seven months that I have been a post-doctoral fellow at the Smithsonian, I have been intellectually challenged over and over again and I’m loving it! One thing that I have had to think about is what direction I want my future research to go and how my current fellowship project is helping to lead me in that direction. Through multiple conversations with both of my advisors, Dr. Robert Fleischer at the National Zoo and Dr. Gregory Ruiz at the Smithsonian Environmental Research Center, I have been able to hone in on my particular research interests and figure out how to alter some aspects of my fellowship project to better incorporate them.

I have realized that I am particularly interested in disease reservoirs. Unfortunately, this term is difficult to define. But basically, a disease reservoir can be anything (living or nonliving) where a disease-causing organism can survive outside of its host. As part of my fellowship project, I had already intended to use genetic tools to look for protozoan parasites in oysters and water samples. After further consideration, I have decided to also use genetic tools to look for parasites in other environmental reservoirs. It’s hard to predict what environmental reservoirs would be best to collect, so I was advised to choose a site, collect a few samples and just see what parasites are present. Then, I can use those results to help me decide how I should conduct a more extensive sampling scheme in the future.

With that in mind, Kristy and I headed to Punta Culebra to collect some reservoir samples. I was really excited, even though I wasn’t entirely sure how or what I was going to collect. But I was confident that I would know when I saw it. I decided to take three samples from five different sites along the rocks, roughly matching the sites where we had previously collected oysters. At low tide there are small tide pools within the rocks. I decided to collect from within these pools. In the end, I took three samples from each site. One was a sediment sample, which ranged from fine muddy sediments to larger coarse sediments with lots of shell bits. The second sample was from the living material that blanketed the rocks, which was probably a combination of mud, bacteria and turf algae. The third sample I took was a sample of a distinct clump of turf algae. I am really excited to see what protozoans I find!

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From the Field: Playa Veracruz

Tuesday, January 29th, 2013

by Katrina Lohan

Veracruz Beach on the Pacific side of Panama at low tide. (Kristina Hill)

In search of more Striostrea sp., Kristy and I, with our collaborator from the Smithsonian Tropical Research Institute, Mark Torchin, traveled to the beach at Veracruz at low tide. As we have been typically finding this species of oyster submerged in small ponds or attached to rocks in the intertidal, we were prepared to sample fast to beat the incoming tide.

To get to the right habitat, we had to carry all our gear about a mile from the beach, across a sand spit to the rocks that are exposed at low tide. Unfortunately for us, the sampling did not go particularly quickly. While these oysters tend to be large, they were also covered in mud and algae, making it difficult to distinguish between the rocks and the oysters. With each oyster that I was able to hammer off, the tide was slowly pushing me back into the rocks. Finally, Mark warned us that we should start heading back as we didn’t want the tide to trap us on these rocks by covering the sand spit before we had crossed it.

I quickly took a sample of the surface water, in the hopes that I can compare the parasites found in the surrounding water to the parasites found in the oysters. Then we started to head back, picking up a few more oysters along the way. As these oysters are big, they are also heavy! So our journey back to the beach was much slower than our journey out to the rocks. Thankfully we returned safely to the car, with all our gear and oysters, and headed back to the lab to process them.

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From the Field: A Warm Welcome in Bique

Monday, January 28th, 2013

by Kristina Hill

The mangrove-lined path down to Bique beach.
(Kristina Hill)

The first thing on our to-do list for our Panama Part II adventure was to head to Playa Bique on the Pacific Coast of Panama to find more Striostrea sp. and Saccostrea palmula oysters. In order to get to Bique, we had to travel down an unpaved, rocky clay road that wended through lush green vegetation with white cows grazing on hillsides. The beautiful scenery distracted me enough that I didn’t feel my head hit the roof of the truck with every single bump in the road, and distracted Katrina enough that she was able to keep her breakfast!

We arrived at Bique to find a small village with brightly colored houses and friendly people. There were also several dogs in the village anxious to welcome us–as we unpacked our gear, one decided to mark his territory right on the side of our bucket! (Is there an old saying about a dog urinating on a bucket bringing scientists good luck? If not, there should be.) Then we tromped down a sandy, mangrove-lined path to the rocky intertidal, where we were able to find the oysters we were looking for.

The Striostrea species we found were large and seemed to like the tidal pools found in the rock formations at low tide. They were large oysters (we were finding 80-100 mm ones), and it looked like people were “harvesting” the meat and leaving the shells behind—it was very difficult to pry the oysters from the rocks without shucking them open. The Saccostrea palmula oysters we found were much smaller (20-60 mm), so they probably aren’t consumed from this location.

We headed back to the lab, cleaned our bucket and set straight to processing the oysters for metazoan and protistan parasite analyses.

Here’s to hoping the rest of our collections go as well!

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From the Field: Regresamos a Panamá!

Monday, January 28th, 2013

by Katrina Lohan

Beach at Punta Culebra, on the Pacific side of the Panama Canal. (Katrina Lohan)

Our first trip to Panama felt like a whirlwind! We learned a lot about what worked and what didn’t for processing all the oysters we collected. We also learned that identifying oysters just by looking at them is really hard. To prepare for this trip, Kristy, Greg and I went to the Smithsonian’s Natural History Museum to meet with our collaborator, Ellen Strong, who is the curator of all of the bivalves. She showed us the oyster collection, and the three of us spent a few hours examining the shells of the different oysters. I’m really glad we did, because we all left feeling much more confident in our ability to identify oysters in the field and in the lab–something that will be very useful!

Our current trip to Panama is expected to be three and a half weeks long, and we have an ambitious schedule. The first few days will be spent finishing our collections on the Pacific side of the Panama Canal, then onto the Smithsonian’s Marine Station at Bocas del Toro for a week and half, and then back to the Naos Laboratory to finish sampling the Atlantic side of the Panama Canal. It’s time to put those oyster identifying skills to the test!

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From the Field: Farewell, Panama

Friday, December 28th, 2012

by Kristy Hill

The oyster Isognomon sp. in the crevices of a rocky reef at Fort Sherman on the Atlantic coast of Panama. (Kristy Hill)

Yesterday we ventured to the Caribbean coast of Panama, where we had beautiful weather for sampling. Our first stop was near Fort Sherman, a former United States Army base, where we found lots of Isognomon oysters on the subtidal rocks. These oysters are unusual because instead of cementing their shell to a hard surface, they attach themselves to rocks and mangroves with a threadlike structure. We also were able to collect a Crassostrea sp. and a few Ostrea sp. as well.

We then headed to the Smithsonian Tropical Research Institute (STRI) Marine Laboratory in Galeta. We braved the somewhat turbulent waters and snorkeled to collect from the mangroves, despite reports of crocodiles that frequent the area. Oh, the lengths we’ll go to in the name of science.

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