Author Archives: Erik Sotka

25 August 2015 – Dedicated undergrads present summer research.

We had an outstanding and talented team working on the Gracilaria vermiculophylla project this summer: Undergrads Lauren Lees, Paige Bippus and Sarah Shainker (CofC), REU student Aaron Baumgartner (U. Akron), GPMB graduate student Ben Flanagan, and our intrepid postdoc Stacy Krueger. The project is just beginning to yield fascinating results, three of which were presented during end-of-summer undergrad presentations. I am so appreciative of their hard work and dedication this summer, and they have every reason to be proud of what they’ve done.

Aaron Baumgartner (Using photosynthetic efficiency to quantify the condition of an invasive red seaweed after salinity stress)aaron talk

 

 

 

 

 

Sarah Shainker (Evolution of heat stress tolerance of the invasive seaweed Gracilaria vermiculophylla)

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Paige Bippus (Herbivory resistance in the invasive alga Gracilaria vermiculophylla).

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Meeting Seeds-to-Shoreline teachers: citizen science!

AR-150519731Yesterday, I enjoyed meeting inspiring K-12 teachers with EV Bell @SCSeaGrant. Seeds-to-Shoreline is a fantastic program that gets K-12 kids to rear salt marsh plants in their classrooms, and then transplant them to the field. I’ve been collaborating with EV and local teachers, and seeing if we can’t get high-quality reciprocal transplant experiments done at the same time. Last year, I was able to recruit one class from Ashley Hall Elementary. This year, I hope to get several more, and yesterday’s workshop was a great opportunity to meet teachers that are veterans of the program, in some cases 5-year veterans. Here‘s a great story about a Sullivan’s Island class that reared and transplanted Spartina this spring. We can do ‪#‎citizenscience‬ with ‪#‎Spartina‬. Photo credit: Dustin Waters, Moultrie News.

17 June 2015 – Alyssa Demko successfully defends her M.S. thesis

Alyssa Demko completed her MS thesis defense on Friday June 13 on Latitudinal gradients in seaweed nutritional content and palatability to generalist marine herbivores. She now moves onto Paul Jensen’s laboratory at Scripps Institute of Oceanography to pursue a PhD in microbial ecology. 2015-06-12 10.21.23Very excited for her, but sad to see her leave. She will be missed. Her thesis abstract is here: 

Over the past century there has been an unprecedented rise in global ocean temperatures as a result of increased anthropogenic activity. The increase in ocean temperatures has already begun to facilitate the movement of tropical marine herbivores and seaweeds into temperate systems with dramatic consequences to ecosystem dynamics, function, and overall productivity. In an effort to gain insight into the seaweed-herbivore interaction over a latitudinal gradient, we assayed the palatability of 50 seaweeds (31 Rhodophyta and 19 Phaeophyta) collected from polar (Antarctica; 66ºS), temperate (California; 33 and 38ºN), and tropical (Fiji; 18ºS) locations to generalist crab and urchin herbivores from the Atlantic Ocean that were naïve to these seaweeds. Overall, seaweeds from polar and temperate locations were twice as palatable as were seaweeds from the tropical location. This latitudinal increase in palatability is largely explained by the response of urchins to Rhodophytes. In contrast, the palatability of Phaeophytes did not significantly differ across latitude. Some of the latitudinal increase in palatability was attributable to latitudinal increases in nutritional content, as measured by percent carbon, nitrogen, and ash-free dry mass. In contrast, protein and polyphenolic content (a putative chemical defense) did not significantly vary with either latitudinal origin or palatability. After accounting for the positive effect of organic content on palatability, a residual analysis indicated that tropical red seaweeds were significantly less palatable than temperate and polar reds than was expected. This suggests that undescribed chemical defenses of tropical red seaweeds lowers their palatability to generalist herbivores. To our knowledge, this represents the first study to assess palatability of any primary producer on a global scale. It also suggests that the diffuse coevolution of seaweed-herbivore interactions is intensified within tropical habitats. We predict that ongoing movement of marine herbivores and seaweeds into temperate habitats may both increase the relative success of herbivores with higher tolerance for chemical defenses and seaweeds with lower palatability.

 

 

 

18 December 2014 – Courtney Gerstenmaier defends her MS thesis

Way to go, Courtney!  Her field survey and experiments demonstrated that polycultures of an invasive red seaweed Gracilaria vermiculophylla can have higher growth rates than monocultures do.  Genetic diversity benefits ecosystem functioning and services within most species, but in this invasive, genetic diversity may facilitates invasion success.

10 Sept 2014 – Sotka lab collaborates with Patriot’s Point

We are excited to announce a partnership with the Patriot’s Point Naval and Maritime Museum.  The Museum educates 20,000 students each year on natural history and marine science, and all 5th graders in Charleston County School District since 2006.  In collaboration with a former CofC undergraduate and now Science Program Coordinator, Hannah Giddens, the Sotka lab has become their “Science Spotlight” laboratory.  This program links our research on local ecosystems with their 5th grade curriculum.  We are very proud to be a part of this effort and look forward to working with her and other dedicated teachers in the Charleston area.  Click here for an overview of the program and here for a logbook of activities in our lab.

 

29 July 2014 – a busy summer

we have had lots of folks working in the lab this summer.    virtually everyone is working on Gracilaria vermiculophylla (the lone exception is alyssa, who is working on biogeography of seaweed defenses).

Hannah Waddell (Academic Magnet High School – HHMI fellow)

Sarah Shainker (CofC undergraduate – HHMI fellow)

Connon Thomas (SUNY-Syracuse – REU fellow)

Meredith Smylie (former GPMB MS student, now a part-time technician)

Carrie Hemphill (former Clemson student, now a part-time technician)

Alyssa Demko (GPMB student)

Courtney Gerstenmaier (GPMB student)

Stacy Krueger-Hadfield (NSF-funded postdoc)