Lindavia intermedia (Manguin ex Kociolek & Reviers) Nakov et al. ex Daniels et al. comb. et stat. nov.
Sorry for the complicated title, but this blogpost is about a complicated little diatom. We just published a short nomenclatural article in the online journal Notulae Algarum that rectifies naming problems that have plagued the centric diatom currently known as Lindavia intermedia. The diatom was originally described from samples taken in Alaska (hence my interest), but has undergone a myriad of genus changes and status changes (ie. changing from a variety to a species). In writing the article, I learned a great deal about the rules of taxonomy and how we name organisms, especially algae. A fun project, and special thanks to Mark Edlund and Phil Novis for helping get this out. For more on this diatom, refer to the article here, or to the Western Diatoms webpage.
Urban ecosystems and green spaces are paramount to the mental well-being of communities. Lakes and ponds in particular provide a critical venue for recreational opportunities from swimming and fishing in the summer, to ice-skating in the winter, and in some cases provided drinking water to local communities. Because of their proximity to residential and industrial developments, urban ponds are also vulnerable to local sources of pollution such as road and lawn runoff and factory effluent. No pond typifies both the importance and vulnerability of urban ponds better than Providence’s Mashapaug Pond.
Mashapaug Pond has received considerable attention from scientists and local activists throughout the years. For an excellent overview of the sociological importance of the pond as well as information on how local industrial development have affected the pond and community, refer to the Urban Pond Procession website and video archives. For his PhD thesis at Brown University, Bernabo reconstructed vegetation communities around the lake using pollen assemblages in a sediment core. Settlement by Europeans and later industrial development activity are both reflected in changes in the pollen spectra. One of the largest polluters, historically, was the Gorham Silver Company, which likely released considerable heavy metal and organochemicals into the pond and along the shoreline in the late 1800’s. While the silver company has long-closed, scientists wonder about the long-lasting legacy of such pollution. Currently, the RI EPA advises strongly against eating fish from the pond as well as swimming in the pond. Efforts are underway to assess the recovery of the pond post-contamination and to establish baseline criteria for managing the pond in the future.
As part of the efforts surrounding Mashapaug Pond, Brown University undergraduate Sophia Rudin (advisors: Dave Murray, Tim Whitfield), is reconstructing the history of heavy metal pollution using two methods. First, she is comparing metal concentrations in plants collected today with plants collected over 100 years ago and stored in Brown’s Herbarium collection. Secondly, and this is where I come in, she is using lake sediment cores to reconstruct the ecological changes and heavy metal changes that have occurred since the mid-1800’s. Preliminary analysis of the sediment core shows a very obvious heavy metal signature of industrialization, and importantly, a gradual return towards baseline conditions (pre-industrialization sediments had essentially no heavy metals), although baseline conditions have not yet been achieved, and may not ever. Along with the heavy metal changes, there are clear changes in diatom assemblages and primary productivity, which are more likely linked to phosphorus and nitrogen pollution over the same period of industrialization. Investigation is ongoing.
Here are photographs from the sediment coring expedition, which occurred in October, 2016. Sophia Rudin, Dave Murray, and I had an excellent day to core this lake.
Well, classes are wrapping up at Brown and my official duties as Limnology TA are done. But my unofficial duties aren’t complete until I get some more awesome limno field trip pictures online. The class does two trips to Pout Pond (Belmont, NH) each year. The first trip is in winter (see previous post), and the second trip, shown here, is in spring.
Hi. I hope that my abundance of field-work related pictures does not lead you to believe this is all I do. The vast majority of my time is spent in the lab or on the computer analyzing samples and data, and making figures and writing. These are all very exciting things to do. None-the-less, I am sharing more field work pictures because they are prettier.
Two field projects I helped with this spring involved sediment coring in Rhode Island.
The first project was to help Stephanie Spera collect sediment cores from Succotash Salt Marsh. Stephanie is a 5th-year graduate student in my department and she is teaching a Climate Change course at Wheaton College this semester. For this class, Stephanie wanted her students to gain firsthand experience with the idea of paleoclimatology. For a full description of the Succotash sediment cores, see my previous blog posts or “7oo yr sedimentary record of intense hurricane landfalls in southern New England” by Donnelly et al. (2001). In brief, sand layers in the sediment core represent local landfalls of past hurricanes, and so we can reconstruct the history of large storms.
The second project, also seen in pictures, examines the effects of nitrogen remediation in Narragansett Bay. First-year graduate student Sydney Clark is pursuing this project and plans to use nitrogen isotope in sediment cores to qualitatively assess the effectiveness of adding tertiary treatment to East Providence’s wastewater treatment plant. We collected replicate sediment cores from Swan Point in the Seekonk River, immediately across from the treatment plant and Sydney is now busy in the lab with these sediments.
Succotash Salt Marsh – March 20, 2016
Swan Point, Seekonk River – March 26, 2016
Hello blogosphere! Happy 2016!! We survived winter and the geology field season is ramping back up in the northern hemisphere. To kick off the 2016 fieldwork campaign I went with Brown University’s Limnology class, taught by Jim Russell, on a field trip to New Hampshire. The goal of the class is for students to become familiar with and proficient in all things related to lakes, and this includes field sampling. Six students, Jim, and I went to Pout Pond, near the town of Belmont, NH to take water measurements and samples. Students measured lake temperature, pH, dissolved oxygen, conductivity, alkalinity, and secchi depth, and took water samples to measure salts and nutrients.
Here are some pictures from the beautiful day.
I recently moved into a house on Transit St. in Providence. Legend has it that the house was built by the aunt of composer George Cohan (this was a big selling point for me, no doubt). But, that is only kind of cool in comparison to the etymology of the street name itself. Transit Street was so named because in the 18th century, it was considered one of the prime locations in the world to view the Transit of Venus (the passage of Venus between Earth and the sun) and astronomers from New England gathered there to watch the event in 1769.
The pictures below are not the Transit of Venus, but they do represent a planetary transit that I captured earlier this fall. It is the blood moon – a combination supermoon and complete lunar eclipse. I took pictures at 30x optical zoom with my Nikon point-and-shoot camera mounted on a tripod. I was pleased with the outcome from such a small camera. Enjoy.
This blog is about the Kaktovik Oceanography Program and the wonderful experience I had volunteering with the program in 2015. The KOP is an annual week-long natural science camp for local students in the town of Kaktovik, Alaska. It is hosted by the US Fish and Wildlife Service (thanks Greta Burkhart and Allyssa Morris), and largely coordinated by Ken Dunton’s research group from University of Texas. Students spend the week thinking about ecosystems, evolution, geology, etc., and do a lot of hands-on field work in the local lagoons and coastal habitats. Our goal was to show the participants that doing science is not only important and interesting, but also fun and a potentially viable career path.
This year, thanks to an NSF grant to Brown University’s Yongsong Huang (PI), I was able to travel to Alaska to lend my geology expertise and to help teach in the science camp. The theme of the camp was “Life as an Arctic Scientist”. The pictures below will guide you through the day-to-day events of the camp.
Day 1: Life as an Arctic Ecologist. Students explored lagoon foodwebs, with the goals of understanding what factors affect where/how marine organisms live, and understanding how scientists collect and analyze data to make conclusions. We made measurements of habitat characteristics such as temperature, salinity, dissolved oxygen, etc. and used a seine to collect lagoon fish. Lastly, we set up an aquarium in the classroom and populated it with flounder and 4-horned sculpin (aka Myoxocephalus quadricornis, aka Kunyuk) from the seining activity. We monitored the aquarium every day for temperature, pH, dissolved oxygen, and nitrogen concentration, and thought about why these parameters mattered and why they changed.
Day 2: Life as an Arctic Geologist. On the second day, we played with MUD. Or more accurately, we played with SEDIMENT. The obectives of this day were to 1) think about the relationship between environment and sediment, 2) retrieve a sediment core from the center of Kaktovik Lagoon to see if we could observe changes in sediment, and therefore changes in environment, through time. The students tested the hypothesis that KL used to be a lake, and that some time in the recent geologic past the lake was captured by rising seas to become the modern saltwater system that it is today. Unforunately, our sediment coring was stymied by sub-lagoon permafrost about 50 cm into the sediment, so we couldn’t get very old stuff. Oh well, worth a try, and that is sometimes what life is like as an arctic geologist!
Day 3: Life as an Arctic Ecologist Part II. The third day of KOP began with a guest presentation by USFWS researchers. Claire, Will, Gabriella, and Damion talked with the students about their ongoing project to survey wild Eider population that inhabits the barrier islands along the Alaskan Coast. Such an incredible project and a great opportunity for the students to see science in progress. Participants had the chance to try candling eggs, a method where a light placed behind an egg illuminates the developing embryo.
The afternoon was marked by more hypothesis testing with the students. The goal was to compare the coastal ecosystems inside and outside of the lagoon barrier. Students made several hypotheses about how animals, water quality, and sediments might vary between these sites.
We also did more thinking like a geologist. Coastal erosion is a process of immediate concern for the residents of Kaktovik, with the barrier island eroding at a rate of 10 meters per year (compare to 2 meters per year historically). The students came up with a method to study the erosion rate year after year, and we took some baseline measurements. Students walked along the foot of the bluff marking GPS location of the bluff edge. Yearly transects should show the gradual retreat of the bluff face. Scary stuff, and it was apparent to the kids why this was such an important scientifict question to address. Unfortunately, the cause of bluff erosion acceleration is likely a combination of climate-related sea-ice loss, windiness, waviness, and permafrost thaw, all of which are more difficult to fix than to measure…
Day 4: Life as an Arctic Hydrologist. Thursday was the first day of real school for the students, so, instead of kids coming to the community center for camp, the USFWS and UT crew went into the local school to speak with high school students. After school was out, Craig and Jeff, two UT graduate students, talked with kids about the water cycle and took them outside to try their hands at collecting soil water. Thursday evening we also held an activity night for the younger children of Kaktovik – it was a night of popcorn, juice, science-adventure-related movies and games, chaos, learning, and fun.
Day 5 ; Life as an Arctic Artist. Our final day of camp was a scientific recap followed by a cultural discussion and fish printing on t-shirts. For the cultural experience, Allyssa Morris (USFWS) put together a really nice presentation about different types of food eaten around Alaska, so the kids could think about the connection between their livelihoods and the resources around them. The presentation was followed by a smorgasbord of wild game from different parts of Alaska. So tasty. Most of the kids said their favorite food was either seal or whale. I didn’t get a chance to try either, but the local fish was delicious. Fish printing, or gyotaku, is a very old tradition, originally meant as a way for fisherman to prove how big a fish they caught. While some people still use real fish for their printing, we used rubber versions of local Arctic species to make our prints.
Day 6 and 7. The KOP finished successfully on Friday; we had two days to clean and pack up our gear, and this left plenty of time to look around the island, explore the lagoon, and just take in the scenery. Here are some general pictures from my time in Kaktovik. Enjoy
And that wraps up the highlights of the 2015 Kaktovik Oceanography Program and my time in Kaktovik. Thanks!
Today Brown geology grads, undergrads, and postdocs celebrated our third successful season with the URI Watershed Watch program. The WW, coordinated by the URI cooperative extension, monitors about 120 RI water bodies on a weekly basis from May to October, all through the volunteer efforts of RI citizens. The long-term data (>20 years for some lakes) are used to assess restoration efforts, pollution impacts, climate change impacts, etc. Full information can be found at the URI-WW website.
Using the foldable boat, aka the ‘coin purse’, our crew has now monitored Cunliffe Pond for three years.
Specific measurements we make include, on a weekly basis: temperature, secchi depth, dissolved oxygen; on a biweekly basis: chlorophyll a; and three times per year: bacteria coloforms, phosphate, ammonium, nitrate, and cyanobacteria abundance. Here are some data highlights from our sampling effort, as well as some photos from the most recent sampling season.
2015 is the year of New England coring expeditions for me. This spring we started out retrieving sediment cores from Siders Pond, MA for ancient DNA work (see previous post). Next I cored Providence-local Roger Williams Park ponds to assess nutrient pollution and heavy metal contamination since European settlement. If you have followed earlier blog posts on our weekly water quality monitoring, you may already be familiar with Cunliffe Pond in RWP. There are a total of 5 ponds in the park, all linked together by small streams and navigable by swan boat.
Dave Murray is the environmental chemistry facilities manager at Brown. He oversees important instrumentation and also teaches a course called Instrumental Analysis. For this course, students collect environmental samples for the dual purposes of learning a variety of analytical techniques, and also for answering some outstanding environmental science questions. This year, students focused on tracing contaminants through the RWP pond network through space, time, and the food web. I helped a couple of students and Dave retrieve sediments for this project. The pictures below outline our field day of sediment collection.