Sixteen Bowdoin students were awarded fellowships for coastal or marine faculty mentored summer research this summer. The projects spanned multiple disciplines, including biology, ecology, geology, visual art, environmental studies, marine biology and chemistry. While some of the work took place at the Coastal Studies Center, utilizing the marine lab, terrestrial lab, the dock or grounds, other projects were based in the midcoast region or on Bowdoin's main campus. Three students from Randolph Macon College joined Jonathan Allen and some of the Bowdoin fellows at the marine lab. All the students presented research findings or an overview of their artistic projects at seminar sessions at the Coastal Studies Center in July.
Student fellowship presentations at the Coastal Studies Center
Caitlin Beach ‘10
Advisor: Linda Docherty, Award: Rusack Fellowship
“Toilers of the Sea”: Depicting Maine Coastal Industry in Early Twentieth Century American Art (PDF)
At the turn of the twentieth century, American society stood at the precipice of modernization. Art at this time captured the changing nature of national life; among the most enduring of these images were truthful scenes of industrialization and urbanization. The picturesque representations of Maine’s pristine coastline and foaming waves were joined by lobstermen and dockworkers, sailing boats and dry docks. Caitlin's research explores the representation of Maine's coastal industry in the landscape art of the early twentieth century. The questions she raises in her project present a certain relevance to the nature of Maine coastal society today. "At a time when small coastal industries, particularly lobstering, are waning, the question of how themes of labor and landscape are represented informing reality becomes increasing pertinent."
Andrew Bell '11
Advisor: John Lichter, Award: Freedman Fellowship
Submerged aquatic vegetation and anadromous fish in Merrymeeting Bay (PDF)
Merrymeeting Bay is a large freshwater tidal bay that drains over a third of the area of Maine. Historically the bay was a thriving and productive ecosystem known for supporting abundant populations of waterfowl and anadromous fish. By the middle of the 20th century, three centuries of environmental stress led to the colllapse of Merrymeeting Bay and its fish populations. Andy's research is expanding on previous student research begun last year with a study of the importance of submerged aquatic vegetation (SAV) habitat for juvenile anadromous fish such as alewive, river herring, and American shad. Andy seeks to resolve questions about nursery habitat of anadromous species to provide insight into the cause of the slow recover of fish populations. The question of habitat preference may be crucial for restoration of the Merrymeeting Bay ecosystem as well as for the nearshore cod fishery at the mouth of the Kennebec River.
Alexandria Brasili ‘10
Advisor: Amy Johnson, Award: Rusack Fellowship
Temperature and growth in the green sea urchin Strongylocentrotus droebachiensis (PDF)
Biological growth has long been an area of intense study in the field of biology. This project looked at the relationship between growth, temperature and size in the green sea urchin Strongylocentrotus droebachiensis. The demand for green sea urchins in Maine has led to their decline, from a biomass of 61,000 tons in 1987 to a mere 11,000 tons in 2004. Furthermore, once urchin beds are overfished, other forms of sea life move in, making recolonization efforts extremely difficult. This project focused on the process of sea urchin growth and how such knowledge could be put to use in restoring the sea urchin populations in the Gulf of Maine.
Jill Dixon '09 (Randolph Macon College)
Advisor: Jonathan Allen
The role of encapsulation in the marine gastropod, Nucella lapillus
Like many other marine gastropods species, adult Nucella lapillus encapsulate their embryos. Different reproductive strategies are specialized in particular gastropods to increase survival. However, the role of encapsulation is unclear. Encapsulation is typically thought of as "protection" from predation or desiccation, but encapsulation may protect against bacterial attack, osmotic changes, temperature shock or wave action. To determine the relative predation on Nucella lapillus embryos, Jill measured loss rates for encapsulated and unencapsulated agart. Contrary to predictions, we saw trends toward slightly higher predation on encapsulated baits. However, these results were based on a small sample size, and predation rates were equivalent across encapsulated and unencapsulated baits suggesting that the capsules do not provide predation protection. These results may help explain that while the capsule alone may not be a good source of protection, combined with a particular life history strategy; encapsulation may be the key to survival.
Shem Dixon ‘11
Advisor: Barry Logan, Award: Rusack Fellowship
Effects of mistletoe infection on shading and photosynthesis in white spruce (PDF)
The parasitic Eastern dwarf mistletoe (Acreuthobium pusillum) has devastated the white spruce tree forests along the Atlantic coast. These parasites cling onto the host and slowly drain the life out over the course of ten to twenty years. An infected white spruce tree is easy enough to spot – it is the one with a “witch’s brooms”: tangled masses of branches unlike the white spruce’s normally two-dimensional, organized splays. Part of a team-effort led by Professor Logan, this project constructed a chamber to enclose and seal an infected branch. The chamber was used to to measure the rates of photosynthesis, yielding data that can aid in the understanding of just how the brooms actually function.
Katharine Doubleday ‘11
Advisor: Dan Thornhill, Award: Doherty Fellowship
Effects of coral hybridization on specificity of coral-Symbiodinium symbiosis in Caribbean reef-building corals (PDF)
The foundations of coral reefs are the symbiotic corals, home to photosynthetic algae in the genus Symbiodinium. This symbiotic relationship provides up to 90% of the coral’s energy through photosynthesis, and allows for the extensive reef-building that is at the foundation of the coral reef ecosystem. However, a variety of factors including rising ocean temperatures and ocean acidification have led to coral bleaching, which breaks down the coral-Symbiodinium symbiosis.
A curious twist of evolution has made coral reproductively compatible with coral from different genetic lineages in a union called hybridization. Not only do the coral mix, but so do the Symbiodinium the coral carry. For some reason this hybridization occurs frequently in some areas, such as the Bahamas, but rarely in others. If certain Symbiodinium species with increased tolerance to environmental factors could be introduced to coral reefs around the world, coral bleaching may well be negated, or slowed down. However, study of the flexibility of a coral host in the number of Symbiodinium species it can hold is incomplete. Using the M. annularis and M. faveolata coral species found in the Florida Keys and Bahamas, the project determined that the evidence points away from hybridization in the Florida Keys. Further experiments will explore hybridization in the Bahamas and identify DNA gene sequences from both areas to create a more in-depth analysis on a relatively untouched field.
Whitney Grass ‘10
Advisor: Peter Lea, Award: Kibbe Fellowship
Exploring nutrient dynamics in the Androscoggin Lake watershed: Bioavailable phosphorus in agricultural runoff. (PDF)
Androscoggin Lake discharges into the Androscoggin River under normal flow conditions. During high runoff events, however, flow direction within the Dead River reverses, and Androscoggin River water surges into the lake. Since the early 1900's the Androscoggin River has been heavily polluted and conventional thought ascribed poor water quality in the lake to periodic back-flooding of the polluted Androscoggin River. Much of the concern with the lake water quality centers upon nutrients, particularly high levels of phosphorus, which stimulates algal growth which reduces water clarity, depletes the water oxygen level and hinders aquatic life. Research conducted by Peter Lea's Watershed Hydrology course found that sites with the highest phosphorus concentrations are located along the Dead River and not in the Androscoggin River. This pattern suggests that farmland bordering the Dead River, with its runoff of manure, fertilizer and exacerbation of soil erosion by plowing and tilling could be responsible for the poor water quality. Whitney's research analyzed non-point sources of nutrient loading along the Dead River, particularly in regard to agricultural influences.
Merrymeeting Bay is a large freshwater tidal estuary at the confluence of the Androscoggin and Kennebec Rivers which has suffered from extensive pollution during the mid-20th century. Any recovery effort will depend on both eliminating pollutant sources and determining how quickly polluting compounds already in the Bay can leave. Part of eliminating pollution from the Bay is determining how phosphorous has been stored in sediments before, during, and since the period of extreme pollution during the mi-20th century, as phosphorous in sediments can be released into the water, complicating any recovery effort. This project looked at the level of phosphorous in the sediments of Merrymeeting Bay, providing information for any recovery effort.
Samuel Hankinson ‘10
Advisor: Ed Laine, Award: Rusack Fellowship
The influence of oceanographic and hydrological factors on blooms of the harmful phytoplankton Alexandrium fundyesnes in Harpswell Sound.
Harpswell Sound is the home of recurring blooms of the harmful phytoplankton Alexandrium fundyense, with the largest bloom occurring during the spring season. However in 2008 the ‘spring bloom’ occurred long before it was expected. Various explanations have been considered – the current one points to a large influx of fresh water from the Kennebec River – but the picture is far from complete. By examining the record of river discharge for the Kennebec, the three year-long hourly time series of temperature from the buoy in Harpswell Sound, similar temperature time series from nearby GoMOOS buoys, and from two years of twice weekly discrete sampling in Harpswell Sound, this investigation focused on determining whether the freshwater input was sufficiently large enough to influence water temperatures enough to create a suitable environment for a bloom of A. fundyense, or perhaps if there were other factors involved in warming the water such as currents from shallower regions of Casco Bay.
William Hatleberg ‘11
Advisor: Dan Thornhill, Award: Doherty Fellowship
Diversity of Host/Symbiont Endosymbiosis in Marine Siboglinid Worms (PDF)
The recently discovered siboglinid worms have a unique feature – they completely lack a digestive system. Instead, they are home to endosymbiotic bacteria who reside in a unique organ called the trophosome, where they provide nutrition to their siboglinid hosts who in turn provide shelter. Despite the bizarre life history of the siboglinids and their bacterial symbionts, very little research has been done about this complex symbiotic relationship.
The focus of the research was on two groups of the siboglinids – Frenulates and Osedax. Almost nothing is known of either siboglinid groups, despite the ready availability and diversity of the Frenulates. Indeed, they are likely the most common marine endosymbiotic organisms in the world. With the collaboration of Dr. Thornhill, the research was split into two routes – analyzing the molecular genetics of both host and symbiont of the Frenulate family, and collecting the Osedax siboglinid. For the first, Frenulates collected from coastal Norwegian fjords were examined on a molecular level, using polymerase chain reaction and DNA sequencing. In the second, the bones of an 80’ long, dead Finback whale were scattered at strategic sites around the Gulf of Maine, and later collected to observe the Osedax presence.
For an update on Will's work with Dan Thornhill, read this recent web story.
Jane Koopman ‘10
Advisor: Peter Lea, Award: Doherty Fellowship
Dynamics of Estuarine Sand Dunes in Merrymeeting Bay
Merrymeeting Bay is a large tidal, freshwater bay that feeds Maine’s coastal beaches with sand. With rising global sea levels however, there is concern that much of this key sediment supply could be trapped in the bay and estuary, depriving Maine’s coast of its lifeblood.
By observing the sand dunes of the bay over a period of time and correlating this data with flow data obtained through the department’s Acoustic Doppler Current Profiler (ADCP) and side-scan sonar, I will look at the relationship between dune characteristics and flow variations (high and low tides, spring and neep cycles). The outcome will be a better understanding of both the spatial and temporal variation of how sand moves within these dunes in response to changing currents.
Molly Kwiatkowski ‘11
Advisor: Patsy Dickinson, Doherty Fellowship
The sheath as a barrier to FLRFamide peptide diffusion in the stomatogastric nervous system of the lobster, Homarus americanus
Central Pattern Generators (CPGs) are complex networks of neurons that control rhythmic processes such as eating, walking, and breathing in all kinds of organisms. Due to their complexity, CPGs are best studied in simple cases such as the well documented and easily dissected stomatograstic nervous system of the American lobster. Modulation of rhythmic behavior, such as faster of slower breathing, is controlled both within CPGs and by hormones released into the bloodstream. The effect of hormones on the CPG is replicated in the lab by removing the protective sheath from the nerves, covering the nerves in a saline bath, and recording neural behavior in response to hormone changes. A recent study by Roberta Dennison* suggests that the protective sheath might prevent some hormones from reaching the nerves and thereby raises questions about the accuracy of this technique. Dennison's results indicated that the protective sheath prevents some hormones from reaching the nerves and by removing the sheath the results can be skewed. This study will survey the role of the sheath as a barrier to hormones in the stomatograstic nervous system of the American lobster. This study will also provide unique research experience that will prove to be invaluable as Molly pursues a PhD of MD/PhD program. * Doherty fellow 2006
Parasitic plants depend on and often influence the development and physiology of host plants. The parasites penetrate host tissue to establish a vasucular connection that enables them to access the nutrients and water of the host. I will be using a published computer model of plant architecture, Y-plant to examine the impact of growth deformations on self-shading and photosynthesis in white spruce infected with the parasite dwarf mistletoe. Mistletoe infection upsets host developmental regulation, resulting in dense branching which may lower tree rates of photosynthesis via self shading. Read this recent article for more information about research on Dwarf Mistletoe infection of white spruce.
Laura Newcomb '11
Advisor: Dan Thornhill, Award: Doherty Fellowship
Investigating the Nature of a Temperate Coral Symbiosis Coral (PDF)
Symbiosis is defined as a close association between two organisms for a sustained period of time. There are many types of symbioses, including mutalisms, commensalisms, or parasitisms. Mutualists interact in ways that is beneficial for both organisms, while commensalists interact in a way that one of the organisms benefits, and the other is unharmed. In a parasitism, one organism is harmed to benefit the other. One example of symbiosis in a marine environment occurs on tropical coral reefs where reef-building coral and single-celled photosynthetic algae, also known as Symbiodinium, form mutualisms enabling this ecosystem to thrive.
One local example of symbiosis between corals and Symbiodinium exists in the Gulf of Maine; the coral Astrangia poculata. Here, only a single species of symbiodinium, known as B2 can withstand periods of low temperature and recover when temperatures are raised. Considering the low temperatures in the Gulf of Maine it is unclear how Symbiodinium B2 could be providing energy to A. poculata. My research seeks to determine the nature of the symbiosis between A. poculata and Symbiodinium B2. I will be testing the hypothesis that the relationship between Symbiodinuim and A. poculata is no longer a mutualism but has shifted intoa parasitic relationship with Symbiodinium gaining at the corals expense.
Emily Norton '10
Advisor: Amy Johnson, Award: Doherty Fellowship
Mathematical modeling of underwater walking in three species of intertidal crabs: Carcinus maenas, Hemigrapsus sanguineus, and Cancer irroratus (PDF)
The goal of this project is to improve models used to describe underwater walking and make predictions about which animal morphologies and densities are favorable for walking and which are not, using a Froude number equation that takes into account buoyancy, added mass and damping. Crabs are good underwater walkers, and some research has modelled some aspects of their walking; however no Froude numbers have been determined. We will use three species of crab found on the Maine coast, and will film and analyze crabs of different size and species walking at different speeds and compare our results to previous research. To see a film of crab walking see this recent webstory.
Elissa Rodman '10
Advisor: James Mullen, Award: Rusack Fellowship
Deconstructing the perceived realities of Maine's Identity: a study in painting and photography
Without even visiting many places people often feel that they know a place because they are familiar with the images associated with it. These notions of reality are not necessarily negative, but they detract from an indivdual's experience of any "familiar" location because they drive the viewer to seek images and experiences they already know and understand. In this project Elissa examined the origins of the perceived realities of coastal Maine to understand the functions and ramifications of contsructed identity more thoroughly. The typical modes of disseminarion for the characteristic Maine identity are through painting and photography, and Elissa researched and worked in both media, both to understand how they affect the collective unconsciousness, but also to learn how to manipulate the media in order to relay meaning.
Amanda Santoni (Randolph Macon College)
Advisor: Jonathan Allen
Predator induced plasticity in maternal investment of the mud snail Ilyanassa obsoleta
Phenotypic plasticity occurs in various organisms including marine gastropods. In many instances plasticity is in response to predator cues in the environment. In addition to direct plasticity to predator cues, gastropods can also respond indirectly through transgenerational plasticity. This project examined whether the presence of predators can induce changes in the maternal investment of the mud snail Ilyanassa obsoleta. Mud snails and their egg capsules were treated to exposure to marine predators Carcinus maenas, Pagurus longicarpus, and Littorina littorea, as well as a 'no predator' treatment. As a positive control, Ilyanassa will also be exposed to Strongylocentrotus droebachiensis because they do not prey on mud snails or their egg capsules. Ilyanassa responded to predator cues from Carcinus maenas by increasing the average number of eggs allotted per egg capsule, and decreasing the average egg size.
Teerawat Wiwatpanit '11
Advisor: Patsy Dickinson, Award: Doherty Fellowship
SYWKQCAFNSCFamide, a peptide from C-Type Allastostatin Family, Modulates Heart and Cardiac Ganglion of the American Lobster Homerus Americanus (PDF)
Neural networks can produce flexible outputs that result in behaviors. Repetitive movements, such as chewing, walking, breathing and the generation of a heartbeat are controlled by pattern generators, which consist of groups of interacting nerve cells. Although the output of a fixed network tends to be very consistent, properties of both the nerve cells themselves and the interactions between them can be modulated. The modulations of these pattern generators result in a variety of rhythmic patterned behaviors, for instance, walking and running or the slow and fast heartbeat during different activities. This flexibility allows the organism to adapt itself to the changing environment. Although the detailed mechanisms by which these patterns are modulated vary among species, the fundamental control is the same- the interaction between modulators and neurons inside the generators.
In this project, the C-Type Allastostatin-like peptide (SYWKQCAFNSCFamide) neuromodulatory properties will be observed in the caridac nervous system on both semi-intact heart and isolated (CG) preparations. The results from this study will contribute to our understanding of the functions of the novel peptide family, C-ASTs. Together with the findings from past studies, we will be able to understand the complex modulation of the lobster heart neuro-modulation, forming fundamental evidence for publication and presentation.
Read about the student research presentations at the Coastal Studies Center.