Bergmann’s rule describes the correlation between increased body size and living at higher latitudes, seen in many endothermic animals. However, there is debate over if Bergmann’s rule is applicable to ectotherms. Using an exhaustive review of the literature, we investigated whether the relationship between body size and latitude is consistent with Bergmann’s rule in >100 species of Alpheus snapping shrimps. We found a significant correlation between body size and latitude (i.e., latitudinal midpoint of the range), using both raw species correlations and correlations corrected for phylogeny (phylogenetic independent contrasts). We discuss multiple hypotheses that may explain adherence to Bergmann’s rule in this group of shrimp, and the broader ecological implications of variation in body size during a time of global change.

Benthic foraminifera are shelled single-celled marine microorganisms which are particularly sensitive to changes in their environment. A census of species found in an area can function as an indicator of the health of a marine ecosystem. My project focused on the distribution in 2018 of foraminiferal assemblages in Budd Inlet, near the city of Olympia, to assess the recent health of the area and the presence of pollutants. I examined nine sediment samples for foraminifera and identified the species. I then compared the abundance and diversity of species found to previous pollution data to pinpoint problems in Budd Inlet. My analysis found a low species diversity overall, as well as a correlation between the distribution of heavy metals and the presence of key species of foraminifera. The strong presence of the species Buccella frigida and Cribroelphidium excavatum and the low species diversity are consistent with a concentration of heavy metal pollutants, and mark Budd Inlet as an area of heavy anthropogenic impact.

The rugged intertidal of the Pacific Northwest serves as a nursery for ecologically and commercially valuable vertebrate and invertebrate species. Climate change is creating a persistent multiple stressor environment that could permanently decrease the survivability of these organisms. Green urchins (Strongylocentrotus droebachiensis) are ideal organisms to examine concurrent abiotic and biotic stressors on intertidal trophic relationships because they are resilient, have long life spans, and their preferred food source (bull kelp, Nereocystis luetkeana), and natural predators (sunflower sea star, Pycnopodia helianthoides) are well studied. In this study, we assessed the independent and interacting effects of abiotic environmental stressors and the presence of a predator on green urchin survival and stress response. Using kelp consumption as a proxy for stress response we designed an experiment consisting of three stressors: (1) elevated water temperatures (+6°C), (2) altered photoperiod (representative of drastic habitat changes due to excess or absence of bull kelp or substrate disruption), and (3) a predator chemical signal (via an isolated sunflower sea star). Urchins were fed a slight excess of bull kelp three times a day to ensure that food was not a limiting factor. Results indicate that exposure to either predator presence or an environmental stressor inhibited survival and increased stress, with the combination of multiple environmental stressors being the most inhibitive. The results imply that green urchins will be unable to fully cope with additional predation pressure in the presence of persistent abiotic stressors. Green urchins mitigate stress by maintaining or disrupting their habitat, and disruption can mask spawning cues causing irreparable loss of biodiversity. Using this information in future studies I will examine a long-range study of stressor response in adult urchins and work to clarify larval recruitment and response to persistent stressors.

Prehistorically, people of Alaska carved household tools from rocks, mostly slate. ‘Ulu’ is an Inuit word that translates as ‘woman’s tool’. It was used for household needs such as meat cutting. The Unangan civilization (Aleuts) in the late Aleutian phase (1000-200 BP) adopted the use of ulus sourced from slate, due to the rock’s durability and ease to sharpen. The paradox is, there is no slate widely present on the Aleutian Islands, yet fine grained volcanic rocks are abundant. In this study, I analyse 5 ulu fragment samples that were excavated on the Tanaxtaxak Spit (UNL_55), Amaknak Island of Unalaska where volcanic rocks and argillite were common. Kodiak Island, the nearest source of sufficient slate, is ~880 km away. The UNL_55 samples in this study were collected from different chrono-stratigraphic layers of the same site.The UNL_55 samples have previously been classified as slate, based solely on visual analysis. This implies possible inaccuracy in identification, since aphyric volcanic rocks and silicified argillite visually resemble slate. Using the Scanning Electron Microscope, I investigate the microtextures and minerals in the ulu fragments to identify whether they are slate, volcanic rock or argillite. Determining the rock type will guide inferences related to inter-island trade and migration of people in the prehistory of the Aleutian Islands. I expect the results to indicate rock composition that is similar to rocks that abundantly exist at the excavation site; volcanic. 

Perchlorate is a water-soluble endocrine-disrupting contaminant that is ubiquitous in our environment and is known to be toxic to humans, however it is not currently regulated in our drinking water. Daphnia magna, an aquatic microcrustacean and established model for ecotoxicology, will be used to study the interactive effects of perchlorate and hypoxia (low oxygen) on the invertebrate endocrine system. Exposure of D. magna to hypoxia is known to increase the expression of the protein hemoglobin, and results in an observable phenotypic shift in color from clear to pink. Another characteristic of D. magna that will allow us to identify environmental stress is the juvenile hormone present in the endocrine system of this species. Juvenile hormones play a role in modulating the switch between asexual (when environment is stable) to sexual (when environment is stressed) modes of reproduction. The regulation of juvenile hormones may be disrupted by some environmental endocrine-disrupting contaminants, like perchlorate. In this study, I will test the hypothesis that D. magna respond to hypoxia and perchlorate through transcriptional regulation of hemoglobin and phenotypic plasticity. Specifically, D.magna will be chronically co-exposed to different concentrations of perchlorate and different levels of hypoxia using a factorial design. Gene expression changes will be evaluated using quantitative real-time PCR of hemoglobin genes (dhb1, dhb2, and dhb3). Phenotypic plasticity will be assessed using microscopy, with an emphasis on quantifying morphological characteristics and mode of reproduction. I anticipate that perchlorate and hypoxia exposure will cause the reproductive modality of D.magna to be altered due to disruption of the juvenile hormone by perchlorate, and additionally, that hemoglobin genes will be transcriptionally upregulated. The data we generate from these studies is critical for future policy related to perchlorate regulation, which will ultimately help protect human and environmental health.

Understanding the microbial process in the conversion of food waste into methane is necessary to realize the societal need to convert waste into a sustainable energy source. A critical step in the process is the synergistic breakdown of butyrate to methane. My project Food Waste to Energy allows us to mimic the degradation of food waste to isolate the microbial partners responsible for the production of methane. This process is carried out by a syntroph and a methanogen. Although we do not know the specifications of either organism, identification can allow us to improve the way we utilize bio-reactors dependent on food waste to produce clean energy. Each organism has been grown using media designed to allow for their specific development, doubling methane production within four months on average. We are in the process of conducting a dilution to extinction to reduce the contaminating microbes while selecting for the target majority by close observation of the purity of each sample microscopically. We will sequence the genome of each organism to characterize their respective genetic capabilities and identity which we suspect is novel. Activity and growth characteristics will then be studied to understand the growth kinetics when the organisms grow separately and together. Once the organisms are isolated, we look forward to accelerating methane production by selecting mutants that can catalyze the conversion of butyrate into methane. By identifying the organisms responsible for the conversion of butyrate to methane, we can begin to introduce highly productive bioreactors in urban, rural, and manufacturing settings to combat the use of non renewable energy and create energy from the 40 million tons of food waste produced annually in America.