Predicting species and ecosystems responses to climate change and extreme conditions presents major challenges in ecology. Often understanding these responses requires looking not only into the present ecological conditions and physiological experiments but studying the past evolution and the events that the extant species ancestors may have experienced. This is important because today we are observing shifts in our climate, changes in ecosystems not unlike that of the past major mass extinctions. My broad interest involves predicting species responses to environmental conditions, and the conservation of endangered species and their environments.
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Seagrasses-
In the San Juan’s, Washington State, and globally seagrass meadows are experiencing decline and localized extinctions. I have been monitoring several sites for last eight years. I maintain field sites within around the San Juan Islands: False bay, Picnic cove, Westcott Bay, Beach haven, Shallow Bay, and Picnic Cove; along with Padilla bay and Fidalgo Bay near Anacortes. In these field sites I monitor seagrass (Zostera marina, and Phyllospadix scouleri) populations, disease levels, and water and soil chemistry. More specifically I record sulfide and hydrogen sulfide, pH, temperature and salinity levels throughout the bays. This research is partnered with the Friday Harbor Laboratories and Samish Tribe. Through surveys I have identified a plausible mechanism for the decreases in seagrass populations. I hypothesize that as temperature and bio-matter increase, sulfide and hydrogen sulfide levels within these bays also increases (1). This may be caused by the bacteria decomposing the bio-matter. Neither the less - this is, in part, causing the death of individuals and lowering the resilience of the species - causing extinction(s) not unlike those of the past. Current field and physiological experiments have shown that seedlings are highly vulnerable to low and modest levels of H2S, and high concentrations (mM) cause depression of photosynthetic output, as well as causing Photosystem II to become inactive (2-3). The low toxcitiy within seedlings helps to explain the die-offs and inability of seedling recruitment in many of these locations where H2S has been observed. Understanding how hydrogen sulfide affects the plant on a mechanistic level is still unknown. |
Green lake, New York, USA
Understanding how plants evolved in a world full of H2S is very important in understanding how modern plants will respond to changing conditions and possible exposure to H2S. Green lake, (http://en.wikipedia.org/wiki/Green_Lake_%28New_York%29) is a chemically stratified lake into an oxygenated upper portion (mixolimnion) and a euxinic deeper portion (monimolimnion).Because of this different bacterial and algal communities live under drastically different conditions (meromictic character) that mimic deep time and are believed to represent a possible analog to ancient ocean environments during the Precambrian and during times of environmental stress. We recently discovered that Charophytes live in the transition zone and can tolerate high levels (mM) of hydrogen sulfide (Gupta et al). Understanding this is key to understanding plant evolution during times of euxinic environments.
Understanding how plants evolved in a world full of H2S is very important in understanding how modern plants will respond to changing conditions and possible exposure to H2S. Green lake, (http://en.wikipedia.org/wiki/Green_Lake_%28New_York%29) is a chemically stratified lake into an oxygenated upper portion (mixolimnion) and a euxinic deeper portion (monimolimnion).Because of this different bacterial and algal communities live under drastically different conditions (meromictic character) that mimic deep time and are believed to represent a possible analog to ancient ocean environments during the Precambrian and during times of environmental stress. We recently discovered that Charophytes live in the transition zone and can tolerate high levels (mM) of hydrogen sulfide (Gupta et al). Understanding this is key to understanding plant evolution during times of euxinic environments.
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South Pacific Nautilus research -
Upon joining the Ward lab I have been a part of several paleontological and ecological projects. One such is evaluating the cephalopod nautilus habitat, distribution and population across the Indo-Pacific. I have been part of several research expeditions where I assisted in evaluating the physiology of nautilus and population stresses. In doing so I have traveled to Fiji, American Samoa, Australia, Vanuatu, and the Philippines. Partnering with Dr. Greg Barord and save the nautilus (http://savethenautilus.com/) we established a comprehensive report that populations are declining (4). My colleagues Lauren Vandepas and Dr. Billie Swalla and I evaluated the genetics between the different geographic populations. We constructed a phylogeny using COI and 16S from Nautilus across the Indo-Pacific. Using this phylogeny we discovered that, contrary to the current paradigm, samples from the Philippines have the highest genetic diversity and several named Nautilus species may comprise one widespread species (5). Based on these results we recommended to CITIES that Nautilus should not be fished. Even though Nautilus research is a step from my main thesis project involving seagrass and sulfide accumulation, this project is dear to my heart and I will continue to engage in research and Nautilus conservation. |
St Thomas, Virgin Islands, USA
Tropical seagrasses experience different limiting factors and environmental stresses then those in the temperate regions. However, with increases in global temperature and bio-accumulation, inshore environments may experience increases in sulfide levels and euxinic conditions. Recently (winter 2014), I established a partnership with University of Virgin Islands, monitoring seagrass sites, and conducting physiological experiments similar to those that I conducted at the University of Washington.
Tropical seagrasses experience different limiting factors and environmental stresses then those in the temperate regions. However, with increases in global temperature and bio-accumulation, inshore environments may experience increases in sulfide levels and euxinic conditions. Recently (winter 2014), I established a partnership with University of Virgin Islands, monitoring seagrass sites, and conducting physiological experiments similar to those that I conducted at the University of Washington.