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innovative tools
- 1. Innovative Tools forStudent Research Shaun M. Gill, Tim Arienti, Troy Thibeau University of New England Marine Science Center, a UNE Center of Excellence Variable Speed Crustacean Treadmill ‘11 Tide Simulation Systems ‘09 Flow Through Seawater Chiller ‘13 Oscillating Salinity System ‘10 The flow-through water chiller is a portable by-catch holding system made for installation on commercial vessels fishing the North Atlantic. It was purpose built to hold deep water by-catch specimens in a temperature controlled environment for up to 48 hours. Insulated commercial totes hold chilled seawater and house custom bent stainless steel coils which act as heat exchangers when submerged in an ice water slurry. The system is capable of chilling and maintaining water to within +/-1°C of bottom water temperature. Extreme differences between bottom water and deck conditions post-capture can be extremely stressful to by-catch. This system minimizes on-deck stresses, allowing for unprecedented direct observation of by-catch and understanding post-capture mortality rates of commercially important species. The system was a team design lead by graduate student Ryan Knotek ’15 in collaboration with the New England Aquarium and Virginia Institute of Marine Science. The system helps the Sulikowski Lab understand the impacts of commercial fishing on by-catch, which is critical for making informed decisions about managing commercially important fish stocks. Knotek and his teammates were mentored in tool-use and prototype fabrication. The team built all system components including the heat exchange coils and water distribution systems. They learned how to fabricate as well as understand the design and function of each component they created. The chilled water system and the science behind it were showcased in Commercial Fisheries News, September 2013, Vol 41, No 1. This two-tiered tank system uses digitally controlled ball valves to strategically drain and fill tanks synchronized with natural tidal intervals. Salinity is diluted and re- concentrated as it would be in natural tidal estuaries. Both tiers of the system are flow-through, requiring only gravity and head pressure to move water. Ambient water baths ensure temperature control and stand pipes regulate water volume. Seawater is precisely mixed with freshwater to create custom salinity profiles that shift with daily high and low tide intervals. The oscillating salinity system was designed for graduate and undergraduate research in the Frederich lab. The students operate and maintain system and have been collecting publishable data with it since 2010. Creating estuarine conditions in the lab synchronized to local conditions with local seawater maximizes similarity to in situ environmental conditions. In this particular instance, salinity parameters are altered to induce physiological stresses in the invasive green crab, Carcinus maenas . The stresses simulate conditions the crabs might experience might experience when living at estuary extremes. When used in conjunction with the crab treadmill, researchers can compare the effects of stress on physiological performance which is administered in the form of treadmill exercise. This research helps the Frederich lab understand how C. maenas has adapted to living in rapidly changing environments and also helps describe the molecular physiology involved during different molt stages. The crab treadmill is a reverse engineering project inspired by the semi-infamous YouTube sensation “Shrimp on a Treadmill”. Except for the hardware and the brushless motor, all parts for this project were fabricated using manual machining equipment and a table saw. The project represents approximately 100 hours of build time and many more hours of rendering and design research. Quick disconnect fittings allow easy plumbing to a peristaltic pump that recirculates modified seawater throughout the chamber. The treadmill was built for Dr. Markus Frederich and his students to study the physiology of the invasive green crab, Carcinus maenas. Carcinus were introduced to US waters in the 1800’s, arriving on European trading ships. Carcinus rapidly outcompete North American species and decimate ecologically and economically important species such as the soft shelled clam (aka Steamers). The treadmill helps the Frederich Lab study marine invertebrate regulation of energy metabolism under stress. Understanding invasive species physiology helps predict how far the crabs can spread within an ecosystem and as well as how they compete with native species. The treadmill induces exercise, a form of stress, which manipulates crab physiology of under different treatment regimes. Carcinus maenas, appears in red and green color morphs. The Frederich lab investigates potential differences between these two color morphs by exposing them to stressors like hypoxia (low levels of oxygen available) and tests the animals’ performance. By forcing the animals to run underwater on the treadmill after exposing them to different time periods of hypoxia, red morphs’ running endurance decreases faster than their green counterpart’s. Whether this difference is reflected in ecological success or in molecular and genetic parameters is currently being investigated. Scan this QR code with a mobile device to see the treadmill video on YouTube! Green crabs, Carcinus maenas, exposed to these oscillating salinity conditions are affected by decreasing and increasing ion concentrations in their hemolymph (blood). The Frederich lab investigates resulting changes in the ion regulatory machinery at the molecular and genetic level. First results indicate that these oscillating salinity conditions pose less energetic stress that an exposure to continuously low salinity Salinity profile in the oscillating tank with alternating 6 hours of regular strength sea water (32 ppt) and 6 hours of low salinity sea water (13 ppt), simulating a typical tidal cycle. Salt marshes and the critical ecosystem services that they provide - such as water filtration, or as a nursery ground for fishes – are at risk due to predicted rises in sea level associated with global warming. Salt marsh persistence in the face of sea-level rise will be determined, in part, by the balance between plant production which helps build salt marshes, and decomposition by microbes which reduces marsh elevation. Students from the Zogg and Travis labs have been examining these processes for several years, using both outdoor and indoor tide simulation systems. (Right) An outdoor tidal simulation system was created by plumbing 5’ diameter fiberglass tanks with actuated ball valves controlled by timers. This allowed researchers to regulate when and for how long the tanks were flooded, so that they could simulate sea level rise due to global warming. This outdoor system takes advantage of natural sunlight, which allows scientists to work with photosynthetic organisms, such as salt marsh plants (Bottom) A scaled down version of the tidal simulation system was constructed inside the MSC to study effects of sea level rise on processes that do not require sunlight, such as the activity of microbes in salt marsh sediments. Sean Balschi ‘14 Anthony Himes ‘14 Kate DiVito ‘11 Anthony Himes ‘14 Ryan Knotek ‘15 Connor Capizzano ‘15 Liese Carleton ‘ 14 Joe Langan ‘ 15 Ryan Knotek ‘15 Liese Carleton ‘ 14 Joe Langan ‘ 15 Ryan Knotek ‘15 Ryan Knotek ‘15 Connor Capizzano ‘15