Archive for the ‘Earth & Marine Sciences’ Category

Melting During Cooling Period

Friday, April 18th, 2014

Rannoch Moor

A University of Maine research team says stratification of the North Atlantic Ocean contributed to summer warming and glacial melting in Scotland during the period recognized for abrupt cooling 12,900 to 11,600 years ago in the Northern Hemisphere.

Prevailing scientific understanding has been that glaciers advanced in the Northern Hemisphere throughout most of the Younger Dryas Stadial (YDS) — a 1,300-year period of dramatic cooling.

But carbon-dated bog sediment indicates the 9,500-square-kilometer ice cap over Rannoch Moor in Scotland retreated at least 500 years before the end of the YDS, says Gordon Bromley, a postdoctoral associate with UMaine’s Climate Change Institute (CCI).

“Our new record, showing warming summers during what traditionally was believed to have been an intensely cold period, adds an exciting new layer of complexity to our understanding of abrupt events and highlights the fact that there is much yet to learn about how our climate can behave,” Bromley says.

“This is an issue that is becoming ever more pressing in the face of global warming, since we really need to know what Earth’s climate system is capable of. But first we have to understand the full nature of abrupt climate events, how they are manifest ‘on the ground.’ And so we were compelled to investigate the terrestrial record of the Younger Dryas, which really is the poster child for abrupt climate change.”

Glaciers, says Bromley, respond to sea surface temperatures and Scotland is immediately downwind of the North Atlantic Ocean.

“Scotland was the natural choice as it lies within the North Atlantic Ocean — widely believed to be a driver of climatic upheaval — and thus would give us a robust idea of what really transpired during that critical period,” he says.

What the team found was that amplified seasonality driven by greatly expanding sea ice resulted in severe winters and warm summers.

While sea ice formation prevented ocean to atmosphere heat transfer during winters, melting of sea ice during summers created a stratified warmer freshwater cap on the ocean surface, he says. The increased summer sea surface temperature and downwind air temperature melted the glaciers.

Bromley says this research highlights the still-incomplete understanding of abrupt climate changes throughout Earth’s history.

“Ever since the existence of abrupt climate change was first recognized in ice-core and marine records, we’ve been wrestling with the problem of why these tumultuous events occur, and how,” he says.

Kurt Rademaker, Brenda Hall, Sean Birkel and Harold W. Borns, all from UMaine’s Climate Change Institute and School of Earth and Climate Sciences, are part of the research team. So too is Aaron Putnam, previously from CCI and now with Lamont-Doherty Earth Observatory at Columbia University/Earth Institute. Joerg Schaefer and Gisela Winckler are also with Lamont-Doherty Earth Observatory and Thomas Lowell is with the University of Cincinnati.

The team’s research paper, Younger Dryas deglaciation of Scotland driven by warming summers, was published April 14 on the “Proceedings of the National Academy of Sciences” website.

Contact: Beth Staples, 207.581.3777

History Repeats

Tuesday, February 18th, 2014

ice core

A team of University of Maine scientists studying nearly 11,700-year-old ice cores from Greenland found that history is repeating.

Paul Mayewski, director and distinguished professor of UMaine’s Climate Change Institute, says today’s climate situation in the Arctic is equivalent to, but more localized, than the warming during the Younger Dryas/Holocene shift about 11,700 years ago.

Mayewski led the research team that examined Arctic ice formed 11,700 years ago during a rapid climate transition from the Younger Dryas (near-glacial) period to the Holocene era (period of relative warm since then). Ice cores, in essence, are timelines of past climates.

The abrupt shift then included a northward shift in the jet stream, an abrupt decrease in North Atlantic sea ice and more moisture in Greenland. These changes resulted in milder weather, fewer storms and initially more than a doubling of the length of the summer season around Greenland, the team says.

“It is highly unlikely that future change in climate will be linear as evidenced by the past and by the recent, abrupt and massive warming in the Arctic,” Mayewski says. “Understanding and ideally predicting the likelihood, timing and location of future nonlinearities in climate is essential to realistic climate prediction, adaptation and sustainability.”

The ice formed during that one-year onset of the Holocene climate “sheds light on the structure of past abrupt climate changes and provides unparalleled perspective with which to assess the potential for near-term rapid shifts in atmospheric circulation and seasonality,” Mayewski says.

Additional exploration of the ice cores, with respect to the length of seasons, is expected to yield information about precursors for abrupt climate shifts. “Identifying and using the precursors will fill an essential void in climate prediction models by testing for sensitivity in the context of past analogs,” the researchers say.

In the university’s W.M. Keck Laser Ice Facility, the researchers had the first-ever ultra-high-resolution look at ice cores formed during the swift shift from the near-glacial period to the current period of relative warmth. The ice core samples were removed from a depth spanning 1,677.5 meters to 1,678.5 meters, or from 11,643 to 11,675 years ago.

Mayewski has led more than 50 expeditions to the Arctic, Antarctica, Himalayas, Tibetan Plateau, Tierra del Fuego and the Andes. He has shared his research with numerous media venues including “60 Minutes,” “NOVA,” BBC, “Fresh Air” and “The Diane Rehm Show.”

The research team includes Sharon Sneed, Sean Birkel, Andrei Kurbatov and Kirk Maasch, all from UMaine. The researchers’ findings are included in the article, “Holocene warming marked by abrupt onset of longer summers and reduced storm frequency around Greenland,” published in the January 2014 issue of the Journal of Quaternary Science.

Contact: Beth Staples, 207.581.3777

Pooling Expertise

Tuesday, February 18th, 2014

colorimeter

University of Maine researchers have designed a handheld device that can quickly detect disease-causing and toxin-producing pathogens, including algal species that can cause paralytic shellfish poisoning.

The device — a colorimeter — could be instrumental in monitoring coastal water in real-time, thereby preventing human deaths and beach closures, says lead researcher Janice Duy, a recent graduate of UMaine’s Graduate School of Biomedical Science and Engineering. Duy is now conducting postdoctoral research at Fort Detrick in Maryland.

The research team, which includes UMaine professors Rosemary Smith, Scott Collins and Laurie Connell, built a prototype two-wavelength colorimeter using primarily off-the-shelf commercial parts. The water-resistant apparatus produces results comparable to those obtained with an expensive bench-top spectrophotometer that requires technical expertise to operate, says the research team.

The instrument’s ease of use, low cost and portability are significant, say the researchers. The prototype cost researchers about $200 to build; a top-shelf spectrophotometer can cost about $10,000.

A touch screen prompts users at each step of the protocol. Researchers say an Android app is being developed to enable future smartphone integration of the measurement system.

Duy says the device almost instantaneously identifies pathogenic organisms by capturing target RNA with synthetic probe molecules called peptide nucleic acids (PNAs). A cyanine dye is added to visualize the presence of probe-target complexes, which show up as a purple solution; solutions without the target RNA are blue.

The versatile instrument can also be adapted to detect other organisms. The researchers say, in theory, any organism that contains nucleic acids could be detected with the simple colorimetric test. They have verified the system works with RNA from a soil-borne fungus that infects potatoes.

The research team’s teaching and expertise spans several UMaine schools and departments, including Electrical and Computer Engineering Department, the Laboratory for Surface Science and Technology, the Graduate School of Biomedical Science and Engineering, the Department of Chemistry, the School of Marine Sciences and the Department of Molecular and Biomedical Sciences.

The instrument is being incorporated into fresh and marine water testing in the Republic of Korea and the researchers say they’ll give several devices to state officials to test and use in the field in Maine.

The researchers published their findings in the journal Biosensors and Bioelectronics.

Contact: Beth Staples, 207.581.3777

Ecological Changes, Economic Consequences

Monday, November 18th, 2013

pershing

A $1.8 million grant from the National Science Foundation will allow a multidisciplinary team of researchers to examine the impact of rising ocean temperatures on the ecology and economics of the Gulf of Maine.

Led by Andrew Pershing from the University of Maine and Gulf of Maine Research Institute (GMRI), the team will conduct a four-year project as part of the NSF’s Coastal SEES (Science, Engineering and Education for Sustainability) Initiative to support collaborative studies.

“Climate change is impacting the distribution of fish and lobsters in the Gulf of Maine,” Pershing says, “and these ecological changes can have significant economic consequences.”

For instance, record warm ocean temperatures during 2012 prompted lobsters in the Gulf of Maine to migrate shoreward about a month early, making them easier to catch. Lobstermen proceeded to haul in record numbers of the crustaceans, but the overabundance of product on the market tanked the price paid to lobstermen.

There’s a growing realization among scientists that complex problems like climate change and fisheries require us to work with people from other fields,” says Katherine Mills a co-investigator on this study from UMaine and GMRI.

The team includes climate scientists, oceanographers, fishery scientists and economists from UMaine, GMRI, Stony Brook University, NOAA’s Northwest Fisheries Science Center (NWFSC) and NOAA’s National Center for Atmospheric Research (NCAR).

“The Gulf of Maine is an ideal test site to examine relationships between climate change, oceanography, ecology and economics,” Pershing says. In addition to its economically valuable lobster and groundfish fisheries, the Gulf has strong temperature gradients and has been warming rapidly in recent years.

“Rising temperatures impact spatial and seasonal distributions of many fish and invertebrates,” says Janet Nye, an assistant professor at Stony Brook University. Shifts in the distribution and abundance of species drive changes to their interactions with each other, as well as changes to where, when and how many are caught.

As part of its multidisciplinary approach, the project has a dedicated education component through GMRI’s LabVenture! Program that annually reaches 10,000 Maine fifth- and sixth-grade students. The researchers will work with GMRI’s education specialists to develop a hands-on experience that enables students to explore how computer models help scientists understand complex interactions among species and the environment.

In addition to Pershing, Mills and Nye, the team includes Andrew Thomas, Richard Wahle and Yong Chen from the University of Maine; Jenny Sun, Tom Farmer and Frank Chiang from GMRI; Dan Holland from NWFSC; and Mike Alexander from NOAA Earth System Research Laboratory.

Contact: Beth Staples, 207.581.3777

UMaine Marine Scientist Joins Elite International Group of Adventurers

Monday, November 18th, 2013

University of Maine marine scientist Rhian Waller has been named a Fellow in an elite international group of adventurers who encourage scientific discovery while exploring land, sea and space.

Founded in 1904, Explorers Club members attempt to attain new heights and depths; they’ve been the first to reach the moon, North Pole, South Pole, the Mount Everest summit and the deepest part of the ocean.

Waller, an associate research professor in UMaine’s School of Marine Sciences, fits right in. In 2013, National Geographic Magazine celebrated her as a 21st-century risk taker who presses the limits in this “New Age of Exploration.”

Based at the Darling Marine Center (DMC) in Walpole, Maine, Waller has pushed the limits of diving during more than 40 expeditions around the planet. In a submersible, she has plunged to a depth of 3,600 meters to examine corals on the New England Seamount chain.

“I feel extremely honored to have been voted into the Explorers Club, and really pleased to have been recognized for the scientific exploration work I’ve been doing across the globe,” Waller says.

“There are so many conservation issues surrounding the deep ocean, I hope I can use this opportunity to spread the word more widely that the deep sea is important to our whole planet, and does need our protection.”

As a Fellow, Waller has access to the Explorer’s Club research collections, including a library and map room, and she’s connected with a global network of expertise, experience, technology, industry and support. The Explorers Club supports exploratory expeditions and provides opportunities for the 3,000 members worldwide to carry an Explorers Club flag on voyages that further the cause of exploration and field science. Since 1918, flags have flown at both the North and South poles and aboard Apollo 11.

The seven founders of the Explorers Club were two polar explorers, a curator of birds and mammals at The American Museum of Natural History, an archaeologist, a war correspondent/writer, a professor of physics and an ethnologist. Today its members — including archaeologists, astronomers, entomologists, mountaineers, zoologists and a now a new deep-sea researcher — conduct explorations and research in more than 60 countries around the globe, and beyond.

For her research, Waller routinely scuba dives in temperatures 35 F and colder. She studies how environmental factors such as climate change, fishing and oil exploration affect deep-sea coral ecology and reproduction, as well as what effect that altered life cycle could have on the rest of the marine ecosystem.

Last summer, Waller was part of a research team that discovered two deep-sea coral communities in the western Jordan Basin and Schoodic Ridge regions of the Gulf of Maine.

Last month, Waller returned from an expedition to Chile. She had traveled to Huinay Scientific Field Station near the northern Patagonian fjords to collect final samples from a yearlong deep-sea coral monitoring program. She’s examining how climate change, salmon farms, fishing and oil exploration affect deep-sea coral reproduction, and what effect any altered life cycle could have on the marine ecosystem.

In her Oct. 11 blog on that trip, Waller wrote that corals, which she calls the rainforests of the ocean, “are not just beautiful to look at … they’re also extremely important to the health of our oceans, and ultimately the health of the planet.”

Next year, Waller will utilize a $381,384 National Science Foundation grant to investigate how Antarctic corals, which provide habitat for thousands of connected species, are coping with warming ocean water.

Contact: Beth Staples, 207.581.3777

Understanding Phytoplankton Paths

Thursday, November 7th, 2013

diatoms

Two University of Maine researchers are teaming up with a University of California-Berkeley professor to study the sinking rate and trajectories of phytoplankton in relation to particle shape and water turbulence. Phytoplankton provide the food supply at the base of the marine food web and help maintain the health of the atmosphere by absorbing and sequestering carbon dioxide and producing oxygen.

Lee Karp-Boss, a marine scientist and associate professor in the UMaine School of Marine Sciences, is a principal investigator of the project along with Evan Variano, a researcher in the Civil and Environmental Engineering Department at UC Berkeley. Pete Jumars, a UMaine professor of marine sciences and oceanography who is based at the Darling Marine Center (DMC), is a co-principal investigator of the study.

The National Science Foundation recently awarded $409,035 to the UMaine researchers and $315,869 to Variano for the three-year project that began in September 2013.

The purpose of the study, “Collaborative Research: Trajectories and spatial distributions of diatoms at dissipation scales of turbulence,” is to create a better understanding of how turbulence and particle shape affect the sinking velocity and paths of phytoplankton — specifically diatoms.

“Phytoplankton are microscopic organisms that are responsible for food production in the ocean and they account for about half of the oxygen that we breathe,” Karp-Boss says of the plant-like organisms.

Since phytoplankton are photosynthetic organisms and need light, they grow in the upper layer of the water column in oceans where turbulence caused by wind and waves prevails. Many phytoplankton types either can’t swim or have a limited swimming ability and are at the mercy of turbulence.

Turbulence mixes the cells, and if it’s strong and deep enough, transports them out of the illuminated upper layer of the ocean, or photic zone.

“That mixing affects the light fields they experience and that will ultimately determine rates of photosynthesis and production in the ocean,” Karp-Boss says.

Cell components have densities larger than seawater and therefore tend to sink. If phytoplankton sink too quickly, they exit the illuminated zone. Cells that settle away from the photic zone too deep serve as a food supply for organisms in the deep ocean. A fraction of these settling cells may get buried in sediments, effectively removing carbon dioxide from the atmosphere into the interior of the ocean, which explains the interest in the rate phytoplankton sinks, Jumars and Karp-Boss say.

Simple turbulence operates in all directions, carrying phytoplankton up and down. Scientists originally assumed a cell would move up or down at the same average speed in turbulence as it would in still water, but results have shown otherwise. Whether they sink or rise, more intense turbulence makes them move quicker. However, the methods used in the last decade give little insight into the mechanisms behind this acceleration, according to the UMaine researchers.

Studies conducted by atmospheric scientists have found key components of turbulence are the small eddies or vortices whose friction with the surrounding fluid — air or water — drains away the kinetic energy in turbulence. These eddies spin small water droplets out and make them more likely to collide, Jumars says.

Those findings don’t tell the whole story for phytoplankton because it doesn’t explain how buoyant particles are accelerated upward by turbulence. Testing this requires the ability to track individual phytoplankton cells in three dimensions as they move through eddies.

That’s why Karp-Boss and Jumars teamed with Variano, the UC Berkeley researcher, who with colleagues has developed a system that allows scientists to look at the trajectories of thousands of individual particles as they move.

Variano has developed a borescope with a double iris and video camera that gives the instrument binocular vision and captures the 3-D position of the cell.

“If you capture many quick snapshots, you can put all the frames together and see how this particle is moving in the water. If you calculate the distance and you know the time between frames, you can get velocity. You can also see whether their trajectories are straight or curved and how they settle or rise in the water. It gives us more information than just looking at mean sinking speeds of a population,” Karp-Boss says.

Most of the particles researchers have studied are spherical, while particles in nature are a variety of other shapes.

“Diatoms exhibit a striking morphological diversity, and we argue the shape of the particles will determine the trajectory and how fast they settle,” Karp-Boss says.

Karp-Boss and Jumars hope the project will also teach researchers more about the effects of turbulence on the distribution of phytoplankton cells. Whether the cells are randomly distributed or group together to form patches carries important implications to foraging strategies of grazers that feed on the cells. Turbulence is likely to play a role, but the underlying mechanisms are not yet fully understood.

The researchers will work together at both institutions throughout the project. The tanks design and construction, as well as characterization of the turbulent flows, will be done at UC Berkeley, while the experiments and analysis will be completed at UMaine.

In addition to their research, the PIs plan to hold a workshop at UMaine’s DMC in Walpole, Maine to bring together students from various departments who have similar interests in the dynamics of particles in flows.

“These types of questions are of interest to many STEM fields including  engineering, physics, atmospheric science and — of course — oceanography. Learning from each other’s approaches, models and measurements can greatly enhance understanding of how particles and flows interact,” Karp-Boss says.

Convening students from different fields who deal with particles in turbulent flows at earlier stages of their careers will hopefully give them an opportunity to form lifelong interactions and collaborations across fields. Karp-Boss and Jumars met Variano at a similar conference devoted to this range of topics.

Contact: Elyse Kahl, 207.581.3747

Ocean Acidification and the Aleutian Islands

Thursday, November 7th, 2013

ocean acidification

The National Science Foundation has awarded University of Maine researchers $574,617 to study the effects of ocean acidification on the marine ecosystem of the Aleutian Islands.

UMaine professor Bob Steneck and postdoctoral research associate Doug Rasher, both based at the Darling Marine Center in Walpole, Maine, will work with Jim Estes of the University of California, Santa Cruz to determine whether ocean acidification, ocean warming and food web changes are reshaping species’ interactions in nature and threatening Clathromorphum nereostratum, a slow-growing coralline alga in the subarctic North Pacific Ocean.

During C. nereostratum’s 2,000-year lifetime it accretes massive bioherms, or mound-like reef structures, that form the foundation of the archipelago benthos upon which kelp forests grow. Preliminary research suggests the calcium carbonate skeleton of the coralline alga is weakening due to increased ocean acidification. With the recent ecological extinction of sea otters, the number of sea urchins has increased and, in places, they have grazed the kelp forest, leaving behind barren ancient coralline reefs.

During past cycles of sea otter/urchin/kelp booms and busts when ocean acidity was steady, C. nereostratum fared better. Now in a weakened state, it’s falling prey to urchins, crumbling away through bioerosion.

The three-year study will include a 2104 summer-long research expedition to the western portion of the Aleutians, from Adak Island to Attu Island. Researchers will survey kelp forests and urchin barrens, measure ocean acidity and collect samples of the ancient coralline bioherms.

Subsequent laboratory-based research will include urchin feeding experiments at past and present levels of ocean temperature and acidity to confirm processes driving patterns observed in the field. Additional studies will focus on the bands of calcium carbonate (similar to tree rings) in the coralline samples.

Contact: Linda Healy, 207.563.8220 or Beth Staples, 207.581.3777

Deep-Sea Dive Discoveries

Thursday, October 24th, 2013

Coral

A research team recommending that greater conservation measures be applied to two rare, dense coral garden communities that it discovered in the Gulf of Maine has three University of Maine connections.

Rhian Waller, associate research professor at UMaine’s Darling Marine Center in Walpole; Steven Auscavitch, master’s candidate in marine biology; and Les Watling, Professor Emeritus in the School of Marine Sciences and now a faculty member at the University of Hawaii at Manoa, were part of the team headed by Peter Auster of the University of Connecticut that found two deep-sea coral communities in July 2013 in the western Jordan Basin and Schoodic Ridge regions of the Gulf of Maine.

While deep-sea octocorals have been in the Gulf at least since the late 19th century when fishermen delivered them to museums as bycatch, researchers say bottom-scraping fishing gear has reduced their presence to small refuges. Due to the corals’ vulnerability and sensitivity to disturbance, the team advised that spatially explicit protection measures be applied to them.

“Discovering these lush coral gardens in the Gulf of Maine was an amazing experience this summer; some of the large coral trees we saw were over 2 meters high and have been growing in these protected pockets for an extremely long period of time,” Waller says. “These corals provide really important habitat for many of our local fisheries species, so finding areas where these corals have survived intense fishing pressure is a real boost to our understanding of habitat diversity and functioning in the Gulf of Maine.”

The team located the two deep-sea coral communities at depths greater than 200 meters. The topography was complex and areas with steep vertical rock faces had the highest densities of octocorals, say the researchers. The large-bodied corals extend up into the water and capture food with their hollow tentacles.

Pandalid shrimp were frequently found with the coral colonies, says the team. In addition, the team viewed Acadian redfish taking cover in the corals and saw Atlantic cod, cusk, pollock and silver hake catching prey among the octocorals.

Morgan Kilgour of UConn and David Packer of the National Oceanic and Atmospheric Administration (NOAA) also took part in the research. The team’s preliminary findings, “Octocoral gardens in the Gulf of Maine (NW Atlantic)” were published Oct. 16 in the online edition of Biodiversity.

Contact: Beth Staples, 207.581.3777

U.S. Department of Energy Awards $16 Million to 17 Organizations Including UMaine for Projects

Tuesday, September 17th, 2013

Tidal_power

The University of Maine is one of 17 recipients to split $16 million from the U.S. Department of Energy to fund projects related to efficiently capturing energy from waves, tides and currents.

The projects are expected to increase the power production and reliability of wave and tidal devices and help collect data on how deployed devices interact with the surrounding environment, according to a Department of Energy press release issued Thursday, Aug. 29.

“Wave and tidal energy represent a large, untapped resource for the United States and responsible development of this clean, renewable energy source is an important part of our all-of-the-above energy strategy,” said Assistant Secretary for Energy Efficiency and Renewable Energy David Danielson in the statement.

The UMaine project is one of seven “Environmental Monitoring of Marine and Hydrokinetic Projects” under the funding. The $494,000 project received $394,000 from the Department of Energy to use data on fish interactions with Ocean Renewable Power Company’s TidGen Power System in Cobscook Bay, Maine to predict the probability of fish naturally encountering deployed energy devices.

The project will build on research that began in 2009 that established baseline patterns of fish abundance and distribution at the turbine location, according to the project proposal.

The funding will allow the project to provide post‐deployment data for comparison, improve techniques for distinguishing between fish species using undersea acoustic sensors, and implement a probability‐of‐encounter model. The research will also aid in the assessment and understanding of the effects of marine and hydrokinetic devices on local fish populations, the press release states.

Gayle Zydlewski, associate professor and researcher in the UMaine School of Marine Sciences and member of the Maine Tidal Power Initiative, is the principal investigator of the project which is expected to last two years and include five researchers under the DOE funding.

“This funding will enable our research team to provide quantitative data on fish behavior in tidally dynamic regions and how fish interact with a tidal power device that’s not being collected anywhere else in the U.S. or globally,” Zydlewski says. “In addition, it will allow us to retrospectively analyze data to enhance their utility for natural resource decision makers.”

Contact: Elyse Kahl, 207.581.3747

Ten-State Study Focuses on Hurricane Sandy’s Effects on Tidal Marsh Birds, Plants

Monday, August 5th, 2013

Olsen

The effects of Hurricane Sandy’s devastation on plant and bird communities in coastal marshes from Maine to Virginia are the focus of a 10-state study by researchers from the University of Maine, University of Connecticut, University of Delaware and Maine Department of Inland Fisheries and Wildlife.

Information gathered from more than 1,700 sites before and after the October 2012 hurricane will advance researchers’ understanding of how major disturbances affect these populations and what characteristics make a marsh more vulnerable.

The data will also provide information on the allocation of millions of dollars of federal restoration funds, coastal management planning and the status of species at risk of endangerment.

The yearlong study was awarded nearly $200,000 from the National Science Foundation and is part of the Saltmarsh Habitat and Avian Research Program, which was founded by a group of academic, governmental and nonprofit collaborators — including UMaine — to provide tidal-marsh bird conservation information.

Brian Olsen, assistant professor in UMaine’s School of Biology and Ecology, is a co-principal investigator of the study. Maureen Correll, an ecology and environmental Ph.D. student in Olsen’s lab, is working on the project as part of her dissertation. Two additional student researchers from UMaine are expected to participate in the study.

Other co-principal investigators include Tom Hodgman, senior wildlife biologist at the Maine Department of Inland Fisheries and Wildlife; Chris Elphick, associate professor of ecology and evolutionary biology at the University of Connecticut; and Greg Shriver, associate professor in the Department of Entomology and Wildlife Ecology at the University of Delaware.

Before Hurricane Sandy, Olsen’s team was working on a study to assess the distribution and densities of tidal-marsh birds from Maine to Virginia. The study was intended to give the U.S. Fish and Wildlife Service more information on bird populations that are in danger due to the loss of tidal marshes from sea level rise, particularly the saltmarsh sparrow, Olsen says.

Hurricane Sandy struck in the middle of the researchers’ survey range after they had collected data for two years, giving them information from both inside and outside the storm’s path. The team sought NSF funds to conduct the surveys again to see which birds and marshes were most affected within the hurricane’s range. The marshes outside the storm’s path will serve as control sites, Olsen says.

“What predicts whether you’re a winner or a loser if a hurricane hits you is really an open question,” Olsen says.

The study will also test two common ecosystem stress hypotheses among researchers. One of those hypotheses, Olsen says, is that stresses on an ecosystem build up over time, making the addition of any new stress more dramatic than if it were to act alone. Multiple stresses can bring any species of the entire community closer to collapse with every additional stress.

“The hurricane ends up being the straw that broke the camel’s back,” he says.

Another common theory says multiple stresses eliminate the weak players, leaving only the strong ones.

“When the hurricane comes in, all the sensitive players have already been eliminated by previous stressors and you’re only left with the ones that are robust to stress; they can handle it, and the hurricane has little effect,” Olsen says.

Based on this theory, the pristine tidal marshes — ones that have more sensitive plants and animals that aren’t accustomed to stress — may appear to have been more affected by the hurricane, he says.

“I’d really like to understand what makes marshes sensitive to large-scale disturbances and how marshes are likely to respond to the predicted increase in storm frequency and intensity in the future,” Olsen says. “What makes them sensitive and what’s likely to happen as the climate changes?”

Researchers will also pay attention to whether urban development had any effect on how the storm affected the marshes.

“You get the same hurricane that’s barreling down on two different marshes. Do marshes that are completely developed right up to the marsh edge fare better, worse or the same as those that are in pristine habitats in national parks? Does conservation do anything to birds that are still around or does that not matter when there’s a wall of water coming down on you? We get to ask that for a fleet of different species,” Olsen says.

Saltmarsh sparrows, clapper rails, Nelson’s sparrows, seaside sparrows, willets and black ducks are the six major bird species in the study. Plant species the team will study include smooth cordgrass (Spartina alterniflora), salt hay (Spartina patens), seashore saltgrass (Distichlis spicata) and black needlerush (Juncus gerardii).

The surveying of saltmarsh sparrows is important because the team is able to track the species’ entire range and population. The species is also declining fast and talks have begun on whether to list them under the Endangered Species Act. The team’s data on the birds will be used to help make that determination, Olsen says.

Using the information from hundreds of marshes with different characteristics, Olsen’s team hopes to be able to predict what causes ecosystems to shift from one type of tidal marsh to another following a major storm, or more dramatically, what causes shifts from tidal marsh to open water or beach dunes. By determining these factors, researchers will have a better understanding of where to focus energy for conservation and where to expect ecosystem shifts in the future, Olsen says.

“We’ve visited a couple places already this summer where last year it was a beautiful tidal marsh with picturesque streams, and now it’s sand dunes or open water; it’s just gone,” he says.

The team hopes their information will help influence agencies using Hurricane Sandy relief funds to restore wildlife communities by prioritizing the marshes that would benefit the most from conservation efforts and have the lowest chance of being destroyed by a similar storm in the future.

Contact: Elyse Kahl, 207.581.3747