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
La Tercera, a Chilean newspaper, recently reported on coral research by Rhian Waller, an associate research professor in the School of Marine Sciences at the University of Maine. The article, “Corals of cold water: the unknown forest under the Patagonian sea,” focuses on Waller’s findings from a deep-sea coral expedition in Chile, which she blogged about on the National Geographic website.
The National Science Foundation’s website Research.gov published an article on research by a Maine Experimental Program to Stimulate Competitive Research (EPSCoR) Sustainability Solutions Initiative (SSI) team at the University of Maine. The team is developing tools to help Maine communities better understand and prepare for the potential local effects of climate change. NSF is funding the project.
Paul Mayewski, a professor and director of the University of Maine’s Climate Change Institute, and George Jacobson, state climatologist and professor emeritus of biology, ecology and climate change at UMaine, were quoted in a Morning Sentinel article about a climate change forum held at Kennebec Valley Community College. The pair spoke about the importance of climate change and the technical aspects of how climates have evolved in various parts of the world. The symposium was organized by the Mid-Maine Climate Adaptation Working Group and focused on the effects of climate disruption on our health, the economy, extreme weather events, the sea level and our water supply.
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
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
A team of University of Maine researchers studying diatom algae populations and their effects on climate change in Greenland was featured in a report by The National Science Foundation’s Science Nation.
The researchers gathered samples of diatoms — a type of algae that respond rapidly to environmental change — to study how climate change is affecting the Arctic ecosystem.
The story and video focus on Jasmine Saros’ recent NSF-funded research. Saros is the associate director of UMaine’s Climate Change Institute and is a professor in the School of Biology and Ecology. Her research team included graduate student Ben Burpee, who was partially supported by a Dan and Betty Churchill Exploration Grant through the Climate Change Institute to do related research.
Paul Mayewski, director of the Climate Change Institute at the University of Maine, was featured in a Q&A article for GlobalPost. Mayewski spoke about the importance of climate change for the article titled “Calamity Calling: Climate change expert says Earth is having its ‘Independence Day’ moment.” He is also the science adviser for Calamity Calling, GlobalPost’s yearlong investigation into climate change.
Aaron Putnam, a research associate at the University of Maine’s Climate Change Institute, is a co-author of a journal article for Proceedings of the National Academy of Sciences of the United States of America (PNAS). Wallace S. Broecker, Newberry Professor of Geology at Columbia University’s The Earth Institute, is the lead author of the article titled “Hydrologic impacts of past shifts of Earth’s thermal equator offer insight into those to be produced by fossil fuel CO2.” As fossil fuel CO2 warms the planet, the researchers expect Northern Hemisphere continents to warm faster than the Southern Hemisphere oceans. The researchers predict a northward shift of Earth’s thermal equator, sparked by the temperature contrast, may produce hydrologic changes and warm periods causing the American West, Middle East and southern Amazonia to become drier, and Asia, Venezuela and Africa to become wetter, the article states.
An effort by the state to save a Popham Beach bathhouse with a temporary seawall of fallen trees and beach scraping is an example of an appropriate engineering endeavor to save beach-front property without harming the landscape, according to research by a University of Maine professor.
Joseph Kelley, professor of marine geology in the University of Maine’s Department of Earth Sciences and cooperating professor at the Climate Change Institute, studied a 2009 action by the Maine Division of Parks and Public Lands to save public property from beach erosion by mimicking natural processes.
“This paper points out that in special circumstances, engineering efforts, which typically destroy the dynamic of beaches and dunes, can prove beneficial,” Kelley says. “We hope these approaches work, but erosion on other parts of the beach is continuing.”
Previous approaches used to slow beach and property erosion in Maine are no longer allowed or economically feasible.
In Maine, seawalls were banned in 1983. Replacement of storm-damaged buildings is also not allowed, and a precedent case on Popham Beach in the 1980s ruled an owner had to remove an unpermitted building from a site where an earlier structure was damaged, the study states.
So when erosion threatened the newly built bathhouse on the parking lot at Popham Beach in 2009, the the remaining options for the state were moving the building back from the ocean — a costly choice — or applying temporary measures.
Because the inlet channel causing the erosion would eventually change course, the state decided to create a temporary seawall with fallen trees at the site. In December 2009, the Maine Bureau of Parks and Lands roped together fallen pine trees and secured them to standing trees on the top of the dune. The treewall was legal as a temporary structure and lessened wave and current energy in an attempt to reduce erosion. The creation of the treewall was also used to assure the public that action was being taken, according to the study.
Once the inlet channel changed course, beach scraping was used. Sand was scraped from the lower to the upper beach — without adding new material — to deflect the current away from the bathhouse.
The use of temporary solutions of beach scraping and biological barriers successfully saved the building without having to create a permanent structure or resort to expensive replenishment, Kelley writes.
“Popham Beach, Maine: An example of engineering activity that saved beach property without harming the beach” was published in the peer-reviewed science journal Geomorphology.
Contact: Elyse Kahl, 207.581.3747