Archive for the ‘Earth & Marine Sciences’ Category

Glacial Geology

Thursday, June 25th, 2015
Map of MongoliaAaron Putnam, a research associate with the University of Maine Climate Change Institute, is conducting glacial geology research in Mongolia with doctoral student Peter Strand.

Fieldwork will include mapping and collecting samples of moraines and glacial geomorphologic features around Khoton Nuur. Khoton Lake is at the foot of the Altai Mountains near the border of China.

Strand and Putnam, who is also associated with Lamont Doherty Earth Observatory, are blogging about their experiences during the monthlong research trek, which is being done in collaboration with Mongolia University of Science and Technology, at umglacialgeology.tumblr.com.

A DeLorme inReach Satellite Communicator is broadcasting the team’s location every two hours. People interested in following the researchers can visit share.delorme.com/PeterStrand; the password is “glacier” to view the researchers’ location, send a message and follow their progress.

“The last glacial termination represents the last great global warming and the last time CO2 rose by a substantial amount before the industrial period. And yet the role of CO2 in causing the last great global warming is not certain,” Putnam and Strand blogged June 18.

They say this research could advance understanding of “the sensitivity of atmospheric temperature to CO2,” as well as increase knowledge about the processes that catapult the Earth out of an ice age.

When Strand and Putnam, who this fall will be a faculty member in the UMaine School of Earth and Climate Sciences, return to UMaine, they’ll process the collected samples and create a chronology that documents the reduction of glacier volume since the peak of the last ice age.

The research team also includes David Putnam, professor at University of Maine Presque Isle; Caleb Ward, a student at University of Maine at Presque Isle; Sarah Kramer, a graduate student at Medill School of Journalism; and Pagamsuren Amarsaikhan and Tsetsenbileg Bavuu from the Mongolian University of Science and Technology. Tanzhuo Liu, of Lamont-Doherty Earth Observatory; and Hayley Walcott, a student at the University of Saint Andrews, will join the team in the field.

Contact: Beth Staples, 207.581.3777

‘Rainforests of the Sea’

Tuesday, June 23rd, 2015
SteneckUniversity of Maine marine scientist Bob Steneck encouraged Dominican Republic officials and stakeholders to preserve and improve coral reefs — what he calls the tropical rainforests of the sea — in a keynote address on World Oceans Day, in Santo Domingo.

“They contain 25 percent of all species on Earth. However, they are also among the world’s most endangered ecosystems and, as such, the biodiversity, breakwater function, food resources and ecotourism value they provide for people are all at risk,” says Steneck.

“They are threatened worldwide but this is especially obvious in the Dominican Republic, where competing activities, such as coastal development and fishing pressure, have taken their toll.”

Steneck encouraged the Dominican Republic government and nongovernment organizations to work together to preserve reefs that are healthy and continue efforts to improve those that are degraded. His recommendations included banning the harvesting of parrotfish and investing in enforcement.

Although coral reefs suffer from global climate change and ocean acidification, Steneck says there are remarkable bright spots.

While quantifying corals, seaweed and sponges in transects in March, Steneck says he and fellow researchers found a wide range of reef conditions, from the bright spots — some of the best coral in all of the Caribbean — to some of the most degraded.

Repeatedly, it appeared the presence of healthy fish populations, especially parrotfish, corresponded with the healthiest coral reefs, says Steneck, a professor of oceanography, marine biology and marine policy based at the Darling Marine Center in Walpole, Maine.

“The Dominican Republic is a remarkably diverse country,” says Steneck. “However, its greatest diversity may lie underwater and out of sight of most people.”

The vibrant reefs, he says, were within sight of the border with Haiti, while reefs adjacent to Punta Cana, the heavily populated easternmost tip of the Dominican Republic, were the most degraded.

About 400 people attended Steneck’s keynote at the conference, which was sponsored by Propagas Foundation. Creative lighting and decorations made the conference room appear to be underwater, he says.

Several media outlets, including El Dia, covered Steneck’s speech (eldia.com.do/experto-revela-deterioro-de-arrecifes). Steneck also was a guest on two radio shows before returning to Maine.

Contact: Beth Staples, 207.581.3777

Study Shows Bluefin Tuna Going Hungry Due to Size of Prey, not Abundance

Tuesday, June 23rd, 2015
Maine coastBluefin tuna are going hungry in a sea full of fish because their foraging habits are most efficient with larger — not necessarily more abundant — prey, according to a study led by a University of Maine marine scientist.

Walter Golet, assistant research professor in the School of Marine Sciences and the Gulf of Maine Research Institute, led a research team that involved marine scientists from five institutions, including Bigelow Laboratory for Ocean Sciences, University of Massachusetts Amherst and Simon Fraser University.

How can bluefin tuna go hungry in a sea full of fish?

In a paper in the journal Marine Ecology Progress Series titled “The paradox of the pelagics: why bluefin tuna can go hungry in a sea of plenty,” the seven authors outlined how the overall condition (fat content) of Atlantic bluefin tuna Thunnus thynnus in the Gulf of Maine declined despite an abundance of Clupea harengus, Atlantic herring — their preferred prey.

The Gulf of Maine is an important foraging ground for bluefin tuna, which spend up to six months there consuming high-energy prey such as the herring and in doing so accumulate as much as 200 pounds in fat. Energy acquired in the Gulf of Maine is vital to support bluefin tuna migration and reproduction.

The population of Atlantic herring has increased over the past two decades suggesting that foraging conditions should have been favorable for bluefin tuna. A decline in bluefin tuna condition despite abundant prey resources was puzzling, so the researchers tested hypotheses related to the energetic payoff of eating herring of different sizes, comparing this across different regions of the northwest Atlantic. Researchers had expected to find that due to the high abundance of herring in the Gulf of Maine, foraging would have been favorable for the bluefin tuna, thereby increasing their lipid stores and overall body condition. Their results suggest bluefin tuna are more sensitive to the size of their prey rather than prey abundance (i.e., for bluefin, bigger prey is better than smaller prey).

Researchers identified a correlation between bluefin tuna body condition, the relative abundance of large Atlantic herring and the energetic payoff resulting from consuming different sizes of herring. The correlation is consistent with the optimal foraging theory, a model used to predict how an animal behaves when it’s searching for food.

These correlations could explain why the condition of bluefin tuna suffers even when prey is abundant. According to the researchers, this may also explain a shift in distribution of bluefin tuna to offshore banks and locations further north on the northwest Atlantic shelf where herring (and their corresponding energetic payoff) are larger.

Management strategies for small pelagic fish, including sardines, herrings and anchovies, have the potential to alter food web dynamics and energy flow through changes in the size and abundance of these species. Changes in these fish stocks impact marine mammals and other large warm-bodied fish (like bluefin tuna) whose physiology is geared toward high energetic returns while foraging.

The researchers utilized the extensive data collected from the Maine Department of Marine Resources, the Canadian Department of Fisheries and Oceans and the National Marine Fisheries Service.

Contact: Amanda Clark, 207.581.3721

Bloom Plankton Hitches Rides on Eddies

Tuesday, March 31st, 2015
EddyJust as crocus and daffodil blossoms signal the start of a warmer season on land, a similar “greening” event — a massive bloom of microscopic plants, or phytoplankton — unfolds each spring in the North Atlantic Ocean from Bermuda to the Arctic.

Fertilized by nutrients that have built up during the winter, the cool waters of the North Atlantic come alive during the spring and summer with a vivid display of color that stretches across hundreds and hundreds of miles.

North Atlantic Bloom turns ocean into sea of plankton

In what’s known as the North Atlantic Bloom, millions of phytoplankton use sunlight and carbon dioxide (CO2) to grow and reproduce at the ocean’s surface.

During photosynthesis, phytoplankton remove carbon dioxide from seawater and release oxygen as a by-product. That allows the oceans to absorb additional carbon dioxide from the atmosphere. If there were fewer phytoplankton, atmospheric carbon dioxide would increase.

Flowers ultimately wither and fade, but what eventually happens to these tiny plants produced in the sea? When phytoplankton die, the carbon dioxide in their cells sinks to the deep ocean.

Plankton integral part of oceanic “biological pump”

This so-called biological pump makes the North Atlantic Ocean efficient at soaking up CO2  from the air.

“Much of this ‘particulate organic carbon,’ especially the larger, heavier particles, sinks,” says scientist Melissa Omand of the University of Rhode Island, co-author of a paper about the North Atlantic Bloom published March 26 in the journal Science.

“But we wanted to find out what’’s happening to the smaller, nonsinking phytoplankton cells from the bloom. Understanding the dynamics of the bloom and what happens to the carbon produced by it is important, especially for being able to predict how the oceans will affect atmospheric CO2 and ultimately climate.”

University of Maine Darling Marine Center researchers Mary Jane Perry, Ivona Cetinić and Nathan Briggs were part of the team with Omand, Amala Mahadevan of Woods Hole Oceanographic Institution and Eric D’Asaro and Craig Lee of the University of Washington that did just that.

They discovered the significant role that swirling currents, or eddies, play in pushing nonsinking carbon to ocean depths.

“It’s been a challenge to estimate carbon export from the ocean’s surface waters to its depths based on measurements of properties such as phytoplankton carbon. This paper describes a mechanism for doing that,” says David Garrison, program director in NSF’s Division of Ocean Sciences. The NSF funded the research.

Tracking a bloom: Floats, gliders and other instruments

During fieldwork from the research vessels Bjarni Saemundsson and Knorr, the scientists used a float to follow a patch of seawater off Iceland. They observed the progression of the bloom by making measurements from multiple platforms.

Autonomous gliders outfitted with sensors gathered data including temperature, salinity, as well as information about the chemistry and biology of the bloom — oxygen, nitrate, chlorophyll and the optical signatures of the particulate matter.

At the onset of the bloom and for the next month, four teardrop-shaped seagliders gathered 774 profiles to depths of up to 1,000 meters (3,281 feet).

Analysis of the profiles showed that about 10 percent had unusually high concentrations of phytoplankton bloom properties, even in deep water, as well as high oxygen concentrations usually found at the surface.

“These profiles were showing what we initially described as ‘bumps’ at depths much deeper than phytoplankton can grow,” says Omand.

Staircases to the deep: ocean eddies

Using information collected at sea by Perry, D’Asaro and Lee, Mahadevan modeled ocean currents and eddies (whirlpools within currents), and their effects on the spring bloom.

“What we were seeing was surface water, rich with phytoplankton carbon, being transported downward by currents on the edges of eddies. Eddies hadn’t been thought of as a major way organic matter is moved into the deeper ocean. But this type of eddy-driven ‘subduction’ could account for a significant downward movement of phytoplankton from the bloom,” says Mahadevan.

Perry, interim director of the DMC, says the discovery reminds her of a favorite quote from French chemist and microbiologist Louis Pasteur: “Where observation is concerned, chance favors only the prepared mind.”

“I feel that this project is a wonderful example of the chance discovery of an important process in the ocean carbon cycle,” she says. “It all started when I was chief scientist on the R/V Knorr during the North Atlantic bloom expedition, spending hours and hours staring at profiles of temperature and phytoplankton.

“Initially it was very puzzling — how could high surface concentrations of phytoplankton and oxygen make it down intact to 300 and 400 meters? But the combination of many measurements from autonomous gliders and simulations from models lead to the unexpected finding that ocean eddies or whirlpools are important forces in transporting phytoplankton and their associated carbon to great depths.”

In related work published in 2012 in Science, the researchers found that eddies act as early triggers of the North Atlantic Bloom by keeping phytoplankton in shallower water where they can be exposed to sunlight to fuel photosynthesis and growth.

Next, the scientists will seek to quantify the transport of organic matter from the ocean’s surface to its depths in regions beyond the North Atlantic and at other times of year, and relate that to phytoplankton productivity.

Learning more about eddies and their link with plankton blooms will allow for more accurate global models of the ocean’s carbon cycle, the researchers say, and improve the models’ predictive capabilities.

“The processes described in this paper are demonstrating, once again, how important the ocean is for removal of atmospheric carbon and controlling Earth’s climate,” says Cetinić.

Contact: Beth Staples, 207.581.3777

A New Frontier

Friday, February 27th, 2015
Aleutian islandsUniversity of Maine marine scientist Bob Steneck is part of an international team that has unlocked an underwater time capsule in the North Pacific that has been monitoring the climate for centuries.

The time capsule is the long-living, slow-growing alga Clathromorphum nereostratum that creates massive reefs in shallow coastal regions of Alaska’s Aleutian archipelago. These solid calcium carbonate structures have fine growth rings — similar to tree growth rings — which Steneck says contain historical environmental information.

The team used a cutting-edge microisotopic imaging technique to reconstruct 120 years of seasonal changes in ocean acidification (pH) in the region. The technique uses lasers to measure isotope ratios of the element boron at the scale of tenths of millimeters.

The technique, Steneck says, provides researchers with a detailed historical timeline, including rate of ocean acidification both seasonally and over hundreds of years. The scientists learned that since the late 19th century, the ocean has been acidifying at a rate that corresponds with rising carbon dioxide levels in the atmosphere.

“The next frontier is to determine millennial records so we get a better sense of what was normal for ocean acidification in cold water coastal zones,” Steneck says.

The alga grows approximately 1 millimeter every three years, so plants collected last year that are nearly half-meter thick could easily be more than 1,000 years old, he says.

“These and similar types of coralline algae are living in all oceans,” says lead researcher Jan Fietzke of the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany. “Thanks to laser ablation techniques, in the future we can use other samples to look much further back into the past…”

In fact, UMaine postdoctoral associate Doug Rasher is currently in Scotland analyzing specimens that he and Steneck collected last year in Alaska.

The team’s seasonal analyses also indicated strong variations of pH in each year.

The researchers, who also hail from the United Kingdom and Canada, say the annual variation is likely due to large kelp forests in the region that consume large amounts of carbon dioxide in the spring and summer as they grow.  The kelp forests then completely die back each winter.

“In a sense, these ecosystems are breathing by inhaling CO2 each summer and releasing it every winter,” says Steneck, who is based at the University of Maine Darling Marine Center in Walpole.

Each year, more carbon dioxide enters the atmosphere, some of which is absorbed by the ocean as carbonic acid. This, in turn, decreases the pH and increases acidity of the ocean, say the researchers.

Steneck says 90 percent of marine resource value in Maine involves shellfish, including lobsters, scallops, oysters and clams. Lobsters and other organisms depend on high pH to create limestone shells and it takes metabolic energy to make limestone.

When the ocean is more acidic, the metabolic cost necessary to make shells increases, he says. Some energy that would normally be allocated to organisms’ immune systems could be compromised, possibly increasing their susceptibility to disease.

Lobsters afflicted with shell disease increased fivefold between 2010 and 2012 in Maine; in southern New England during that time, scientists and lobstermen indicated that one in four lobsters caught was diseased.

Steneck says being able to determine if acidification in a specific coastal area might be affected by extreme rainfall events or sewage treatment, for example, could help create more localized ocean management policy.

To retrieve specimens for the research, Steneck dove in 34-degree water off the Aleutian Islands and used a jackhammer to cut off chunks of the Clathromorphum nereostratum. The chunks were loaded into cargo nets, airlifted to the surface, towed to the boat and lifted aboard with a crane. Onboard, Steneck cut the chunks into pieces for research.

A paper about the findings will be published Feb. 24 in the Proceedings of the National Academy of Sciences journal.

Contact: Beth Staples, 207.581.3777

Follow a Researcher

Friday, February 27th, 2015
Follow a researcherConnecting K–12 students in Maine and around the world with researchers in the field is the goal of a new program offered by the University of Maine Cooperative Extension with support from UMaine’s Climate Change Institute (CCI) and the Maine 4-H Foundation.

Follow a Researcher aims to give students a glimpse into a scientist’s world by providing live expedition updates and facilitating communication between the youth and scientist.

“Science isn’t just white lab coats and pouring things into beakers,” says Charles Rodda, a doctoral student at CCI and the program’s first researcher. In his case, science means putting on crampons, scaling glaciers and drilling ice cores in Peru and Tajikistan to conduct research focused on abrupt climate change.

In March, Rodda and fellow CCI graduate student Kit Hamley will travel to Peru to collect snow and ice from glaciers high in the Andes. During the summer, he will travel to Tajikistan to join an international team that will retrieve and research samples from the world’s largest nonpolar glacier.

While in the field, Rodda will interact with participating classrooms and students by sharing prerecorded weekly videos and live tweeting in response to questions.

“We’re interested to see what they’re interested in,” Rodda says. “We of course are focused on the science, but we’re hiking in some of the most beautiful regions on Earth.”

To interact with students, Rodda will use the inReach Explorer, a global satellite communicator created by Maine-based company DeLorme. The tool allows him to text or tweet directly to students from the glacier. It also will track his movements and generate an online map so students can follow his trek in nearly real time. To document his journey, Rodda also will take several cameras, including a GoPro; a solar panel and battery pack to charge electronics; an iPad; satellite receiver; and memory cards.

In advance of the weekly question-and-answer sessions, prerecorded videos of Rodda explaining aspects of the expedition and research will be released. The videos were created to spark discussion among students and are aligned with Next Generation Science Standards.

Rodda, who has participated in several outreach events around the state as a UMaine Extension 4-H STEM Ambassador, says having a science-literate society is important and getting students interested at an early age is essential.

“I think that’s the time — middle and early high school — when students seem to decide if they’re going to be interested in science or not. There’s great research happening here at the University of Maine and we want to make sure students know about it,” he says.

Several schools from around Maine, as well as schools in Iowa, Ohio, Rhode Island and Connecticut have already signed on to take part in the program, which is funded by the Maine 4-H Foundation. Rodda and Hamley plan to visit participating Maine classrooms after they return from Peru in April.

In Peru, Rodda and Hamley will look at signals that have been captured in the ice during El Nino events, or warming in the waters of the equatorial Pacific. They hope to see what El Ninos look like in climate records to determine if those events may be a trigger that shifts the climate system in Central and South America from one phase to another. Rodda completed preliminary research in Peru in 2013.

This summer in Tajikistan, Rodda will work with researchers from around the world to drill a long core that will be split among teams from the University of Idaho, Japan, France, Germany and Austria who will study a variety of the core’s characteristics. Rodda will focus on the ice’s chemistry makeup while others will focus on topics including physical measurements or biological signals, he says.

In advance of Rodda’s Peru trip, youth in grades six through eight took part in a UMaine 4-H Science Saturday workshop where they were challenged with determining how to keep ice core samples frozen and intact for research. Students were given ice and materials and were tasked with designing a container that would keep ice frozen under a heat lamp for a specific amount of time.

In reality, Rodda says bringing ice cores home from Peru is more like “Planes, Trains & Automobiles.” It involves horseback riding, long car rides, even longer airplane rides, and a lot of dry and blue ice, which he describes as heavy-duty freezer packs.

“It’s a great way to get students on campus to sort of demystify the university and show them some of the cool stuff we do at the university and in the sciences,” Rodda says of 4-H Science Saturdays, which are offered by UMaine Extension.

“Follow a Researcher is part of a big effort to connect youth in Maine with current university students. It may be the first time a youth has contact with someone who is going to college, or their first connection to a university,” says Laura Wilson, a 4-H science professional with UMaine Extension. “STEM Ambassadors are working in areas all over the state, from an after-school program in Washburn to programs offered in urban areas of Lewiston and Portland.”

Organizers would like to continue Follow a Researcher after the pilot year, as well as expand it to other disciplines throughout the university.

“By connecting youth to campus, we may be inspiring them to explore higher education, and perhaps come to UMaine in the future,” Wilson says.

Teachers interested in following Rodda on his expeditions may call Jessica Brainerd at 800.287.0274 (in Maine), 581.3877; or email jessica.brainerd@maine.edu. More about Follow a Researcher is online.

Contact: Elyse Kahl, 207.581.3747

Marine Ecosystem Health

Monday, November 10th, 2014

Seaweed

Understanding the biodiversity of bacteria associated with marine algae that contribute to marine ecosystem health is the focus of a study led by three University of Maine researchers.

Susan Brawley, a professor of plant biology in the School of Marine Sciences and a cooperating professor in the School of Biology and Ecology, is leading the three-year project. At UMaine, Brawley is working with John Singer, a professor of microbiology, and Benildo de los Reyes, a professor of biological sciences.

The three-year study is a collaborative research project with Hilary Morrison at the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts, and is funded by a more than $1.4 million grant from the National Science Foundation — $986,515 to UMaine and $480,016 to MBL.

“The macroalgal microbiome in space and time — maintaining primary producers in the Atlantic rocky intertidal zone,” will focus on interactions between microbes and intertidal macroalgae, and how their relationships change in response to natural and human-driven stresses.
(more…)

UMaine, NOAA Officials Formalize Partnership, Announce Internship Program

Friday, October 31st, 2014

The University of Maine’s College of Natural Sciences, Forestry, and Agriculture formalized its relationship with the National Oceanic and Atmospheric Administration’s Northeast Fisheries Science Center (NEFSC) by signing a memorandum of understanding Oct. 30.

Edward Ashworth, dean of the College of Natural Sciences, Forestry, and Agriculture, and William Karp, NOAA Fisheries Northeast science and research director, met to establish a framework to formally recognize previous research collaborations and help initiate new opportunities between UMaine’s School of Marine Sciences; Department of Wildlife, Fisheries, and Conservation Biology; School of Biology and Ecology; and NOAA scientists.

The agreement lays the foundation for more collaborative research projects between the institutions as well as increased NOAA participation in graduate projects, undergraduate research internships and mentoring.
(more…)

Oceanographer Tracks Gulf of Maine Changes From Orono Lab

Friday, October 31st, 2014

satellite imageAndrew Thomas has a bird’s-eye view of the Gulf of Maine from his lab in Aubert Hall at the University of Maine in Orono.

The oceanography professor directs the University of Maine Satellite Oceanography Data Lab, which receives daily real-time high-resolution data from NASA’s meteorological satellites.

In this Sept. 27, 2014 satellite image of the Gulf of Maine, Thomas observes several points of interest, most notably the contrasting green summer foliage near the coast and to the south and the developing fall foliage in northwest regions.
(more…)

Marine Scientist Explores Ecosystem Balancing Act on Caribbean Coral Reefs

Tuesday, October 28th, 2014

University of Maine marine scientist Bob Steneck participated in a study that indicates overfishing and climate change have collided to create a new dynamic on Caribbean coral reefs.

The study, led by University of Exeter geographer Chris Perry, was published in the journal Proceedings of the Royal Society B.

It highlights the delicate balance between bioerosion caused by feeding and excavating of bioeroders — sea urchins, sponges and parrotfish — with the natural production of carbonate that occurs on coral reefs.
(more…)