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Editor's Notes
Enjoying the spring melt

Growing seaweed sustainably
The Gulf of Maine is one of the best spots in the world to grow seaweed

Herring: A small fish that is a big deal
Balancing management regulations with the needs of the fishing industry.

Gulf Voices
A marsh in winter looks deceptively barren, but a host of plants and creatures lie in wait for spring’s light and warmth

Science Insights
Septic systems are gaining respect with new technology to boost performance

special web-only story
Q&A: Cameron Wake
Watching the changes in New England’s climate

Where eagles fly
Monitoring tagged eagles could reveal why river habitat is important

A visitor to the Bay of Fundy yearns to meet whales on their own terms

Marnie Reed Crowell waxes poetic on the spring melt, lichens and nature

Book Review
Atlantic Coast Beaches
explains the tides, creatures and storms that shape and change our beaches

Research Update:
Undersea vehicles use the latest technology to monitor offshore aquaculture pens

In the News

In the News

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Genetics sorts local from alien seaweed

Shelly DareBeach combing on a frigid, blustery New England winter day might not be a very popular activity, but for researchers at the University of New Hampshire, or UNH, it’s helping to solve a scientific puzzle in the seaweed world. The mystery involves a “who’s who” in which two plant types may look the same but are vastly different. One type is native, while the other came from Japan, perhaps carried by shellfish or the hulls of ships or spread by growers of the seaweed in certain areas off the Northeast U.S. coast.

The first piece of the puzzle involves collecting samples. Jeremy Nettleton, a master’s candidate in plant biology at the university, searches for red seaweed (genus Porphyra) along the intertidal zone. From December through May, Nettleton travels to sites along the New England coast to collect long blades of Porphyra. Conducting field research during the winter is a necessity, since that is when it is easiest to find the blades.

Back at the lab, Shelly Dare, also a master’s candidate in plant biology, searches through seaweed specimens from regional herbariums to determine if previously collected samples were misidentified and to find out how long each species has been growing in a particular region. These two students, along with their advisors Art Mathieson and Chris Neefus, both UNH professors of plant biology, often work side by side in the field and the lab. They are investigating Porphyra in New England as part of a New Hampshire Sea Grant-funded project.

The puzzle involves sorting out red seaweed species. Researchers, resource managers and others are concerned over whether or not many of the Porphyra species found in New England are originally from the region or if they are instead a Japanese cultivar, a plant variety propagated for specific traits. This concern stems from the potential of non-native species to use the habitat and resources necessary for the survival of native plants.

Porphyra is commonly known by the Japanese name “nori” and is the seaweed used to make sushi, Neefus explained. It is grown on nets in Asia to supply the $1.2 billion per year nori industry, he said, but has escaped and become widely established in natural habitats.

“This cultivar is selected to grow more quickly and have larger blades, and it is more likely to outcompete native species if environmental conditions are favorable,” Nettleton added. Therefore, it is important to determine their current and historical distribution in New England. This requires comparing both new samples and specimens collected years ago from the same region. Many of the old samples were misidentified, so seaweed thought to be native might actually have been the Japanese cultivar.

telling the difference between seaweed

“I can’t tell the difference between the native species and the Japanese cultivar by sight,” Dare laughed, and she works with them every day. The morphological traits are too similar, she said, and thus genetic analyses are necessary to separate the two.

“My samples are pretty fresh, so it’s easy to conduct molecular analyses on them,” said Nettleton. However, the older herbarium samples that Dare works with are not always in as good a condition. This makes the task of sorting out native versus cultivar more difficult.

DNA sequencing of the species requires being able to compare present-day samples collected throughout the coastal regions of New England with species collected from the region in the past. This enables researchers to determine if new species have begun colonizing the region or if samples from the past were simply misidentified. It is possible that a species considered to be a newcomer to the area has actually been here for quite a long time, Mathieson said.

This research requires going back to historical collections of seaweeds held in herbariums where samples are kept from 200 years ago in some cases, rehydrating the samples, and then doing genetic analyses on a small piece of the old seaweed.

Once analyses are conducted on both the old and new samples, the genetics can be compared to see if a Japanese cultivar has been introduced recently and is spreading or if it was here hundreds of years ago without scientists knowing it. However, it can be extremely difficult to determine how a species came to be in a particular region. The Japanese cultivar tends to have narrower blades. The genetic analysis indicates there may be different chromosome counts for different Porphyra species, but more research is needed.

The goal is to determine the potential impacts the Japanese cultivar might have on native species. Once this puzzle is more complete, the information will be used to improve management along the coast of New England.

“We want to inform coastal managers about the threat that the Japanese cultivar may or may not pose to native plant species, and then help managers decide what actions they should or should not take as a result,” Nettleton added.

Rebecca Zeiber writes for New Hampshire Sea Grant in Durham, New Hampshire.

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Kathleen LeydenMaine coastal manager wins Susan Snow-Cotter Award

Kathleen Leyden, coastal planning manager in the Maine State Planning Office, was awarded the first Susan Snow-Cotter Award for Excellence in Coastal & Marine Resource Management by the National Oceanographic and Atmospheric Administration (NOAA). She received the award at a ceremony in late February in Washington, DC. NOAA will present the annual award to honor people for outstanding contributions in helping the nation maintain healthy coastal and ocean resources. Susan Snow-Cotter, former director of the Massachusetts Coastal Zone Management and a tireless environmental advocate, died in late 2006 (see Gulf of Maine Times, Winter/Spring 2007, Page 2).

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The Presumpscot: A river in recovery

Presumpscot River WatchFor decades, locals turned their backs to the Presumpscot River, the largest freshwater source to Casco Bay in Maine. One of the earliest industrialized rivers in New England, the Presumpscot was notorious for emitting noxious fumes, some might say, strong enough to peel the paint off of those houses unfortunate enough to be built near its shores.

Despite its polluted past, or perhaps because of it, the river also has known many allies, including former Senator George Mitchell (Dem., former Senate Majority Leader), who once declared, “It’s not often we’re given a second chance with something as fragile as a river. Let’s keep working on it. After all, the Presumpscot River has worked hard in the service of mankind for hundreds of years. It’s time we returned that favor.”

Recently, concerned stakeholders have joined with municipalities, non-governmental organizations, industry, and state and federal agencies to do just that. In 1999, pulp mills ceased discharges to the Presumpscot, dramatically improving water quality. In 2002, the Smelt Hill Dam, the lowest of the nine dams on the river, was removed so the lower seven miles (11 kilometers) of the Presumpscot and 100 miles (160 kilometers) of tributaries now flow freely to Casco Bay, allowing unrestricted access for anadromous (sea-run) fish. In 2005, a project to enhance fish passage at the Highland Lake dam enabled the return of alewives to spawning grounds. In 2007, citizen, industry and agency stakeholders reached a preliminary agreement to restore fish passage at existing dams on the Presumpscot main stem (see the Gulf of Maine Times, Fall 2007).

Even the historical pollution has served as an unlikely ally to keep the land undeveloped. That land along the river corridor today presents unique opportunities for land protection adjacent to urban areas.

To address the need for further water quality improvements that promote the return of native fish species, the Casco Bay Estuary Partnership, in collaboration with the Presumpscot River Watershed Coalition, was awarded a $740,000 U.S. Environmental Protection Agency Targeted Watershed grant in 2005.

As part of the Presumpscot Watershed Initiative, farmers have volunteered to steer livestock away from tributaries toward alternate watering systems to prevent fecal contamination. Youth conservation corps have restored riparian buffers and mitigated decades of erosion while fostering stewardship in their communities. Watershed golf courses have agreed to strive for Audubon International Sanctuary certification to improve habitat, reduce water quality impacts and appeal to the green-minded golfer.

Municipalities continue to commit substantial amounts of staff time, equipment and materials to stabilize degraded stream crossings and replace undersized culverts, while promoting yardscaping programs that encourage residents to embrace low-impact lawn care. Students are learning about the history and ecology of the river through place-based experiential lessons. All the while, dedicated volunteers are sampling water quality, complementing thousands of data points and building a baseline of data for the future.

Despite centuries of intensive industrial use and pollution, the citizens of the Presumpscot watershed are showing that it is never too late to turn back to the river. The Presumpscot is now a river in recovery.

Matt Craig is the technical program coordinator with the Casco Bay Estuary Partnership in Portland, Maine.

For more information visit: http://presumpscotcoalition.org

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Outside the Gulf

Fish think fast to catch prey: German researchers have modeled the compact neural circuitry that allows archerfish to make accurate and flexible decisions about its insect prey in a flash. The researchers chose the archerfish because it is known for its unique way of shooting its insect prey with water and making rapid-fire decisions about where it will land. The fish pinpoints its prey in a four-dimensional space and maps it precisely onto a fine-tuned, two-dimensional motor space. In another set of experiments, the simple archerfish network also had to choose the most rewarding target out of two and decide when a response is likely to succeed, the researchers reported. The circuitry must be tuned on the basis of what the fish have learned previously.

“Small Circuits for Large Tasks: High-Speed Decision-Making in Archerfish,” by T. Schlegel; S. Schuster at Universitat Erlangen-Nurnberg Institut fur Zoologie II in Erlangen, Germany. Science, January 4, 2008, 1149265, 104-106.

Migratory birds can compensate for longitude. Eurasian reed warblers captured during their spring migrations and released after being flown 1,000 kilometers (621 miles) to the east can correct their travel routes and head for their original destinations, researchers reported in the online version of Current Biology on Jan. 31. The new evidence suggests that the birds have true navigation, meaning that they can identify at least two coordinates that roughly correspond to geographic latitude and longitude. The findings challenge the notion held by some that birds might be limited to navigation in the north-south direction. But scientists still don’t know how they do it.

Chernetsov et al.: “A Long-Distance Avian Migrant Compensates for Longitudinal Displacement during Spring Migration,” Chernetsoy, et. al., Current Biology 18, 1–3, February 12, 2008.

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From the Scientific Literature

The ocean’s uneven heat gain: While overall temperature in the North Atlantic Ocean has risen over the past half century, it has not been consistent across the area, researchers reported in the journal Science. This example fits with the general pattern of global warming, but before scientists can accurately predict what the impacts of warming will be, they need to understand the spatial pattern of temperature change. The researchers found that in the North Atlantic, the tropics and subtropics have warmed, but the subpolar ocean has cooled over the last 50 years. Using an ocean general circulation model, they interpret the change as mostly the result of wind and buoyancy forcing associated with the North Atlantic Oscillation, which is a climate phenomenon caused by differences in sea-level pressures.

The researchers suggest that while the spatial pattern of temperature change in the North Atlantic does not directly reflect global warming, it may be the indirect result of warming as transmitted through large-scale changes in atmospheric circulation.

“The Spatial Pattern and Mechanisms of Heat Content Change in the North Atlantic,” by M.S. Lozier; M.S.C. Reed; N.J. Moore at Duke University in Durham, NC; S. Leadbetter; R.G. Williams; V. Roussenov at Liverpool University in Liverpool, UK; and N.J. Moore at Michigan State University in East Lansing, MI, Science, January 3, 2008, 1146436v1.

How diatoms build their shells: Diatoms, some of which are so tiny that 30 can fit across the width of a human hair, are so numerous that they are among the key organisms taking the greenhouse gas carbon dioxide out of the Earth’s atmosphere. The shells of diatoms are so heavy that when they die in the oceans they typically sink to watery graves on the seafloor, taking carbon out of the surface waters and locking it into sediments below. Scientists reported in the online edition of the Proceedings of the National Academy of Sciences their discovery of whole subsets of genes and proteins that govern how one species of diatom builds its shell. For oceanographers, the work might one day help them understand how thousands of different kinds of diatoms—and their ability to remove carbon dioxide from the atmosphere—might be affected by something like global climate change. The new work took advantage of the genomic map of the diatom Thalassiosira pseudonana published in 2004 by a team led by University of Washington oceanography Professor Virginia Armbrust, who is a corresponding author of this paper.

“Whole-genome expression profiling of the marine diatom Thalassiosira pseudonana identifies genes involved in silicon bioprocesses,” Mock et. al. Proceedings of the National Academy of Sciences, 2008; 0: 0707946105v1-0.

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