Marine Bulletins

Connecticut

Why Phragmites Rules
For thousands of years, Phragmites australis, or common reed grass, was a minor component of the vegetation found in North American wetland ecosystems. But in recent years, Phragmites has expanded aggressively and rapidly: It now dominates in many marshes along the northern and middle Atlantic coasts and is expanding further south. Phragmites has a reputation as an unwelcome invader to tidal marshes because, once established, it tends to proliferate in monocultures, decreasing native biodiversity, and it is not as high in nutritional value as the salt marsh grass that it displaces. While Phragmites invasions often occur when marsh water decreases in salinity, other factors affecting its establishment are less well known. Randy Chambers, Fairfield University biology assistant professor, and David Osgood, University of New Haven biology and environmental science assistant professor, have been examining other conditions that encourage or discourage Phragmites. Preliminary results indicate that Phragmites may tolerate prolonged periods of flooding at low salinities better than Spartina (salt marsh) grasses. Further studies will examine the roles of nutrients, porewater dynamics, and sediment chemistry in relation to Phragmites vigor.

In another marsh study, Kristiina Vogt, Yale University School of Forestry and Environmental Studies ecosystem ecology professor, and doctoral candidate Laura Ahern-Meyerson are examining ways that Phragmites may succeed in dominating a site because of its ability to control the cycling of certain critical nutrients, such as phosphorus and ammonium. The team has hypothesized various mechanisms by which Phragmites may sequester or immobilize nutrients, making them unavailable to other wetland plants. Preliminary results on plant tissues show that Phragmites takes up very large amounts of phosphorus in comparison with Typha (cattails) and other wetland plants. While no significant differences were found in the uptake of nitrogen, the fact that dense, tall Phragmites stands have such a large volume of biomass means that a lot of nitrogen is tied up, too. Even after the reeds die, the stems decompose very slowly and can remain standing for two to three years. Further research analysis will look at the possible roles of silica and aluminum in immobilizing phosphorus.

Maine/New Hampshire

Where Do Toxic Algae Winter?
The threat posed to human health by toxic algal blooms has galvanized communities, scientists, and the media. With support from Maine/New Hampshire Sea Grant, Maureen Keller, Bigelow Laboratory for Ocean Sciences, and Neal Pettigrew, University of Maine School of Marine Sciences, have been studying the phytoplankton Alexandrium in the Casco Bay area. They want to know more about the physical mechanisms that generate spring blooms in Casco Bay and whether a "seed bank" of Alexandrium cysts remains in the bay after the bloom is over.

When water temperatures drop, Alexandrium goes into a dormant stage, resting as a cyst on the ocean bottom until spring and summer. "Because the Kennebec River is an estuary, we thought that perhaps the salt wedge along the river bottom collected both sediment and Alexandrium cysts," explains Keller. During the spring melt, the river moves sediment and cysts from its mouth southwest into Casco Bay.

The scientists conducted two years of cruises in the Kennebec River and Casco Bay, collecting water and sediment samples. "We’ve found that there are plenty of cysts remaining in Casco Bay to invoke a spring bloom" even before the Kennebec plume reaches the bay, explains Keller. Their research concludes in 1999.

Sea Grant and NMFS Address EFH Issues
The reauthorized Magnuson-Stevens Fishery Conservation and Management Act charges the eight regional fishery management councils with factoring fish habitat considerations into their resource management decisions. This requirement has led managers, scientists, environmentalists, and other stakeholders to explore issues involved in protecting essential fish habitat (EFH) from overfishing, nonselective fishing, and loss or degradation.

In April, staff from the Northeast Sea Grant programs and the Northeast National Marine Fisheries Service gathered in Portsmouth, NH, to examine the major EFH issues and to explore research and outreach collaboration opportunities. Cochaired by Brian Doyle, Maine/NH Sea Grant associate director, and Ken Beal, NMFS Saltonstall-Kennedy grants administrator, the colloquium also attracted fisheries management council members, scientists, environmentalists, representatives of state agencies, and others interested in this critical issue.

Underlining the importance of collaborations in protecting essential fish habitat, Ron Baird, National Sea Grant College Program director, told the gathering that in his view the EFH provisions of the Magnuson-Stevens Act are the most significant environmental legislation since the Clean Water Act of 1972. "The issues are complex and broad, and they must be addressed comprehensively," he said. "Finding solutions will require collaborations at all levels involving all stakeholders. The time is now. It is too late to be pessimistic."

Baird announced a planned National Strategic Initiative on EFH, through which Sea Grant will provide a new source of funds for addressing habitat issues. He also described a new graduate fellowship program in population dynamics and marine resource economics, which will be sponsored jointly by NMFS and Sea Grant.

MIT

Reducing Ship Risks in U.S. Ports
Most ship accidents occur in ports—where traffic is heaviest and water is shallower—so researchers have been studying the risk of groundings and collisions in U.S. ports. Nicholas Patrikalakis, MIT ocean engineering professor; Hauke Kite-Powell, WHOI Marine Policy Center research specialist; and their colleagues and students examined data on groundings and collisions of commercial vessels in the ports of New York, Tampa, Houston, and San Francisco. The three-year study was funded by MIT Sea Grant, the U.S. Coast Guard, and the U.S. Army Corps of Engineers.

Annual costs of groundings and collisions in U.S. waters run between $2 billion and $3 billion. However, agencies responsible for maritime safety have limited resources to battle this problem. Understanding what leads to accidents can help those agencies spend that money most wisely.

The researchers looked at data on accidents, including the number of ships going in and out of ports, and environmental conditions at the time of accidents. While they had suspected that inaccurate nautical charts based on ocean surveys taken 50 to 100 years ago might play a role in groundings, such was not the case. In addition, the study showed that ships did not run aground primarily during low tide, perhaps because deeper draft ships tend to move in and out of ports during high tide.

The researchers did find that larger, less maneuverable vessels have higher risks than smaller ones. Accidents also seem to be triggered by factors associated with visibility, including nighttime transits. But Kite-Powell notes that more comprehensive and accessible data regarding the number of ships transiting during daylight and dark are needed.

Kite-Powell also reports that better navigational tools would help reduce risk when visibility is poor. One such tool might be an electronic chart system coupled with a global positioning system to give real-time information about location in relation to hazards and other ships. He also adds that reducing the number of conventional (and costly) physical navigational aids—such as buoys, lighthouses, light towers, and onshore range markers—might be a mistake. "People use visual cues extensively to navigate—even today," he says.

New York

Developing a PSP Toxin Analyzer
In a New York Sea Grant–funded project, Gregory Boyer and his team of researchers at the SUNY College of Environmental Science and Forestry (ESF) are working on ways to analyze the toxins that cause seafood poisoning. Two instruments are being developed: one for laboratory purposes and another for use by shellfish harvesters and aquaculturists.

Paralytic Shellfish Poisoning (PSP) is caused by marine algae, scientifically known as Alexandrium or Gonyaulax. These species, members of the order Dinophyta, produce a red pigment that discolors the water, hence the name "red tide." Some species are toxic to fish, while others produce a series of neurotoxins that accumulate in shellfish and cause paralytic shellfish poisoning in humans who consume them. Through a series of collaborative projects, Boyer has been studying links between these PSP toxins and various organisms. "We have analyzed several bacterial samples for researchers interested in the importance of bacteria in the formation of PSP toxins. We have also analyzed a series of copepod fecal pellets for a researcher in Newfoundland studying the movement of PSP toxins through the food chain and have collaborated with an Ohio University researcher as part of his studies on nutrient effects of PSP production in toxic dinoflagellates."

Boyer reports completion of the laboratory unit, termed ECOS, designed for use by regulatory agencies and research laboratories skilled in PSP toxin analysis. This instrument is undergoing testing in a shellfish monitoring laboratory. Key to the operation of this analyzer is the preparation of a detailed technical manual on the setup and maintenance of the ECOS instrument. Copies of the manual, due out at the end of the summer, will be available through New York Sea Grant.

Boyer and his team are also working on a PSP analyzer designed for use by the shellfish industry. This unit will require only minimal laboratory experience to operate. "Our goal is to construct a simple device that can easily be used on a scallop boat to tell immediately if that day’s catch is potentially contaminated. [Our] experience installing the research unit in governmental analytical labs has convinced us that our goal is possible." However, Boyer cautions that the endeavor will not be an easy one. "Problems regarding proteins and fats in the shellfish, which can interfere with the toxin analysis, must be eliminated before the instruments are made available to the shellfish industry."

Rhode Island

Grant Expands Eelgrass Studies
With East Coast seagrass beds reduced as much as 50 percent in the last 30 years, activities likely to disturb remaining beds draw attention. So the Army Corps of Engineers (ACE), anticipating dredging in four salt ponds along Rhode Island’s south shore, has tapped Rhode Island Sea Grant researchers to measure water quality in the proposed dredge sites to set baseline conditions.

Because good water quality is vital for healthy seagrass, Stephen Granger, URI marine research associate, with divers and research assistants in Sea Grant Director Scott Nixon’s lab, will monitor water quality indicators for a year. The researchers will also define seagrass beds around the potential dredge sites, expecting any changes in water quality pre- and post-dredging to be reflected in the health of adjacent beds. Findings from these efforts will guide selection of seagrass restoration sites once dredging is completed.

Loss of seagrass diminishes critical habitat for commercially important fish and shellfish. Restoration efforts have failed to keep pace with losses, partly because traditional techniques—transplanting whole plants from donor beds—are costly, labor-intensive, and only moderately successful. Nixon and Granger have focused instead on using seeds to reestablish vanishing beds.

The $68,000 ACE grant extends a six-year study of eelgrass (Zostera marina) habitat in Narragansett Bay. Past experiments have produced techniques for winnowing seeds from shoots and distributing them for maximum germination. The mechanics of planting seeds efficiently, economically, and uniformly are in the hands of Brian Maynard, URI plant science assistant professor, who is developing an underwater planting device.

Experimental Fishery Permit Targets Groundfish Data
Reliability of data is a perennial sticking point in fishery management. Balking at increased net-mesh size and minimum catch sizes proposed for the groundfish management plan, the industry turned to Sea Grant for updated studies. For data that would determine, rather than project, what size fish really get through what size mesh, Rhode Island Sea Grant applied for an experimental fishery permit.

Initially aimed at the winter flounder fishery in southern Rhode Island waters, the experimental fishery was expanded to cover various flatfish and to include Massachusetts, Connecticut, and New York. It was scheduled to run from mid-summer through October aboard volunteer fishing vessels.

"The only way to get the fisheries involved is to get them to believe the data," says Joseph DeAlteris, Marine Extension fisheries, aquaculture, and seafood coleader. "And the way to get them to believe is to involve them in the science."

WHOI

Squid Mating Strategies May Ensure Their Viability
Commercial fishing for long-finned squid, Loligo paelei, has increased in recent years with the development of domestic and foreign markets. This year-round fishery—offshore in the winter, near-shore in the summer—has seen increasing market prices. And, with added fishing pressure on inshore summer fishing grounds, the inshore catches are decreasing substantially.

But it is the expansion of the offshore winter fishery that worried Roger Hanlon, a senior scientist and director of the Marine Resources Center (MRC) at the Marine Biological Laboratory (MBL) in Woods Hole.

The offshore winter fishery, which concentrates on pre-spawning adults and juveniles, is harvesting more than three times the tonnage of the inshore fishery. Landings per unit effort data from the National Marine Fisheries Service’s Northeast Fisheries Science Center indicate the possibility of an inverse relationship: As more fishing occurs offshore, the inshore landings decrease.

That possibility caught Hanlon’s attention. Scientists do not know whether spawning adult squid have sufficient reproductive potential to ensure adequate gene distribution and successful fertilization of enough offspring to keep the population viable.

With WHOI Sea Grant support, Hanlon and his colleagues are studying squid mating behavior, strategies, and tactics. Their findings suggest that the mating system of L. pealei results in genetic diversity in the next generation. That is good news for the squid and, to a certain degree, the fisheries managers, who are most interested in determining at what level long-finned squid can be fished.

The Impact of Sea-Level Rise on Salt Marshes
Jeffrey Donnelly, a Brown University geological sciences doctoral student, and Brown geologist Thompson Webb III are working on a WHOI Sea Grant–supported study of the impact of storms and sea-level rise on marsh ecosystems over long periods of time.

"Marshes provide important nutrients to other coastal ecosystems," explains Donnelly. "They also provide an important habitat for migrating fish and wildlife and serve as sinks for pollutants."

Sediment cores extracted from marshes often contain plant fragments, pollen, and other materials that are, essentially, preserved in the marsh peat. By examining cores from this study and a previous Sea Grant–supported project, the researchers can compile historical records. Information from these cores can shed light on a marsh’s climate, vegetation, and habitat from hundreds or even thousands of years earlier.

The current work includes creating marsh vegetation maps to document modern vegetation patterns and help quantify the impacts of events such as storms and sea-level rise on the vegetation. The combination of historic and modern data gathering is important, says Donnelly, because "understanding how marsh communities have been altered by changes in sea level in the past provides clues to how they might be modified in the future. This is especially important given current concerns about global warming and sea-level rise."