Two newly published studies by a team of Brown University researchers provide ample new evidence that the reason coastal saltmarshes are dying from Long Island to Cape Cod is that hungry crabs, left unchecked by a lack of predators, are eating the cordgrass. (See sidebar on marsh die-off and greenhouse gasses.)
PROVIDENCE, R.I. [Brown University] — A marathon summer of field work by Mark Bertness, professor of ecology and evolutionary biology, and a squadron of students may finally help settle the heated debate about what’s killing the coastal saltmarshes of southern New England and Long Island. The group’s work has yielded two new papers that offer clear evidence of the cause. (more…)
Combined research efforts by scientists involved in the Gulf of Maine Toxicity (GOMTOX) project, funded by NOAA’s Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) program, and administered by the National Centers for Coastal Ocean Science (NCCOS), have led to enhanced understanding of toxic algal blooms on Georges Bank. This new information, coupled with an at-sea and dockside testing protocol developed through collaboration between GOMTOX and U.S. Food and Drug Administration (FDA) investigators, has allowed fishermen to harvest ocean quahogs and surf clams in these offshore waters for the first time in more than two decades.
The shellfish industry estimates the Georges Bank fishery can produce up to 1 million bushels of surf clams and ocean quahogs a year, valued $10 – 15 million annually. “There is a billion dollars’ worth of shellfish product on Georges Bank that is property of the United States but that can’t be harvested because of the threat of toxicity, and 99.9% of the time, it is good wholesome product,” says Dave Wallace of North Atlantic Clam Association and a GOMTOX participant. “In an unusual and unique partnership, we worked with GOMTOX scientists, the FDA, and the states of Massachusetts, Rhode Island, New Jersey and Delaware and now that huge resource can go into commerce, which helps the entire country.” (more…)
Ecologists are wary of non-native species, but along the shores of Cape Cod where grass-eating crabs have been running amok and destroying the marsh, an invasion of a predatory green crabs has helped turn back the tide in favor of the grass. The counter-intuitive conclusions appear in a new paper in the journal Ecology.
PROVIDENCE, R.I. [Brown University] — Long vilified, invasive species can sometimes become an ecosystem asset. New Brown University research published online in the journal Ecology reports exactly such a situation in the distressed salt marshes of Cape Cod. There, the invasive green crab Carcinus maenas is helping to restore the marsh by driving away the Sesarma reticulatum crabs that have been depleting the marsh grasses. (more…)
Unlike most organisms, they don’t need iron, but they crave manganese
Scientists have confirmed that the pathogen that causes Lyme Disease—unlike any other known organism—can exist without iron, a metal that all other life needs to make proteins and enzymes. Instead of iron, the bacteria substitute manganese to make an essential enzyme, thus eluding immune system defenses that protect the body by starving pathogens of iron.
To cause disease, Borrelia burgdorferi requires unusually high levels of manganese, scientists at Johns Hopkins University (JHU), Woods Hole Oceanographic Institution (WHOI), and the University of Texas reported. Their study, published March 22, 2013, in TheJournal of Biological Chemistry, may explain some mysteries about why Lyme Disease is slow-growing and hard to detect and treat. The findings also open the door to search for new therapies to thwart the bacterium by targeting manganese. (more…)
Students studying what they love is a well-established principle at Brown. For Tyler Coverdale, that meant the outdoors, the environment, and, ultimately, some provocative research on Cape Cod salt marshes through GIS-assisted analysis of historical aerial photography. He loves it.
Tyler Coverdale’s newly published study in Frontiers in Ecology and the Environment on the collapse of salt marsh habitats along Cape Cod tells an intriguing, if unfortunate, tale of how three different human activities spanning 70 years finally added up to a problem that no one anticipated. The story of how he made the discovery — which is generating some buzz in ecology — while a Brown undergraduate is a tale of happier serendipities. (more…)
Goal is to Understand the Ecological Role of Seals in North Atlantic Waters
People come from miles away to see the seals off the shores of Cape Cod and surrounding regions, but the animals are creating some challenges for local fishermen. Recent increases in local seal abundance have led to concerns about fisheries interactions. The urgency of documenting, understanding, and mitigating these interactions has become more apparent.
These and other issues and challenges presented by seal populations have led to the creation of a new effort to improve our understanding of the ecological role of seals in the northeast United States. “This encompasses all issues: how they live, where they go, what they eat, their health and illnesses, and interactions with the world—including us—around them,” says Andrea Bogomolni, a Research Associate at the Woods Hole Oceanographic Institution (WHOI). (more…)
As recreational fishing activity has reduced predators in many of Cape Cod’s salt marsh ecosystems, Sesarma crabs have feasted on grasses, causing dramatic die-offs of the marshes, according to a new study. The researchers assessed the “trophic cascade” in several experiments that also ruled out alternative explanations for the problem.
PROVIDENCE, R.I. [Brown University] — Recreational fishing is a major contributor to the rapid decline of important salt marshes along Cape Cod because it strips top predators such as striped bass, blue crabs, and smooth dogfish out of the ecosystem, according to new research by Brown University ecologists.
With far fewer predators in areas where recreational fishing is prevalent, native Sesarma crabs have had relatively free rein to eat salt marsh grasses, causing the ecosystem to collapse, said Mark Bertness, chair of Brown’s Department of Ecology and Evolutionary Biology and the paper’s senior author. He led a series of experiments and measurements published online in the journal Ecology that he said unavoidably implicate recreational fishing in marsh die-off. (more…)
