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…)
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…)
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…)
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…)
