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REHOBOTH BEACH -- A new type of seaweed has been discovered in Delaware's inland bays and is so dominant that other species -- including the once-troublesome sea lettuce -- are far less plentiful than they used to be.

No one is sure what this signals -- whether it is a sign of changing ecological conditions in the bays, of water quality improvement or degradation or a shift in species because of climate change or some other factor.

Adding to concern is the fact that very little is known about the new species -- called ceramium -- and that could be a problem for the fragile ecosystems of the inland bays.

The new variety appears to be replacing two types of algae that have some beneficial effects on the creatures that live on the bottom of the bays, although bay scientists are not sure about that yet.

If ceramium is edging out the older varieties and does not support aquatic life as well or at all, the change could add further stress on a subsurface environment already suffering from the loss of natural grasses, low levels of dissolved oxygen on hot summer days and continued pollution.

Scientists believe the new algae warrant more study and perhaps a program for citizens to help with comprehensive monitoring, much as they now do with other water quality indicators.

"This may prove to be an essential indicator of system response to ongoing pollution abatement efforts," said Robin Tyler, the state scientist who conducted a study of large algae species in Rehoboth and Indian River bays last summer.

Large seaweeds have caused problems in the Indian Bays in the past, blanketing the bottom of the waterways and causing strong odors as mats of seaweed washed ashore and began to decompose.

The situation was so bad a decade ago that state environmental officials brought in an aquatic harvester to pull the seaweed from areas where it was most abundant.

Tyler said there were three key species in the bays a decade ago: Ulva, commonly called sea lettuce because of its flat, neon-green, lettuce-like appearance; agardhiella, a red algae that looks like a miniature shrub; and gracilaria, a second species of branching red algae.

Tyler said state environmental officials started getting calls about a new "black" algae in 2008.

At a Science and Technical Advisory Committee meeting at the Center for the Inland Bays last week, Tyler displayed a picture of ceramium, which in 1999 was an "incidental" species, he said.

"Here's the new kid on the block," he said.

Once calls started coming in, Tyler and a team of researchers surveyed the bays.

The ceramium "is what we found everywhere in the places we have found gracilaria and agardhiella before," he said.

They had similar findings last summer.

They also discovered something else. Places such as Thompsons Island and off the Rehoboth Bay manufactured-home community -- where sea lettuce was a significant problem in 1999 -- had almost no sea lettuce last summer.

Kent Price, a fisheries scientist who spent decades studying the Indian Bays during his career as a professor and researcher at the University of Delaware's former College of Marine Studies in Lewes, said he recalled that the species was identified years ago in Barnegat Bay in New Jersey.

No one is certain whether the species is native to Delaware waters.

William Ullman, a professor of marine and geological sciences at the University of Delaware's College of Earth, Ocean and Environment, said he'd be interested to know whether the species supports a different community of animals that live at the bottom of the Inland Bays.

Tyler said more work is needed.

Among the questions to be answered are whether citizen volunteers could help monitor seaweed in the inland bays, whether the shift in species dominance is a temporary anomaly or a sign of a larger change and why there has been such a decline in the other dominant species, Tyler said.

"Are pollution control efforts bearing fruit?" he said. "The key will be routine monitoring."

Source: New seaweed found in Del.'s inland bays | delmarvanow.com | The Daily Times

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This algae has not really been noticed before in the area and they can suggest it be a good thing? I wonder what the studies from Barnegat Bay say about this species?

I guess for every question I have the scientist have two. Let's just hope it is a good thing.

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