MSI tool detects toxin before disease strikes
BY PHIL REYNOLDS SOUTH JETTY REPORTER

When the UT-Austin Marine Science Institute (MSI) got a new Imaging FlowCytobot, they predicted it might give scientists an edge on learning when harmful organisms enter local waters.

Boy, were they right.

It was the Imaging FlowCytobot that alerted researchers to the presence of a rare toxin in oysters from Aransas, Copano and Corpus Christi bays earlier this month, leading state health officials to recall any oysters taken from those bays.

The toxin, known as dinophysis, is normally found in colder waters and mainly in Europe, said Dr. Ed Buskey of MSI, who is associated with researchers who installed the flow meter. It's among the last things they expected to see in their microscopes when the meter turned it up.

Their first step was to ship it by overnight express to a laboratory in Mississippi for positive identification. Once the dinophysis was confirmed, the Texas Department of State Health Services was told. That agency closed Aransas, Copano and Corpus Christi bays to oyster fishing and recalled all oysters taken from them since March 1.

Oysters fed to crowds attending the annual Oysterfest in Fulton March 7- 9 were OK, because they came from Louisiana, biologists said.

Buskey estimated it took less than a week from the time the toxin was first seen until the bays were closed.

It was a prime example of using a research tool for a practical purpose, he said.

"Normally, with red tide, somebody sees dead fish on the beach and decides to see if there's toxin, or with oysters, somebody gets sick. This time, we saw it first and recognized it as a potentially toxic species," Buskey said.

Like karenia brevis, the algae that causes so-called red tides, dinophysis is a floating, or planktonic, dinoflagellate. It also can form blooms, or concentrations, in the ocean.

dinophysis can cause a shellfish poisoning with symptoms including vomiting, diarrhea, nausea and cramping. The poisoning is not usually life threatening. The toxin does not affect other seafood, and cooking affected shellfish doesn't destroy the toxin.

The Imaging FlowCytobot was installed as part of a research program being run by Texas A&M-College Station professor Lisa Campbell and Woods Hole Oceanographic Institute scientists Rob Olsen and Heidi Socik. Buskey, whose specialty is marine zooplankton ecology, is overseeing the MSI installation.

Buskey said because researchers weren't expecting to see dinophysis between the north and south jetties here, it took a bit longer to identify the toxin.

"It's never been reported in this area," he said. "If it had been red tide, we'd have gotten results quicker."

Buskey said researchers will monitor Coastal Bend oysters to see how long it takes the toxin to leave the oyster tissues. Oysters, because they feed by filtering water around them, concentrate some chemicals in their tissues. Over time, that concentration sometimes diminishes.

The good news, he said, is that the dinophysis was caught before an incident was reported.

It also gives researchers a better shot at learning what causes the toxin in the first place.

"We can learn a lot more about understanding the environment if we can be alerted in time to get samples and information," Buskey said. "If you don't know about it until you find dead fish on the beach, you don't get the causative factors."

It's not the first score for the FlowCytobot, although it more immediately affected the general public. Late last year, it detected the dinoflagellate brachidinium in the ship channel (the Aransas Pass). Brachidinium was previously thought of as a rare species existing only in tropical Pacific Ocean waters off the coast of Japan and in the Mediterranean Sea.

While Buskey has had flow meters - devices that keep an eye on water flow in the laboratory - for some time, he said this is only the second FlowCytobot that's been built to stay in the water and send real-time results to scientists.

"It's cutting edge," he said.