Lake Ronkonkoma, once a thriving summer resort, to be focus of an environmental survey

Lake Ronkonkoma will get a checkup next week when a Stony Brook University research team conducts a daylong study of Long Island's largest freshwater lake.

The study -- led by marine sciences professor Darcy Lonsdale and part of an annual survey of local waters conducted by students from the university -- will include measurements of the lake's water temperature and samples of plankton and algae, said Bill Pfeiffer of Nesconset, a member of Suffolk County's Lake Ronkonkoma Task Force. Pfeiffer said he is loaning a 24-foot boat from his diving company for the survey.

Students will traverse the environmentally ailing lake on Tuesday, including sections that had not been visited during three previous research excursions, Pfeiffer said.

Legis. Leslie Kennedy (R-Nesconset) said the study will help county officials learn whether efforts to clean up the lake have been successful.

"We stay on top of that lake, so we are thrilled that this doctor, who is known for her marine studies, is coming to take samples," Kennedy said. "That will assist us in keeping that water body cleaner."

The researchers are expected to present their findings to county officials, who will compare the data to results from previous studies, Pfeiffer said. He said the researchers for the first time will be able to chart the locations of their studies using his boat's GPS system.

"Now we'll have pinpoint results," Pfeiffer said. "We can create a database that's very specific. . . . We can enhance the quality of the report that comes out and then continue to do that in the future."

Lake Ronkonkoma, a kettle-hole lake carved by receding glaciers at the end of the ice age, once was the centerpiece of a thriving 20th-century resort area, with swimming, fishing and sunbathing. Now the lake, which is in Smithtown, Islip and Brookhaven towns, is polluted with rainwater runoff and trash. Parts of the lake are 60 feet deep.

Pfeiffer said his company, Island Diving, has conducted side-scanning sonar surveys of the lake for the county, which found debris such as docks, amusement park rides, and a 12-foot rowboat on the lake bottom.

The Stony Brook study, Pfeiffer said, could help officials make the lake "as clean and clear as possible."

Kennedy said state efforts to restock the lake's fish supply appear to be working -- she has seen as many as 20 anglers plying the waters. "Nothing gives us greater pleasure than seeing them fishing," she said.

By Carl MacGowan

carl.macgowan@newsday.comCarlMacGowan

Carl MacGowan is a Long Island native who covers Brookhaven Town after having previously covered Smithtown, Suffolk County courts and numerous spot news and feature stories over his 20-plus year career at Newsday.