A sunken freighter believed to be leaking copper from its hold will be investigated by scientists who want to evaluate its impact on sea life. A crew of 22 specialists will use sonar equipment similar to that used to probe the wreck of the Titanic to locate the wreck of the Pac Baroness. Then cameras will be sent down to aid the investigation, said Stanley Margolis, a geology professor at the University of California, Davis. The ship sank in 2,000 feet of water on Sept. 21 about 15 miles south of Point Conception, a major fishery for bottom-dwellers such as Dover sole. Besides checking for pollution around the ship, researchers hope that traces of copper will show them more about how such pollutants are affected by currents. They also want to check how trace pollutants move up the food chain. Researchers from the Marine Science Institute of the University of California, Santa Barbara, along with scientists from a private firm and federal agencies plan to work around the clock at the site for about five days. The scientists will lower a remote vehicle equipped with a color video camera and still cameras to survey the wreckage and the surrounding sea floor.