A well-known whale expert who frequently appeared at local elementary school assemblies was arrested yesterday and charged with possessing more than 400 images of child pornography, police said.

Stuart Goldman, 63, known as the Whaleman, built a career of making presentations on whales for more than 20 years to children throughout the mid-Atlantic states.

According to his Web site, he is a former teacher in the Philadelphia public schools. City school officials could not immediately confirm that.

The pornographic images were found on a personal computer that was seized during a previous arrest at Goldman's home in Barrington, Camden County, said Sgt. Stephen Jones, a state police spokesman.

On St. Patrick's Day, troopers from the Marijuana Eradication Squad raided Goldman's home and said they discovered 193 pot plants growing under lights. They also said they found more than three pounds of processed and packed marijuana ready for distribution.

The squad's commander, Billy Peacock, would not say what led authorities to Goldman's house. He said many of the unit's tips were generated through the hot line 1-888-798-WEED.

Goldman asked to use the computer as troopers confiscated the marijuana. Peacock said he spotted a pornographic image flicker across the screen as Goldman started the machine. The image disappeared after a split second, Peacock said.

Goldman, charged on drug counts, was lodged at the Camden County jail and was released after posting $200,000 bail.

The seized computer was sent to the state police technical center, where experts confirmed there were 400 images of preteens engaged in various sexual acts.

Goldman surrendered to Barrington police yesterday and was charged with endangering the welfare of a child. He posted an additional $2,500 bail and was released.

Police said they did not believe Goldman produced the child pornography.

Goldman charged $500 per school assembly and appeared at schools including Penn Valley Elementary School in Lower Merion, the Milton Hershey School in Hershey, Pa., and Moorestown Friends School. Police said he gave his most recent elementary school lecture last month.

As a condition of his bail, Goldman is prohibited from having any contact with children, Peacock said.

Contact staff writer Sam Wood at 856-779-3838 or at samwood@phillynews.com.