ZEBALLOS, B.C. -A marine scientist says he expects rescue efforts to help coax a stranded killer whale calf from a shallow lagoon off northern Vancouver Island to continue today despite federal Fisheries Department concerns about limited opportunities due to changing tidal flows. Jared Towers, who’s with the whale research group Bay Cetology, says attempts to use recorded killer whale vocalizations to convince the calf to leave the lagoon over the past few days have not been successful. But he says other options are available, including using a large line to guide the orca out of the lagoon or setting off noise-making devices that could frighten the young killer whale out of the lagoon. Towers says the rescue team has about 30 minutes daily when the tide rises to the point…