SHADOWS IN THE WATER

This second of the ``Starbuck Family Adventures'' runs a gamut of genres from ecology thriller to fantasy. Fraternal twins Liberty and July travel to the Florida Keys with their younger identical siblings, their father, and their teacher Zanny. All four children are now proficient in talking to one another telepathically. In addition, Liberty and July connect up with a dolphin community and learn that the toxic disposal industry in the area has seriously injured an ``albino'' dolphin, turning it lavender. A boy they meet, also exposed to the toxin, has burned purple hands. Here, unfortunately, the unfolding of a solid environmental mystery turns limp and flowery whenever leatherback turtle nestings or the dolphins are discussed, while the expansiveness in these passages clashes with the twins' no- nonsense approach to their discoveries. Some facts are also so oversimplified as to be misleading (e.g. the hatching of leatherbacks), or so glossed over they become gratuitous (a lesson on navigation). In paying tribute to the Keys, Lasky is affectionate and winning; but a consistent style and a truly persuasive narrative are sacrificed in the process. (Fiction. 8- 12)