SWIMMING WITH HAMMERHEAD SHARKS

Investigating the hammerhead shark for a new IMAX movie, Mallory, of the New England Aquarium, dives with oceanographer Pete Klimley to study hammerheads off the coast of Baja California and with the IMAX crew off the coast of Costa Rica. According to the author, there are nine species of hammerhead sharks, each with a distinctively shaped head. Hammerheads are the brainiest of the sharks, and unlike other shark species, frequently travel in groups of several hundred. Scientists are studying why they travel in schools and how they migrate and find their way to an undersea mountain without visual landmarks. The text is full of quotes from working scientists explaining how they observe, hypothesize, conduct experiments, and use new high-tech equipment such as ultrasonic telemetry tags and diving gear like the closed-circuit re-breather apparatus (that avoids creating bubbles, which disturb the sharks). The text is enlivened with striking underwater photographs of the sharks and divers. There are awesome deep-blue photographs of schooling hammerheads, dancing on their tails and rising vertically like some alien black calligraphy. It must take a special kind of scientist to don a black-and-white dive suit with fins to resemble a killer whale in order to dive with the orcas, but even armchair travelers can enjoy this undersea science adventure. Includes further reading and an index. A welcome addition to the Scientists in the Field series. (Nonfiction. 10-12)