Dive Dry with Dr. Bill

102: The Leopard Shark

Many island residents and visitors are aware that our nearshore shallow waters teem with sharks in early summer. Few are afraid of this phenomenon and continue to swim in the waters from Pebbly Beach to Hamilton Cove despite this "threat." I am referring to the many harmless leopard sharks that enter warmer, shallow coastal waters here reportedly to mate and accelerate the development of their young. There is no reason to fear this species, and an encounter with them can help dispel the notion that all sharks are dangerous.

For the first time in my memory I've started seeing and videotaping leopard sharks swimming in the shallow channels of the dive park. The other day there were a number of them in Avalon Bay's swimming area, although they were vastly outnumbered by the junior lifeguards swimming safely with them. I often see them as I kayak along the coast from Descanso towards White's Landing. One summer two of my sisters were visiting and kayaked with me. We encountered a group of two dozen leopard sharks near Frog Rock and I tried to convince my sisters to jump in and swim with them. The media-induced fear of all sharks was too great.

Admittedly leopard sharks are members of the requiem shark family and are related to the great white. Thankfully they received the "gentle genes" in that family! Their sleek shape may unnecessarily elicit the same fears. However, they are small sharks usually 2-5 feet and reach a maximum length of only seven feet. Their gray bodies are covered with distinct dark blotches and spots that make this species easy to identify. I was surprised to discover that they are most common in northern California and considered only "occasional" in central, southern and Baja California.

Although they may be seen in depths up to 300 feet, they are most common in the shallow waters (20 ft. or less) of bays. The bottom habitat may be varied as they are observed over mudflats, sandy and rocky bottoms and near kelp forests. According to UCSB ichthyologist and humorist Dr. Milton Love, they are highly mobile and move quickly from one location to the next.

Leopard sharks are sexually mature at 3-4 ft in length when they are 7-10 years old. They spawn in spring. Females retain the eggs inside their body where they develop and hatch as 8-9" babies numbering up to 30 or more. The young grow more quickly in the warmer waters frequented by the females in early summer. Adults are known to live as long as 24 years.

These beautiful sharks feed largely near the bottom. Here they take a varied menu including crabs, shrimps, clams, fish and fish eggs. They are apparently quite fond of herring and smelt eggs found attached to algae or rocks. Fish prey include sand dabs, shiner perch, bat rays and some small sharks. Their remains are fairly common in Native American middens indicating they were eaten by our early inhabitants. Contemporary fishermen only recently became aware of their value as food, and gillnetters and longliners take many for human consumption.

If you encounter these normally shy sharks, take the opportunity to swim with them and learn to appreciate their sleek beauty. Like all wild animals, they should be treated with respect. Keep your distance and don't try to touch them. Even a "harmless" shark can become irritated and try to bite if you are pulling on their tails or fins, and probably if you are playing rap music on one of those new underwater MP3 players.

© 2004 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays.

Leopard shark cruising through the shallows of the Casino Point Dive Park

This document maintained by Dr. Bill Bushing.
Material © 2004 Star Thrower Educational Multimedia