Gary Davis, Channel Islands National Park marine biologist (retired), discusses the different types of abalone found in the Channel Islands
Abalone are large, marine snails with low, open spiral bowl-shaped shells that can reach a diameter of 12 inches (30 cm). They can live for over 30 years.
There are fifty species of abalone worldwide. Seven species live around the Channel Islands. The names for each of the local species come from their external or outside appearances. For example, red abalone are brick red and wavy; pink abalone are deep pink and corrugated; black abalone are smooth, black, silver, and blue; while green abalone are brown and greenish-yellow with a rippled surface.
The insides of abalone shells are coated with a strong, smooth, waterproof surface. This iridescent mother-of-pearl-like surface is very beautiful. A muscular foot moves the abalone across the seafloor as they graze on algae. The foot can clamp down on the seafloor to keep fish, lobsters, and octopuses from eating the abalone.
Abalone was an important source of food and raw material to make useful things. The shells were carved into circular fishhooks, made into lamps and bowls, and used as digging or scooping tools. Middens (ancient trash piles) found on the Channel Islands contain huge piles of abalone shells.
Abalone shells are alkaline, and this has caused the middens to decay slowly over time. As a result archeologists have been able to collect abundant evidence indicating that people have lived on the islands for more than 10,000 years and that they relied on the ocean for food, utensils, tools, and jewelry.
Sadly, overfishing in the 1900s (twentieth century) severely reduced abalone sizes and populations. Disease also threatened the local population. All abalone fisheries in southern California were closed for recovery in 1997. California’s white abalone, once common at the Channel Islands, was declared endangered in 2001. Efforts to save the white abalone and other abalone species from extinction continue along the west coast of North America.