Hawaii’s waters are home to a diverse array of marine life, including sea turtles. These reptiles have navigated the world’s oceans for millions of years. Understanding the different types of sea turtles found here enhances appreciation for this vibrant marine ecosystem.
Common Hawaiian Sea Turtles
The most commonly encountered sea turtle in Hawaii is the green sea turtle, known as Honu (Chelonia mydas). These are the largest hard-shelled sea turtles, with adults weighing over 350 pounds and measuring 3 to 4 feet. Their carapace can range in color from brown with yellow and light brown streaks to black, while their plastron is often light yellow. Adult green sea turtles primarily consume algae and seagrasses, which gives their internal fat layer a greenish hue, hence their common name. They are frequently observed in shallow coastal waters, grazing on algae along coral reefs and rocky shorelines, and are unique among Hawaiian sea turtles for their basking behavior, resting on beaches to warm themselves.
The hawksbill sea turtle, or Honu ʻea (Eretmochelys imbricata), is also found in Hawaiian waters. These turtles are smaller than green sea turtles, weighing between 100 and 200 pounds and reaching up to 4 feet. Hawksbills are distinguished by their pointed, hawk-like beak, which they use to extract food from crevices in coral reefs. Their diet consists of marine sponges, invertebrates like crabs, and algae.
Their shells feature beautiful patterns, characterized by overlapping scutes, giving them a serrated appearance along the shell’s edge. While they inhabit coral reef regions, they are a much rarer sight in Hawaii compared to the green sea turtle.
Less Common Hawaiian Sea Turtles
Several other sea turtle species are less frequently encountered in Hawaiian waters, often being transient visitors rather than resident populations.
The loggerhead sea turtle (Caretta caretta) is known for its massive head. These turtles are primarily carnivorous, feeding on hard-shelled prey like crustaceans and mollusks. Loggerheads can be identified by their reddish-brown shells and large heads, though they are not commonly seen in nearshore Hawaiian waters, preferring deeper offshore environments.
The leatherback sea turtle (Dermochelys coriacea) is the largest sea turtle species, growing to more than 6.5 feet and weighing up to 2,000 pounds. Unlike other sea turtles, leatherbacks possess a leathery, soft shell covered by black or brown skin with seven ridges. These highly migratory animals are deep divers, often hunting jellyfish in the open ocean. Sightings in Hawaii’s nearshore waters are rare.
The olive ridley sea turtle (Lepidochelys olivacea) is the smallest and most abundant sea turtle. They have adult carapace lengths of about 2 feet and weigh less than 100 pounds. Their name comes from their heart-shaped, olive-green carapace. While found in tropical and subtropical waters, including around Hawaii, they are seen only in deep oceanic waters, making nearshore sightings uncommon. Nesting by olive ridley turtles has been rare in Hawaii, with only a few documented instances.
Protecting Hawaii’s Sea Turtles
All sea turtles in Hawaii are protected under both federal and state laws, including the Endangered Species Act (ESA) and Hawaii Revised Statutes Chapter 195D. This comprehensive protection makes it illegal to touch, harass, or disturb these animals, whether they are in the water or resting on a beach. Violations of these laws can result in significant fines.
The green sea turtle, Honu, holds a special place in Hawaiian culture, symbolizing good luck, longevity, and wisdom. They are considered `aumākua, or ancestral spirits and guardians, connecting people to the land and sea. Depictions of Honu are found in ancient Hawaiian petroglyphs and mythology, underscoring their historical and spiritual importance.
Despite protections, Hawaiian sea turtles face various threats. These include habitat loss due to coastal development and sea-level rise, entanglement in fishing gear, and ingestion of marine debris, particularly plastics. Boat strikes and a disease known as fibropapillomatosis also pose risks. Climate change can affect nesting success and hatchling sex ratios, as warmer temperatures can lead to a higher proportion of female hatchlings.
Responsible viewing is crucial for the well-being of sea turtles. Federal guidelines advise maintaining a distance of at least 10 feet from sea turtles, both on land and in the water. Never touch, chase, or feed sea turtles, as this can alter their natural behaviors and cause stress. Avoiding bright lights on beaches at night during nesting season also helps prevent disorientation of nesting adults and hatchlings. Reporting injured, sick, or entangled turtles to the NOAA Marine Wildlife Hotline helps conservation efforts.