Coral Reefs

“Hanau ka ‘Uku-ko‘ako‘a, hanau kana he ‘Ako‘ako‘a, puka”
Born was the coral polyp, born was the coral, came forth
—Kumulipo (Hawaiian creation chant)

 

Large coral head provides shelter for a group of small fish

NPS Photo

Coral reefs hold immense significance in Hawaiian culture. According to the Kumulipo, the Hawaiian creation chant, the coral polyp, or Koʻa, is the first living organism, giving rise to all other life forms. The early Hawaiians maintained a relationship with the ocean that was vital to their way of life. From ancient times to present day, Hawaiians used these waters as a major source of food and careful management was practiced to sustain the resource. This profound historical and cultural connection to the ocean is a key reason why about half of Kaloko-Honokōhau National Historical Park is under the sea!

Recognizing this cultural heritage and ecological wealth, Kaloko-Honokōhau National Historical Park protects about 600 acres of marine territory. Coral reefs dominate the park’s marine ecosystem, and are one of the most biodiverse marine habitats. The reefs at Kaloko-Honokōhau provide home to hundreds of marine species, including fish, sea turtles (honu), Hawaiian monk seals (‘īlio holo i ka uaua), manta rays (hāhālua), spinner dolphins (naia), invertebrates and algae (limu).

Kaloko-Honokōhau is one of only four national park units in the Pacific Islands containing a coral reef ecosystem, and is the only national park in Hawai‘i with extensive coral habitat. Unlike most of the others, the reefs at this park can be accessed by several dive boats operating from Kailua-Kona. On calm days, visitors can also enjoy great snorkeling in the waters near ‘Ai‘ōpio Fishtrap.

 

Corals

Around the world, coral reefs provide habitat for over 25% of all marine species, despite the fact that they cover less than 1% of the sea floor. This complex web of organisms begins with tiny coral polyps that require clean, clear water and sunlight to survive. Coral polyps are tiny, soft-bodied invertebrate animals that are related to jellyfish and sea anemones. By capturing calcium and other nutrients from the water, they are able to build hard skeletons in a surprisingly wide variety of shapes and sizes, including branching fingers, lobes, mounds, plates, tables and bushes. Much like the trees in a rainforest, corals are the foundation of these topographically complex ecosystems that provide food and shelter for hundreds of other species.

 

A coral reef built primarily by Finger Coral (Porites compressa)

NPS Photo

Corals have a mutual relationship with photosynthetic algae called Symbiodinium. Symbiodinium are microscopic algae that live inside the coral’s tissue and provide the major source of food and oxygen that the coral needs to survive. In return, the coral provides protection to the Symbiodinium. This symbiotic relationship creates the basis for highly productive ecosystems in areas with very low nutrients.

Some of the most common species of coral in Kaloko-Honokōhau National Historical Park are the Lobe Coral (Porites lobata), Mound Coral (Porites evermanni), Finger Coral (Porites compressa), Cauliflower coral (Pocillopora meandrina) and Rice Coral (Montipora capitata). These species appear in different areas of the reef, primarily depending on the depth and wave energy of each zone.

 

Threats to Coral Reefs

Unfortunately, coral reefs are very vulnerable to environmental changes, such as climate change, ocean acidification, pollution, overfishing, boat groundings and marine debris. These changes can cause a coral to become stressed and expel the Symbiodinium that live inside their tissues. As the coral loses its main source of energy, it begins to lose its color and slowly starves to death. This process is known as coral bleaching, and it is one of the main contributors to reef decline around the world.

In Kaloko-Honokōhau National Historical Park, reefs were particularly affected by an abnormally strong El Niño event in 2015. Increased water temperatures during the summer months caused a global bleaching event that significantly affected the reefs in the park. Monitoring in the park is still trying to determine the impacts of this global bleaching event and how the coral reefs in the park could recover.

 

NPS Photo

What You Can Do

• Learn more about coral reef research and coral bleaching here in Hawaiʻi. Ask our Park Rangers for more information at the Park Visitor center.

• Protect our reefs. Corals are fragile and are easily damaged by swimmers/snorkelers, so watch where you step. If you are diving, make sure to swim at a reasonable distance from the corals to avoid accidentally kicking them with your fins.

• Follow fishing regulations to protect the species of fish that are most important to our reefs.

• Avoid sunscreens containing Oxybenzone and Octinoxate. Wear sun protection like hats, long sleeve clothing, and sunglasses.

• Observe, report areas of active coral bleaching to the Park Visitor Center (808-326-9507) and to Eyes of the Reef Hawaiʻi (https://eorhawaii.org/make-a-report/) .

• Reduce your carbon emissions to help minimize the intensity of changes in ocean temperature that severely affect corals. Small changes in your daily routine can make a big difference in your carbon footprint.

• Eliminate single-use plastics such as water bottles, utensils, plastic bags, and straws. Bring a reusable water bottle for your next visit to the park.