Hawaii’s Coral Reef’s. So Important to the health of the islands.

Dec 12, 2020 | General Information

At Tom Barefoot’s Tours, we consider ourselves stewards of corals in Hawaii as well as the state’s tropical fish. The reasons are deeper and well-beyond simply business self-interest since Tom Barefoot’s Tours offers so many snorkeling, scuba, snuba and other tours in Hawaii’s waters that depend on the health of coral.

By the time you finish this article we hope that you will understand why, on June 1, we join other Hawaiian businesses to mark World Reef Day focused on raising awareness of the importance of the health of coral reefs in Hawaii and around the world. We also hope that, as visitors to Hawaii, you will learn about human-induced impacts to coral reef habitats and make all of your activities in and beneath Hawaii’s waters contribute to the health and survival of coral.

What is Hawaii’s Coral Reef Made of?
Coral reefs in Hawaii comprise over 80% of U.S. coral reefs. Hawaiian reefs possess some of the most abundant levels of marine species in the world as well as sheltering over 700 species of fish, 400 species of algae and over 2000 species of invertebrates. Hawaii’s coral reefs protect shorelines of the islands from storms and wave damage.

Coral reefs often are described as “underwater gardens” or “rainforests”. Coral reefs are complex communities of plants and animals. The colonies of corals that grow next to and on top of each other form the basis for a fascinating community, providing food, shelter, and living spaces for many kinds of plants and animals. Coral polyps have the unique ability to grow in nutrient-poor water, thereby supporting fish and marine life in waters that otherwise might be barren.

Coral reefs can be made of hundreds of different species of coral. Coral consists of two types: “hard” with an outer skeleton of calcium carbonate and “soft” corals that embed bits of calcium carbonate inside their bodies. All coral, irrespective of shapes and sizes, consist of tiny polyps (a tiny animal that resembles a jellyfish upside down). Reefs are formed when hard coral colonies grow next to and on top of each other.

The hard or reef-building corals that generate coral reefs in Hawaii consist of several types of coral including branching, finger-like and table-like forms. Each of these forms is adapted to live in a different type of habitat, such as shallow or deeper waters to avoid wave action. Non-reef building corals live in very deep water, including Black Coral, Hawaii’s official state gem, below where the sun penetrates.

What do Coral Eat?
Corals are plankton-eating invertebrate animals (polyps) that often are mistaken for minerals because of their skeletal, rock-like structure and slow-growing, immobile nature.In hard corals, polyps sit in little cups that they build out of calcium carbonate. During the day polyps stay in their cups. At night, they emerge to catch plankton with their stinging tentacles. But plankton is only part of their diet. Each polyp has a special algae in their body (zooxanthellae). These one-cell plants use sunlight and carbon dioxide to produce oxygen (photosynthesis).

In addition, coral polyps reproduce, using sperm and eggs. Sperm from male polyps fertilize eggs within female polyps. Baby corals leave the polyps and float to surfaces to which they can attach and grow into new coral that are exact copies of each other. New corals may grow over dead ones into many generations that result in huge reefs.

Coral vital role in Hawaii
Thus coral plays a unique dual role in the underwater ecosystem as both producers of food for herbivores and supporters of carnivores. Coral “producers”feed the herbivoresthat live around a reef and, in the process, supply herbivores to carnivores such as moray eels, monk seals, and sharks. Darting among the corals, however,also are many beautifully colored “omnivores,” fish that feed on both plants and animals. Some of these omnivores are described in Hawaii’s Tropical Fish: moorish idols, reef triggerfish, and the raccoon butterflyfish.

All the islands of Hawaii: Maui, Oahu, Kauai and the Big Island have large expanses of reef and each plays a huge role in the life cycle of all its marine life.