A colorful mural of the reef at Hanauma Bay
Manini Uhu Kihikihi Lauʻīpala Island of O'ahu Honu Koʻa ʻAha Hanauma Bay Interactive Reef Humuhumunukunukuāpua'a - Reef Triggerfish Moa - Spotted Boxfish Pāki’i - Flounder

Manini

School of Manini swimming over the reef at Hanauma

 

Manini - Convict Tang

Acanthurus triostegus

Convict Tangs are commonly seen throughout the Indo-Pacific region and are native to Hawai‘i. They feed on algae off of reef flats, travelling in large schools for safety in numbers. Their distinctive stripes also help to discourage predators from attacking them by breaking up their silhouette. Their role on the reef as algae eaters helps to maintain a healthy reef; keeping algae from overgrowing and smothering the reef. 

Their common name, the convict tang, refers to their vertical bars as reminiscent of prison bars. In Hawaiian, these fish were an important and abundant source of food and had many names for their various life stages. Throughout their life their names change based on their size and behavior starting with ʻōhualiko, ōhua kāniʻo, palapōhaku, kākala manini, maninini, and finally Manini as adults. 


‘Ōlelo No‘eau:

 Ka i‘a a ke kualau i lawe mai ai.

The fish brought in by the rain at sea. 

The spawn of the manini fish that came to the islands by the millions during the summer months. They were said to come after a shower at sea, in the early morning.

Uhu

A male Bullethead Parrotfish (uhu) swimming along the rocks.

Uhu - Parrotfish

Parrotfish are a group of fish found throughout the Indo-Pacific region. Many species are native to Hawaii with a few that are endemic; found nowhere else in the world. These large animals come in a variety of colors and sizes, but their most prominent feature are their strong beak-like teeth which they use to graze on coral reefs. As they scrape algae off of the reef they also ingest and process the coral in their bodies. The end result is ground up grains of sand that the fish releases into the water. The Hawaiian name "uhu pālukaluka" means "loose bowels".

While common on many reefs, the parrotfish found in Hanauma Bay are some of the largest that can be seen in Hawaiʻi. Outside of Hanauma Bay's protections, parrotfish are regularly caught for food. The removal of large herbivores off of reefs has proven to be very harmful to Hawaiʻi's marine environments like Kāneʻohe bay. Without these herbivores on reefs algae has spread widely, suffocating many of the corals. These same corals provide food and shelter for other fish, which creates a cycle of loss.

The Hawaiʻi Institute of Marine Biology has worked hard to manage algal blooms through the introduction of native urchins to continually graze on algae, but over fishing still poses a threat to other reef ecosystems. We can continue to improve our reef ecosystems by taking a few simple actions. Remembering to shop for sustainably harvested fish helps to discourage over fishing. When fishing, remember to observe size regulations and to take only what you need.

To Learn more visit:

NOAA - Get to Know Your Seafood

Kihikihi

Kihikihi - Moorish Idol

Kihikihi - Moorish Idol

Zanclus cornutus

Moorish Idols are native to Hawaii and found globally in shallow reef environments where they feed on sponges, corals, and other invertebrates. They are commonly seen along the reef alone, though it is not uncommon to see them in pairs or groups. Moorish Idols are one of the most recognizable fishes with their triangular bodies, banded coloration, and long white dorsal fin.

The presence of fish like Moorish idols is a good indicator of reef health. Moorish idols are notoriously picky about their foods in captivity and rely on healthy reef environments to maintain a healthy diet. When reefs have a wide variety of fishes living on them, like at Hanauma bay, that tells us that the reef is alive and thriving. 

To help us understand more about fish abundance and diversity, several organizations work to map this information across different parts of the world. Knowing what fish are commonly found in different parts of the reef helps to paint a better picture of what a healthy reef can look like. 

To learn more about:

Fish counts start here

Lauʻīpala

A Yellow Tang (lau īpala) swimming in the blue water with rocks in the background.

Lauʻīpala - Yellow Tang

Zebrasoma flavescens

Commonly found throughout the Pacific in shallow waters including Hawaiʻi, the Yellow Tang is a beautiful fish that, with the exception of their white tail spine, are entirely yellow. Their Hawaiian names make reference to this, meaning “Yellowed Leaf”. As juveniles these fish are territorial, but calm down as they mature.

The Yellow Tang’s distinct appearance makes them prized fish in the aquarium industry. About 98% of all saltwater fish in aquariums are caught in the wild rather than being bred. However, the removal of fish like Yellow Tangs from the reef, whether for aquariums or food, can harm the natural environment and the fish themselves. Yellow Tangs’ distinct mouth shape and diet make them hard to breed and raise. Equally, fish are needed to maintain the balance between algae and reef growth. Without them one can overtake the other and lead to more fish starving and dying.

That’s not to say that having an aquarium can’t be fun and helpful. Efforts like those at HPU’s Oceanic Institute are working towards breeding and raising saltwater fish for aquarium trade. Always be aware of where your fish come from and how to properly care for them.


Learn more about:

Yellow Tang breeding at HPU’s Oceanic Institute

Island of O'ahu

side view of Hanauma Bay with clear skies.

Hidden amongst the corals and reef is a strange coral head with much to say. One translation of the name "Hanauma" is "Arm Wrestling Bay", and is visualized by this distinctive, though fictional, coral head representation of an arm wrestling match. Within this coral head is the silhouette of the island of O'ahu, with Hanauma Bay highlighted by the nearby Humuhumunukunukuapua'a.

The nearshore waters of Hawaiʻi have been foundational to the lives of its people and is home to some of our most treasured resources. They play host to hundreds of colorful species of fishes and invertebrates; some of which are found nowhere else in the world. They provide food and recreation to their communities and visitors alike. In order to maintain and preserve these valuable resources the state of Hawaii creates Marine Life Conservation Districts (MLCD) like Hanauma Bay. MLCDs provide protected areas where fish and other marine life can thrive and reproduce so that they may be enjoyed by generations to come. On the island of Oʻahu we have three MLCDs: Hanauma, Pūpūkea, and Waikīkī.

You can learn more about:

Marine Life Conservation Districts here.

Place names around Hanauma Bay here.

Honu

A green sea turtle swimming along the bottom of the seafloor.

Honu - Green Sea Turtle
Chelonia mydas


Green sea turtles are found globally in tropical and subtropical climates and are native to Hawaii. Green turtles get their names, not from the color of their skin or shells, but rather the color of their fat, which turns green due to the algae that they eat. Turtles can live well over 70 years in the wild, but do not reach maturity until the ages of 25-35. Green sea turtles spend a majority of their lives at sea, however in Hawai’i they occasionally pull up onto beaches to warm themselves; a behavior uncommon in other green sea turtle populations.

Globally, green sea turtles are listed as an endangered species, meaning they face the threat of extinction in the near future. Turtles face many threats such as loss of breeding grounds, hunting by humans, as well as pollution like ghost nets and marine debris. Turtles will often mistake plastics as food and ingest them, which can lead to starvation or choking. Turtles can also get tangled in stray nets and fishing lines. Due to these threats coupled with their slow reproductive cycle, these turtles are slowly declining in population.

While many populations of sea turtles are declining, the Hawaiian population of green sea turtles has risen greatly over the past few decades. This is thanks to heavy conservation efforts made to protect these animals as well as efforts made by the public. Simple actions such as participating in beach clean-ups can help by removing plastics, nets, and fishing line off of beaches before they wash out to sea.

To learn more you can visit:

NOAA Fisheries

TED-Ed

 If you see a turtle in trouble you can call:

NOAA Hotline (888) 256-9840

Koʻa

Koʻa - Corals

Corals are found around the world in tropical and subtropical climates. While they may look like rocks, these are actually animals that form large stone-like structures in many shapes, sizes, and colors that we call reefs. Corals serve as both food and shelter to a wide variety of marine life and are the foundations of near shore ecosystems. Corals grow very slowly, less than one inch per year, and can live to be hundreds, even thousands of years old. Corals thrive off of an algae called zooxanthellae that grows inside its own body, as well as by collecting floating nutrients in the water. These zooxanthellae are what give each coral species its distinctive coloration.

Corals are threatened around the world due to pollution and rising ocean temperatures. When ocean waters become too hot corals will "bleach", the act of expelling their symbiotic algae from their bodies, which exposes the bare white skeleton beneath. An easy indicator of coral health is color. Dying and dead reefs are often colorless. Without this algae they lose their main source of nutrient and can die. Equally pollutants and harmful chemicals can stunt growth and harm coral reefs.

There are a few simple acts we can take to protect reefs from bleaching. One thing everyone can do is to use reef-safe sunscreens. Some sunscreens use harmful chemicals such as oxybenzone and avobenzone, which are harmful to both humans and marine life. Switching to mineral based sun protection, or full body coverings while in the ocean can greatly reduce the presence of these chemicals on reef ecosystems around the world. Equally, reducing our carbon footprint (the amount of CO2 we produce when using electricity or gas), helps to slow global climate change. Simple things like walking, biking, carpooling, and taking public transit all help to reduce our carbon footprints.

To learn more about visit:

Corals

Reef-safe Sunscreen

ʻAha

a single slender needlefish at the waters surface.

ʻAha - Keeltail Needlefish

Platybelone argalus

Commonly found natively in Hawaii and around the world in shallow waters, the Keeltail Needlefish can be found just below the water’s surface in large schools. They are often seen resting during the day and feeding at night. Their narrow mouths are filled with sharp teeth, which they use to capture prey and swallow them whole. However, small prey animals are not the only things found floating at the surface of the ocean. 

Plastics that make their way into the ocean can float for long periods of time, slowly breaking down into smaller and smaller pieces called microplastics. Many fish can mistake these small fragments for food. Once eaten these plastics will fill an animal's stomach. With stomachs full of plastic and unable to eat real food, these fish can quickly starve. If they don’t starve first, many of these fish become prey for larger fish like ulua (trevally) and ʻahi (tuna). Those plastics stay in the bigger fish and pass on plastics to the next animal that eats them. This process of passing harmful chemicals and plastics from one animal to another up the food chain is called biomagnification. These plastics can eventually make it into the fish that we eat.

However, there are a number of ways we can prevent plastics from reaching our dinner plates. Remembering to reduce plastic use wherever possible, and recycling what can be are great ways to keep plastic out of landfills and the ocean. While many organizations provide large beach clean ups, anyone can pick up a bag and sift through the plastics they find on the beach. Every piece taken off the beach is a piece that won’t reach the ocean.

For more information:

Biomagnification

Research a beach cleanup that fits your schedule or go on your own!

Hanauma Bay Interactive Reef

This stunning mural sits at the entrance to Hanauma Bay's Visitor Center and details the colorful collection of marine life found there. Explore and learn more about our wildlife by clicking on them in the mural.

Hanauma Bay Education Program, Hawaiʻi Sea Grant
HANAUMA, HAND WRESTLING BAY mural by Thomas Deir, 2001
Commission on Culture and The Arts, Art in City Buildings, City and County of Honolulu

Humuhumunukunukuāpua'a - Reef Triggerfish

Humuhumunukunukuapua'a - Reef Triggerfish

Humuhumunukunukuāpua'a - Reef Triggerfish

Rhinecanthus rectangulus

The Triggerfish is one of the most common carnivorous reef fishes of Hawaii. The Waikiki elementary school chose the Reef Triggerfish (Humu) as the state fish of the Hawaiian Islands in 1984. Their Hawaiian name means “fish with a snout like a pig.” 

Their unusual physical features are easily noticeable. The small eyes of the fish are located further away from their mouth. This helps them eat the algae off the sea urchins and other invertebrates without getting poked in the eye. There are two dorsal fins placed forward on the body above and behind the eyes. Triggerfish have tough skins and small but strong mouths. Their independently movable eyes are positioned high and about one third of the way down the body. The position of the eyes allows them to eat long spined sea urchins 

Triggerfish lay and fertilize their eggs on the bottom sea floor and guard them until they hatch.  Although normally wary and shy, they can defend their nests aggressively, charging and even biting those who come close. During nesting season they are not afraid to chase you away from their eggs.

Moa - Spotted Boxfish

Moa - Spotted Boxfish

Ostracion meleagri

Boxfish are protected by an armored plate that covers their whole bodies. Only their eyes, fins and mouths are movable. When threatened, most boxfish can secrete a toxic slime from their skin. This toxin can kill other fish if the boxfish is kept in the same aquarium, but it is not known to affect humans. Males are often more colorful than females. There are five different species of boxfish found in Hawaiian waters, but only three of those species are likely to be seen by the average snorkeler: the Thornback Cowfish, the Spotted Boxfish, and the Whitley Boxfish. Boxfish have been known to forage on sponges, algae, tunicates, worms and small crustaceans.

Pāki’i - Flounder

Pāki’i - Flounder

Bothidae

These fish are found on the sand or gravel seabed. They are nearly invisible to both prey and predator because their bodies are flat against the bottom and they are extremely well camouflaged.They eat small crustaceans and other smaller fish. Flatfish are born like any other fish, with eyes on either side of their heads, but as they grow, one eye moves to join the other eye, and their bodies lean until they are flat against the seafloor.