Exploring Hawaiian Islands Humpback Whale National Marine Sanctuary

By guest writer Elizabeth Weinberg, social media coordinator and editor/writer, Office of National Marine Sanctuaries National Oceanic and Atmospheric Administration

For more than 40 years, national marine sanctuaries have worked to protect special places in America’s ocean and Great Lakes waters, from the Hawaiian Islands to the Florida Keys, from Lake Huron to American Samoa. Backed by one of the nation’s strongest pieces of ocean conservation legislation, the National Marine Sanctuaries Act, the sanctuaries seek to preserve the extraordinary beauty, biodiversity, historical connections and economic productivity of our most precious underwater treasures. And — lucky for you — most of these places are accessible to recreational divers. Sanctuary waters are filled with unique ecosystems, harboring a spectacular array of plants, animals and historical artifacts, all waiting to be explored. We’ll begin our series on national marine sanctuaries with the Hawaiian Islands Humpback Whale National Marine Sanctuary. These places belong to everyone, so dive in.

Hawaiian Islands Humpback Whale National Marine Sanctuary

Since at least the 1840s, North Pacific humpback whales have wintered in the warm, shallow waters surrounding the Hawaiian Islands. Though the humpback whale population was depleted by commercial whaling at the start of the 20th century, an international ban on commercial whaling and protections under the Endangered Species Act and the Marine Mammal Protection Act have enabled the species to bounce back. Some 10,000 whales now return to Hawaii each year to mate, calve and nurse their young. These waters constitute one of the world’s most important North Pacific humpback whale habitats, and the only place in U.S. coastal waters where humpbacks reproduce. Hawaiian Islands Humpback Whale National Marine Sanctuary was established in 1992 to protect these endangered species and their habitat.

Humpback whales visit sanctuary waters each winter to mate, calve, and nurse their young. These whales spend more than 90 percent of their lives under the surface of the water, and often call to one another using complex songs. When diving and boating, make sure to give these majestic animals plenty of space. (Photo credit: NOAA Permit #774-1714)

Humpback whales’ impressive acrobatic displays are often visible from miles away. These whales are often identified by scars and patterns of white pigmentation on the underside of their tails, which are unique to each whale. (Photo credit: NOAA Permit #782-1438)

NOAA diver Shannon Lyday photographs her dive buddy Mitchell Tartt while on a research expedition to document the reefs of Hawaiian Islands Humpback Whale National Marine Sanctuary. Don’t forget to bring a camera with you on your dive — with unforgettable seascapes, you’re bound to get some amazing shots. (Photo credit: Mitchell Tartt/NOAA)

The main Hawaiian Islands are surrounded by small, fringing reefs that are home to roughly 50 coral species — 20 percent of which are unique to the area — and invertebrates like the crown-of-thorns starfish. (Photo credit: Mitchell Tartt/NOAA)

Hawaiian spinner dolphins are found close to shore in shallow coves and bays during the day, where they rest, care for their young and avoid predators. When observing spinner dolphins in the sanctuary and elsewhere in the wild, stay at least 150 feet away to keep from harassing these protected mammals. (Photo: Ed Lyman/NOAA Permit #14097)

The spinner dolphin is named for its unique habit of leaping out of the water and spinning in mid-air. (Photo credit: Ed Lyman/NOAA permit #14097)

Butterflyfish like the milletseed butterflyfish swarm in groups on shallow reefs and seamounts throughout the sanctuary. (Photo credit: Greg McFall/NOAA)

Coral reefs are often called the rainforests of the sea. They support a wide variety of marine life while comprising only a small area of the ocean. With vast number of species living within and around them, they are regarded as the world’s most diverse marine habitat. (Photo credit: Ray Boland/NOAA)

The green sea turtle is the most common sea turtle in Hawaiian waters. Primarily vegetarians, they feed on marine plants like algae in shallow coastal waters. Every 2 to 5 years, these sea turtles migrate across hundreds of miles of open ocean to mate and nest in the Northwestern Hawaiian Islands at French Frigate Shoals. (Photo credit: Ed Lyman/NOAA)

Like many coral reefs throughout the ocean, the reefs of Hawaiian Islands Humpback Whale National Marine Sanctuary are currently experiencing a massive bleaching event. The changing climate means rising ocean temperatures; these warmer temperatures stress the corals, causing them to expel the colorful symbiotic algae that they need to survive. Divers to the area can increase the corals’ chances of recovery by making sure not to touch or kick sediment over the reef. (Photo credit: NOAA)

Humpbacks whales aren’t the only charismatic animal residents of the sanctuary; divers may also encounter Hawaiian monk seals, spinner dolphins, manta rays and sea turtles swimming through this warm water. Dive down to one of the sanctuary’s many coral reefs to see sponges, sea anemones, and corals up close, and to spot many of Hawai’i’s 700 species of reef fish, including the official state fish, the humuhumunukunukuapua’a, or Picasso triggerfish.

If you need a break from diving or have a dry day and want to help the sanctuary keep tabs on the humpback whale population, join the Sanctuary Ocean Count project and help monitor humpback whales from the shores of O’ahu, Hawai’i and Kaua’i. Check out the wonders of Hawaiian Islands Humpback Whale National Marine Sanctuary via our photos, and see more here.

*Cover image credit: Ed Lyman/NOAA Permit #774-1714