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Kahaluʻu Bay
Seven Sisters
Coordinates: 19.579208, -155.967896
Visit The Seven Sisters With Us!
The area nicknamed the “Seven Sisters” is an ecological wonder. These giant Porites evermanni coral colonies are hundreds of years old and have survived all this time in some crazy harsh conditions! They are living tributes to resilience that give us hope for the reefs, even as we face the devastating effects of climate change. Scroll down to learn more…
What is brown lobe coral?
Evermanni coral is one of the species found at Kahaluʻu Beach Park, located in Kona on the Island of Hawaiʻi. Evermanni coral, also known as Porites evermanni, is a species of stony coral that belongs to the Porites genus. It is a common species of coral found in the Indo-Pacific region, including Hawaiʻi. Evermanni coral typically grows in an encrusting lobe or mound form and features a range of colors, including brown, tan, blue-gray, and purple. Like many other corals in Hawaiʻi, this species relies on photosynthetic algae called zooxanthellae for energy, and is sensitive to changes in water temperature, quality, and acidity.
In Kahaluʻu Bay, the coral serves as a vital habitat for many species of fish and invertebrates, providing shelter, food, and breeding grounds. The degradation of coral reefs, including the decline of evermanni coral, poses significant threats to the biodiversity and health of the ocean, which can have far-reaching impacts on the local environment, the economy, and the species that rely on these habitats for survival. Preserving the vitality and diversity of evermanni coral in Kahaluʻu Bay is essential for the long-term health of the wider marine ecosystem.
SEVEN SISTERS | FIVE MINUTE TOUR IN KAHALUʻU BEACH PARK | KONA, HAWAIʻI
Take a leisurely dive around the Seven Sisters and immerse yourself exploring these centuries-old coral colonies in Kahalu’u Bay.
FISH QUIZ: Watch full-screen and see how many species of fish you can identify. We spotted at least 10 different species!
Sea Life Around The Seven Sisters
This area under the water in Kahaluʻu Beach Park is always full of surprises. There is a large lava rock tidal shelf just mauka (toward the mountain) of the Seven Sisters. This black rock shelf is submerged in shallow water during high tide, and is completely exposed in the lowest tides. When the tide goes out, the water from the rock shelf flows into and near the Seven Sisters, bringing with it lots of nutrients from this tidal shelf micro-ecosystem. The result is usually lots of fish but not-so-clear water.
STOCKY HAWKFISH
Sporting bold and fiery coloration that's both distinctive and oddly camouflaging, this little predatory fish has a reputation for being a stealthy hunter, waiting in the shadows for its next meal to swim by. And when it does, the hawkfish strikes with lightning-fast reflexes. But, don't let its showy and tough exterior fool you, the hawkfish has a softer side too. When feeling vulnerable, it quickly retreats to hide in crevices in the reef.
YELLOW TANGS
The yellow tangs of Kahaluʻu Bay are like the sunshine of the ocean. With their bright, bold coloring and easy-going personalities, they bring joy and light to the underwater world. These fish are a common sight in the bay, darting around the coral reef and showing off their acrobatic skills. They're pretty chill fish, often coming very close to snorkelers!
2021 | BRISTLE WORM AT THE SEVEN SISTERS
Some bristle worms have toxic bristles that can cause itching and burning. The coral might just know this, too! Watch super closely and you can see the individual polyps on the left start to retract a bit as the worm passes by at about 00:16. Remember, it’s so important to remember to avoid touching marine life— for your safety and theirs!
2022 | COOL SEVEN SISTERS FIND! LION’S PAW SEA CUCUMBER
Are you ready to meet the wiggliest, squishiest creature in Hawaiʻi? Say aloha to Euapta godeffroyi. This funny-looking sea cucumber (called the lion’s paw) loves to wiggle and squirm its way across the ocean floor. It's tentacles help it sense its surroundings and find food to eat. They usually spend the day in hiding, so it’s pretty rare to spot them out in the bay like this!
Stressors Affecting The Seven Sisters in Kahalu‘u Beach Park
The stressors acting on these ancient coral colonies are many and synergistic. Some of them are natural and longstanding related to the immediate coastal topography. Others are directly related to human-created negative impacts. We will highlight a few examples below, and you can learn more about the many stressors facing Kahaluʻu Bay and what’s being done to try to alleviate them on the The Digital Coral Ark Pilot Project page and the Kahalu‘u Bay | Then and Now video.
HEAT
Thermal stress near the Seven Sisters can be extreme. The rock shelf has shallow standing water which heats up from the black lava rocks baking in the strong tropical sun. When the tide goes out, much of this super-heated water flows directly into the Seven Sisters area.
TRAMPLING AND FISHING
Walking on the rocky ocean floor here kills new coral colonies. Trampling is a problem in this area because it’s so close to the entrance. Also, the removing of too many algae-eating fish (through fishing pressure) disturbs the reef’s ability to self-regulate.
SEDIMENT AND TURBIDITY
Note that you can barely make out the snorkeler approaching. Freshwater springs and submarine groundwater discharge bring increased nutrients and, combined with the organic matter particles that wash off the lava rock tidal shelf, contribute to increasing turbidity (or murky water).
SEWAGE AND RUNOFF
There are over four dozen cesspools near Kahaluʻu Bay. Untreated sewage leaching from cesspools into the groundwater system can carry pathogens such as bacteria and viruses. And runoff can inundate delicate marine ecosystems with pesticides, fertilizer, and even fecal matter.
2021 | TURBIDITY OF SEVEN SISTERS ON A TYPICAL DAY
Remember earlier when we said that the landscape surrounding the Seven Sisters makes for a lot of fish but not-so-great visibility? This clip shows some typical conditions— lots of suspended matter in the water, limited visibility, and quite a bit of turbidity. It can get much, much worse than this, to the point that you can barely make out your snorkel buddy. But, on some rare and magical mornings, you might catch a hour or so of crystal clear water here (which was the case about 45 minutes before this video was taken).
How The Seven Sisters Have Changed Over Time
Crazily enough, the Seven Sisters area has remained remarkably stable over time, especially given the profound changes in human impact over the past several decades AND the mass bleaching event in 2015. We have some hypotheses as to why this might be (more on this later), and the tenacity of these majestic coral colonies is cause for hope. However, there are definite signs of coral stress in this area, which we will illustrate after this “flyover” from 2018.
2018 | SEVEN SISTERS 3D FLYOVER
This video of the Seven Sisters area is an excerpt from a Structure from Motion (SfM) technology pilot project contributed to the Digital Coral Ark by Silver Spiral Seas, LLC. SfM is a photogrammetric range imaging technique for estimating three-dimensional structures from two-dimensional image sequences. You can find out more about the SfM photogrammetry survey pilot project for Kahaluʻu Bay here.
Coral Stress at Seven Sisters In Kahalu‘u Bay
Although most of the large coral colonies present in recent decades are still alive here, if you look closely, you can often see signs of coral stress. When corals become stressed, they are more vulnerable to disease and death caused by pathogens that they might otherwise be able to fight off. Like most living organisms, corals are faced with stress on a regular basis, such as predation, naturally occuring fluctuations in weather and environment, etc. But, humans have significantly impacted the bay through development, tourism, climate change, and pollution. And, coral disease and death are undeniably present. Ultimately, we are witnessing the decline in mature corals and the difficulty that younger corals have in establishing and growing, but no one is entirely certain of exactly what is happening to the corals inside the bay, or why— much less what the future will hold. Thatʻs why it’s so important to mitigate as many stressors as we can, as soon as possible.
This is a skeleton of a large mounding coral colony. People often mistake this for a convenient rock to stand on while snorkeling. This will kill any young coral colonies trying to re-establish on this structure.
The whitish areas on this coral indicate stress. The black-looking grooves on the lower portion of the image are actually channels built by a common reef creature— the petroglyph shrimp.
This mounding colony shows areas of previous coral death (which are the rocky-looking depressions), living coral, and stressed coral (which looks like it has a greenish-yellow coating).
This is another example a Seven Sisters mound with a mucousy coating on part of the colony. The next image will show a closer look at this phenomenon.
This small coral might have a chance to grow up to be like its big sisters in a couple hundred years or so. But, it’s not doing so great. The stressors mentioned above take their toll, and if visitors to the bay step on it, well…
Here’s a closeup view of the coating sometimes present on the mounding coral at the Seven Sisters. You can see green algae growing on top of this coating.
The mucousy coating on the left side of this coral is suggestive of stress. We’ve seen this coating become covered in algae, heralding coral decline, but we’ve also seen it shed off, revealing coral polyps underneath that continue to live.
And here is an even closer view. In this photo, you can see the living coral polyps starting to shed both the coating and the algae that’s been growing on it. Phew!
Why The Seven Sisters Give Hope For The Future
As most people know by now, there’s this little thing called climate change. And, many readers will also be aware that even a small rise in ocean temperature can bleach and kill corals. In fact, huge percentages of the world’s coral have died in the last 10 years, and unmitigated further loss will threaten virtually every aspect of life on this planet. But here, in Kona’s own Kahaluʻu Bay, we have large coral colonies that survive daily fluctuations in temperatures that are so marked they’re actually startling sometimes. Swimming through a cold freshwater spring in this area makes almost anyone shiver. And, sometimes the sun-heated water pouring off the black lava rock tidal shelf feels like a hot bath. Yet, they survive decade after decade— despite a boatload (small pun intended) of additional human-influenced stressors, which we know have synergistic negative effects with warming waters on coral health. These coral colonies are true survivors, and perhaps can help guide scientists in the future as they strive to understand resiliency in the face of climate change.
How You Can Help Protect The Seven Sisters
(And All Of Kahalu‘u Bay)
Visitors to Kahaluʻu Bay have the incredible opportunity to make a positive impact on this beautiful marine ecosystem. By taking simple yet meaningful actions, you can contribute to the protection and preservation of this precious habitat. First and foremost, respecting the bay's guidelines and regulations is essential. Refraining from touching the coral or standing on the ocean floor, being careful to avoid chemical sunscreens, and refraining from feeding or harassing marine life are critically important steps to promote the well-being of the bay and all its inhabitants. The Reef Teach volunteers from the Kahaluʻu Bay Education Center (KBEC) are almost always available to help visitors understand how to visit the bay responsibility. They also share interesting facts, assist with fish identification, and offer safety advice— all of which help both the visitors and the reef.
We canʻt count how many times weʻve heard visitors, when asked to avoid standing in the coral, say something like “I’m not. This is just a rock.” But here’s the thing— Even if it is a rock (which it usually isn’t, prompting the intervention in the first place), there is almost certainly marine life living on it. Whether it’s coralline algae cementing and fortifying the reef, coral larvae settling on the ocean floor in hope of becoming keiki (baby) coral colonies, or untold other organisms sharing the bay, it’s best to avoid trampling them!
MORE WAYS TO HELP KAHALUʻU BAY
We highly recommend watching the 10-part video series Aloha ʻĀina Kahaluʻu created by our friends at the Kahaluʻu Bay Education Center (KBEC), a program of the Kohala Center. This series introduces the bay and show how to respectfully engage with this wahi pana— a sacred, cherished, and storied place. These videos are a must for first-time visitors!
We also invite you to visit the Dear Ocean webpage How To Visit Kahaluʻu Bay Responsibly for some quick tips to help you prepare for your adventure and visit the bay sustainably.
With regard to the Seven Sisters specifically, the following are particularly important:
Watching extra closely to avoid touching the coral or kicking up sediment. It’s often murky around the Seven Sisters, lowering visibility and making it difficult to see the smaller marine life. Also, there is a heavy layer of sediment in this area, which if kicked up, will smother the coral.
Being super careful to avoid chemical sunscreens both on the beach and in the water: The Seven Sisters is close to the main entry into the bay as well as a lava rock tidal shelf that empties into the ocean in this area.
Making sure everyone in your party knows how to visit the bay responsibly, especially since the Seven Sisters is one of the easier spots to reach in the bay, attracting novice and advanced snorkelers alike.
Donations to Dear Ocean and our community partners such as KBEC and Mission Blue are always much appreciated and go a long way in raising awareness and protecting this marine treasure.
We’d like to leave you with this relaxing six minute video sharing some of the amazing, beautiful, and wonderful fish who love the Seven Sisters as much as we do. If you watch through to the end, you’ll be treated with some adorable keiki wrasses growing up in the shelter of these ancient coral colonies. ENJOY!
Do You Have Any Photos/Videos to Share?
IF SO, PLEASE VISIT OUR PHOTO/VIDEO CONTRIBUTOR PAGE AND GET IN TOUCH!
WE’RE LOOKING FOR PHOTOS AND VIDEOS OF KAHALUʻU BEACH PARK SNORKELING THAT:
have sufficient clarity and resolution to visually identify species of fish and/or coral.
can be identified by date and location (either by personal knowledge or embedded camera data).
are owned by adults 18 and over willing to grant permission to use in the historical database.
are from 2016 or earlier, especially.
ADDITIONAL READINGS
World Register of Marine Species: http://www.marinespecies.org/aphia.php?p=taxdetails&id=288900
Eyes of the Reef: https://eorhawaii.org/photo-galleries/learn-your-corals-gallery/
Coral Diseases - Eyes of the Reef: https://eorhawaii.org/photo-galleries/train_your_eye_gallery/coral-disease-gallery/
http://www.hawaiisfishes.com/books.htm
https://www.marinelifephotography.com
We welcome observations you would like to share or corrections you might note. Contact us!
Photo/Video credits: Pam Madden & Christine Zalewski for Dear Ocean, Silver Spiral Seas LLC, & Google Maps.
This page was reviewed by Pam Madden.