top of page

(c) Cory Fults


  • Why are we seeing more whale sharks in Hawai'i than ever before?
    We at Hawai'i Uncharted get this question all the time. As with many questions about relatively unknown pelagic species, the answers are rarely simple and there are often many possible contributing factors. We do know that, anecdotally, people on the water are seeing more whale sharks than previously reported. That doesn’t necessarily mean that there are more whale sharks here, but there could be. The answer to this question requires a long-term data set, which is why our efforts are so important. It will take several years to be able to effectively determine if there are really more whale sharks being seen than before. Also, our current data shows where people are looking for and finding whale sharks, and this is a great start. In the future, we would like to pair these photo-ID efforts with additional surveys that can better determine where the whale sharks are and how many there may be. Our first recorded sighting in our database (officially submitted to Hawaii Uncharted) is from 1991 and the species was likely seen here well before that time. Seeing whale sharks is not a new phenomenon but the recent frequency of sightings has caused quite a buzz in the ocean-going community. Islands-wide we had 25 individuals submitted to us in May and 19 submitted from June of this year (2019). We also know that we are likely not getting submissions from all the whale sharks sighted. As tourism increases in Hawai'i, and with the advent of affordable underwater cameras, there are more people on and in the water hoping to get the perfect underwater shot. This increases the likelihood of someone seeing a whale shark if it is present in near-coastal waters, especially if it is near a popular dive/snorkel spot. There have also been some changes to our marine environment in recent years. With sea surface temperatures increasing, there will continue to be changes in the ocean environment. In addition to the effect on coral reefs, changes in temperatures and climate can affect oceanography including wind and currents. For whale sharks, this could change the distribution of their plankton prey. Internationally, whale shark movements have been closely linked to sea surface temperature. It is too early to know the extent of the effects of these changes. In addition to this, globally, whale shark aggregation sites are largely determined by prey availability- seasonal blooms in plankton cause seasonal aggregations in whale sharks in many locations. Our nutrient-poor waters may not have the obvious blooms as other places world-wide, but anything new in the environment that may send signals (like smell) of food, may draw any whale sharks visiting the area into closer proximity to one another. In the future, HURC hopes to look at plankton composition and environmental conditions in frequented areas to get a better idea of the preferences of whale sharks in Hawai'i.
  • Do whale sharks live here year-round?
    The short answer is that we aren’t sure. From our research, we have been able to confirm whale sharks are present in Hawaiian waters every month of the year. There has been very little research done on whale sharks here in Hawai’i and we aren’t really sure if there are local populations that cruise between/around the islands or if they are just cruising by on the way to another destination. Previous research has shown that whale sharks do travel very long distances, sometimes across whole ocean basins. We collaborate with our international partners to see if the individuals that we are seeing here are also sighted in areas where large aggregations of whale sharks are common.
  • How do I tell the sex of a whale shark (male vs female)?
    Whether a shark is male or female can be determined by a quick peek between the pelvic fins, which are the paired fins between the belly and the caudal (tail) fin. Males have claspers whereas females do not. In many species of sharks, even when they are young, the claspers are clearly visible, however, whale sharks are UNIQUE! The presence or absence of claspers is not always obvious from the side view. When males are immature (less than about 26-30 feet long) their claspers do not extend past the pelvic fins and sometimes can not be seen from the side or even from behind the shark. It is not until the males are fully mature that you are able to easily see the claspers. The only way to confidently confirm whether an individual is male or female is to swim underneath the shark and get a clear view between the pelvic fins.
  • What photos should I send you of an encounter?
    We get this question a lot! So, what is the perfect submission? The short answer: ALL OF THEM with left, right, and underneath photos Our catalog is based on photos/videos of the left side of whale sharks. This is because the left side is an International standard and allows us to collaborate with international photo-identification projects (ie. WildBook for Whale Sharks) and helps to ensure that we do not have duplicate individuals in our catalog. The left side photos/videos are not the only thing that matters. We match these images to our catalog and also document as much information about each sighting (and each individual) as possible. These photos are only a small piece of the puzzle. With the photos, we request information about the sighting. This information, paired with the photos, allows us to start a profile for an individual whale shark, but it doesn’t stop there. Right sides are also unique to each individual and they do not mirror or match the left sides. We encourage people to STILL SUBMIT a sighting even if they don’t get the left side. We can use right side photos to compare to past and future sightings. If you’re able to send in a left and right side of the same whale shark and later someone sees the same shark and only gets a photo of the right side, we are still able to match this individual. This allows us to monitor individuals and build information about movement patterns. One of the pieces of information we request, if known, is whether the individual is a male or female. Unfortunately, with photos only from the side/profile view or above the individual, we have no way of knowing this information. The only way to confidently confirm whether an individual is male or female is by getting a clear, in-focus photo/video from between the pelvic fins to confirm the presence or absence of claspers. The perfect submission (the one that provides the most information about any individual) is one with clear photos from both the right and left sides (as perpendicular to the animal as possible) and from underneath to see between the pelvic fins. Even if you think someone has already submitted a sighting to us, we encourage you to send in your photos/videos from every sighting. The ones you send in may provide valuable information that is missing in a shark’s profile and help us learn more about that individual in the future. So in summary: ANY AND ALL PHOTOS OR VIDEO IS HELPFUL!
  • How do I get to name a whale shark?
    If you are the first person to submit an ID photo/video (left side, clear profile view) with the accompanying information for an individual that is new to our catalog, you get to name that whale shark! The best and easiest way to submit your photos is directly from this website. There is a link in the tabs above to submit your photos. Don’t forget to include all of the information about the animal and the sighting! Left-side photos are required to establish the unique identity of the animal, but any and all photos are helpful to learn more about each individual. Ready to submit? click here.
  • How can I help? How can I be more involved?
    There are many ways to help and support the whale sharks and our efforts. Get the word out! Let other people know about our work and encourage them to submit sightings Donate! Hawai’i Uncharted Research Collective is a non-profit organization that relies on your support. The process of cataloging sightings and future projects to learn more about whale sharks in Hawai’i takes a large amount of time and funding for equipment. Show up! Show your support by attending one of our community presentations, booth events or beach clean-ups Reduce, Reuse, Recycle! A clean and healthy ocean helps to protect marine life, including whale sharks
  • I want to learn more.
    Our team of researchers are working on publishing findings in scientific journals and attending international conferences to share new and exciting information regarding our Hawaiian whale sharks. Since this is a community-based citizen-science research effort, we also prioritize community events and presentations to share our findings as they are discovered. Stay tuned to our website and social media for updated information, presentations, and publications.
  • Are whale sharks protected?
    The whale shark is identified as a migratory species under the International Convention on Migratory Species and are considered Endangered worldwide by the International Union for Conservation of Nature and Natural Resources (IUCN). This species is only protected in and around 13 of over the 100 countries that it is known to visit. Work continues to achieve protection in other countries that still permit the hunting of whale sharks. Despite their Endangered status, internationally, they are not currently listed on the Endangered Species Act in the United States. Through our research at Hawai’i Uncharted, we hope to clearly understand where our Hawaiian population fits into the worldwide picture in hopes to offer better protection and regulatory measures for animals in the state of Hawai’i.
  • Is it legal/illegal to "ride" whale sharks in Hawai'i?"
    The quick answer is no, it is not illegal to touch or ride a whale shark in Hawai’i. The long answer is such that these animals are listed as Endangered by the IUCN, and it is proven that physical contact can cause stress to the animal. Often in response to discomfort they will show a fast 'banking' behavior which can also cause injury or harm to the swimmer, most commonly followed by a dive or more evasive behavior. We strongly recommend that no one disturb them with any form of physical contact. Please visit the downloadable guides section of our website for more information that will help to answer conduct-related questions.
  • Do whale sharks have predators?
    Sadly, humans are considered the biggest threat to whale sharks world-wide. Increased boating activity, ecotourism, and lack of knowledge regarding animal safety can lead to significant injuries to the animal. This species is still killed in some parts of the world for its flesh, liver oil, cartilage, and fins, which have become increasingly popular for use in shark-fin soup. Due to their relatively large size, whale sharks’ fins are sold for very high prices and there is still a market for whale shark meat in several countries, including China and Taiwan. As for ocean predators, blue marlin and several species of shark are known to prey on smaller whale shark individuals. Adult whale sharks are so large in size that potential predators are limited to Orcas and large species of sharks (like great white sharks).
  • How long do they live?
    The whale shark life cycle is widely considered to still be mysterious. Despite years of research, little is known about the exact age they can live to. That being said, it is generally accepted that they live an average of 60-80 years and known that they can live upwards of over 100 years of age.
  • What do whale sharks eat?
    Whale sharks are filter-feeders and their diet consists of very small prey. Diet varies regionally and seasonally. Some items that are commonly prey for whale sharks include copepods, euphausiids (krill), coral spawn, tuna and snapper spawn. They are also known to feed on small schooling fish and have been seen feeding on Nehu off the island of Molokai.
  • How large can whale sharks get? When do they mature?
    Whale sharks reach sexual maturity at around 25-30 ft (8-9 m) in length and it is suggested that individuals of this size are 25-30 years of age. The largest whale shark measured was 65 feet long (19.8 m) and weighed nearly 34 tons (68,000 pounds). However, most commonly animals tend to average around 30 feet long and weigh around 20 tons.
  • Are you guys part of/ever heard of Wildbook for whale sharks?
    We are not part of Wildbook for whale sharks or the WildMe organization, but they are one of our international collaborators. Wildbook for whale sharks is an organization that has some similar goals to what we have here at HURC, on an international scale and compile the international database and catalog for whale sharks. We have a research account with Wildbook and are providing our database/catalog to document sightings in Hawai’i. Also, we manage all sightings from Hawaiian waters submitted through Wildbook and are able to compare them with our catalog.
bottom of page