We will be undertaking a field project off the island of Kaua‘i starting on July 31st. This will be our 13th year of working off the island since our first trip here in 2003, and our 18th field project off Kaua‘i (our last off Kaua‘i was in February 2020). This project is funded by U.S. Pacific Fleet through the Marine Species Monitoring Program.
The primary objective of this project is to obtain information on movements and behavior of a number of species of toothed whales before, during and after a Navy Submarine Command Course, through the deployment of depth-transmitting satellite tags. Most of the tags we will be using have Fastloc GPS capability, giving us much more accurate movement information than normally obtained by Argos tags. Such tag deployments give us information on movement patterns and diving behavior, and we are collaborating with Navy scientists to look at exposure and potential responses to mid-frequency active sonar (MFAS). Check out our most recent report on MFAS exposure and response at this link.
We also have a number of other objectives, including obtaining photos of most species of odontocetes we encounter, to contribute to ongoing studies of residency patterns and social organization and to estimate population sizes, and collecting biopsy samples for toxicology and genetic studies. If you are expecting to be on the water off Kaua‘i between July 31st and August 14th and would be willing to call if you see any whales or dolphins (other than spinner, bottlenose, and rough-toothed dolphins), please contact Robin Baird (at rwbaird (at) cascadiaresearch (dot) org) for his cell phone number - we would much appreciate a call or text!
Like other projects off Kaua‘i in recent years we expect to have higher encounter rates than normal since we'll be working in collaboration with the Navy scientists with the Naval Information Warfare Center and from the Marine Mammal Monitoring on Navy Ranges (M3R) program, using the Navy's hydrophone range off Kaua‘i to localize animals. When on the water we will be in constant contact with Navy researchers to help direct us to groups that they are detecting acoustically, or to work in areas away from the range when there are no acoustic detections of priority species. Responding to acoustic detections allows us to visually confirm the species (to aid in using the acoustic range for research purposes on different species), and increases our encounter rates for tagging, photo-ID and biopsy sampling.
Species that we are expecting to see, based on our past efforts off the island in July and August, include short-finned pilot whales, bottlenose dolphins, rough-toothed dolphins, spinner dolphins, but we also have a pretty good chance of seeing melon-headed whales and pantropical spotted dolphins, and may also see Blainville's beaked whales, false killer whales, or sperm whales
The research team includes Colin Cornforth, Kimberly Wood, Shannon Vasquez, Brijonnay Madrigal, Robin Baird and a number of volunteers.
The photo above is of a sperm whale fluking in the Kaulakahi Channel between Kaua‘i and Ni‘ihau, seen during our August 2018 project.
End of project update
Over the last two weeks we've encountered eight different species of whales and dolphins (as well as lots of seabirds, a whale shark, and a Hawaiian monk seal), taken over 37,000 photographs of cetaceans (and a lot more of birds etc), collected four genetic samples, and deployed 14 satellite tags on six different species of cetaceans. Overall it was an amazingly successful project! We want to thank the 26 different volunteers we had out, folks in the tour industry who reported sightings, and our Navy partners for getting us to so many groups of whales and dolphins!
August 11th update
One of our highest priority species for this project, but one that we rarely ever see off Kaua‘i, are Blainville's beaked whales. This species is known to show behavioral responses to high-intensity mid-frequency active sonar, and thus is a high priority species for the Navy. If we find Blainville's, our goal is to be able to deploy one or more satellite tags on the group, to be able to monitor and learn more about their behavioral responses during exercises involving mid-frequency active sonar. Today we were directed to an acoustic detection of Blainville's beaked whales on the range, found the group, and were able to work with them for over an hour.
Most excitingly, we were able to deploy two SPLASH10-F satellite tags, one on an adult male (shown above), and one on an adult female. These tags record both diving behavior and provide Fastloc-GPS locations of the tagged individuals, so we should be able to document their behavior over the coming week or more to see how behavior changes in all three dimensions in relation to the upcoming Navy exercise.
The group included seven different individuals, including three adult female/juvenile pairs (shown in the photo above), and we were able to get good ID photos of all seven individuals, to compare to our long-term photo-identification catalog of this species. If you want to learn more about Blainville's beaked whales in Hawaiian waters, check out this book chapter on our Hawai‘i beaked whale work in 2019.
August 10th update
We have had a couple of very productive days on the water. Today we re-located the group of short-finned pilot whales that we had encountered on August 9th, using the satellite tag we had deployed then to track down the group. As shown in the photo above, conditions were much better today, and we were able to deploy two additional LIMPET satellite tags as well as get good ID photos of most of the individuals present.
On August 9th we had several good encounters with rough-toothed dolphins, and were able to get lots of good identification photos, deployed two LIMPET satellite tags, and witnessed two predation events. The spots on the belly of the leaping dolphin above are scars from cookie-cutter shark bites.
For one of the two predation events we were able to document the species of fish, a mahi mahi. Although rough-toothed dolphins will feed on mahi mahi during the day, we published a paper earlier this year showing they feed on a wide variety of species and likely feed mostly at night on mesopelagic fish and squid.
We deployed two different types of LIMPET satellite tags on rough-toothed dolphins -- the one above is a location-only Argos tag (a Wildlife Computers SPOT6 tag), and the other is a depth-transmitting Argos tag (a Wildlife Computers SPLASH10 tag).
We were also directed to a group of melon-headed whales based on an acoustic detection from the researchers monitoring the hydrophone range, and were able to get lots of good identification photos as well as deployed one satellite tag. The individual above has a damaged dorsal fin, most likely caused by a line injury.
This was our second encounter with melon-headed whales for the trip, and a different group from the one we encountered August 1st.
August 8th update
Today was a good day. On our Kaua‘i field projects we typically leave the harbor before sunrise, to take advantage of lighter winds early in the morning. Today we had our first sighting at 5:56 Hawai‘i time, well before sunrise and 11 minutes out of the harbor, encountering a group of false killer whales! Although it was a bit dark for photos initially, we stayed with the group for several hours as they traveled east along the south shore of Kaua‘i. We were able to get one satellite tag deployed, collected two biopsy samples (for genetics, stable isotopes, and hormone chemistry analyses), and obtained ID photos of over a dozen individuals.
Kaua‘i is an area where all three populations of Hawaiian false killer whales overlap -- in previous encounters off this island we've seen groups that are part of the Northwestern Hawaiian Islands population, and groups from the endangered main Hawaiian Islands population, so we are excited to learn who these individuals are!
We finally had to leave the group as they headed east of the island, but we are hoping they'll make it back during our last week of effort! To topp off the day, on our way back to the harbor we encountered a group of short-finned pilot whales!
Our short-finned pilot whale encounter was equally as productive -- despite the rough seas we were able to get a satellite tag deployed!
August 7th update
Today we encountered our first group of short-finned pilot whales of the trip, thanks to a call from Fathom Five Divers! The group contained about 20 animals, and were moving east offshore of southern Kaua‘i. While we weren't successful at deploying a satellite tag, we were able to get good photos to identify more than half the individuals in the group.
A very distinctive pilot whale from our encounter today -- the hole in the dorsal in is likely caused by a cookie-cutter shark bite. For more information on pilot whales in Hawaiian waters check out our web page for this species.
A short-finned pilot whale off the south shore today -- this group was in relatively shallow water (~350 m) -- our earlier work has shown that pilot whales in Hawaiian waters vary in how far offshore they are with lunar cycles, and during a new moon are closer to shore than during a full moon.
As usual, we've been recording all seabirds we see when out on the water, and taking photos of rare species. The photo above is of an endangered endemic Hawaiian Petrel seen August 5th. In addition to a few Hawaiian Petrels, we've seen a few Newell's Shearwaters, up to a dozen or so Band-rumped Storm Petrels on days we've been able to get out into deeper water, as well as lots of Wedge-tailed Shearwaters, Red-footed Boobies, Brown Boobies, and smaller numbers of Black Noddies, Sooty Terns, Great Frigatebirds, White-tailed Tropicbirds, and Bulwer's Petrels. For more information on seabirds in Hawaiian waters check out our seabird page.
August 4th update
On August 4th we encountered our fifth species of odontocete for the trip, with three separate encounters with rough-toothed dolphins. We were able to obtain good quality photos for our photo-identification catalog of this species.
We also encountered a group of spinner dolphins that included this individual, with a major injury on the dorsal fin. The cause of this injury is unknown, but based on the jagged edges may have been from a shark bite.
We've seen bottlenose dolphins over both of the last two days, and have been able to get lots of photos to compare to our photo-identification catalog of this species. A recent analysis of abundance and trends in this population showed evidence of a decline from the 2000s to the 2010s, so such photos will be of great value to understanding how this population is doing.
The individual above is HITt0275 in our catalog, an adult male first documented off Kaua'i during our first trip to the island in 2003. For more information on bottlenose dolphins in Hawaiian waters check out our web page for this species.
August 2nd update
Although our work is focused on dolphins and whales, we also record sightings of other species, including sea turtles, sea birds, and Hawaiian monk seals! Today we saw a monk seal offshore of Polihale beach.
We also encountered a large group (~100 individuals) of spinner dolphins along the northwest part of the island. Although there is no active spinner dolphin photo-ID catalog off this island, whenever we encounter this species we work to obtain good identification photos, anticipating some future research interest in this population. Spinner dolphins are sexually dimorphic, with males having taller and straighter dorsal fins - the animal in the foreground of this photo is an adult male.
August 1st update
Strong winds prevented us from getting out on the water on July 31st, but today, despite a forecast of east winds to 25 knots, we had a very good day on the water. The most exciting and unusual sighting was of a group of Fraser's dolphins! This was only our 7th encounter with Fraser's dolphins in our 21 year+ study in Hawaiian waters, and our first encounter of this species off Kaua‘i (all our previous sightings were off Hawai‘i Island).
Fraser's dolphins are highly sexually dimorphic, both in dorsal fin shape and in pigmentation - the first photo is of an adult male, showing both the very triangular fin and the bold black stripe along the side of the body. Fraser's dolphins in Hawaiian waters are primarily found in deep offshore waters -- unlike many other species there is no insular population of this species in Hawaiian waters.
The Fraser's dolphins were actually encountered in the middle of a much larger group of melon-headed whales! We had been working with the melon-headed whale for a while when the Fraser's popped up in the middle, but it is possible they were associated the entire time -- it can be hard to spot a small group of animals within a much larger group (estimated over 200 individuals) that are widely spread. We were successful at deploying a satellite tag on an adult male melon-headed whale - the tag deployed is a Wildlife Computers SPLASH10-F tag, and should record both dive data and Fastloc-GPS locations.
The map above shows our prior survey effort (yellow lines) during late July and August off the islands. The red line is the outer boundary of the Navy's Pacific Missile Range Facility.
This research is being undertaken under NMFS Scientific Research Permit No. 20605. Contact Robin Baird (rwbaird (at) cascadiaresearch (dot) org) if you'd like more information on this project.