Written by Matthew Scott
The American Cetacean Society hosted their 15th international cetacean conference in Monterey last month. The conference included a host of well-known names and a ton of interesting current research. I want to share with you some of the topics that relate to the bay area as well as some of the interesting advances in the field of cetacean science.
‘Coastal bottlenose dolphins move north to San Francisco and beyond’
Isidore Szczepaniak presented his talk on the distribution of bottlenose dolphins along the California coast and specifically recent work documenting the distribution and behavior of bottlenose dolphins inside the Bay. Izzy works with Golden Gate Cetacean Research (GGCR) who conducts photo ID work from the Golden Gate Bridge as well as from research boats inside the Bay.
Before a large El Nino event in 1982-83, bottlenose dolphins were only known to reside as far north as southern California. With the warm water that the El Nino brought north, researchers saw a shift in the population distribution of bottlenose dolphins into Monterey Bay and as far north as Pacifica (8km south of SF). In 2001 GGCR had their first sighting of a bottlenose in San Francisco Bay.
The bottlenose dolphins seem to be moving further north because in 2016 GGCR had sightings coming in of bottlenose as far north as Mendocino (200km north of San Francisco). Bottlenose dolphins are now regularly seen inside the Bay.
Their study area for bottlenose dolphins ranges from San Mateo County to Sonoma County. They use a method of photo ID that involves photographing the dorsal fins and identifying individuals with persistent scar patterns along the trailing edge of the dorsal fin. By doing this they have identified 91 dolphins around the Bay Area, 93% of these animals are seen in Monterey Bay and 50% are seen in the Southern California bight region.
When bottlenose dolphins moved north and started inhabiting the bay they moved into an area already occupied by harbor porpoise. One interesting interaction that can occur when these two species are living in proximity is porpicides. That is, the killing of harbor porpoises by bottlenose dolphins. It was first documented in Scotland’s Moray Firth by researchers in 1996 and has recently been seen by Izzy inside the bay this year in June. Working with The Marine Mammal Center, GGCR can look at stranded porpoises for signs of a porpicide event. They have documented 56 since the dolphins started coming into the Bay.
This research is still in its early stages with much more to discover about the charismatic creatures that live their lives inside the bay. Much of the research couldn’t be achieve without collaboration with other photo ID work conducted on bottlenose dolphins along the California coast line.
Futuristic technology involved in cetacean science
At the conference this year researchers highlighted a number of different technologies used to study cetaceans in different ways and help pull back the veil of their underwater lives. Among those presenting, David Johnston of Duke University and David Cade of Stanford’s Hopkins Marine Station both showcased technologies that are changing cetacean science today.
The marine environment is more complex and much harder to conduct research in than land based equivalents. Therefore, equipment like hydrophones and pressure sensors have been used to quantify whale behavior in the past. Recently the use of video on drones and in suction-cup tags has helped move this research forwards another step.
David Cade showcased some work he and his research team have been conducting around the world recording video of whales as they feed on krill.
Tags such as this have a 3D movement detector built in so video can be paired with real time movements (to determine what orientation and how deep whales are in the water). This allows researchers to uncover the complex movement patterns of whales in relation to their food, it allows them to look at how tiny fish react to a whale lunging into a bait ball, it allows researchers to look at which point during a feeding lunge whales open their mouths to take in their prey and it allows them to look at the complex behaviors of whales whilst feeding on bait balls. With information such as this researchers can begin to piece together the behavioral lives of different whale species.
David Johnston out of Duke University has been working with his team to push back the possibilities of drones and other technologies for use in whale research. They are using fixed wing and multi rotor copters to help undertake research efforts.
http://superpod.ml.duke.edu/uas/fixed-wing-platforms/
Fixed wing aircrafts can fly for 45 minutes, map the ground with a resolution of 2.5cm/pixel, can be totally autonomous and can be launched and recovered from boats.
The fixed wing drone can be programmed to follow a virtual quadrat overlaid onto a map. This means it can survey an area without human supervision, you just throw it into the air and it works out wind speeds and height and then tracks the virtual quadrat and takes photographs of the area in question. You wait 20 minutes and then it flies back, assesses the best landing direction and can be caught out of the air. This compared to an aerial survey in the past that would have been done in a manned aerial vehicle like a helicopter or plane is much more efficient, less costly and much safer.
Multi-rotor drones can hover where the fixed wing can’t, follow individual animals, can fly low for sub-cm resolution per pixel and stream back video for real time assessment.
The multi-rotor drones can be used for more versatile functions because it can hover and have a larger range of instruments attached to it. For example, an attached thermal camera can be used to assess cetacean entanglements and injuries because a whale will flood an inflamed area with blood, making it hotter. If you know the flight height and the sensor dimensions you can use the pixels in a picture to measure length and girth of an animal. These drones can be kitted out to collect snot samples which allow hormones during pregnancy to be measured and assessment of a whale’s microbiology.
Real time video and a drone’s ability to follow a target means there is potential for drones to be used as monitoring and deterrent equipment whilst patrolling marine protected areas. With the advent of drones that can stay in the air for longer and longer time periods there is potential to have unmanned aircrafts patrolling these areas and watching for illegal activity for longer time periods.
Another new technology being implemented by David’s team at Duke is 360 video. By developing a method of overlaying a 360 degree image into 2 dimensional information, these 360 video devices can be placed inside a mass feeding aggregation and capture everything that happens, instead of just one view. The distance between whales or sea lions and the direction animals are travelling can be quantified instead of estimated, as well as it providing incredible footage for education and outreach.
Happywhale: a new tool promoting collaboration and real time photo ID feedback
Ted Cheeseman presented a talk on an upcoming new whale ‘social media’ called Happywhale that can provide you with real time information about the whales you are watching: what sex they are, where they have been recently, how many calves they have had etc.
Because the individuality of whales is very important in helping people connect with them, Happywhale has designed software that allows you to see an individual whose history you know and who you may have been interested in seeing for a long time.
This kind of thinking towards whales already exists in some species such as orca whose males have extremely tall dorsal fins. Specific humpbacks that are easy to identify capture the public’s imagination as well. Migaloo is an all-white humpback that is seen off the east coast of Australia. Because he is easy to identify people can recognize him on an individual level and learn his story very easily. Whales that can be easily identified tend to increase peoples enthusiasm of them, Migaloo has his own website!
Happywhale is revolutionary when it comes to easily identifying any individual in a population of humpback whales. And this is Happywhales mission, to provide a real time ID of any humpback whale based on its tail fluke. While they are not quite there yet, a large proportion of humpbacks along the west coast of America have been identified and are in the database and they are working to increase the size of the database in all populations around the world as well as expanding to include many other species of cetacean as well.
Happywhale is a great website with a lot of information about humpbacks seen around the Bay Area, and I encourage you to check them out. You never know, you might be able to see that whale in person the next time you go out on a whale watching trip or spot a tail fluke from the Golden Gate Bridge. You can reach the website at www.happywhale.com.