A Sea of Opportunities

This post is one of a series on projects supported by the New England Aquarium’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists, and grassroots organizations around the world as they work to address the most challenging problems facing the ocean. 

By Natalia Botero-Acosta, PhD

Humpback whales are one of the biggest conservation success stories of the 20th century. Almost all regional groups were hunted to the brink of extinction, until only a couple of hundred individuals remained. Despite the recovery shown by many of the populations following the ban on commercial whaling in 1986, their recovery has coincided with widespread conservation threats including climate change, entanglements, pollution, and vessel collisions. Such threats are present not only in feeding and breeding grounds but also in the migratory corridors where whales cross between national borders and exclusive economic zones, blissfully unaware of human-made limits, and experiencing various levels of protection and disturbance.

Shortly after graduating from Universidad de Antioquia as biologists, my colleagues and I first visited the Gulf of Tribugá as researchers at the Macuáticos Colombia Foundation in December of 2009. As recommended by a colleague that had visited Coquí before to work with amphibians and reptiles, we reached out to a local family, the Moreno-Martínez, with the hope of establishing contact with the local community and getting more information regarding local expenses. What we found, in terms of the ecosystem itself and the local communities that inhabit it, changed our lives forever. In 2010, we made several visits to the area to document what species were there, when they were there, and where in the Gulf we could find them. Three years later, this aquatic mammal inventory culminated in the creation of a monitoring program that focused on humpback whales but also recorded small cetaceans opportunistically during sightings and in cooperation with fishers and tourism operators through citizen science reports.

In 2013, the humpback whale monitoring included photo-identification to individually identify animals based on the coloration patterns and trailing edges of their caudal fins, bioacoustics to record song, and investigating presumed structural changes over time, geo-referencing the spatial location of all sightings to assess habitat use, and recording behavioral frequencies to determine if different group compositions behave differently and to detect presumed impacts of whale watching vessels. In time, genetic sampling, hormone extraction/quantification, soundscape acoustics, and satellite/multisensory tagging have been added to our scientific repertoire thanks to collaborations with fellow nonprofits, research institutes, and universities in Colombia and all over the world.

In 2023, the main goal of the monitoring conducted by Macuáticos Colombia Foundation during the humpback whale breeding season was to expand on our simultaneous passive acoustic program and remote biopsy efforts. From July to October, and after consultation with the local community councils and the environmental agencies, we conducted a total of 73 boat trips, spending over 322 hours in the water and traveling more than 3,493 kilometers. These efforts allowed us to encounter a total of 152 groups of whales. During the season, we were able to collect 198 tissue samples through remote biopsy and opportunistically during active behavior at the surface, almost tripling the sample size of previous years. Passive acoustic devices recorded several thousand audio files, 4,836 to be exact, in locations carefully chosen in the north and south of the Gulf of Tribugá.

While previous data has been informative on the acoustic pristineness of the area, correlating sound source levels with indicators of humpback whale reproduction, physiological stress and nutritional state is quite innovative and highly significant for developing conservation and management actions, both locally and regionally. Overall, the 2023 field season has been the most successful in the history of our efforts in the Gulf of Tribugá, northern Colombian Pacific. It is challenging not to be excited about the prospect of future work.

The 2024 season brings a continuation of the efforts funded by the New England Aquarium’s Marine Conservation Action Fund (MCAF) while also considering the need to balance effort and capacities with work done in the Antarctic Peninsula with this same population during the feeding season. During the Austral winter, sunlight is almost permanent, the sea bursts with productivity, and Antarctic krill fills the bellies of thousands of humpback whales, making their prolonged fasting and annual migration to the Colombian Pacific possible. Among other research groups, collaborative efforts led by the Biotelemetry and Behavioral Ecology Lab at the University of California Santa Cruz onboard expedition cruises allow for paired drone-based photogrammetry measurements of whale length and body condition and genetic/hormone monitoring. While this long-term monitoring—expanding well over a decade now—is extremely valuable to inform conservation and management actions, there is a piece of the puzzle missing: looking at the whole story by considering what happens in a breeding area like the Gulf of Tribugá. At the moment, we are on the brink of coming full circle with this plan, one that seemed far away when we started this work.