If the endangered basking shark is a water-column explorer, what is the real status of its population?

UC Davis
Davis, California
DOI: 10.18258/7847
Raised of $4,000 Goal
Funded on 11/21/16
Successfully Funded
  • $4,059
  • 101%
  • Funded
    on 11/21/16

About This Project

Marine predators are an important part of our ocean's ecosystems. However, overfishing has reduced predator populations worldwide. My study focuses on one such species: the endangered basking shark. Recent studies have shown a drastic decline in the areas inhabited by basking sharks. Most studies rely on surface sightings to estimate population size, so I want to see if any sharks are hiding beneath the surface by tracking how they move vertically through the water column.

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What is the context of this research?

The world's second-largest shark, the basking shark listed as endangered on the IUCN Red List. They can be seen in areas of the northern Atlantic, slowly filter-feeding on plankton at the surface along the coasts of Ireland and Scotland. These massive creatures (up to 8 meters, or 26 feet, long) have been hunted to near extinction by harpoon fisheries over the past century. What’s more, they now face another challenge: increasing shipping traffic, which can lead to boat strikes.

My project will focus on a basking shark hotspot off the coast of Northern Ireland. A recent population census in this area estimated a drastic decline over the course of just two years, from 985 individuals in 2010 to only 201 individuals in 2011 (Gore et al, 2016).

What is the significance of this project?

While it may seem obvious that this hotspot is in need of government protection, we need to examine the accuracy of these population estimates to determine if we can protect this area as an MPA (Marine Protected Area). Many population estimates depend only on surface sightings. However, it is possible that basking sharks only spend some of their time feeding at the surface. The zooplankton on which they feed can actually be distributed throughout the water column, and the sharks may dive more frequently than we expect to follow these “patches” of prey into deeper water. My goal is to determine how basking sharks move vertically within the water column of the ocean, to see how much time they spend feeding at the surface.

What are the goals of the project?

My goals are simple: 1) I want to examine how basking sharks move vertically through the ocean’s water column. How much time do they spend at the surface, and can we accurately estimate their population based on surface sightings alone? 2) I want to see what factors cause these movements – are the sharks feeding? Are they resting? Do they prefer a certain temperature or pressure? When might they be observed at the surface?

With this information, I will be able to work with policy-makers in the United Kingdom to establish boat practices that limit the possibility of a boat-strike with a surface-feeding shark. It is clear that this is a species in need of protection – we simply need accurate data to determine the best way to do so.


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Fortunately, my laboratory already has access to much of the equipment required for this project, and our collaborators are providing extensive knowledge about tracking basking sharks within this habitat. However, my study requires depth-sensing tags to attach to the individual sharks in order to determine their movement within the water column. Ideally, we would like to tag multiple individuals. My team also requires the use of a boat to follow the sharks as they move. These are the most critical components of my methodology. I am in the process of applying for external funding for the long-term project examining annual trends in habitat use; however, I require funding for a smaller pilot study this coming summer.

Endorsed by

I will be providing guidance to Alexandra during her research tenure here. She and I have developed this project, and it will be a collaborative effort with Jonathan Houghton and his graduate students at Queens University, Belfast. We are working with them to grow the basking shark research project at Malin Head, the northernmost point in Ireland -- to establish an interpretive center and research laboratory. This study has a strong scientific basis, determining whether the abundance of basking sharks is related to zooplankton densities.

Meet the Team

Alexandra McInturf
Alexandra McInturf


University of California - Davis
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Alexandra McInturf

One of my favorite quotes comes from renowned biologist E.O. Wilson: “We are not afraid of predators, we’re transfixed by them, because fascination creates preparedness, and preparedness, survival.” Like many children, I felt that fascination at a young age. Unlike most others, I haven’t been able to relinquish it since.

Originally from Cincinnati, Ohio, I graduated Cum Laude from Williams College (MA) with a biology and English degree. I am now a PhD candidate in Animal Behavior at the University of California - Davis, where I am a member of the Biotelemetry Laboratory. In this past year I've had first-hand experience with many large carnivorous shark species, including white sharks, tiger sharks, hammerhead sharks, and sandtiger sharks, through internships with Oceans Research in South Africa and the Bimini Shark Lab in the Bahamas.

My current focus is the planktivorous basking shark. My research will use this species as a model for determining trophic interactions and ecosystem health. The results will have a significant conservation impact that will inform the establishment of marine protected areas (MPAs), and I want to use my interdisciplinary background to bridge the gap between scientists and policy-makers in the broader community.

Additional Information

I will be working in collaboration with Dr. Jonathan Houghton and his students at Queens University - Belfast, who inspired this in-depth study of the basking shark.

For more information on the Irish Basking Shark Project, led by collaborator Emmett Johnston, visit http://www.baskingshark.ie/

Project Backers

  • 55Backers
  • 101%Funded
  • $4,059Total Donations
  • $73.80Average Donation
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