David Sims (biologist)

Background

He gained a Ph.D in animal behaviour in 1994 under the supervision of Dr Quentin Bone FRS of the Marine Biological Association whilst in receipt of a personal studentship from the Natural Environment Research Council. He was a lecturer in the Zoology Department at the University of Aberdeen before taking up a NERC-funded Fellowship at the Marine Biological Association Laboratory in Plymouth in 2000.

Awards

Awards for research include a ‘Scientist of the New Century’ Lecture Award from the Royal Institution of Great Britain (2001), Life Membership of the Royal Institution of Great Britain (2001), the FSBI Medal from the Fisheries Society of the British Isles (2007), and the Stanley Gray Silver Medal [1] from the Institute of Marine Engineering, Science and Technology, IMarEST (2008).

In 2016 he was elected a Member of Academia Europaea, the Academy of Europe.

Research

David Sims is known for research on the behaviour, ecology and conservation of sharks studied using remote tracking technology (telemetry) and for making advances in the field of animal movement ecology.

His research has identified common scaling laws that describe movement paths and behaviour patterns of highly diverse aquatic and aerial predators such as jellyfish, cephalopods, reptiles, sharks, bony fish, penguins, and albatrosses.

It is argued that Sims’ work has provided the strongest empirical evidence for the existence of movement patterns that are well approximated by biological Lévy flights and Lévy walks, a special class of random walk that theoretically optimise random searches for sparsely distributed resources. It is said that Sims’ work has shifted the debate on biological Lévy walks from whether they exist, to how and why they arise. He has also conducted the first empirical tests of the Lévy flight foraging hypothesis, which states that since Lévy walks can optimise random searches, search patterns must have naturally evolved in organisms to exploit Lévy walks. The hypothesis has been supported in several of Sims' studies, presenting the possibility that optimal searching movements approximated by Lévy patterns have evolved in organisms.

In the book Bursts: The Hidden Pattern Behind Everything We Do, the physicist and best-selling author Albert-László Barabási writes: “Yet if a Lévy flight offers the best search strategy, why didn’t natural selection force animals to exploit it? In February 2008 David Sims showed that it did, in fact.”

Sims' 2008 Nature paper announcing the discovery of Scaling laws of marine predator search behaviour is a Web of Science Highly Cited Paper. Since then robust evidence for biological Lévy walks has accumulated across a wide range of taxa including microbes and humans and in fossil trails of extinct invertebrates, suggesting an ancient origin of the search strategy. The research challenges the decades-old model of Brownian motion (normal diffusion) for animal movement and dispersal. His work contributes to the emerging understanding in animal movement ecology that normal diffusion is insufficient for describing natural movements such as searching behaviour but that anomalous diffusion is required.

In related work he has provided the first measurements of how predatory fish actually respond to variations in prey density gradients in the ocean, empirical data that has informed search algorithms, and the biological significance of ocean fronts to predators, which have potential as candidates for high seas marine protected areas (MPAs).

In 2016 Sims led an international team tracking the ocean-wide movements of sharks and found pelagic sharks like the shortfin mako actively select and aggregate in space-use “hotspots” characterized by fronts and high plankton biomass. However, data showed longline fishing vessels also targeted the habitats and efficiently tracked shark movements seasonally, leading to an 80% spatial overlap. The work suggests current hotspots are at risk from overfishing and argued for introduction of international catch limits. The results were reported widely in the media including in The Times newspaper and the journal Science.

Sims and colleagues also demonstrated how timings of migrations of commercially important fish and squid vary in response to rapid climate-driven changes in sea temperature that have occurred over the past few decades They found phenological changes in migration shifted by up to two months in years with the greatest temperature changes, variations which have consequences for fisheries and their management.

Sims is also known for his long-term study of the behavioural ecology of the plankton-feeding basking shark, the world’s second largest fish. He showed from natural experiments and theoretical calculations, and tested the predictions directly using satellite tracking in 2003, that basking sharks do not hibernate in winter, overturning an understanding which had stood for nearly 50 years. Sims’ satellite tracking of basking sharks were some of the first long-term trackings of any shark species and contributed directly to successful conservation proposals listing basking sharks on Appendix II of the Convention for International Trade in Endangered Species (CITES) (Feb 2003) and the Convention for the Conservation of Migratory Species of Wild Animals (CMS) (Nov 2005).

Sims’ research group has also investigated geographical sexual segregation of sharks, demonstrating that socially aggressive interactions between males and females can account for many of the observed patterns. Females appear to select suboptimal habitats to avoid males and unsolicited courtships. They also identified that sexual segregation can interact with spatially focussed longlining fisheries to increase the risk of population decline in these vulnerable species.

They have also been involved with several technological advances, such as the first use of GPS tags to track large fish in the ocean.

Science and media

His research on basking shark behaviour was the subject of an award-winning documentary, "Email from a shark", by the Cornish film company Shark Bay Films, that aired on Sky in December 2004. The film won the British Council Youth and Science Award at the Helsingborg Film Festival, Sweden, in 2004. Sims' research has received media attention, including articles in New Scientist, Science, Science News, Physics World, and in documentaries programmes for BBC Television, such as BBC1 "Animal Camera" with Steve Leonard (10 March 2004), BBC Radio 4 Natural History Programme, and Channel 5 "Nick Baker's Weird Creatures" episode 5 – the basking shark (16 February 2007).