I am interested in the timing of life events of Arctic zooplankton. One particular behaviour is that of Diel Vertical Migration – an adaptation of zooplankton which allows them to feed on surface living phytoplankton during the night, and swimming to depth during the day to avoid being seen and eaten by visual predators. This behaviour is driven by sunlight, and the timing of swimming up and swimming down changes with season and latitude dependent on day length. High latitude environments (such as the Arctic) present a unique light environment as the sun doesn't set and doesn't rise for periods of time (days to month in duration) during what is known as the polar night and the midnight sun.
In addition to the daily occurring behaviour of DVM, some zooplankton (such as a group of crustaceans called copepods) enter a state of hibernation in the winter known as diapause. The timing of diapause is affected by water temperature and the timing, amount, and quality of prey (phytoplankton).
I am use a life-history model developed specifically for copepods (Coltrane) to investigate how variability in these parameters affects zooplankton, and how this might change in a future Arctic when climate change is considered.
Current research projects
Arctic ABC. Funded by the Research Council of Norway 2016-19: I am working on the use of acoustic data to observe zooplankton responses, and also tying in observational science with modelling work.
Arctic PRIZE. Funded by NERC 2017-20: For WP4 (Led by Kim Last) I provide integration of the quantitative aspects of zooplankton behaviour developed from acoustic data in WP4 into the trait-based modelling programme.
Past highlight projects
Circadian rhythms of Arctic zooplankton from polar twilight to polar night – patterns, processes, and ecosystem implications (CircA). Funded by the Research Council of Norway 2012-15. Read the final CircA report.
Hobbs L, Banas NS, Cohen JH, Cottier FR, Berge J, Varpe Ø (2021) A marine zooplankton community vertically structured by light across diel to interannual timescales. Biol. Lett. 20200810. https://doi.org/10.1098/rsbl.2020.0810
Hobbs L, Banas NS, Cottier FR, Berge J and Daase M (2020) Eat or Sleep: Availability of Winter Prey Explains Mid-Winter and Spring Activity in an Arctic Calanus Population. Front. Mar. Sci. 7:541564. https://doi.org/10.3389/fmars.2020.541564
Henley SF, Porter M, Hobbs L, Braun J, Guillaume-Castel R, Venables EJ, Dumont J, Cottier F (2020) Nitrate supply and uptake in the Atlantic Arctic sea ice zone:seasonal cycle, mechanisms and drivers. Philosophical Transactions of the Royal Society A 378: 20190361. https://dx.doi.org/10.1098/rsta.2019.0361
Hobbs, L.J., Cottier, F.R., Last, K.S., Berge, J. (2018) Pan-Arctic diel vertical migration during the polar night. Marine Ecology Progress Series. https://doi.org/10.3354/meps12753
Darnis, G., Hobbs, L.J., Geoffroy, M., Grenvald, J.C., Renaud, P.E., Berge, J., Cottier, F., Kristiansen, S., Daase, E., Søreide, J.E., Wold, A., Morata, N, Gabrielsen, T. 2017. From polar night to midnight sun: Diel vertical migration, metabolism and biogeochemical role of zooplankton in a high Arctic fjord (Kongsfjorden, Svalbard). Limnology and Oceanography. 62(4), 1586-1605.
Grenvald, J.C., Callesen, T.A., Daase, M., Hobbs, L.J., Darnis, G., Renaud, P.E., Cottier, F., Nielsen, T.G., Berge, J. 2016. Plankton community composition and vertical migration during polar night in Kongsfjorden. Polar Biology. 39(10), 1879-1895.
Last, K.S., Hobbs, L.J., Berge, J., Brierley, A.S., Cottier, F.R. 2016. Moonlight Drives Ocean-Scale Mass Vertical Migration of Zooplankton during the Arctic Winter. Current Biology. 26(2): 244-251.
Teaching
University of Strathclyde: Tutorial leader for MM116 mathematics for chemists, 2016
SAMS guest lecturer: Marine Science BSc 'Behaviour and Biological Clocks' year 4 module, 2014
UNIS guest lecturer: Course AB320/820 Arctic zooplankton (Postgraduate level), 2014
Prizes and awards
UHI Postgraduate Student of the Year 2016
Roland Levinsky Memorial Fund award winner for Baffin Island project, 2010
Professional memberships
Royal Geographical Society: Fellow since 2012
UK Polar Network: Educational Officer 2010-13; President 2013-14; Vice-President 2014-16; APECS representative since 2016
Association of Polar Early Career Scientists (APECS): Member since 2010; Council member 2016-17
Expedition experience
Two-week Polar Night cruise along western and northern Svalbard, from Tromsø to Longyearbyen, Ny-Ålesund, and Rijpfjorden. Experience includes mooring recovery and deployment, net sampling (Tucker Trawl, WP3, Multi-net), acoustic instrument deployment (ADCPs, AZFPs). January 2013.
Three-week cruise along western Svalbard, from Longyearbyen to 82° Experience includes mooring recovery and deployment, net sampling (Tucker Trawl, WP3, Multi-net), acoustic instrument deployment (ADCPs, AZFPs), zooplankton identification under microscope, interpretation of acoustic data. September 2012.
Four-week expedition on foot on Baffin Island, hiking between Qikitarjuaq and Pangnirtung in Nunavut. Experience includes glacier walking, glacier camping, polar bear avoidance, working and living with indigenous communities, glacier safety, working under extreme conditions with a team. August 2010.
Outreach / public engagement
Delivered talks and/or workshops to ~30 schools and colleges (varied from age 5 to 18). 2011 – 2016.
Article for Ocean Challenge on PhD work p43-46
Creation of school resources based on zooplankton migrations for age group 14-16 years, in collaboration with independent school’s consultant on behalf of Research Councils UK.
SAMS News video Arctic Icebreaker
Voiceover narration at the Ocean Explorer Centre, Oban
Invited speaker to a Women in Science event, targeting teenage females and their mothers. 2011
I have sourced funding for, organised, and/or run the following workshop and events:
A set of three weekend long events for the public at science centres across the UK (Dundee, Bristol, Birmingham): Sea-ice, Science, and Shackleton. Funded by Foreign and Commonwealth Office. 2014.
Two-day early career workshop (NOC Southampton, 2013): Science and Society: Do they have to be Poles apart? April 2014.
Two-day public event to highlight centenary of Captain Scott: Polar Fun Day, Plymouth. 2012.
School sessions at the British Science Festivals of 2011 and 2012. Helped at event in 2010. Title of events: Life in the Freezer
Training courses
Marine bioacoustics. Friday Harbor Laboratories, University of Washington. 2013 (four week programme)
Zooplankton in Arctic Waters (AB320). University Centre in Svalbard. 2012 (seven week programme)
Employment history
Since 2017: PDRA. SAMS and University of Strathclyde
2016-17: PDRA. University of Strathclyde
2011-13: Host. National Marine Aquarium
2011-12: Education Manager. Education Through Expeditions
Qualifications
2016 PhD Marine Science. University of Aberdeen
2012 MSc Applied Marine Science. University of Plymouth
2010 BSc (Hons) Marine Biology and Oceanography. University of Plymouth