Southern Right Whale Project

The following text is my PhD project's ("Southern right whale project") abstract and publication output. The dissertation thesis was successfully defended in June 2023 at Charles University (Prague, Czech Republic).

Population biology and evolutionary genetics of southern right whale (Eubalaena australis)

Southern right whale (Eubalaena australis) is a species from the Balaenidae family with a range in the southern hemisphere, which evolved in connection with Neogene climate oscillations. Its population biology involves migration between coastal waters of South America, southern Africa, Australia, and New Zealand to its high-latitude foraging and feeding grounds in the Southern Ocean. Intensive historical hunting from the 18th to 19th century has impacted the population dynamics of baleen whales substantially. After the whaling moratorium, the species has been recovering from the heavy exploitation, however, recently it is facing anthropogenic changes, such as climate change. The South African population, considered to be the largest one globally and intensively studied for the last several decades, is showing an increase in the calving interval, a decline in the female condition, and a dramatic shift in migration routes since 2010, possibly as a consequence of significant changes in marine food webs. Methods of molecular ecology were applied to monitor the population genetics and its dynamics not only in the context of the global population but also to compare different periods - 1990s and 2010s. The majority of the samples were collected noninvasively in cooperation with commercial whale-watching companies. Such a citizen science approach was shown as highly effective and allowed the collection of large numbers of different sample types, including blow samples. Cetacean DNA was successfully isolated from such a sample type collected from a non-captive whale for the first time. Sloughed skin samples were further used in the study of the genetic connectivity of South Georgia feeding grounds and showed that South Georgia individuals show affinity to the South American cluster. The genetic analyses of the South African population confirmed the connectivity of the South Atlantic populations, which conforms with the previous studies. Two samples from the Namibian population, which has not been studied before, put the Namibian population in the South Atlantic cluster, suggesting a strong connection with South Africa. However, further analysis indicated there might be remnants of an originally separate stock. A comparison of the two periods revealed increased inbreeding in the South African population and a strong increase in the gene flow from Africa to Australia. Further studies of stable isotopes illustrated that South African right whales underwent a dramatic northward shift and diversification in foraging strategy from the 1990s to the 2010s. Major causal factors behind these changes involve food web alterations, for example, the southward retreat of the krill range, as a result of climate change. Considering further predictions of the significant impacts of global warming, the future of the southern right whales and other marine megafauna is uncertain.

Publications

Petra Neveceralova, Emma L. Carroll, Debbie Steel, Els Vermeulen, Simon Elwen, Jakub Zidek, Jason K. Stafford, Wilfred Chivell, & Pavel Hulva. Population changes in a whale breeding ground revealed by citizen science noninvasive genetics. Global Ecology and Conservation, Volume 37, 2022, e02141, ISSN 2351-9894, https://doi.org/10.1016/j.gecco.2022.e02141

Emma L Carroll, Paulo H Ott, Louise F McMillan, Bárbara Galletti Vernazzani, Petra Neveceralova, Els Vermeulen, Oscar E Gaggiotti, Artur Andriolo, C Scott Baker, Connor Bamford, Peter Best, Elsa Cabrera, Susannah Calderan, Andrea Chirife, Rachel M Fewster, Paulo A C Flores, Timothy Frasier, Thales R O Freitas, Karina Groch, Pavel Hulva, Amy Kennedy, Russell Leaper, Matthew S Leslie, Michael Moore, Larissa Oliveira, Jon Seger, Emilie N Stepien, Luciano O Valenzuela, Alexandre Zerbini, & Jennifer A Jackson. Genetic Diversity and Connectivity of Southern Right Whales (Eubalaena australis) Found in the Brazil and Chile-Peru Wintering Grounds and the South Georgia (Islas Georgias del Sur) Feeding Ground, Journal of Heredity, Volume 111, Issue 3, May 2020, Pages 263-276, https://doi.org/10.1093/jhered/esaa010

van den Berg, G.L., Vermeulen, E., Valenzuela, L.O., Bérubé, M., Ganswindt, A., Gröcke, D.R., Hall, G., Hulva, P., Neveceralova, P., Palsbøll, P.J., & Carroll, E.L. 2021. Decadal shift in foraging strategy of a migratory southern ocean predator. Global Change Biology 27 (5), 1052–1067. https://doi.org/10.1111/gcb.15465

Derville, S., Torres, L. G., Newsome, S. D., Somes, C. J., Valenzuela, L. O., Vander Zanden, H. B., Baker, C. S., Bérubé, M., Busquets-Vass, G., Carlyon, K., Childerhouse, S. J., Constantine, R., Dunshea, G., Flores, P. A. C., Goldsworthy, S. D., Graham, B., Groch, K., Gröcke, D.R., Harcourt, R., Hindell, M. A., Hulva, P., Jackson, J. A., Kennedy, A. S., Lundquist, D., Mackay, A. I., Neveceralova, P., Oliveira, L., Ott, P. H., Palsbøll, P. J., Patenaude, N. J., Rowntree, V., Sironi, M., Vermeulen, E., Watson, M., Zerbini, A. N., & Carroll, E.L. (2023). Long-term stability in the circumpolar foraging range of a Southern Ocean predator between the eras of whaling and rapid climate change. Proceedings of the National Academy of Sciences, 120(10), e2214035120. https://doi.org/10.1073/pnas.2214035120

The team

Supervisor

Prof. Pavel Hulva, PhD
Charles University in Prague
Czech Republic

PhD Student

Petra Neveceralova
Charles University in Prague 
Czech Republic

Consultants

Roman Vodicka, MVD, PhD et PhD
Prague Zoo, Czech Republic

Wilfred Chivell
Dyer Island Conservation Trust
Gansbaai, South Africa

Cooperation

Ivanhoe Sea Safaris
83 Vyfer Str.
Gansbaai, South Africa
www.whalesafarisa.com

Dyer Island Conservation Trust
5 Geelbek St.
Kleinbaai, 7220, South Africa
https://www.dict.org.za/