Focus: Stranding Networks
​
....by Kate High
My first introduction to the Marine Mammal Stranding network was during my undergraduate career, when I was interning for a vertebrate ecology lab. I quickly came to realize not only the vast amount of information a scientist could learn from dead marine mammals, but more so how important this work was, even if I felt it could still continue to reach a larger population of the community. The Marine Mammal Center (TMMC) and California Academy of Sciences (CAS) partner together to cover almost 400 miles in the northern Central California region. The success of the two organizations would not be possible if it were not for the help of the amazing volunteers and all the private citizens who have taken the time to call in a report.
Responding to stranded marine mammals has contributed to the existing knowledge of changes in mortality patterns, species presence and diversity, age class within populations, migratory ranges of species, and the health status of individuals within a species globally (Berrow and Rogan, 1997; Bogomolni et al., 2010; Byrd et al., 2013; Costa et al., 2017; Foord, 2019; Wilkinson and Worthy, 1999). However, I was noticing stranding locations that could possibly be patterns, and I kept searching for records and papers, but I couldn’t find a study that had the exact information I was looking for. I noticed that certain beaches always seemed to have much higher numbers of strandings then other beaches our group would respond to. Many studies have been done to look at diseases or cause of death that could have potentially cause these higher stranding rates, and in recent years El Niño, though no one was looking at physical factors that could have potentially caused these animals to wash up where they had.
I pitched the idea of analyzing CAS’s stranding network data, which will hopefully allow us to have a better understanding of stranding locations and map them using a geographic information system (GIS). I had been sitting on the idea for about a year before I pitched it to anyone, and surprisingly all my supervisors loved it. When I had a meeting with Ellen Hines and gave her my project idea, she was so excited and had wanted a student to do a project with stranding network data for years! That’s when I knew this project was truly meant to be.
California Academy of Sciences’ official stranding network began in the 1990’s, however, CAS has been collecting records of marine mammals independently since 1908. For this research, I will investigate the stranding patterns along the northern Central California coastline from 1908-2019 for all dead marine mammals. A study of this magnitude has never been conducted utilizing California Academy of Sciences’ long term data and historical data. The northern Central California coast is a unique area because it shares boundaries with multiple National Marine Sanctuaries including: the Cordell Bank National Marine Sanctuary (CBNMS), the Greater Farallones National Marine Sanctuary (GFNMS), and the Monterey Bay National Marine Sanctuary (MBNMS) (Gulf of Farallones National Marine Sanctuary Final Management Plan, 2014). The area is characterized by periods of strong upwelling making the GFNMS highly productive. Little is understood about whether or not currents, bathymetry or surface winds have a strong impact on how deceased marine mammals movements through water and effect where they strand. Information gathered from this study may lead to a more productive distribution of resources throughout the stranding network, and could provide useful information on management actions during unusual mortality events (UME) in the area.
This is a project I have been incredibly passionate about from the very beginning. I would like to thank the countless volunteers and staff who have collected and made this huge dataset possible, without your dedication and efforts, this project would not exist.
Berrow, S., & Rogan, E. (1997). Review of cetaceans stranded on the Irish coast, 1901-95. Mammal Review, 27(1), 51-76.
​
Bogomolni, A., Pugliares, K., Sharp, S., Patchett, K., Harry, C., LaRocque, J., Touhey, K., & Moore, M. (2010). Mortality trends of stranded marine mammals on Cape Cod and southeastern Massachusetts, USA, 2000 to 2006. Diseases of Aquatic Organisms, 88, 143–155. https://doi.org/10.3354/dao02146
​
Byrd, B. L., Hohn, A. A., Lovewell, G. N., Altman, K. M., Barco, S. G., Friedlaender, A., Harms, C. A., McLellan, W. A., Moore, K. T., Rosel, P. E., & Thayer, V. G. (2014). Strandings as indicators of marine mammal biodiversity and human interactions off the coast of North Carolina. Fishery Bulletin, 112(1), 1–23. https://doi.org/10.7755/FB.112.1.1
​
Costa, A. F., Siciliano, S., Emin-Lima, R., Martins, B. M. L., Sousa, M. E. M., Giarrizzo, T., & Silva Júnior, J. de S. e. (2017). Stranding survey as a framework to investigate rare cetacean records of the north and north-eastern Brazilian coasts. ZooKeys, 688, 111–134. https://doi.org/10.3897/zookeys.688.12636
​
Foord, C. S., Rowe, K. M. C., & Robb, K. (2019). Cetacean biodiversity, spatial and temporal trends based on stranding records (1920-2016), Victoria, Australia. PLOS ONE, 14(10), e0223712. https://doi.org/10.1371/journal.pone.0223712
​
Gulf of Farallones National Marine Sanctuary Final Management Plan 2014
Wilkinson, Dean and Graham A.J. Worthy. “Marine Mammal Stranding Network.” (1999): 396-411.
​