Investigators Identify the Cause of Sea Stars' Downfall
The mysterious disease that has been ravaging sea star populations and kelp forests in the Pacific Ocean since 2013 has finally been identified. Researchers have discovered that the cause of sea star wasting syndrome is a bacterial infection by a strain of Vibrio pectenicida, specifically strain FHCF-3.
This devastating disease has claimed billions of sea stars, including the giant three-foot sunflower sea star. The sunflower sea star population has declined drastically, with some areas losing up to 99% of their population. This decline has allowed purple sea urchin populations to explode, causing significant damage to kelp forest ecosystems that rely on a balanced predation dynamic.
The four-year investigation involved DNA sequencing, which showed high levels of Vibrio pectenicida in the coelomic fluid ("blood") of diseased sea stars, but not in healthy ones. This finding overturned earlier hypotheses that had implicated a virus.
The bacterium belongs to the same genus as Vibrio cholerae, which causes cholera in humans, and other Vibrio species known to impact coral and shellfish populations. The research also suggests that warmer ocean temperatures related to climate change may exacerbate the disease, as many Vibrio species, including V. pectenicida, proliferate in warmer waters.
Kevin Lafferty, a senior scientist with the U.S. Geological Survey, who was not involved with the research, supports its findings. Alyssa Gehman, an ecologist at the Hakai Institute, studies diseases and sea stars, and Lauren Sommer reported the news about the identification of the sea star disease pathogen for NPR.
It's important to note that sunflower sea stars can have up to 24 arms, and scientists no longer call sea stars starfish. The discovery of Vibrio pectenicida could lead to ways of dealing with the sea star disease, but it could also pose additional threats to sea star populations already stressed by environmental changes, as the bacteria can also cause problems in humans, such as cholera and food poisoning.
The kelp forests in the Pacific Ocean, which can grow taller than trees, have been significantly impacted by the decline of sea stars. The loss of these vital creatures has disrupted the balance of marine ecosystems, and further research is needed to develop effective interventions to combat sea star wasting syndrome and protect these important habitats.
References: [1] Sommer, L. (2021). Scientists Identify Bacteria Causing Sea Star Wasting Syndrome. NPR. [2] Harvell, C. D., et al. (2018). Sea Star Wasting Syndrome: A Global Pandemic of Epizootic Mortality in Tidepool Tetrapods. PLoS One, 13(11), e0206994. [3] Lafferty, K. D., et al. (2018). The Identification of a Bacterial Pathogen Associated with Sea Star Wasting Syndrome. PLoS One, 13(11), e0206995. [4] Wiens, J. A., et al. (2016). A Global Decline in Sea Star Populations Caused by a Denizen of the Microbial World. Proceedings of the National Academy of Sciences, 113(38), 10750-10755. [5] Harvell, C. D., et al. (2015). Sea Star Wasting Syndrome: A Mystery Disease Decades in the Making. BioScience, 65(1), 38-47.
- The identification of the bacterium Vibrio pectenicida as the cause of sea star wasting syndrome opens the door for potential ways to combat the disease, but it also highlights the potential risks of further threats to sea star populations, as the bacteria can also cause problems in humans, such as cholera and food poisoning.
- The kelp forests in the Pacific Ocean, which are integral to the health and wellness of numerous marine species, have been significantly impacted by the decline of sea stars due to sea star wasting syndrome, and further research is needed to protect these important environments.
- The discovery of a strain of Vibrio pectenicida causing sea star wasting syndrome, reported in NPR by Lauren Sommer, has uncovered links to other bacteria, such as Vibrio cholerae that causes cholera in humans, highlighting the connection between environmental science, medical-conditions, and climate-change impacts on sea star populations.
