Dead dark stinging sponge (Sarcotragus foetidus). Credit: Fikret Öndes
Key points:
- Researchers identified the role of 3 Vibrio bacteria species in outbreaks of mortality in the dark stinging sponge.
- Vibrio are heat-loving bacteria and did not seem to infect sponges later than October, but global warming may impact the disease dynamics and prevalence.
- Identifying and combatting disease outbreaks like those seen in dark stinging sponges is critical for protecting marine ecosystems.
Vibrio bacteria live in brackish or salt water, either swimming free or living as pathogens or symbionts in fish, crustaceans, mollusks, and corals. Because these bacteria thrive at relatively high temperatures, outbreaks in marine animals will likely become more frequent with global warming.
A new study, published in Frontiers in Microbiology, identifies the role of Vibrio bacteria in outbreaks of mortality in the dark stinging sponge.
Researchers studied 117 dark stinging sponges along the Turkish Aegean coast. Each sponge was photographed, measured, and used for DNA analysis. The majority (64%) of sponges appeared healthy, but 27% were visibly impacted by partial necrosis and 9% appeared dying or dead.
By identifying ribosomal RNAs exclusively present in diseased, dying, and dead sponges, the team found three distinct Vibrio species—V. fortis, V. owensii, and V. gigantis. None of these species occurred in all the diseased sponges studied, suggesting that vibrosis may be a secondary infection that worsens the course of the disease.
As the researchers failed to observe the disease later than October, they concluded that the heat-loving Vibrio bacteria play a role as a primary or secondary agent.
“Climate change is currently affecting marine ecosystems, including water temperature,” said first author Egzi Dinçtürk of Izmir Katip Celebi University. “These changes appear to impact disease dynamics in sponges and their pathogens.
Looking ahead, the team wants to determine if the same pathogens are responsible for other marine mass mortality events. Identifying and combatting disease outbreaks like those seen in dark stinging sponges is critical for protecting marine ecosystems.