Marine bacterial communities are resistant to elevated carbon dioxide levels

Area of Science:

• Marine biology
• Microbial ecology
• Oceanography

Background:

• Rising atmospheric carbon dioxide (CO2) is absorbed by oceans, leading to a decrease in pH, a process known as ocean acidification.
• Marine bacteria are vital to oceanic biogeochemical cycles, making their response to changing ocean conditions a critical research area.

Purpose of the Study:

• To investigate the direct effects of elevated CO2 and lower pH on the resistance and resilience of marine bacterial communities.
• To assess the impact of predicted ocean acidification on marine bacterial abundance, structure, and composition.

Main Methods:

• A replicated temporal seawater mesocosm experiment was conducted to simulate future ocean conditions.
• Marine bacterial communities were exposed to elevated CO2 levels and contrasted with ambient conditions.
• Community resistance and resilience were measured using taxa–time and distance–decay relationships.

Main Results:

• Marine bacterial communities demonstrated high resistance to the imposed elevated CO2 and lower pH conditions.
• No significant differences were observed in bacterial community abundance, structure, or composition between treatments.
• Taxa–time and distance–decay relationships indicated stable bacterial community turnover.

Conclusions:

• Marine bacterial communities are not directly affected by predicted ocean acidification levels.
• The bacterial component of microbial plankton exhibits sufficient flexibility and evolutionary capacity to adapt to future ocean changes.
• These findings suggest a robust role for marine bacteria in biogeochemical processes despite ongoing ocean acidification.