Bacterioplankton assembly and interspecies interaction indicating increasing coastal eutrophication

Area of Science:

• Marine microbiology
• Coastal ecology
• Biogeochemistry

Background:

• Anthropogenic activities negatively impact coastal ecosystems, leading to increased eutrophication.
• Understanding microbial community dynamics is crucial for assessing ecosystem health under environmental change.
• Bacterioplankton play significant roles in coastal biogeochemical processes.

Purpose of the Study:

• To investigate the response of coastal bacterioplankton communities to increasing eutrophication levels.
• To determine the relationship between eutrophication and bacterial community composition and spatial distribution.
• To assess the potential of bacterioplankton as bio-indicators of eutrophication.

Main Methods:

• Examined bacterioplankton community compositions (BCCs) along a gradient of anthropogenic eutrophication.
• Analyzed spatial distribution patterns and the influence of deterministic processes.
• Correlated changes in bacterial family abundances with eutrophication levels.

Main Results:

• Bacterioplankton community composition and deterministic processes were strongly associated with eutrophication levels.
• Eutrophication attenuated the distance decay rate, leading to random spatial distribution at higher levels.
• Interspecies interactions were enhanced under moderate eutrophication but declined under heavy eutrophication.
• Changes in 27 bacterial families correlated with eutrophication, reflecting known ecological functions.

Conclusions:

• The magnitude of changes in bacterioplankton communities and their assembly processes are dependent on eutrophication levels.
• Bacterioplankton community buffer capacity is limited, with heavy eutrophication disrupting interspecies interactions.
• Bacterial assemblages are sensitive indicators of environmental change and can serve as bio-indicators for increasing eutrophication.