Sponge-microbe partnerships are stable under eutrophication pressure from mariculture

Area of Science:

• Marine biology
• Microbial ecology
• Environmental science

Background:

• Sponges host diverse symbiotic microbes, vital for their health.
• Mariculture activities can lead to coastal eutrophication, potentially disrupting sponge-microbial partnerships.
• The impact of eutrophication on sponge holobionts remains an area of active research.

Purpose of the Study:

• To investigate the effects of mariculture-induced eutrophication on the microbial communities associated with the marine sponge Gelliodes obtusa.
• To assess the resilience of the sponge holobiont under environmental stress conditions.

Main Methods:

• Marine sponge Gelliodes obtusa were transplanted to different coastal sites, including a eutrophic fish farm.
• High-throughput sequencing of 16S rRNA was used to analyze microbial community composition.
• Quantitative PCR was employed to measure the abundance of the amoA gene, an indicator of ammonium-oxidizing bacteria.

Main Results:

• The microbial communities of Gelliodes obtusa showed no significant shifts after six weeks in the eutrophic fish farm environment compared to control sites.
• Sponges at the fish farm exhibited a higher abundance of the amoA gene, indicating a response to increased ammonium levels.
• The sponge holobiont demonstrated stability despite the eutrophic conditions, suggesting resilience.

Conclusions:

• The marine sponge Gelliodes obtusa and its associated microbiome are resilient to eutrophication caused by mariculture.
• The sponge holobiont can maintain a stable partnership even under elevated ammonium concentrations.
• These findings highlight the adaptability of sponge holobionts in anthropogenically impacted coastal environments.