Investigating seed bank potential of crustose coralline algae using DNA metabarcoding

Area of Science:

• Marine Biology
• Ecology
• Genetics

Background:

• Crustose coralline algae (CCA) are key ecosystem engineers in marine environments.
• CCA may function as seed banks or refugia for various life stages of other species.
• Effective sampling protocols are needed to capture the full diversity within CCA habitats.

Purpose of the Study:

• To evaluate the potential of CCA as marine seed banks.
• To develop and refine DNA metabarcoding protocols for identifying taxa within CCA.
• To compare the efficacy of different preservation methods and sampling regions.

Main Methods:

• Investigated two shallow water CCA species from Raoul Island, New Zealand.
• Compared two preservation methods: ethanol and silica gel.
• Utilized DNA metabarcoding across seven gene regions (16S, 18S, 23S rRNA, cox1, rbcL, tufA, ITS).
• Sampled both inner and outer regions of the CCA crusts.

Main Results:

• Identified immense biodiversity within CCA, with more taxa typically found in inner layers.
• Demonstrated that multiple genetic markers (23S rRNA, rbcL, cox1) are beneficial for comprehensive taxa identification.
• Highlighted limitations of current reference databases for marine metabarcoding.

Conclusions:

• CCA harbor significant, often overlooked, biodiversity.
• Optimized sampling and genetic marker selection are critical for accurate biodiversity assessment in CCA.
• Further research into CCA as marine seed banks is warranted.