Reef benthos of Seychelles - A field guide

Area of Science:

• Marine biology
• Ecology
• Oceanography

Background:

• The 2019 First Descent: Seychelles Expedition investigated shallow and deep reef ecosystems.
• A variety of underwater technologies were deployed to survey benthic flora and fauna.

Purpose of the Study:

• To document and visually identify marine macrophytes, corals, sponges, and invertebrates in Seychelles' reefs.
• To create a photographic guide for organism identification in underwater footage and in the field.

Main Methods:

• Benthic transect surveys were conducted at depths ranging from 10 m to 350 m.
• Stereo-video camera systems were utilized by submersibles, remotely operated vehicles (ROVs), and SCUBA diving teams.
• Approximately 45 hours of video footage were collected and analyzed using annotation software.

Main Results:

• A total of 184 morphotypes were identified across various taxa, including Octocorallia, Porifera, Scleractinia, and Asteroidea.
• Organisms were identified to various taxonomic levels, from phylum to species.
• This catalog represents the first comprehensive benthic diversity assessment from shallow to 350 m depths in Seychelles.

Conclusions:

• The expedition successfully documented a significant portion of Seychelles' benthic reef diversity.
• The developed photographic guide will assist researchers, conservationists, and naturalists in identifying marine organisms.
• This research provides a foundational catalog for future ecological studies and conservation efforts in the region.