About This Project

Marine protected areas (MPAs) are being promoted for shark and ray conservation. However, MPA benefits for some species are still questionable due to unclear objectives set by varied stakeholders. Here, we will compliment the use of BRUVs with eDNA metabarcoding to evaluate shark and ray biodiversity in Gili Islands MPAs. Results will be used to determine the effectiveness of these MPAs as a conservation tool for coral reef sharks and rays.

Ask the Scientists

What is the context of this research?

Sharks and rays are among the most threatened groups of species in the oceans (1), with 59% listed in a threatened category by IUCN (2). Results from the first Global FinPrint Project showed that reef sharks are in severe decline globally, but are more commonly seen in marine protected areas (MPAs) than in unprotected areas (3, 4). Most MPAs in Indonesia were not designed with the needs of large mobile predators like reef sharks and rays in mind (5). We will resample Gili Islands, which was initially sampled in 2016, to see how the number of reef sharks and rays has changed over time and how MPA design features are related to shark and ray numbers and trends.

What is the significance of this project?

Sharks and rays have an important and major role in maintaining the ocean ecosystem and also serving as an indicator of ocean health (6). However, socio-economic and food security considerations pertaining to Indonesian communities add further layers of complexity to the management and conservation of these vulnerable species (7). Marine protected areas (MPAs) are a widely used tool for the protection of biodiversity as a strategy for protecting or restoring shark and ray populations (8). However, are sharks and rays really safe in the MPA? Using both BRUVs and eDNA metabarcoding to find different species of sharks and rays, both through footage and the molecular traces of the organisms, could help determine if the MPA is effective for sharks and rays.

What are the goals of the project?

This project aims to investigate the effectiveness of the MPA in providing sanctuary and protection to the reef shark and ray populations. The MPA's effectiveness will be measured by how the number of reef sharks has changed over time using BRUVs and eDNA metabarcoding. Combining these two non-destructive biomonitoring techniques will improve the assessment, as BRUVs have the advantage of providing visual evidence as well as the relative abundance of the reef shark and ray population using an index called MaxN (9). eDNA metabarcoding offers the advancement of detection for cryptic and/or rare species that may not be interested in the bait used in BRUVs from the extracellular material they expel to the environment (10).