Merle was born and raised in Bremen (Germany) and developed an interest in the ocean from a young age by playing at the beaches on the shore of the Baltic in Denmark or visiting the Marine Aquarium in Hirtshals and Bremerhaven. She has a bachelor’s degree in Biology, followed by a master’s degree in Marine Environmental Science, majoring in Biology and Ecology. An exchange semester and the fieldwork for her master’s thesis brought her to James Cook University and later to AIMS, where she investigated chemical growth in Triton larvae and later assessed microplastic contamination in a range of GBR organisms. After graduating, Merle moved to Halifax (Canada) to work as Research Associate at Dalhousie University. Back at JCU and AIMS, Merle is perusing her Ph.D. with the aim of further understanding the biology of the endangered Giant Triton Snail, Charonia tritonis, and to assess its potential as a Crown-of-Thorn Starfish biocontrol agent.

The biology, monitoring and conservation of the endangered Giant Triton Snail a potential Crown-of-Thorns Starfish biocontrol agent

2022 to 2026

Project Description

The aim of this project is to further understand the biology and ecology of the Giant Triton Snail and to assess its potential as a COTs biocontrol agent. For this, the Giant Triton Snail’s feeding preferences, as well as predator/prey interactions, will be assessed. Genetic methods are used to establish their population distribution and to determine population connectivity. This will then be used to statistically model their potential future impact on COTs populations.

Project Importance

Crown-of-Thorns starfish (COTs) represent a persistent threat to corals that undermines their resilience to bleaching. The Giant triton, as a primary predator, potentially plays a role in regulating COTs populations, as the increase in COTs outbreaks over several decades coincides with the decline in Giant triton populations due to over-exploitation.

Project Methods

The first part of the project will use data collected on the captive brood stock of C. tritonis at AIMS, which includes data on movements and interactions with conspecifics (i.e. mating and egg-laying) and prey (i.e. primarily COTS, but also other echinoderms) from 4+ years. This dataset will be extended to include aquarium-based observational behavioral assays (SeaSIM facility) using a wider range of echinoderms to verify feeding preferences. The second part of the project will investigate the presence of Giant tritons on specific reefs throughout the GBR using standard visual surveys and eDNA techniques. Ultimately, a model displaying the project’s findings across the GBR will be developed in order to reveal new information on the predator-prey interactions. The third part of the project will investigate population genomics to study population structure and connectivity. Extraction methods (from fresh mucous samples obtained initially from captive animals), treatment methods (formaldehyde, ethanol) and genes of interest (CO1, 16S) will be explored and the most suitable technique (nuclear DNA vs mitochondrial DNA depending on sample quality) applied to reveal information about the Giant triton life history and population structure. The final part of the project will review the suitability of the Giant triton’s biological, genetic and biogeographical data to refine modeling of the impacts on COTS populations on target reefs with a focus on the predator-prey interactions.

Project Results

Our results will further the understanding of this endangered species, guide the management and conservation of Giant tritons, and reveal their potential as a sustainable, natural COTs biocontrol agent.

Keywords

Behaviour,
Benthic,
Biostatistics,
Coral reefs,
Crown of Thorn Starfish,
Ecology,
Field based,
Fishing impact,
Genetics,
Management tools,
Modelling,
Molluscs,
Quantitative marine science