Type: Large

SeyCCAT strategic objective: Support new and existing marine and coastal protected areas and sustainable use zones.

Lead Project Partner: Global Vision International – Seychelles.

Partners:  Seychelles National Parks Authority, University of Seychelles, James Michel Blue Economy Research Institute.

Summary:   The sicklefin lemon shark (Negaprion acutidens; Ruppell 1835) is categorized as vulnerable (IUCN 2014), in part due to its coastal preference and consequent proximity to human activity, and it faces many threats to its continued survival. The species is fished throughout its range (Compagno 1990), and its small habitat range and limited movement patterns make it susceptible to local depletion since dispersal is limited (Stevens 1984, Stevens et al. 2000, Shultz et al. 2008). For effective protection of shark species it is important to gain an understanding of spatial movements and habitat preferences of critical life stages. The installation of an acoustic receiver array along the north and east coast of Curieuse Island, together with the acoustic tagging of 20 neonates, will enhance our knowledge of N.acutidensspatial ecology. Furthermore, results from this project will enable MPA practitioners to make informed future recommendations with regards to the protection of this particular species. Curieuse Marine National Park (CMNP), designated in 1979, is 2.9km2and located north of Praslin Island and a key tourism site in the inner islands. The island is surrounded by a shallow fringing reef and seagrass beds and has a healthy stand of mangroves. These habitats serve as key sea turtle feeding and nesting grounds as well as providing nursery habitat for key ecological species such as N. acutidens

The overall outcome of this project will be a greater understanding of the movements of neonate N. acutidens within CMNP and the efficacy of the park size in their protection.  The main objectives are:

  • Obtain an improved understanding of spatial behaviour and habitat use of 20 neonate acutidenswithin CMNP by monitoring their movements for six months using acoustic transmitters.
  • Refine mark-recapture population estimates of neonate acutidenswithin CMNP within 18 months
  • Develop local capacity by training at least 10 Seychellois stakeholders and MPA practitioners in shark research techniques by December 2019.
  • Contribute to national efforts to protect biodiversity by identifying areas of critical habitat within and outside CMNP used by the threatened species, neonate acutidens within 18 months
  • Provide critical habitat data to national park managers and stakeholders within CMNP and other protected areas to better inform management decisions regarding the conservation of acutidens within 18 months

Outputs will include maps showing the movement and critical habitat areas of neonate N. acutidensin CMNP, a training workshop for Seychellois stakeholders and students in shark research techniques, a signboard providing information on the project and a peer-reviewed scientific paper on the findings of the project. These outputs will be enabled by activities to include the installation of an acoustic receiver array and implantation of acoustic receivers in neonate N. acutidens, capacity building of staff and students through in-field research experience, and the production of communication materials to disseminate the key findings from the project. The rationale of the project approach is that by collecting data on the movement and habitat use of neonateN. acutidens, a species that is vulnerable to over-fishing, the effectiveness of CMNP in protecting the critical life stage can be assessed. There would be a wide range of beneficiaries associated with this project including SNPA, protected area managers, shark biologists, university students and local fishers. The project will operate over 18 months, with the following phases: 1) development and training; 2) implementation; and 3) assessment, monitoring and management. The project is well aligned with the objectives of the National Biodiversity Strategy and Action Plan (2015-2020) including: 1.1. To make the Seychelles population aware of the values of biodiversity and the steps they can take to conserve it;3.2. To prevent the extinction and improve the conservation status of known threatened species, particularly those most in decline;5.3. To improve, share, transfer and apply the knowledge, science base and technologies relating to biodiversity, its values, functioning, status and trends, and the consequences of its loss. Finally, the project will contribute to the UN Sustainable Development Goal 14 to “Conserve and sustainably use the oceans, seas and marine resources for sustainable development” under sub-goal 14.2 and 14.a.

SeyCCAT funds:  SCR 550 000

Co-financing:  SCR 550 000

Duration: January 2019 – June 2020

Project Application Form: Project Application Form


Preliminary Results are IN! 

1. We have recorded a total of 329,208 detections for analysis from transmitters implanted in 20 sharks, between the 24th of October and the 22nd of May.
2. Of the total detections, only 1,203 detections were recorded on receivers placed in deeper water, suggesting a very strong preference for shallow water habitats.
3. At least four individuals appear to remain active within range of the receivers, which broadly correlates with observed capture rate patterns during PIT tagging surveys.

Knowledge Sharing

Seminars and workshops have generally been extremely productive. The two seminar at UniSey was very well attended, with interest from a diverse range of attendees. The training workshop attended by GVI and UniSey achieved its intended aims, in that the lead fieldwork personnel are now suitably trained in surgical implantation of transmitters. Training by UniSey partners to 13 GVI and SNPA personnel in transmitter and receiver hardware has also resulted in key personnel being fully conversant in the required techniques. A further training of 7 SIF staff in PIT tagging and transmission insertion surgery.

80 people from five continents viewed webinar about the project.


PIT Tagging

Ongoing capture and PIT tagging of juvenile sharks has resulted in the capture of 30 new individuals during 2019, with 23 recaptures.

There has been some engagement with local fishers, with the distribution of posters describing the project resulting in the return of one PIT tag from a neonate shark apparently captured at the east of Anse Volbert on Praslin, this will be used to enhance the conclusions of the study.

Acoustic Tracking

The timeline for implementation of the acoustic tracking requires the final installation of receivers prior to the beginning of the N. acutidens pupping season in October. All tracking hardware has now been procured and thoroughly tested, and software installed on laptops. Despite some initial delays in the importation of the tracking equipment the project is on schedule to achieve its objectives.

Range testing is underway across the study area and will continue until the end of September. Deep sites were somewhat deeper than expected at approximately 27m, and this may result in an adjustment of the receiver deployment plan, since bottom time using SCUBA is significantly reduced at such depths, and reduced visibility resulting in increased searching time to retrieve receivers may require a adjustment of the plan to shallower depths. There is some concern regarding wave action at some shallow deployment sites, monitoring is underway to assess the security of moorings during the range testing, and adjustments may be required to some shallow receiver deployment locations. The definitive assessment will be made at the conclusion of the range testing, using data on detection range, shallow mooring security and practicality of deep moorings to determine the ideal final deployment locations.