The Maldivian Manta Ray Project (MMRP) lead World Manta Day celebration festivities across the country on Saturday.
This year’s 17th September marks the third World Manta Day, which celebrates manta rays and raises awareness of the threats they face. To celebrate the day, the MMRP held celebratory dives across the country – including one in Greater Male’ lead by Moodhu Bulhaa dive centre. They also held an trivia and open mic night on Sunday evening.
The theme for 2022’s World Manta Day is Education, and in keeping with the theme th MMRP shared highlights of their work across the country. The MMRP is the flagship project of international project Manta Trust (MT), working to conserve manta rays globally.
The MBR is featuring some of their work below.
Local ecological survey on Manta aggregations – Laamu Atoll
In Laamu, Manta Trust’s Assistant Project Manager for Laamu, Ali Jinaad, has been working on a local ecological survey with a masters student from University of Exeter. As part of the survey, Jinaad travelled across the atoll conducting interviews with fishermen, collecting baseline data for the understandings on manta ray presence, distribution, and status in Laamu Atoll. The surveys also looked into understanding the kind of gear that fishers used, and if any specific gear is more susceptible to manta ray entanglement. The lastly, the project was also a chance to increase awareness about MT’s work in the atoll.
Feeding ecology and behaviour of reef mantas – Baa atoll
In Baa, PhD student from the University of Australia, Hannah Maloney has been conducting analysis on zooplankton in the largest manta aggregation site in the world, the UNESCO Biosphere Reserve Hanifaru Bay. “I’m investing the feeding ecology and behavior of manta reasons, and the reason why they visit this special place.” Hannah said in a social media post. Her research looks into what manta rays feed in a day, and she’s able to catch, store and analyse zooplankton from the area.
Hannah is also looking into changes in zooplankton biomass and establishing the critical prey density threshold for the site. In combination with environmental and geographic data, the study used hand-towed plankton tows to sample over the tidal cycle, lunar phase, and affects during the south-west monsoon.
Sublethal injuries in Maldives manta rays – Baa atoll
Elspeth (Ellie) Strike, the MT’s Assistant project manager in Baa atoll has been researching injuries present on reef and oceanic manta rays, based on over 73, 000 photo-ID sightings collected over three decades. She found that anthropogenic injuries are more common in atolls with higher tourism industry, and that juvenile manta rays are especially vulnerable to injuries.
Ellie analysed data from sightings between 1987 and 2019. The likely event of each injury was determined based on visual assessment of photo-ID images. For both oceanic and reef mantas, the majority of injuries were natural, however the most common anthropogenic injuries was fishing lines.
Potential breeding ground and key juvenile aggregation ground – Raa atoll
MT’s Raa atoll Project Manager Jessica Heines has been studying a juvenile aggregation site in the country – Raa atoll Maamunagau’s lagoon. Her research has shown that it is a potential nesting ground for reef manta rays, which is breakthrough research as there is very little understood about where manta rays give birth.
Jess has identified the first nursery habitat recorded for mantas in the Maldives. To qualify for a nursery habitat, it must have 1) high juvenile density within the area compared to elsewhere; 2) individuals present for extended periods of time, and 3) used by juveniles repeatedly over time.
Maamunagau’s large sheltered lagoon is optimal conditions for this, and the Raa atoll team – based at Intercontinental Maamunafau resort – are conducting further studies.