Ray of Hope
A long term study of the manta ray population near Torfu, Mozambique. This is one of the few areas in the world where it is possible to regularly study both the Manta birostris and Manta alfredi species of giant manta in the same location.
Why this is important:
Until recently it was thought that the giant manta ray was a single species of ray but Andrea’s work has shown that this is not the case. Through her meticulous research she has shown that there are in fact at least two, possibly three, separate species of manta ray, each with their own characteristics and life styles. This is of crucial importance to being able to conserve manta rays, not only in Mozambique, but worldwide.
The International Union for the Conservation of Nature (IUCN) currently lists manta rays (Manta birostris) as ‘near threatened’. It’s known that several populations around the world are severely depleted, but not enough scientific work has been carried out to properly assess the species as a whole. Almost nothing is known about their population ecology, use of critical habitat, movements or reproduction, all of which are vital in order to accurately assess the state of the species.
Manta rays are the largest of over 500 different species of rays and skates; their triangular pectoral fins can span almost 8m in width and weight reach over 2,000kg. Andrea has developed a systematic method of identifying individual mantas by their ventral (underside) spot patterns, which are unchanging and present from birth. This has allowed her to establish an identification database based on a single reef site in Mozambique which now contains over 900 individuals, making it the largest and most in-depth manta dataset in the world. When combined with population modeling and behavioural observations, her data suggests that southern Mozambique may host the largest manta population in the world, with possibly 1000 individuals in the area Andrea works in alone.
Acoustic tagging equipment and listening stations sponsored by SOSF have enabled Andrea to examine how individual manta rays use critical habitats, like cleaning stations, along the coastline. Andrea and her group have also begun the genetic sampling of the entire local manta population. Cutting edge genetic research in conjunction with researchers at the University of Queensland is also being planned; in a first of its kind, its focus will be on the relatedness within the local manta population. With the continued assistance of SOSF, Andrea is also conducting comparative research by collecting DNA samples in Mexico, Japan, Yap, Thailand, Indonesia and Australia.
Aims and Objectives
- Properly classify the different species of manta ray.
- Show how the habitats of the different species differ and overlap.
- Inform conservation strategies around the world to better conserve the different species.
Join Dr Andrea Marshall and her PhD student Daniel Van Duinkerken on a recent satellite tagging expedition in Myanmar and Thailand. Andrea notes that Thailand has seen major declines in mantas at its biggest manta aggregation sites in the past…
Exciting news from Mozambique as Andrea Marshall kicks off the year with the first tagged manta! Find out more about how sat tags work and the tagging process in the video blog she sent along below.
Our team is proud to announce the launch of Manta Matcher (www.mantamatcher.org), the first global online database for manta rays! Created in conjunction with Ecocean USA, this site will function much like, www.whaleshark.org, a site that has been tracking whale…
Manta rays, which were only recognized as two distinct species in 2009, were recognized as globally threatened, migratory species in November 2011 for the first time on the IUCN redlist and the Convention for Migratory Species Act in recognition of…
An entire year has passed, and I find myself again in Ecuador, the middle of the earth. Literally. Not much has changed in the sleepy town of Puerto Lopez. Sadly the fish market is still full of sharks. They come…