New Zealand's territorial waters are the fourth largest in the world, and host a diverse range of marine habitats. Oceanic manta rays are consistently sighted during the summer months, but very little is known about them.
Aotearoa New Zealand is a remote island nation, situated in the South-West Pacific Ocean. New Zealand’s territorial waters are the fourth largest in the world and at just over four million square kilometres encompass a diverse range of marine habitats. Subtropical, temperate and sub-antarctic environments host a multitude of seascapes; remote offshore islands, trenches and seamounts which in turn make New Zealand’s waters exceptionally productive and its marine life diverse.
Oceanic manta rays (Mobula birostris) are consistently sighted around the upper North Island’s East Coast during New Zealand’s summer months, typically when sea surface temperatures exceed 18° C. Sightings have been recorded from the North Cape (34° S) down to the Bay Of Plenty (37° S), a search area spanning thousands of nautical miles.
Very little is known about the manta rays that frequent New Zealand's waters, and until now reliable data collection has been sparse. Manta Watch New Zealand (MWNZ) is an innovative and multifaceted research project providing a much-needed centralised data collection platform.
By combining verified sightings data, both historic and real time from a multitude of sources (e.g. citizen science, field observations and photo ID) MWNZ have been able to develop the fundamentals for a comprehensive sightings and ID database. Long term this data, cross referenced with temporal and environmental variables, will enable us to gain better insight into the seasonal distributions and critical habitat use of New Zealand’s manta rays.
Currently, research has yet to confirm whether New Zealand has its own oceanic manta ray population and/or sub populations. It is hoped that with concentrated monitoring efforts in these identified manta hot spots we can greatly increase our chances of encounters, which in turn will assist with ongoing photo ID efforts. By cataloguing ID photos, MWNZ will learn more about individual manta ray movements and location preferences. This data will assist with ongoing population size estimations, in addition to other national and international research and conservation projects.
To gain greater understanding of the ecology and population dynamics of oceanic manta rays (Mobula birostris) in New Zealand waters, and contribute towards national and international management projects to conserve them, promote local awareness of mantas, and foster collaboration.
To achieve our goal, Manta Watch New Zealand is working to meet the following objectives:
(1) Determine whether the oceanic manta rays seen in New Zealand's waters are seasonal visitors, or their own distinct population.
(2) Establish and maintain an interactive citizen science platform whereby verified manta ray sightings data can be shared, centralised, and catalogued.
(3) Determine the impact of environmental variables, temporal and planktonic data on manta ray sightings.
(4) Identify critical use habitats / aggregation hotspots and associated behaviours.
(5) Develop a robust photo-identification database of individual manta rays.
(6) Assist with collaborative satellite tagging projects.
Project Leader - lydia green
Lydia has always felt a deep connection to the ocean. Her parents first recognised her attachment when she was just four years old - no mean feat for a kid born in the centre of the UK! There was never any doubt that she would pursue her love for the ocean professionally.
Whilst collecting data for her dissertation as part of her Marine Biology (Hons) degree, Lydia found herself in blue water for the first time. Surrounded by thousands of common dolphins, feeding fin and minke whales, sunfish and even a basking shark, experiencing the magic of the open ocean first-hand not only blew her mind but galvanised her love of marine megafauna.
In 2007 while working as a biological field assistant for a regional Fisheries Committee, she got her first proper taste of working on boats; assisting with a stingray tagging project. Six months later she relocated and set up her life in Aotearoa, New Zealand. The move provided her with amazing opportunities both in and outside of NZ. She has been an eco-tourism and dolphin guide in NZ, a Dive Master and Whale Shark guide in Western Australia; a Great White Shark nature guide, a Marine Protected Species Observer for the NZ Government, and finally she set-up her own marine education and ecotourism business called Saltwater Eco in 2014.
It was during these years that Lydia’s fascination for manta rays became truly cemented. In 2011 she was part of a research team with the Thresher Shark Conservation Project in the Philippines, undertaking underwater transects on a well-known cleaning station. Mid-dive, a giant shadow blocked out the sunlight, and a huge oceanic manta ray hovered gracefully above her. Lydia knew she’d experienced something special.
Two years later Lydia was project leading conservation volunteer programs in Fiji. She spent three months working alongside the Manta Trust’s Fiji Manta Ray Project scientists, and spent countless hours in the water with reef mantas. In 2017 she was back with the Manta Trust, this time volunteering with their affiliate Mexican Caribbean Manta Ray Project. Halfway through her program everything clicked into place, and she decided it was time to start her own manta ray project in NZ. Shortly after, Manta Watch New Zealand was born.