Komodo National Park is home to some of the world's largest manta ray aggregations, study shows

Scientists from the Marine Megafauna Foundation and Murdoch University collaborated with the public to report a large number of manta rays in the waters of Komodo National Park, which is an Indonesian UNESCO World Heritage site.

Reef mantas, which grow up to 5m, tend to reside and feed in shallow coastal habitats. They visit coral reefs to have parasites or dead skin picked off by small fish. Courtship and trains are next to cleaning stations. The Komodo dragon is the most sought after megafauna for visitors in Komodo National Park.

Scientists collaborated with the dive operator community serving the Komodo National Park to source identification photographs of manta rays visiting the parks waters and submit them to a online database. The majority of the photographs came from four locations.

The local dive community helped us identify over 1,000 individual manta rays from over 4,000.

The abdominal patterns of individual manta rays are unique. The Marine Megafauna Foundation, founded by Dr. Marshall, saw the potential to engage the public with data collection for these threatened and under studied marine animals and worked with software company WildMe to develop an online wildlife database platform.

The people love the manta rays, they are one of the most popular animals in the ocean. The rise of the number of people engaging in SCUBA diving, snorkeling and the advent of affordable underwater cameras meant that photos and videos taken by the public during their holidays could be used to quickly and affordably scale data collection.

The photographs and accompanying time and location information can be used to build a sighting histories of individual manta rays, which can be analyzed with statistical movement models. The models can predict the location of the manta rays. The results of the study showed that some manta rays moved around the park and others as far as the Nusa PenidaMPA, but overall, they preferred specific sites.

Dr. Elitza Germanov said that it was interesting that some manta rays preferred to spend their time in some sites more than others.

Fishing has been banned in many coastal areas within Komodo NP since 1984 and there is some protection to the manta rays that predates the national protection. Due to illegal fishing activity and manta ray movements into heavily fished waters, they face a number of threats. About 5% of Komodo's manta rays have permanent injuries that are likely the result of fishing gear encounters.

The popularity of Komodo National Park for tourism grew throughout the study and resulted in a 34% increase in tourism boats visiting manta ray sites. Increased boating activity and excessive divers can affect the habitats of the manta rays. The Komodo National Park Authority introduced limits on the number of boats and people that can visit one of the most famous manta sites.

The places where tourists commonly observe manta rays are important for the animals to feed, clean and mate. The Komodo National Park should create measures to limit the noise at these sites, said Mr. Ande Kefi, an employee of the park.

The Komodo National Park can be used as a model for manta ray habitats elsewhere in the world, thanks to the additional recommendations made by the authors of the study. The number of tourism boats allowed at one time at all manta ray aggregation sites is one of the ways to minimize the impact from tourism.

Komodo National Park still has large manta ray aggregations that will benefit regional manta ray populations. The study shows that marine protected areas that are large enough to host important manta ray habitats are beneficial.

More information: Elitza S. Germanov et al, Residency, movement patterns, behavior and demographics of reef manta rays in Komodo National Park, PeerJ (2022). DOI: 10.7717/peerj.13302 Journal information: PeerJ Citation: Komodo National Park is home to some of the world's largest manta ray aggregations, study shows (2022, May 16) retrieved 16 May 2022 from https://phys.org/news/2022-05-komodo-national-home-world-largest.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.