Giant Manta Ray Population Found to be 10 Times Larger Than Any Other by Scientists.

Giant Manta Ray Population discovered to be Ten Times Bigger Than Any Other

A population of more than 22,000 oceanic manta rays (Mobula birostris) off the coast of Ecuador is doing quite well for itself, which is promising given the number of species that are threatened by human activity and climate change.

Conservationists are hopeful that this “unprecedented” community of manta rays will provide some insights on the conditions that the fish find attractive because the projected population size is more than 10 times greater than the numbers expected to be in other regions.

Oceanic manta rays were classed as endangered on the IUCN Red List of Threatened Species in 2019. Whether through intentional targeting or unintentional bycatch, commercial fishing poses the species’ greatest threat.

According to Oregon State University’s Joshua Stewart, a quantitative ecologist, “it’s obvious that something different is happening here.” “This is a unique tale of oceanic hope. This species is extremely susceptible since populations in other areas are normally estimated to be between 1,000 and 2,000 animals.”

Giant Manta Ray Population discovered to be Ten Times Bigger Than Any Other

Oceanic manta rays are clearly at risk, yet it is difficult to research and watch over these species because they frequently hang out in remote offshore locations and have erratic migration patterns.

Scientists have been monitoring this particular population of manta rays in coastal Ecuador since the late 1990s. In order to get at the most recent estimate, researchers used more than a decade’s worth of images and field notes collected between 2005 and 2018 to determine that there are currently more than 22,000 people living there.

That indicates that this area of Isla de la Plata is sort of a hotspot for these fish. The team hypothesises that one of the reasons the population has increased is due to a sufficient supply of food, with cold, nutrient-rich water flowing up from the depths and being transported by ocean currents to provide a regular stream of zooplankton snacks.

Although there is good news regarding this demographic, Stewart cautions that it should serve as a warning. “Manta rays seem to be sensitive to changes in the environment, such as variations in ocean temperature and the availability of food.”

If the intensity of upwelling and the amount of food fluctuate along with ocean temperatures, they will probably be affected by a warming climate.

Giant Manta Ray Population discovered to be Ten Times Bigger Than Any Other

This kind of long-term research is crucial because it helps scientists understand global population trends. It is essential to take into account outliers like this group of M. birostris since population status estimates frequently rely on estimates of abundance and averages.

Conservation efforts can be more precisely targeted the more accurate the data is. Despite the fact that manta ray hunting is no longer permitted in this region of the world, other problems such bycatch, fishing net entanglement, and vessel strikes continue to exist. Throughout the research period, several fish were seen to have scars or injuries.

Additionally, the study represents a triumph for both oceanic manta rays and citizen science. Due in large part to pictures taken by scuba divers in the vicinity, the population could be estimated and more than 2,800 fish could be individually identified in more than 3,300 images.

Similar to a fingerprint or the white spots on whale sharks, the distinctive spot pattern on each manta ray’s belly helps scientists identify specific individuals in the photographs. This enables scientists to count, follow, and keep an eye on manta rays throughout time. Re-sightings and ray counts can be used to calculate population size.

According to marine researcher Kanina Harty from The Mantra Trust in the UK, “many of the photos used in our study were supplied by recreational divers who became citizen scientists when they took pictures of manta rays.”

“Just from these pictures, we learn so much about each species,” said the researcher.

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