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The threatened giant manta ray is the only species of manta that occurs in the western North Atlantic Ocean. Giant mantas are vulnerable to an array of ocean activities including fisheries, where they are often caught as bycatch; boat strikes; oil and gas activities; as well as contaminants and pollutants in ocean waters. These threats, along with the slow growth, late maturation, and low reproductive output of giant mantas, all contribute to the decline in abundance of this species. Understanding the distribution of giant mantas along with the environmental drivers of this distribution, will ultimately contribute awareness towards their feeding habits, reproductive strategies and vulnerability, which in turn, can contribute to better protection and conservation of these migrating filter-feeders. To evaluate the distribution of giant manta rays, authors integrated decades of sightings along with survey data from multiple sources, including occurrence records from the OBIS database, in a comprehensive species distribution modeling (SDM) framework. The sighting data from the various sources showed that manta rays were most commonly detected at productive near shore and shelf-edge upwelling zones at surface thermal frontal boundaries at temperatures between approximately 20–30°C. According to the results from the species distribution model, the highest near shore occurrence is predicted to be off northeastern Florida during April, northward as ocean temperatures become warmer. Consequently, higher occurrences are predicted north of Cape Hatteras, North Carolina from June to October, and then south of Savannah, Georgia from November to March as temperatures become cooler. In the Gulf of Mexico, the highest near shore occurrence was predicted around the Mississippi River delta from April to June and again from October to November. The predictions that can be made from the species distribution models will allow resource managers to more effectively protect manta rays from anthropogenic threats and help conserve the vulnerable population of giant manta rays.
Farmer, N.A., Garrison, L.P., Horn, C. et al. The distribution of manta rays in the western North Atlantic Ocean off the eastern United States. Sci Rep 12, 6544 (2022). https://doi.org/10.1038/s41598-022-10482-8
https://doi.org/10.1038/s41598-022-10482-8