The stranding of flying gurnard fish in July on various Oahu beaches was prompted by a natural life-cycle event, the Department of Land and Natural Resources said Thursday.

The U.S. Geological Survey Biological Resources Division tested the carcasses and found that the apparent accidental washing ashore of the small flying gurnard fish was likely linked to juvenile fish becoming adults.

Fish carcasses that were tested were taken from Fort DeRussy, Kakaako Waterfront Park and Ko Olina.

The fish had washed ashore from July 2 to 17 at various beaches, including in the Kahuku area.

The USGS found no evidence of infectious disease, including viruses, parasites, fungi and bacteria, or any microscopic lesions that would indicate toxic disease.

The USGS field surveys revealed the fish were behaving normally.

The USGS noted a similar event occurred exactly a decade ago on Oahu in July 2004, and that it did not find any significant lesions on fish carcasses at that time either.

Beachgoers are urged to report any unusual washing-up of marine life to Eyes of the Reef Network at dlnr.hawaii.gov/reefresponse.