Officials with the Florida Fish and Wildlife Commission (FWC) on Wednesday evening discovered a dead dolphin near the St. Johns River in Jacksonville, Florida.

It is not currently clear how the dolphin died, though there wasn’t anything to indicate “external trauma or human interference,” First Coast News reported.

The discovery came roughly 24 hours after a separate dolphin was found by the FWC. That dolphin was “tangled in blue netting used for crab hunting,” according to the news station, which added that it was possible a boat or another form of watercraft struck the animal.

The FWC has investigated 16 dolphin deaths, including the two most recent cases, so far this year, according to First Coast News.