There could be a pretty simple scientific explanation behind one of Jesus’s most famous miracles, recent research has revealed. It seems the fishy (in all senses of the word) goings on in the Sea of Galilee may be the result of a curious natural phenomenon.

The Sea of Galilee, also called Lake Tiberias or Kinneret, is a freshwater lake in Israel that is prominently featured in the Bible. Its northwestern shore is thought to be associated with a couple of Jesus’s miracles: The Miracle of Loaves and Fishes and The Miraculous Catch of Fish. In the first narrative, five loaves of bread and two small fish fed 5,000 people. In the second, the apostles were fishing unsuccessfully until Jesus told them to cast their nets one last time, after which they were rewarded with a great catch.

Were these “miracles” really the work of Christ, or is there a more logical, more scientific, explanation? According to the new research, probably the latter.

“Nowadays fish-kill events happen at the same location in the lake where the biblical Miracle of Loaves and Fishes and presumably the Miraculous Catch of Fish occurred two millennia before the present,” the team write in their study. “[This] may explain the appearance of large numbers of easy-to-collect fish close to the shore described in the biblical narratives.”

The researchers identified two events, in May and June 2012, which saw thousands of dead fish float to the surface. Using three-dimensional modeling, they worked out a potential mechanism underpinning these major fish kills in the lake: upwelling of low-oxygen water, which reached the surface near the shore and caused the fish to suffocate.

Lake Kinneret mixes from top to bottom just once each year. In summer, it is arranged into layers: a warm upper layer, a cooler lower layer, and an intermediate layer with a strong temperature gradient separating the two. Westerly winds generate internal waves in the lake, which, in turn, force colder, oxygen-depleted water from the lower layers up to the surface. If this upwelling occurs soon after the layers have formed, which they do in March/April, fish would be unable to escape the oxygen-deprived water, and so would suffocate at the surface.

In Lake Kinneret, such instances of fish killing caused by the upwelling of internal waves are rare. Apart from the events in 2012, the authors can only recall two others, one in April 2007 and one in the early 1990s – all of which occurred at the same geographic location, near Tabgha.

Similar events resulting in fish kills have been documented in other locations, including Lake Erie, the Neuse River Estuary, North Carolina, and Hamilton Harbor, Canada – and could also explain Jesus’s “miracles”, the study authors argue.

“Our study suggests a location and time frame for the biblical miracles near Tabgha, documented in the Miracle of the Loaves and Fish, and the Miraculous Catch of Fish,” they conclude.

“It is possible that similar fish-kill events, or even only concentration of live fish near the shore in an event of partial upwelling, happened at the same site on the shore of Lake Kinneret already two millennia ago.”

The study is published in the journal Water Resources Research.