As Lake Jackson waters once again disappear, a grisly discovery of skeletal remains

Lake Jackson’s latest dry-down has revealed two human skulls in the muck of the 4,000-acre aquatic preserve along U.S. Highway 27 north of Tallahassee. 

The remains have been sent to the medical examiner’s office, while the Leon County Sheriff’s Office investigates why and how they came to rest about 80 yards beyond a boat dock near the end of Faulk Drive. 

It is still early in the investigation and Leon County Sherriff's Office spokesman Shade McMillian said it was unclear if foul play was a factor due to "the age and deterioration" of the skeletal remains. 

"I call them artifacts, because we don't know if it's something from way back in the day or the last ten years," he said, adding that those answers will come back with the forensic analysis.

Initial story:Human remains found in Lake Jackson, LCSO investigating

A man on an ATV exploring the Porter Sink area, which periodically opens and drains the lake, reported the find to Sheriff deputies Sunday afternoon. Investigators worked the scene late into the night, but were gone by Monday morning, replaced by scientists, anglers and curious residents. 

Stephen Hight was among the group. He stood with Department of Environmental Protection and Leon County staffers, watching gurgling water carve a 30-foot-deep valley in the lakebed as it drained into a soccer-ball size hole. 

"This happened in 1999 when I first moved here to Tallahassee,” said Hight, an entomologist who recently retired from the USDA and is moving to Kansas by week’s end.  

“Out west sinkholes are more like cave-ins, there’s no water. This is amazing – it’s the perfect bookend for my time in Tallahassee,” said Hight. 

The water flowed in inches-deep brooks from the east and the west, creating a barren valley with steep cliffs as it moved towards the hole. 

The day before, onlookers said, where the two brooks streamed was a 10-foot-deep bubbling boil they compared to a spring head. 

“By tomorrow it could be all gone,” observed Hight. 

Geologists estimate up to 15-million gallons of water can disappear daily into Porter Sink. The water will eventually resurface at Wakulla Springs, about 30 miles to the south. 

Lake Jackson's disappearing act  

When Porter Sink opened in 1999 it drained more than 4.4 billion gallons of water and reduced the lake to fewer than 500 acres, according to the Florida Fish and Wildlife Commission. The lake also went down at Porter Sink in 2012.

It is uncertain whether that will happen again. Monday several ponds were scattered across the lakebed. 

Water has riddled the limestone lakebed with millions of pinholes. When water pressure is high debris plugs the holes. When there is a lack of rain, the pressure lessens, the holes open and create what scientists call a dry down. 

Tallahassee rainfall for this year is down more than 5 inches, according to the National Weather Service. And while the lake has been draining for a couple of months, according to Leon County staff, it “rapidly accelerated over this weekend.”

The lake has been pulling its disappearing act for centuries.

DeSoto and his conquistadors made no mention about a lake north of Tallahassee when they wintered here in 1539-40. They did describe a savannah and big plain where Lake Jackson sits today. And a British trader who worked north Florida in the 1740s, also made no mention of the lake.

More:What makes Lake Jackson drain so quickly?

But early settlers made note of the lake. Especially when it disappeared in 1836.   

And it repeated the feat in 1886, 1909, 1932, 1956, 1982,1999 and 2006 and most recently in 2012. 

Good for Fish

“This is not a bad thing,” said Michael Hill, a retired biologist who led the FWC (Fish and Wildlife Conservation) response and cleanup of the lakebed in 1999. 

Hill said this weekend’s opening is about 15 feet from the 1999 sinkhole. The 1982 hole is about another 10 feet to the west. The 1956 opening is about a mile to the east.  

While the discovery of the skeletal remains adds a new mystery, Hill is intimately familiar with the lake's secrets. He descended into the sinkhole after the 1999 dry down to better understand the intersection of the lakebed and aquifer.

He also supervised the removal of more than 500,000 cubic yards of organic material from the lakebed, while the water was gone. 

Hill said the occasional dry downs help maintain a healthy Lake Jackson fishery. It naturally clears away the muck – enabling the ground to become more compact and firmer so the fish can spawn. 

“The largemouth bass requires a firm substrate to spawn. When its muck they just spin around and the success of the spawn is minimal,” explained Hill. 

Vegetation thrives in the low water level and that provides food for the young bass, bream, and crappie. 

“It’s like a shot in the arm for the food chain, everything grows,” said Hill about the dry downs. 

Contact Christopher Cann at ccann@tallahassee.com and follow @ChrisCannFL on Twitter.

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