When the phone rang at 5 a.m., the immediate worry of some type of emergency was quickly allayed when Lee Rivenbark’s voice was immediately recognized.

“Rivenbark,” Lee announced with the hint of a lilt. “Shrimp jubilee. Pier Street.”

If you’re fortunate enough to be a member of the “jubilee network” on Mobile Bay’s Eastern Shore, the pronouncement of a jubilee is short and sweet – meaning time’s a wastin,’ jump out of bed and get to the bay on the double.

This incredible jubilee phenomenon supposedly happens only in a couple of places in the world, but none with the regularity of Mobile Bay.

Vernon Minton, Director of the Alabama Department of Conservation and Natural Resources’ Marine Resources Division, said a jubilee is caused by a combination of factors.

“You have very warm water, very still water and then the organic load (decaying matter that moves into the bay from the rivers and stream of the Mobile Delta) that creates a situation where the oxygen on the bottom – most of the time it’s just on the bottom – gets depleted,” Minton explained. “And then there’s a slow movement of that oxygen-depleted water to shore. It has kind of a corralling effect and will herd the bottom-dwelling species into the shallows. There they will literally go moribund, and people can just pick them up.”

The good news, according to Minton, is that jubilees last only a few hours and when conditions improve, the bay creatures slowly recover from their stupor and ease back into deeper water.

“Rarely do we have situations where it actually kills the fish or crustaceans,” Minton said. “Most of the time, the wind comes up and causes mixing of the water and it dissipates before it actually kills the creatures. The fish up in the water column will swim off. It’s the bottom-dwellers that are affected.”

I arrived at Pier Street with only my camera in hand because both my cast nets had been ripped on unseen snags. After snapping a few photos, I spotted a familiar face – Dr. John Borom, director of Faulkner State Community College’s Fairhope campus and head of the Mobile Bay Audubon Society.

Borom, a lifelong resident of Fairhope, has a long history of being in the middle of jubilees.

“When I was in high school, I would get up and look for jubilees a lot,” Borom said. “I remember one summer when I was in high school I got in on 13 jubilees. I’ve seen a lot of jubilees but it’s always exciting to see that quantity of marine life come to the beach. You get to see things in large numbers you don’t normally see. Even as you get older, it’s still very impressive and exciting to see something that is so unusual. Most people have never heard of or seen one, so it’s easy to get excited.”

Although they can occur at different times, Borom said August and September are the best months to see jubilees.

“The environmental conditions have to be just right,” he said, echoing Minton’s assessment. “It has to be a mostly northeast wind. It has to be an incoming tide. The northeast wind blows the surface water out into the middle of the bay, and the incoming tide brings the stagnant water into the beach.”

Borom said jubilees come in different varieties, depending on what creatures get trapped between the stagnant water and the beach.

“Usually it’s bottom-dwelling creatures like flounder, crabs and eels,” he said. “But I’ve seen nothing but (saltwater) catfish jubilees; I’ve seen nothing but shrimp jubilees; I’ve seen nothing but crab jubilees. Then I’ve seen a mixture of a lot of different things.”

Jubilees can cover long areas on the Eastern Shore from Daphne to Point Clear or can occur in isolated pockets, depending on the size of the oxygen-depleted water. Occasionally, jubilees occur on the western shore of Mobile Bay but are rare.

As for last week’s jubilee, Borom said it was apparently a combination of migrating white shrimp meeting the stagnant water that pushed the crustaceans to the beach, a hypothesis backed by Steve Heath, Marine Resources’ Chief Marine Biologist.

“Normally, the white shrimp will move slowly down the bay in September,” Heath said. “When we get the first cold front that drops the water temperature below 70 degrees, then they will pile out of the bay. They head for the Gulf with the exception of a few that will stay in the ship channel and a few deep holes where the water stays a little warmer.

“September-October is considered the white shrimp season, and they do tend to run the shore. I know the sandbars south of Point Clear are very popular areas for shrimping this time of year.”

As for the recent jubilee, Heath said it was odd that it affected shrimp almost exclusively.

“Apparently, that was caused by the fact the other animals weren’t there,” he said. “I know the flounder are ganging up at Fort Morgan to go spawn in the Gulf, and this has not been a good blue crab year, landings wise.”

Borom said a lifetime of living near Mobile Bay can reveal clues about jubilees, but there is no surefire way to predict what will be involved.

“People who live around the bay can look at the environmental factors,” Borom said. “You can maybe predict when a jubilee might occur, but you don’t know where it’s going to occur. A couple of weeks ago when we had the hurricane (Gustav) we had a jubilee in that very spot. So jubilees can occur during a tropical system if there is a northeast wind on a hot day.”

As dawn began to break during the most recent jubilee, Borom packed his cast net, picked up his bucket of shrimp and marveled at what had just occurred.

“When you stop and reflect on it, you say, you know this is such a wonderful place to live anyway,” he said, “and here we have this wonderful, rare phenomenon that makes it a pure delight to live on the Eastern Shore and enjoy the bountiful bay.

“The truth is we really have a treasure in our midst.”