I Speak for the Fish: The hardest lake sturgeon dive in the Great Lakes

For two weeks each year, the St. Clair River hosts thousands of spawning lake sturgeon. Hundreds of six-foot females plump with eggs and thousands of 4 to 5-foot-long males gather at the base of Lake Huron. In the span of a few weeks, they will arrive, group up, deposit millions of fertilized eggs on the river bottom and depart.   From an underwater photography perspective, filming the largest spawning population of lake sturgeon in the Great Lakes presents a unique set of challenges.  Like most lake sturgeon spawning grounds, the Blue Water site is located at the fastest flowing section of the river. For the St. Clair River, that spot is under the Blue Water Bridge. There are only a handful of divers with the expertise and fortitude to dive the site which has currents strong enough to rip your mask off your face or depress the purge button on your regulator sending an unexpected blast of air down your throat. Filming on the Blue Water site also requires divers to adopt a completely different approach to how they maneuver underwater. Most divers try to obtain and maintain neutral buoyancy meaning they do not sink to the bottom or float to the surface. The goal on reefs, wrecks and in caves is to hover in the water column like the Goodyear blimp.     A skilled reef diver will never make contact with the delicate corals, anemones or sponges. An accomplished wreck diver can enter and exit a ship without disturbing any sediment. And a good cave diver can spend hours inside a cavern system without creating a cloud of particles. Neutral buoyancy being the key to all three. There are lots of dive locations in the world with strong currents. The standard practice is to simply drift from a starting point to the exit point. It usually makes for a fun ride, providing the opportunity to cover a lot of ground and see a lot of stuff. As divers, we spend a lot of time drifting in the St. Clair River. But blimps can’t stay on the spawning ground. We think of it like rock climbing up a waterfall where you use every muscle in your body including your toes to hang on.

The Dive

Lake Huron blasts into the St. Clair River with enough force to maintain an 80-foot-deep trench down the center. Every minute, 82 million gallons of lake water converge and accelerate as they are compressed into the river’s narrow mouth.  The loose gravel bottom is scoured clean offering few handholds for relief from the current’s force. A dozen shipwrecks are scattered across the bottom above and below the Bridge. Their busted-up hulls are a testament to the river’s relentless force. The wrecks provide divers with a reprieve. An opportunity to hold on, stop kicking and catch your breath. If you’re lucky, a sturgeon may come close enough to film. It happens. But more often, if there are any in sight, to get close enough to film, you’ll have to let go of the sturdy shipwreck and face the river’s force again. While your right hand struggles to hold the camera steady against a flow equal to Niagara Falls, your left hand digs into the rocky bottom grasping for anything to slow you down. Your regulator whines as your lungs demand air and your legs strain to kick with all you’ve got. The conditioning and muscle memory of a seasoned kick is the only kick that stands a chance of holding a diver on the Blue Water site.   At 80 feet, it’s about a 20-minute beast-mode workout before it’s time to head back to shore. Back to shore being the key, as we only surface in the St. Clair River as a last resort.

Overhead Hazards

The 5,000 or so ships that pass directly over the Blue Water spawning grounds each year are the reason the site remains the largest in the Great Lakes. The narrow passageway at the base of Lake Huron is a critical link in the global shipping route. As one of the busiest waterways in the world, more ships pass through the St. Clair River each year than the Panama and Suez Canals combined. Not surprisingly, or unreasonably, most people find the idea of diving under a busy shipping lane ill-advised. The irony is that the freighters are the least of our concerns. Timing freighters passing under the bridge on the Port Huron, MI livestream on YouTube, it takes an upbound 1000-footer a little less than 2 minutes to pass over the site. As long as we don’t surface during those 2 minutes, the freighters basically have no effect on us. Some divers have made claims of being sucked off bottom but what a diver thinks happened and what actually happened are not always the same. A few years back, my husband Greg agreed to take another diver out to the spawning grounds. When a freighter passed overhead, the other diver started to panic. He wrapped his arms around a boulder so tightly that he depressed the fill button on his buoyancy compensator. As his air vest filled up, he struggled to stay on the bottom which caused him to clutch the rock tighter adding more air to his vest. It wasn’t until Greg swam over and released the excess air from his vest that he calmed down and released his white-knuckle grip on the rock. The freighter was long gone but I have no doubt that when he recounts the story, he “almost got sucked up by a freighter.” There are places in the river where the freighters are more concerning but on the Bluewater spawning grounds there is plenty of water between us. Seasoned river divers know that it’s not the freighters that will get you. It is all the other watercrafts zooming around that are far more dangerous to someone bobbing on the surface which is why we always aim to start and end every dive from shore.

Weather Rules

Even if you’re good with an 80-foot dive, you can hold yourself against a strong current, you’re cool with overhead boat traffic, and you’ve invested hundreds if not thousands of dollars in underwater camera equipment, there’s still no guarantee you’ll get to film the Bluewater sturgeon spawning. The Bluewater area is aptly named as the waters flowing from Lake Huron can be a rich cobalt blue offering 60 feet of clear visibility. Twenty-five feet is pretty common. Unfortunately, so is zero. When the big lake is calm, her waters flow clear and blue. When she gets angry and riled up, waves crash on shore and all the churned-up particles travel downstream turning the river to dull muddy brown. The sturgeon spawn by temperature, not visibility. If the water is dirty when it’s time to spawn, they will still go. But if we can’t see, we don’t go. And if we don’t get to go, we have to wait 365 days for the next chance.

---

Catch more news at Great Lakes Now: 

I Speak for the Fish: Is it a rainbow trout or a steelhead? I Speak for the Fish: Hornyhead chubs are cooler than their name implies

---

Featured image: Nearly 30,000 lake sturgeon use the upper St. Clair River for spawning with about 10,000 on site each year. (Photo courtesy of Kathy Johnson)