The Making of a Dinosaur Fish

Imagine spotting a seven-foot long flash of gray armored with five rows of bony plates while you’re enjoying a summer day on the St. Lawrence River. At first, you might believe you saw a “sea monster.” Chances are you really saw a gentle giant that cruises along the bottom of our lakes and rivers sucking up aquatic insects, leeches, and zebra mussels.

Lake sturgeon (Acipenser fulvescens) are New York State’s largest freshwater fish that predate the dinosaurs you and I never knew. Once a more common sight, these swimming fossils have unfortunately been one of many populations of fish to take a hit from human activities like overfishing, dam construction, and pollution.

Recognizing the threat of losing this important species from our waterways, the Service, New York State Department of Environmental Conservation (NYSDEC), and the St. Regis Mohawk Tribe’s Environmental Division have partnered up to bolster lake sturgeon populations. Each year, with the valued support of the New York Power Authority, there is an “egg take” event where the next generation of sturgeon is made.

Making a dinosaur fish is both an art and a science. Here’s how it’s done:

Step 1: Catch the fish

A few strong biologists go out in a boat with gill nets and capture adult lake sturgeon from the South channel of the Moses-Saunders power dam, where fish congregate to spawn each spring. With high water and faster flows than usual, this step in the process was more of a workout for the crew this year. Meanwhile, two staff are on stanby at the New York Power Authority’s dock to inspect the fish and determine whether they’re keepers for the egg take. At least four good adult females are needed in order to maximize the genetic pool of eggs.

Biologists head out to collect adult sturgeon from the St. Lawrence River. Photo: USFWS.

After a tiresome stretch of weeks finding enough viable male and female fish, shuttling them into big blue holding tanks at the Power Dam, and constantly ensuring proper water quality and filtration, it’s time for the magic to happen.

Step 2: Massage the fish

Biologists massage eggs from a female lake sturgeon. Photo: Justin Dalaba, USFWS.

It’s the day of the egg take. Water splashes as a biologist wrangles a female fish out of the tank. Eggs pour into a stainless steel bowl as another hand massages them from her white belly. A syringe of sperm is injected into water and poured over the eggs. Within 30 seconds to a minute, the eggs are fertilized. Shortly after, the milt mixture (as it’s called) is poured off and fresh water is added to reduce fertilization with multiple sperm.

Mike Morgan (NYSDEC) adds the milt mixture to the eggs. Photo: Justin Dalaba, USFWS.

Step 3: The hand off

Like the passing of the torch, the eggs make their way down the assembly line from mother to fish-maker. It all happens so quickly and smoothly that you can see the years of experience these biologists have. Eggs are split between the NYSDEC Oneida Fish Hatchery and Wisconsin’s Genoa National Fish Hatchery, which will each raise their own brood of young fish for the fall stocking.

Scott Schlueter and Doug Aloisi (USFWS) dividing eggs. Photo: Justin Dalaba, USFWS.

Step 4: Chair, feather, and clay

Now things slow down for a bit. The lucky contender will spend the next 30-40 minutes in a chair, rhythmically stirring the eggs, while adding Fuller’s Earth, Iodophor solution, and station water. Sturgeon eggs have an adhesive layer that allows them to stick to rocks and other substrate in the wild. But if they clump together in a jar, that could encourage fungal growth. To prevent that, the simple method of softly stirring the eggs with a turkey feather and clay seems to do the trick. The Iodophor kills any potential bacteria and viruses that may be on the eggs.

Mixing in the Fuller’s Earth. Photo: Justin Dalaba, USFWS

Step 5: Sending the little ones on their way

Once proper de-adhesion and disinfection is achieved, the eggs are then packed up and sent off to their respective fish hatcheries, where they are expected to hatch within a week. Over the next few months, the newly hatched fish are fed a diet of brine shrimp, bloodworms, and krill until they are ready to be stocked in the fall. Of the nearly 130,000 fertilized eggs sent to the hatcheries, the hope is to produce 10,500 fall fingerlings this year.

Fertilized eggs ready to be sent off to the hatchery. Photo: Justin Dalaba, USFWS

Step 6: Saying goodbye to their parents

After making their contribution to the next generation of fish that our grandchildren may get to see, the adult sturgeon are released back into the St. Lawrence from their holding tanks. Since 1993, New York State has been restocked with nearly 105,000 lake sturgeon through this multi-agency effort with supportive funding from the Fish Enhancement, Mitigation, and Research Fund. This is only a small part of a bigger effort to do what we can to save a living fossil.

National Geographic photographer, Jennifer Hayes, films the release of an adult lake sturgeon. Photo: USFWS.

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To learn more about this effort, be sure to check out The New York Times and North Country Public Radio articles.

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A Hopeful Fish Tale

After another spring melt, the swollen streams and rivers had begun to subside.  Water temperatures fluctuated between 7-10⁰C.  Just in time for an important seasonal event, we made our way out into the field.

Walleye are a popular game fish in New York State, commonly known to thrive in large natural lakes and big rivers.  But this time of year, some populations defy expectation.  Like salmon or trout, some walleye make a “spring run” up tributaries in search of suitable spawning habitat.  In some documented cases, walleye have traveled over 100 miles upstream.  For a large lumbersome fish, swimming against the current is no simple feat.

Seven years ago, a barrier that prevented fish from migrating upstream was removed from a tributary to the St. Lawrence River, called Little Sucker Brook.  Despite its name, this small stream accommodates more than just an abundance of suckers.  Walleye are one of the priority species identified during the relicensing of the St. Lawrence Power Project that would be targeted for restoration through the Fish Enhancement, Mitigation, and Research Fund (FEMRF).  Just this winter, with funding provided by the FEMRF, the New York Field Office Partners for Fish and Wildlife staff worked with a private landowner to install two walleye spawning beds upstream of the removed barrier; meaning stones were strategically laid to provide an ideal environment for egg laying.

I joined New York Field Office biologist Justin Ecret to check in on the project.  He had deployed several cement blocks wrapped in a fine mesh into Little Sucker Brook to try and capture any eggs drifting down from the spawning bed.  For the first two days, we had our doubts that we had missed the run.  But on the third day, we had successfully collected some eggs.  Unfortunately, in the field it is nearly impossible to differentiate between sucker and walleye eggs without a microscope.

Then something happened that neither of us were expecting.  Over the berm, where the water begins rippling over the gravel bed, flashed a large fish tail.  It quickly disappeared again into the murky brown water.  Moments later, a small and large tail appeared together.  My heart jumped at the sight of the fish.  I looked over at Justin Ecret for confirmation; we had seen a small male and large female walleye on one of the rocky beds!

With a boost of confidence, Justin Ecret took a closer look at the egg samples back in the lab.  Sure enough, these were walleye eggs.  After just a couple months of constructing spawning beds, the walleye were there to use them.  This is just the first hopeful tale of these FEMRF funded projects, which aim to improve suitable spawning habitat for walleye with the ultimate goal of increasing the walleye population in the St. Lawrence River.  Watch the video of this exciting encounter:

Floating Loon Rafts for Rent: One Occupied This Past Summer

Artificial nesting platform with loon egg.  Photo: NYSDEC.

What does it take to bring back an icon to Northern New York? That’s the question that has left habitat managers scratching their heads for the past decade. After construction of the St. Lawrence Seaway and Power Project, much of the original habitat for shore-nesting birds was flooded out. As it turns out, with four cedar logs, some natural vegetation, and a lot of patience, there might be some hope for restoring the not-so-common loon to the St. Lawrence River.

“Here in the St. Lawrence-Franklin D. Roosevelt Power Project area, there are a few loons that nest in the general area, but there’s open water flowing so it’s not necessarily a great spot,” explains Mike Morgan, who manages the Habitat Improvement Projects (HIPs) on the St. Lawrence.

When the Power Project was up for relicensing back in the late 1990s, the Service, along with the New York State Department of Environmental Conservation (NYSDEC) and other agencies identified potential impacts of the power dam that should be taken into consideration. As a result, the New York Power Authority has helped fund, construct, and implement at least ten Habitat Improvement Projects targeting a variety of fish and wildlife potentially impacted by the dam.

Common loon with chick.  Photo: USFWS.

One of those species is the Common Loon. “Loons are kind of a charismatic species that people care a lot about and are considered for a lot of hydropower projects” says Morgan. Loons are pretty susceptible to water level fluctuations since they generally nest close to the shoreline. “So a pretty common technique to mitigate that is to put out rafts in suitable areas for loons to nest on because the rafts will float up and down with the water and still be easy for the loons to access,” Mike explains.

After roughly five years of trying this on Lake St. Lawrence with no loons nesting on the rafts, some were ready to give up. Having a “you build it, they will come” mentality doesn’t quite work out for loons and other species, as Mike explains. It has been a process of trial-and-error to find areas where placing artificial nesting platforms most effectively meets the needs of breeding loons. Not to mention the amount of energy it takes to haul these water-logged rafts in and out each season. Some years, geese have taken up residency on the rafts before the loons could, posing some competition for breeding space.

“One of our concerns is actually bald eagles, which is kind of funny because we like to have bald eagles around and they’re a pretty charismatic species in their own right, but they’re big enough to make life unpleasant for nesting loons,” says Mike.

First loon chick to successfully hatch and fledge from an artificial nesting platform in the St. Lawrence Power Project area.  Photo: NYSDEC.

Finally, on the tenth anniversary of the start of the HIPs, the first loon chick hatched and fledged from one of the artificial nesting platforms this past summer. That’s not the only good news – 75 osprey chicks hatched on installed nesting poles, and roughly 11,500 common tern chicks hatched on artificial nesting structures during the 10 years of management efforts for St. Lawrence River birds.

Biologists Steve Patch and Scott Schlueter from the Service continue to meet each year with other representatives from the NYSDEC, St. Regis Mohawk Tribe, Northern New York Audubon Society, the Power Authority, and the local government to review progress and make future decisions about Habitat Improvement Projects on the St. Lawrence River.