Think of the Niagara River’s ecosystem as a house of cards, and an often overlooked minnow species holds much of it up.
A lot rides on the 3½-inch-long emerald shiner, everything from fishing for smallmouth bass to catching sight of an osprey or bald eagle.
But researchers see signs of trouble for the native fish. In 2014, they could find the native fish in plentiful numbers in the Niagara River.
But last year, the shiners’ numbers fell by nearly 75 percent.
“If the emerald shiner collapses, everything goes,” said Alicia Pérez-Fuentetaja of SUNY Buffalo State’s Great Lakes Center.
Not much is known about the shiner in the Great Lakes region. But two years into a three-year study spearheaded by the Great Lakes Center, researchers noticed fewer shiners and a big challenge the species faces here. The small fish struggle against strong currents – exacerbated by man-made barriers – in the Niagara River.
“It’s a real gauntlet the shiners have to negotiate in order to get into Lake Erie,” said Andrew Hannes, a U.S. Army Corps of Engineers ecologist.
While the lower numbers could be just one bad year, experts say it could be a harbinger of a bigger problem.
And that would have repercussions. The shiner is considered a keystone species, meaning its existence affects the ecosystem up the food chain. The minnow is the chief food source for various Great Lakes sportfish, a multibillion-dollar regional industry.
More needs to be learned about the species here, said Pérez-Fuentetaja, an aquatic ecology professor who’s leading the Emerald Shiner Project The way Pérez-Fuentetaja sees it, the emerald shiner’s food sources, habitat, spawning locations, population, genetics and hydrological impediments all need to be identified before wider efforts can be made to protect them.
“With no food there, things disappear,” Pérez-Fuentetaja said.
A hard swim
One of the places to find the emerald shiner is where the river narrows near Broderick Park in Buffalo.
The current and an eddy created there by a timber crib appear to be stopping the upstream advance of the shiner.
“It’s pretty easy for a casual observer to see these fish are getting pretty jammed up right there,” said Timothy DePriest, an ecologist with the state Department of Environmental Conservation.
It makes them easy prey.
Bait chasers go there with dip nets. Smallmouth bass, perch and steelhead go there for food.
The Army Corps and UB researchers tested the speed of the river between the Peace Bridge and Black Rock locks.
Using the only data available about the swimming abilities of the shiner – cursory studies collected from other parts of the country – scientists think the river is probably moving too fast for the fish to advance near the 800 foot-long, man-made shoreline timber crib near the foot of Ferry Street.
“All our evidence is that, in the Broderick Park area, the flows and turbulence are in excess of what a shiner can swim against,” Hannes said.
That led UB researchers Kendra Vorenkamp and Brandon Sansom to experiment inside an Ellicott Complex laboratory. There, they tested the strength and endurance of the shiner in a controlled recirculating hydraulic flume.
Think of a long, slender fish tank.
Water is calibrated for temperature, dissolved oxygen levels, proper pH and other parameters to mimic the composition of the Niagara River.
Vorenkamp and Sansom test one and two shiners at a time against a set current for two-hour “endurance periods” and repeat the process 10 times.
In another experiment, the water velocity is ramped up incrementally until the shiners can no longer swim against it.
The fish are also tested in a peak current speed of about 75 centimeters per second, which exhausts the fish in fewer than 30 seconds.
By comparison, the Niagara River water velocities near Broderick Park exceed 100 centimeters per second, according to researcher measurements.
Other areas are double or triple the speed of what shiners can swim against in the flume.
For the next several months, the same experiments will be conducted in the lab with four shiners at a time, then eight shiners at a time, and then 20 and even full schools.
That should help scientists gain insight into the behavior of the fish. Then the scientists can extrapolate what might be happening in the Niagara River.
From there, the UB team and the Army Corps hope to design fish passage structures in the river to help the shiners get where they want to go.
“The ultimate goal of this project is to help them get upstream,” Atkinson said.
Besides some studies in the 1970s in Lake Erie’s western and central basin in Ohio, not much is known about the shiner in the Great Lakes region.
So Great Lakes Center researchers, spearheaded under the direction of Pérez-Fuentetaja, are working to fill the gaps.
For two years, Great Lakes Center research scientists dipped their nets at 16 locations in the Niagara River corridor between Rich Marina in Buffalo and the La Salle Yacht Club in Niagara Falls.
That’s how they spotted the declining numbers of emerald shiners.
It could be from disease, a parasitic infection, incompatible water temperatures, pollution or a combination of factors, Pérez-Fuentetaja said.
“We’ve seen a lot of sick fish, sick emerald shiners,” she said. “The water quality is poor.”
Sewage overflows into the water. The water also contains caffeine, antidepressants and contraceptives.
Besides investigating the year-to-year ups and downs of the shiners’ population, scientists hope to learn more about the types of habitat best suited for shiner reproduction and survival, their food sources like nanoparticles and zooplankton as well as the genetic differences in the fish.
Fish geneticists from Virginia Tech University also are assisting local researchers in pinpointing characteristics in the shiners unique to populations in the upper and lower Niagara Rivers, and in Lake Erie and Lake Ontario, respectively.
“This is kind of a novel research project,” said Bryan Hinterberger, a U.S. Army Corps of Engineers’ project manager and a research collaborator for the Emerald Shiner Project.
Short shiner life
Researchers have gained new insights about the species in the Niagara River during their first two years of work.
There are two or three peak spawning seasons, usually in June or July, after the water temperature reaches about 70 degrees.
Shiners spawn in open water and develop into larvae within a day or two. Larvae are often found in the safe harbor of marinas. They rapidly grow into 1½-inch-long juvenile fish and seek the protection of marshy wetland areas before eventually joining juvenile schools.
In the fall, those juveniles join adult schools. Most never live past a year or two, dying mostly at the mouths or beaks of predators like bass, trout, loons, terns, egrets or seagulls.
“The mortality of the shiner population is very, very high,” Pérez-Fuentetaja said. “Eighty percent die each year related to predation, disease and fishing.”
Field studies by the Great Lakes Center showed 69 percent of the shiners collected were less than a year old, 26 percent were between 1 and 2 years old and only 5 percent were two years or older.
Weather and water temperature may play a role in year-to-year shiner populations, according to the center’s research.
Studies showed that, after the record cold of early 2015, larvae emerged almost a month later than they did a year earlier, and the overall population was down 75 percent from 2014 levels. Data shows Lake Erie’s water temperature reached 70 degrees on June 29, 2014, but not until July 15 in 2015.
Although Lake Erie never froze over last winter, the delay in warm spring weather seems to be hurting the shiner again in 2016, Pérez-Fuentetaja said.
“The spring temperatures are cold this year, and we are seeing a lot of sick emerald shiners this early in the season,” she said.
Other research revealed:
• Emerald shiners comprised 90 percent of the stomach contents of walleye and more than 70 percent of the stomach contents of steelhead trout.
• Lake Erie and the upper Niagara River shiners are more genetically similar to one another than shiners from the lower Niagara and Lake Ontario.
• Shiners in the Niagara River tend to be thinner and more pencil-shaped than those in the lakes, which could be a result of the strong river current.
• Adequate nutrition is available for shiners in the upper Niagara River in the forms of algae and zooplankton.
Researchers said the lives of the emerald shiner and the threatened common tern are delicately intertwined.
Last year’s dip in the shiner population may have had a correspondingly detrimental affect on area terns, researchers say.
“Last year, their chick rearing success was pretty low,” said Jo Johnson, a graduate student on the project. “The emerald shiner is their main food source.”
It’s why researchers stress the importance of the tiny minnow in the larger ecosystem.
“This little minnow is part of the middle of the food web,” DePriest said. “There are so many fish and wildlife that rely on this tiny fish.”
The Niagara River corridor is classified by Audubon as one of three globally “Important Bird Areas” west of Rochester.
So the findings from the Emerald Shiner Project could prove invaluable to the river’s recovery, said Jill Jedlicka, executive director of Buffalo Niagara Riverkeeper.
“It’s not just a study for the sake of a study,” Jedlicka said. “It’s a study to fix and restore.”
And it could help restore the shiner’s habitat, shoreline and water quality not only along the Niagara River but in other ecosystems.
“We’re going to learn a lot at the end of this,” said Hinterberger from the Army Corps. “There might be widespread application of this in the United States and around the world for the small fish in the big river.”