Friday, Nov. 2, 2012
There it was, gently coasting along the shallow waters of the James River just below the urban backdrop of the Richmond city skyline – a giant prehistoric fish that once swam with the dinosaurs.
The rare sighting of an Atlantic sturgeon, one of the oldest species of fish in the world, just under the 14th Street Bridge in downtown Richmond last month generated a great deal of excitement.
Even more compelling during that same week was the discovery of the first fall spawning female – there were eggs in the water everywhere. Coincidentally, folks down on the Roanoke River came across a very similar scene.
No one could be happier about the find than Matt Balazik, a doctoral candidate at Virginia Commonwealth University. He made the initial discovery of the spawning female and eggs in the James.
Balazik is part of a research team at the VCU Center for Environmental Studies and VCU Inger and Walter Rice Center studying the Atlantic sturgeon to learn more about its life history and biology in an effort to protect it and restore it to the coastal rivers of Virginia.
“We now have proof that there is fall spawning sturgeon in the James,” said Greg Garman, Ph.D., director of the VCU Center for Environmental Studies, who has been instrumental in leading the sturgeon restoration efforts at VCU.
“Within the sturgeon world, this kind of news is a big deal … It’s an aspect of the biology and life history that is brand new, and one that could have big impact on the recovery plans that will have to be written,” he said.
In the past 100 years, sturgeon numbers have experienced a significant decline, due largely to overharvesting and the construction of dams that have altered its habitat.
Before that time, the fish was hailed as a legend of sorts, having likely saved the early European colonists in Jamestown from starvation with its sweet, succulent flesh during the winter of 1609-1610, also known as The Starving Time, when little food was available. The glory years for sturgeon harvest were between 1860 and 1900, but by 1920 there were not enough fish to support a fishery, which led to the collapse of the fisheries.
Since the early 1990s, experts believed the Chesapeake Bay population to be extirpated – completely lost beyond recovery – but the VCU team has captured, tagged and released more than 150 different fish.
“That’s a good sign that the population is recovering,” said Balazik.
Another good sign: the VCU team, together with colleagues from the U.S. Fish and Wildlife Service, the University of California and the University of Maryland, recently published findings of a three-year study documenting that the James River Atlantic sturgeon population in Virginia spawn in the fall.
The findings of this research challenge a longstanding view that this species only spawn in the spring. Experts assume that there is spring spawning here in the James River, just as there is one in the Hudson River and in some of the few remaining other rivers with the fish.
According to Garman, the fall spawning may signify some unique ecological trait of the James River yet to be determined and understood.
“The James River that is the only place that still has relatively stable spawning populations of sturgeon and we need to figure out what makes the James so unique … If we can figure that out, that could be the key to restoring the species,” said Garman.
A primitive fish
Donning a suit of armor made up of five rows of large bony plates, called scutes, instead of typical scales like most fish, the Atlantic sturgeon looks like the dinosaurs with which it once coexisted. It has a tail similar to that of a shark – with a large upper lobe and smaller lower lobe
The fish lives much of its life in the ocean, but comes into large rivers to spawn. Adults can weigh up to 800 pounds and be up to 19 feet long. They have been reported to live up to 60 years old, but could probably live for more than 100.
There are approximately 30 different species of sturgeon worldwide and almost all of those are in peril of some form. Individual populations within the species have been extirpated. All of the populations of the Atlantic sturgeon that remain are federally listed under the Endangered Species Act. One of those populations in the Gulf of Maine has been listed as threatened under particular criteria. If that action was not taken, then that species would likely be extinct within approximately 20 years.
VCU is among a handful of research groups investigating the biology and life history of the Atlantic sturgeon. Other groups are looking at Atlantic sturgeon populations in the Hudson River, the Delaware River and the southern end of the sturgeon-range in Georgia.
As of a couple of years ago, the Hudson River likely boasted the largest population remaining on the Atlantic coast, but Garman said that “the James River may be making a run at that title” because the research here is suggesting that there are many unaccounted fish out there.
For the past four years, the VCU team has been monitoring the James River for sturgeon, using ultrasonic tagging to track their movement and collect data. According to Balazik, once the fish is tagged, the tag is typically good for up to 10 years. The more tags that are put out, the more information and data can be collected, such as the sturgeon’s reach of the river, where they are spawning and whether they are moving upstream or more downstream.
The VCU team has caught approximately 220 adult sturgeons and less than 1 percent of those have been recaptures.
“If we’re not seeing the same fish year after year, but we’re still seeing the same number of fish every year, it would be that the population is a lot larger than we might have thought … and again that has huge implications for how quickly we will be able to recover this particular population in the James and how quickly other populations might be recovered,” said Garman.
As Garman and Balazik continue to observe and collect evidence of a fall spawning in the Chesapeake Bay sturgeon species, they hope the findings may ultimately lead to dredge restrictions, similar to what is done in the spring during the anadromous fish run. Anadromous fish, such as salmon, sturgeon, shad and herring, typically are hatched in fresh water such as a river and then spend most of their life in the sea, before returning to fresh water to spawn.
Dredging, the action of pulling up bottom sediments of the river and putting it elsewhere, can kill fish eggs. There are presently no restrictions on dredging during the fall months in the James River.
“If there is no protection for fish that live here when they are reproducing, then their young have a lower chance of survival,” said Balazik.
“The key to reestablishing a [sturgeon] population throughout the Chesapeake Bay – the James, the York, the Rappahannock and Potomac – and that is starting here,” he said.
Spawning reefs, habitat restoration, threats and populations monitoring
With the creation of channels to allow large vessels and ships through the freshwater of the James, much of the preferred spawning habitat of the sturgeon population here has been lost. Garman said that in the past 100 years, the spawning habitat for Atlantic sturgeon has declined from 40 percent to 8 percent. Some of the spawning areas have been buried under sediment due to natural occurrences and human activity.
So in 2010, the VCU Rice Center, together with James River Association and Luck Stone Corp., came together to construct an artificial sturgeon reef – a hard rock surface on the floor of the James River approximately the size of a football field. The reef provides an ideal area for this fish to spawn and deposit eggs. The sturgeon reef was the first of its kind for the Chesapeake Bay watershed and the entire East Coast. Then in 2011, Vulcan Materials donated rock for a second spawning reef. The plan is to construct several reefs in all. Garman said researchers at VCU are actively monitoring the reefs to determine if the fish is able to successfully spawn.
Researchers at VCU also have been evaluating possible threats to sturgeon, including ships or other vessels, dredging and being caught unintentionally.
As part of population monitoring efforts, the team is also collecting data on numbers of fish and their age, size, structure, growth and diet, as well as collecting genetic clips from the fish. Genetic analysis of these clips show that the sturgeon in the James River are unique from other areas and are likely from the same population that has existed in the James for thousands of years.
Two years ago, the VCU team published a study in the journal Biology Letters, a journal of the Royal Society of Publishing, examining age and growth rates of the Atlantic sturgeon spanning a period of 400 years. According to Garman, the team compared Atlantic sturgeon spines from colonial Jamestown that had been located by archaeologists in the area to more recently collected sturgeon spines found in the James River. They found that the sturgeons of the colonial-era population were much larger and older compared to their modern counterparts. Garman said that the difference may be attributed to colder water temperatures during colonial times.
Next on the research agenda, Garman and Balazik will identify critical habitats used by Atlantic sturgeon in the James to learn more about the biology and ecology of young sturgeon, which reside in the river for several years before starting oceanic migrations. Research will focus on effective management and recovery of this unique species.
The big picture
While the sturgeon offers a glimpse into prehistoric times and has played an important role in Virginia’s history, it also is proving to be a big player in our future.
As Garman sees it, studying the sturgeon is a reminder of something bigger and paints a broader picture of how the many different elements of the environment are connected.
“It moves freely between the open ocean and then in two feet of water underneath a bridge in Richmond – and to me it’s an example of how all these different pieces of the environment are linked,” said Garman.
“You can’t manage each of them independently – what we do in the James River, right here in Richmond can impact ultimately what happens elsewhere … and out in the Atlantic ocean,” he said.
“This is an iconic, historically significant, superlative fish – it’s the biggest, longest-lived, migrates the greatest distance - it’s just a privilege to learn about it,” said Garman.
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