September 30, 2010
The fish kills on our smallmouth rivers remain the biggest but not the only news for smallmouth bass anglers in Virginia. (February 2009)
By Bruce Ingram
Author Bruce Ingram holds a South Fork of the Shenandoah smallmouth caught before the fish kills began. The watershed's bass population has improved, but biologists don't know if the improvement is permanent. Photo courtesy of Bruce Ingram.
In a perfect world for smallmouth anglers, outdoor scribes would report all the wonderful places for Virginians to angle for our favorite sport fish. Sadly, matters have been somewhat less than ideal for most of this decade, with major kills on the Potomac and Shenandoah watersheds, and in 2007 and 2008, the James Watershed.
Scott Smith, fisheries biologist for the Virginia Department of Game and Inland Fisheries (VDGIF), relates that the James' woes manifested themselves in May of 2007 when dead fish from Iron Gate in Botetourt County (where the James begins) to Lynchburg began appearing.
From VDGIF sampling, approximately 30 percent of the fish that weren't dead had lesions, bacterial infections or fungal infections. Fish ceased dying in June and the lesions cleared up by late July. All species in the river were affected by this problem, not just bass and sunfish. The VDGIF estimated that 5 to 10 percent of the fish in the river from Iron Gate to Bent Creek died as a result of this kill event.
Smith said that the 2008 kill started in mid to late May -- a little later than it did in 2007, probably due to cooler water temps in the spring of 2008. The VDGIF had a few reports in April of dead fish, but matters didn't really intensify until late May. The spatial extent of the kill this year was shorter, basically from Iron Gate to the mouth of the Maury at Glasgow in Rockbridge County. There were a few reports of dead fish or fish with lesions below Glasgow, but not at the same level as seen upstream or compared with what was seen in 2007. The percentage of living fish with lesions and other ailments was identical to 2007 at about 30 percent. All species were again affected. Based on this, the biologist estimates that another 5 to 10 percent of the fish perished.
"We have still not determined a cause for these kill events," Smith said. "The most popular theory of the public has the kill related to the spreading of poultry litter on agricultural fields. This may indeed be at the very least a contributing factor (if not the main cause), as the kills are somewhat associated with areas that receive poultry litter. We are looking at the poultry litter theory with the same intensity as other theories: pesticides, pathogens, pH, temperature and other possible causes.
"However, there have not been kills in some watersheds that get poultry litter, and there have been kills in some that we don't think get much poultry litter. The data on the litter is incomplete, so it's hard to determine if there's really a link or not. It's a nice hypothesis, but that's all it is at this point. It could be a primary cause, or be completely unrelated. Until we get better info on what's in the litter and where it's all going, we won't be able to determine if it's a causal factor.
"As for other causes, we have pretty much eliminated most of the known fish diseases out there, although we are still looking at a couple of them. At this point, it could still be caused by a pathogen, although some form of water quality stressor seems more likely. If it is a water quality related issue, then the trick will be to determine which compound or combination of compounds is the culprit. Since that list is a long one, it won't be an easy task. Since nothing that I'm aware of has changed, and we have not determined a cause, there's no reason to think these kill events will not continue to happen every year."
Smith does say that the VDGIF has several monitoring programs in place that should provide everyone with a better picture of what's going on during these kill events. When that monitoring is complete, the VDGIF should be better able to focus its search for a cause.
Smith emphasized that several scenarios are likely to play out regarding the upper James' future.
"If the recruitment (spawning success) and growth rates of the fish in the river do not change as a result of these kills, then you will see a decrease in larger (older) fish of all species," he said. "Total numbers may not change very much with an increase in mortality rates of 10 percent, but the numbers of older fish will decline. Needless to say, this will not improve the trophy bass population in the river.
"Catch rates of smaller fish will not be noticeably different, so total numbers of fish out there won't really change. The other scenario (already seen in the Shenandoah) is that spawning success and growth rates both seem to increase in conjunction with these kill events. This may be directly related, or entirely coincidental. The end result of this is that an additional 10 percent mortality won't even be seen in the numbers of larger fish. If there are more (fish) coming into the system, and they are growing faster, then this will compensate for the additional mortality. It remains to be seen whether or not this increased recruitment and growth are truly linked to the kill events or not."
Also, continued Smith, the VDGIF does not know if future kill events will all be at this 5 to 10 percent mortality level. Thus, for the time being, the fish populations are still good. Whether or not they stay that way remains to be seen. There are numerous unknowns, and the range of consequences could range from none to severe.
"Ideally, we will determine the cause and correct the problem before much longer," concluded Smith. "If we don't, the future is uncertain, at best. The small amount of information that we do have suggests that these kills are not catastrophic, and that the impacts are less severe than we would have guessed. However, we are working with a very limited data set, so the potential for more damage than we're currently seeing exists."
VDGIF biologist Dan Michaelson also monitors the James and agrees with Smith's assessment.
"We don't seem to have been impacted by the kill below Scottsville and probably even up to Bent Creek," Michaelson said. "I haven't heard many fishing reports, but what I have heard is that anglers are reporting good catches of fish to 12 inches with some larger fish starting to show up in their catch."
The Shenandoah Watershed largely escaped fish kills in 2008. Herschel Finch, conservation chairman for the Potomac River Smallmouth Club (PRSC), believes a logical reason exists for this reprieve.
"I think that's mostly contributable to the cool, damp spring we had," Finch said. "The gradual warm-up and
regular rains helped the smallmouth immune systems to ramp up in a gradual manner prior to the spawn, and bass didn't have to try and fight off the viral and bacteria blooms we've seen the past few years when there were high temperature spikes and heavy runoffs.
"And I also know that the general levels of pathogens, viruses and bacteria (feared) to cause the fish problems are still present at lethal levels. But the moderate weather we had this spring helped to keep them in check somewhat. I have not seen or heard of any reports of many dead fish or fish with lesions anywhere on the Shenandoah. There have been some reports of fish with lesions in the Potomac around Knoxville Falls and just above Brunswick, but not in the numbers we have seen in past years."
Finch notes that the PRSC has a "go team" in place where club volunteers can take off work with a day's notice and conduct scouting and data-gathering forays on the Potomac and Shenandoah if a fish kill event occurs. They would assist Jeff Kelble and Ed Merrifield, Shenandoah and Potomac riverkeepers, respectively.
As Finch notes, the situation on the Shenandoah is better. VDGIF biologist Steve Reeser said that a light smallmouth kill took place in the spring of 2008 on the upper reaches of the North and South forks of the Shenandoah and signs of stress were noted in the form of lesions. The odd redbreast sunfish and occasional sucker also perished. As readers recall, considerable numbers of smallmouths and other game fish have been dying on the Shenandoah and Potomac watersheds in Virginia and West Virginia since 2002, especially in 2005.
Interestingly, during those fish kill events, recruitment of young smallmouths has been outstanding informs VDGIF biologist Steve Reeser.
"What we're seeing on the James and Shenandoah is a shift in the size structure," he said. "The numbers of bigger bass are going down, although quality fish do exist. There are lots of 1- to 2-year-old smallmouths, especially on the Shenandoah."
Just when there's some good news regarding the fish kill situation, however, harsh reality seems to strike.
"Most disappointing was to hear the Cowpasture and Jackson rivers (which come together to form the James) are now showing the same problems we have on the Shenandoah and the Upper James," continued Finch. "The rivers we're now most concerned with are the Rappahannock and Rapidan.
"There has been a recent increase in chicken litter use in all four of these watersheds. I have also personally seen bio-solid spreading on farm fields almost right next to the Rapidan just east of Culpepper."
John Odenkirk is the VDGIF biologist for the Rappahannock and Rapidan rivers. He notes that smallmouth bass were stocked in the Rappahannock in July of 2007, when 14,725 fingerlings were released at seven sites as part of an experimental exercise. Tote barge electrofishing samples were conducted at four of the seven stocking sites during October, and all smallmouth bass less than 170 mm were reserved for collection. However, out of the 105 fish captured of that size, only one was a stocked fish.
"Based on sampling data from previous years, the smallmouth bass population size and size structure (should have improved) due to record and near-record production in 2004 and 2005 combined with an average spawn in 2006," Odenkirk said. "It appears that production in 2007 was at least average.
"The VDGIF did some supplemental sampling the spring of 2008 with Virginia Tech as part of the Fish Kill Task Force background survey and managed to collect eight yearling fish at Kelly's Ford. Two of these were stocked. Thus, I think it is too early to say if the stocking was a success or failure.
"The Rappahannock is fishing extremely well due to the presence of strong year-classes as noted. I do not think that shad and herring abundance have yet had an impact, as numbers spawning above the old Embrey dam site are still relatively low. I feel this should change with each passing year; and at some point, we should see elevated growth rates due to the presence of additional forage."
MORE GOOD NEWS
Fortunately, good news does exist. VDGIF biologist Tom Hampton reports on the North Fork of the Holston and Clinch.
"We sampled the Clinch and North Fork Holston the spring of 2008," he said. "Catch rates were over 100 smallmouths per hour of electrofishing, which is outstanding for the North Fork Holston. An amazing number of 14- to 18-inch fish are available for anglers, especially in the lower reaches of the river. Catch rates in the Clinch River were about 70 smallmouths per hour of sampling. This catch rate is very good for the Clinch River. There are not as many 14- to 18-inch fish available in the Clinch, but there are some trophy smallmouths waiting for the persistent and fortunate angler."
Claytor Lake is one of the major smallmouth impoundments in the Commonwealth and VDGIF biologist John Copeland gives this update.
"Claytor Lake's smallmouth bass fishery is in good shape, according to electrofishing samples there in the spring of 2007," Copeland said. "I heard reports that smallmouth bass fishing on the lake was good in 2008. Claytor Lake accounts for an average of about 19 smallmouth bass citations each year over the past 10 years, so it is not the place to look for trophy smallmouth bass, when compared to the New River.
"Claytor Lake offers good smallmouth bass fishing for bass up to 3 pounds. The best areas to look for smallmouth bass are in the middle and lower lake areas downstream from the mouth of Peak Creek."
Copeland adds that the New River's smallmouth fishery is in good shape and could possibly become even better. The biologist describes the spawns of 2004, 2005 and 2007 as "abundant" and trophy-sized bass from the good spawns of 1996 and 1998 still swim the river. The New remains the best place to go in the state for trophy smallmouths.
In this era of threats to Virginia's riverine smallmouths, anglers need more than ever to disabuse themselves from misinformation. Biologist Steve Reeser listed a couple of commonly held myths.
€¢ Myth One: Fishing for river smallmouth bass during the spawn has a negative impact on the population. The reality, Reeser emphasizes, is that angling pressure has little to no effect on the success of a spawn. What truly matters is that water levels be moderate during and after the spawn. High water can hurt spawning success and drought conditions can make fry vulnerable to predators.
€¢ Myth Two: Catch-and-release is always good for bass. Reeser said the reality is that spawning success is what "drives" these fisheries. Catch-and-release may help "recycle" some of the older/larger smallmouths so they can be caught several times over multiple years. However, catch-and-release will not always help increase anglers' catch rates. Anglers can observe fluctuations in the number and size of smallmouths they catch from year to year. This change is influenced primarily by spawning success in p
revious years. When a river experiences two or more poor spawning years in a row, the outcome is fewer bass in the short term and a decrease in quality-size bass in the population four to six years later. Catch-and-release cannot fully mitigate for decreases in the population brought on by environmental conditions.
A number of organizations in Virginia are engaged in activities that are designed to help smallmouth fisheries in the state. Among these organizations and activities are:
€¢€‚Riverkeepers Ed Merrifield (www.potomacriverkeeper.org) and Jeff Kelble (www.shenandoahriverkeeper.org) work to protect and improve our fisheries.
€¢€‚The conservation group Potomac River Smallmouth Club (www.prsc. org) also seeks to improve smallmouth fisheries.
€¢ The VDGIF efforts involving the fish kill investigations and in their habitat improvement programs. The agency also offers numerous programs to improve riparian zones and protect headwaters (www.dgif.virginia.gov).
€¢ Additionally, there are various Friends of Rivers groups. All of our major rivers have such groups and these organizations can easily be found by doing Google searches for them on the Web. A few examples include the James River Association, Friends of the Rappahannock, and Friends of the Shenandoah.
€¢ Individual anglers can also help by sending reports of any sick or dead fish they observe to the Virginia Department of Environmental Quality at (800) 592-5482, fishreports@deq. virginia.gov.
(Editor's Note: Bruce Ingram is the author of the following books (cost in parentheses): The James River Guide ($17.25), The New River Guide ($18.25), Shenandoah/Rappahannock Rivers Guide ($18.25), and his new book, Fly and Spin Fishing for River Smallmouths ($19.25). To purchase one, contact Ingram at P.O. Box 429, Fincastle, VA 24090.)