Shad/Nutrients/Water level fluctuation

[Quillback]

Saw this on the AFC website. It pertains to Greers Ferry, but you can see the similarities to any Corps lake.

GREERS FERRY – What is going on with the fish in Greers Ferry Lake? That’s a question Arkansas Game and Fish Commission is getting from concerned anglers over the past year. We know that historically low water years result in a reduction in productivity in lakes such as Greers Ferry Lake. High water years increase the nutrients in the lake through increased runoff and inundation of terrestrial vegetation.

As the flooded vegetation decomposes, nutrients are released into the water column. The nutrients made available are akin to putting fertilizer on your yard or garden. As the lake temperatures warm above 60 degrees, phytoplankton and zooplankton begin to bloom prolifically. These blooms are what cause the water to have a stained or dingy look. These microscopic plants and animals are the base of the aquatic food chain.

The AGFC can artificially induce these productive blooms on our smaller, Commission-owned lakes through fertilization. Fertilizing a lake the size of Greers Ferry Lake is cost prohibitive and there are limitations due to its use as a municipal water supply. This puts the AGFC and Corps of Engineers at the mercy of the weather in trying to maintain adequate lake levels for good fish production. In reviewing the hydrograph for the past 16 years there have had high water events on Greers Ferry Lake in 1999, 2002, 2004, 2008 and 2011 where the lake stayed up in the flood pool until at least July 1. In fact, 2008 (+23 ft.) and 2011 (+18 ft.) were the highest water levels on record with water levels in the flood pool well beyond July 1. This means there’s only had been one high water year in the past seven years. For a high water year to be truly effective it needs to stay up at least 60 days post spawn, or about July 1. The longer the water stays in the flood pool, the more it benefits the lake.

Gizzard and threadfin shad are the dominate forage species in the lake. Threadfin shad seem to be preferred since their maximum size is about 6-inches. Much research has been conducted concerning fish diets and most predators (black bass, walleye, crappie, hybrids) prefer 2 to 4-inch shad, due to the size of their mouth. Since both shad species feed entirely on plankton, they are especially sensitive to plankton densities. The more nutrients available result in better plankton blooms which results in better growth and production of shad. The stronger shad population results in better growth, reproduction and condition for predators such as largemouth bass, crappie, hybrid striped bass and walleye. If high water levels occur every three years in the spring and early summer, sport fish populations remain plentiful. Unfortunately that is impossible to control.

The management tools the AGFC uses on Greers Ferry Lake are: stocking, creel and length limits, and manipulation of habitat. The Corps of Engineers reservoir operating guide does not allow lake elevations to stay in the flood pool very long, unless they are forced by downstream flooding due to their Congressional mandate for flood control and the negative effects if has on their facilities around the lake.

AGFC fisheries biologists have spent considerable time on the lake this winter and spring conducting gillnet sampling and electrofishing. They have taken all three black bass species (largemouth, spotted and smallmouth) to the AGFC fish pathologist for a complete health analysis including viral swabs for the presence of largemouth bass virus. Data for age and growth were collected over the past year for walleye, hybrid striped bass, largemouth bass, spotted bass and smallmouth bass. This data is currently being processed and analyzed. Biologists will be able to compare the growth data to records to determine if low water years are significantly affecting growth. They are also in the process of developing models that predict shad densities based on the hydrograph of Greers Ferry Lake. Preliminary results indicate that there is a relationship between lake elevation and shad production.

Once all of the data is analyzed, a report will be written documenting the impact of the low water years on the game species. In addition to documenting game species abundance, biologists have anecdotally noticed that threadfin shad are virtually nonexistent. This is likely due to the cold winters the state has experienced the last couple of years. Threadfin shad are a subtropical and southern temperate fish preferring warm waters. Water temperatures in the low 40s can cause significant mortalities in threadfin shad populations. In smaller lakes the entire threadfin population can die. Threadfin shad may still exist in Greers Ferry Lake, but their abundance appears to be very low.

[merc1997 Bo]

interesting, but i can't help but put my observation of what i saw a couple of days ago, and see what others opinion is. i was visiting friend staying at big cedar. looking from their porch i was looking down on the big cedar cove, and that thing was solid , what i call, sewer moss. a good portion of the water had big floating mats of it. the bottom was cover with it, which in itself would make fishing any bottom contact lure impossible. now, i know we have this issue on a good portion of the lake, but not to this magnitude.

i feel it is directly related to sewage going into the lake. question is how is big cedar taking care of sewage?? i questioned someone that lives in the area is familiar with big cedar and they stated they only knew of two small sewage ponds on the property.

same question can be asked about all the condos, and any housing lake side. do any of them have any where near adequate sewage treatment. when build a house on a lot that is all rock like we have here, there is not anyway that enough lateral line could be installed to take care of sewage. you could cover the entire lot with line and not have an adequate drain field.

sure, this green mess we have growing somewhat goes away with hot weather, but it leaves a brown sludge all over everything, and when this brown sludge is all over every rock, there are never any crawdads around in that sludge. it is easy to witness this by shining a light along the banks at night and see if you see many crawdads around. you will not.

my observation is we have many nutrients going into the lake that are really not good.

bo

[m&m]

bo, I've often wondered if that has any relation to the lack of shallow grass beds. I know that the majority of the lake bottom is rock but we all see areas that you'd normally expect to see grass growing in the water.

Mike

[merc1997 Bo]

we have never had grass growing in the lake. we used to have a clean lake bottom. now ever pebble is covered in sludge, and every tree left is covered with the same brown sludge. this can be directly related to the near lake population growth and the septic systems that go with them that will not work in any way shape or form when you are dealing with mostly rock.

ever really take a look at farm ponds that livestock uses. this same slimy moss is common in every one. the mdc will not stock a pond that is not fenced off from livestock for a reason. hey!! wonder if that is why the mdc refuses to do any stocking programs on table rock???

spring branch on table rock has little to no homes near the lake. it is one of the few areas of table rock that will not have the green slimy moss growing right now. there most definitely is a connection of lake housing population and the sewer moss in the lake, in my opinion.

bo

[Pepe]

In the 90's there was an issue with Springfields lack of Waste Water Treatment Facilities an there was a noticeable effect on the James and into TR. There was litigation and the new SWWWTP was built. This cleaned up that water some.

Many folks don't know that municipal sanitary sewer and storm sewers come together into WW treatment facilities. In heavy rains the facilities are inundated and the sewage often bypasses the treatment system for lack of capacity. The Clean Water Act provides a means to bring pressure for facility improvements/replacement.

zoning regulations, regular inspection & code enforcement is effective in controlling septic deficiencies - except we all hate being regulated.

I believe Bo is right. The "Mung Weed" is not consistently found evenly around the lake. It is directly related to sewage and poor septic systems.

[mjk86]

More and more people using the same finite resource. More and more money to be made on the prime real estate around the lake. The branson explosion. Unfortunately the mung isnt going anywhere it will probably just get worse. I dont ever fish Loz but is it terrible there too? The good news is fish seem to do alright in that crap. Lots of shallow urban lakes are full of it yet loaded with largemouth.

[Terrierman]

Big Cedar Lodge has a state of the art Sequencing Batch Reactor wastewater treatment plant. It is operating at about 60% of its rated capacity. Phosphorus is removed via chemical coagulation and post secondary treatment filtration. The effluent is disinfected with high intensity U.V. lamps. In the entire history of the operation of that facility there has not been even one instance where the treated effluent failed to meet all permitted limits.

[merc1997 Bo]

well, terriermanm, what you said may be true, but the fact still remains that the big cedar cove looks like a sewer pond. how is it that areas of the lake that have very little close up housing do not look like the big cedar cove? it is hard to deny what is seen.

bo

[Terrierman]

well, terriermanm, what you said may be true, but the fact still remains that the big cedar cove looks like a sewer pond. how is it that areas of the lake that have very little close up housing do not look like the big cedar cove? it is hard to deny what is seen.

bo

What I said is true. There has been a LOT of research done on Table Rock Lake water quality. It's easily googled. You can learn a lot and while I've been doing this for a living for the last 40 plus years, the main thing I've learned is there are rarely simple answers to what often look like simple questions.

You asked a specific question about Big Cedar Lodge wastewater treatment. And you got a factual answer.

[dtrs5kprs]

There are times the goop is really bad, and others not so much. Seems like it shows up more when we have a lot of wind to push it around. Breaks loose and becomes more visible. Purely anecdotal of course.

We will probably wish it back if the Zebras take off.