Weirs Closed

[mr crab]

Originally Posted by Smalls

But freshwater inflows are still greater when they occur. You have a much larger drainage area for the Sabine and Neches rivers than the Calcasieu.

I admit, I did miss the Neches SWB though.

For whatever reason saltwater has had a greater effect to this point on Big Lake than on Sabine.

It may be what some have said before.."not all marsh is created equal"..idk..maybe the vegetation, soil make-up, or elevation makes the Sabine marsh more salt tolerant? or maybe its dying off too, and nobody has noticed? Heck IDK

[Natural Light Kid]

Originally Posted by mr crab

saltwater barriers on the neches and the sabine. Also the main determining factor for the freshwater flowing into Sabine is he dams on Rayburn and Toledo. When they ain't generating power at those dams, the water don't flow. And the gulf pours directly into sabine...straight shot. It doesn't sit off to the side of the channel like B.L. does, so if anything, I would say Sabine receives more of a direct saltwater influx from the gulf?

It may see a more direct influx of saltwater but it probably sees more influx of freshwater too. I used to fish Sabine quite a bit before Rita and my father-n-law used to guide in it. My personal opinion (no scientific backing like the rest of my thoughts) is that Sabine gets "turned over" more often than Calcasieau does. There are times when it's fresh and times when it's salty. More like the way Mother nature intended.

[DA COVE]

If man would leave most things alone, NATURE would take care of itself. We can help, but we'll never control it..

[Natural Light Kid]

I've heard old timers talk about how back in the day before the channel they would sometimes catch tarpon in Prien and other times they caught bass. wish I were around when it was a natural estuary.

[Duck Butter]

Originally Posted by MathGeek

Smalls, I agree there are challenges when assigning importance to competing hypotheses when multiple factors are in play. We've developed new analysis techniques (based on multivariate analysis techniques in other fields) that are effective in unravelling food web dynamics of complex ecosystems given sufficient years of data. With a decade of data, inferences are possible with greater statistical confidence than possible now. If hypothetical causes are relatively uncorrelated, confident inferences may result from only 5-7 years of data. Empirical methods to estimate interaction matrix elements in the coupled Lotka-Volterra equations are something of a holy grail in population modeling. Our analysis approach shows promise toward accurately estimating species interaction coefficients (matrix elements) as well as making inferences regarding competing hypotheses in food web dynamics.

For example, suppose current trends hold for a decade (they might not). If the mean annual relative condition factors of a given length class of a given species (say bull redfish > 800 mm) have a strong correlation (r > 0.8; P < 0.05) with oyster stock assessments, but relatively weak correlations with other hypothetical factors (r < 0.5; P > 0.2), then there would be greater statistical confidence that oyster reef condition plays the strongest role in bull redfish condition. Likewise, suppose a different length class/species combination (say redfish 400-500 mm TL) is most strongly correlated with the exchange between the marsh and lake (r > 0.7; P < 0.05), but only weakly correlated with other factors (r < 0.5; P > 0.2); one could confidently infer that weir operation has a strong role. Finally, suppose that the shortest sampled length class of specks (290-400mm TL) is most strongly correlated with exchange between marsh and lake (r > 0.8; P < 0.05), weakly correlated with population of speckled trout (r > 0.5; P < 0.05), and uncorrelated with other factors. This would suggest a rank ordering of weir operation (lake-marsh exchange) then speck overpopulation (limits) above other hypotheses regarding the relative condition factor of specks 12-16" TL.

Right now, there are three years of data, and we'll have a fourth year by the end of June. More can be said than with one or two years of data, but less than possible with a decade of data. For example, if the speck limit were a dominant factor in the lake's food web impacting redfish and drum and gafftops as well as specks, one would expect that the condition factor of specks (especially the shorter length classes, since they have the highest populations) would be more strongly reduced than the relative condition factors of redfish. This is because the food competition is stronger within a given species than with other species. One would also expect Kn of different length classes and species to be highly correlated with each other, since the underlying cause would be the same. However, that is not what we see. The Kn of shorter specks has been between 0.95 and 1.05 in all sampling years (2011, 2012, and 2013); whereas, the Kn of redfish in the 500-650mm length class (that tend to stack up strongly at the weirs) has dipped below 0.95. Weir operation seems to be having a bigger impact on redfish between 20-26" long than the change in the speck limit. This seems more likely than not with available data , but cannot be inferred with a 90% or 95% confidence level. With a decade of data, this apparent inference might wash out in the noise or it might be established with greater confidence.

Another factor to consider is that Kn for all length classes and species (except for Gaftops 450-550 mm TL and bull redfish) rebounded strongly in 2013 over 2012. Only the shorter length classes of specks and redfish 400-500 mm TL topped 1.0 (returned to normal). Most length classes and years had Kn increase by about 5%, whereas specks (combined lengths) had a Kn increase of 9% (+/- 1.5%). This rebound cannot be explained by a recovery of the oyster reefs. However, the rebound does coincide with much lower salinity levels in the lake for the first six months of 2013 (compared with 2011 and 2012) that allowed the weirs to be opened and bait to flow back and forth from the marsh and lake. Based on available data, it seems more likely than not that the exchange with the marsh plays a significant role in relative condition factors in these cases. Once again, this inference might wash out in the noise with a decade of data, or it might be established with greater confidence.

Salinity levels have been a bit in 2014 than in the same period in 2013, but lower than 2011 and 2012; however the weirs have hardly been opened so exchange with the marsh has been small. If we had LDWF's 2014 oyster stock assessment data (not available yet), we could weight the different factors and make some Kn predictions for each length class and species based on past years and our current understanding of the relative importance of each factor. If the 2014 oyster stock assessments are still down, I expect Kn's closer to what was measured in 2012 than in 2013.

Louisiana law mandates wildlife resources be managed with the "best available" science. My issues with the speck and tripletail limits is that CCA pushed for more restrictive regulations with no data at all. Available data was not reviewed; there were no hints of stock assessments; existing data from trawl studies and LDWF's fishery independent surveys was not consulted. In contrast, oyster stock assessments and the best available fisheries dependent data for Big Lake both suggest that oyster dredging is doing real and lasting harm. Volumes of published scholarly papers document valuable ecosystem services provided by oyster reefs, additional annual fisheries production around restored reefs, and the negative consequences on estuaries from the destruction of oyster reefs.

It is sad to think that a humble relative condition factor study may constitute the "best available" data on the state of the fishery in Calcasieu Estuary, but until LDWF and CCA improve their scientific committment, this may be the situation. Air Force support for the project dried up about the time of the sequester and furlough, right before I left the Academy and moved back to Louisiana. The study moves forward on a bit of private funding, exiting equipment, many volunteer hours, and kindness of those who let us weigh and measure their fish. Will we manage to get hundreds of fish weighed and measured in a three week window every year from now until 2021? I don't know.

MG, need a link to that 2000 USGS study you keep quoting please

[Smalls]

Originally Posted by DA COVE

If man would leave most things alone, NATURE would take care of itself. We can help, but we'll never control it..

So what is nature to do when it can't take care of itself because of human alterations? The problems in the cameron-creole are directly linked to the saltwater intrusion caused by the Calcasieu Ship Channel. The vegetation was dying so rapidly that there was nothing to take its place.

[MathGeek]

Originally Posted by Smalls

But freshwater inflows are still greater when they occur. You have a much larger drainage area for the Sabine and Neches rivers than the Calcasieu.

I admit, I did miss the Neches SWB though.

For whatever reason saltwater has had a greater effect to this point on Big Lake than on Sabine.

Sabine has a much smaller (narrower) coupling between the lake and channel at the southern end. Most of the salt water coming into the channel flows up and around and actually enters the lake at the northern end because the coupling at the N end is the full channel depth (40 ft) whereas the coupling at the S end is shallow (5 ft). There are many times when Sabine Lake is actually saltier at the N end than the S end.

Big Lake has a wide open coupling between the lake and channel at the S end that is about 15 times longer than the coupling between the channel and S end of Sabine. The salt water coupling from the Gulf to the lake is much stronger on Big Lake. The wide open gap between channel and lake at the S end of Big Lake is the place to stop the salt.

[DA COVE]

Originally Posted by Smalls

So what is nature to do when it can't take care of itself because of human alterations? The problems in the cameron-creole are directly linked to the saltwater intrusion caused by the Calcasieu Ship Channel. The vegetation was dying so rapidly that there was nothing to take its place.

And with it's continued human alteration and the increase in shipping traffic in the near future, it's pretty fuch screwed.

[mallardhead]

Originally Posted by DA COVE

If man would leave most things alone, NATURE would take care of itself. We can help, but we'll never control it..

Amen

Sent from my LGL45C using Tapatalk 2

[Cripley]

I understand now with the human alteration it can't just be left to nature in saying direct link to ship channel and continued dredging so will creating a narrower passage via longer jetty or rocks coupled with a more limited controlling weir than now be a beneficial means of just closing the weir have to say this conversation has given me a broader understanding of the Lakes issues

I also had a question when we talk about more fresh water coming into Sabine does the locks and saltwater barrier hurt more than help

["W"]

I know enough about fishing this lake to know the weirs are a major problem.

Fish are not holding because the bait is not here

It's freaken April almost May and I have not seen one group of birds picking shrimp( heard a few who saw a group or two lately)


Over oystering is also a problem and too deep a ship channel is also a problem

So right now we have a perfect storm!!

[MathGeek]

Originally Posted by Cripley

I understand now with the human alteration it can't just be left to nature in saying direct link to ship channel and continued dredging so will creating a narrower passage via longer jetty or rocks coupled with a more limited controlling weir than now be a beneficial means of just closing the weir have to say this conversation has given me a broader understanding of the Lakes issues

I also had a question when we talk about more fresh water coming into Sabine does the locks and saltwater barrier hurt more than help

I don't think so, other than the human costs and inconvenience of maintaining the system and waiting to cross if you're in a boat.

["W"]

CCA get off there azz and do some marsh restoration instead of sunshine pumping a useless half million dollar reef maybe we can save the marsh and allow weirs to stay open


Hell I bet we could start a save the Marsh foundation to raise money to restore marsh on a trade to leave them open

[Goooh]

I quit reading when someone asked what Mother Nature did before the weirs...

[Smalls]

Originally Posted by "W"

CCA get off there azz and do some marsh restoration instead of sunshine pumping a useless half million dollar reef maybe we can save the marsh and allow weirs to stay open


Hell I bet we could start a save the Marsh foundation to raise money to restore marsh on a trade to leave them open

You want to W? I'm in.

["W"]

Originally Posted by Smalls

You want to W? I'm in.

If there was a way to get a foundation going and set up a meeting with the weir guys


We could have a fundraiser start it up

[Smalls]

Originally Posted by "W"

If there was a way to get a foundation going and set up a meeting with the weir guys


We could have a fundraiser start it up

Find some contacts Mr. Big Shot. I got confidence in you. I'll gladly jump in on that. I'll even be your VP. I can see it now, Waltrip and Smalls, long time rivals, tag teamin to save the marsh and Big Lake.

[Cripley]

I know a lot of people who would join including myself first get a following then funding then the meetings with the boards will happen you have to get people and money for them to feel pressure

[Smalls]

The Big Lake Coalition. I think that sounds appropriate.

[MathGeek]

Originally Posted by Cripley

I know a lot of people who would join including myself first get a following then funding then the meetings with the boards will happen you have to get people and money for them to feel pressure

Making the lake itself less salty is a multi-million dollar project. The best you can do with the realistic financial potential of a regional conservation group is improve the science on when the weirs are opened and closed and perhaps exert a bit of policy pressure investigating options to lower salinity in the lake.

By installing salinity sensors on the lake side and the marsh side, you can open the gates any time conditions show that open gates would lead to a net flow of salt out of the marsh and close them when actual local conditions show open gates would add salt to the marsh.

Until this is handled, efforts at replanting vegetation are risky because improper weir management will let too much salt into the marsh and kill the veggies.