Oyster Overharvesting in Calcasieu Estuary in 2010- 2011: References needed

[CharlieFoxtrot]

Probably, how West Cove has any oysters left amazes me!! Zero seeding and months of dredging

Any talk of reseeding to at least make an attempt at habitat rebuilding and conservation?

[MathGeek]

Originally Posted by CharlieFoxtrot

Any talk of reseeding to at least make an attempt at habitat rebuilding and conservation?

The ideal would be to reseed the west side and close it to harvest for several years until oysters are re-established. But the political reality is that Calcasieu was opened to dredging in 2005 or so and a number of businesses invested heavily in equipment. Nearby areas (Sabine and the east side) are closed for very sound reasons, so closing the west side is not politically viable. It is too bad that closing most of LA oyster waters in 2010 caused such focussed pressure on the east side that 90% of Louisiana market oysters that year came from Calcasieu. The system is in slow recovery. See the attached graph that was prepared by a colleague using LDFW survey data.

A legitimate concern is that reseeding the west side would bring additional harvest pressure that would make the reseeding a net loss. Better to let natural reseeding from remaining west side oysters and from drift fro the east side and from Sabine contribute. This will yield less localized oyster bars that are not so easily located and destroyed. In the meantime, one hopes that local oystering infrastructure will be largely dismantled and that ongoing local pressure will be more commensurate with naturally occurring supply. Reseeding just keeps the local harvest pressure up and begins to engender an entitlement mentality as if the government has taken the ability to earn a living away from people if the cycle of seeding and raping is not maintained.

Plans to build a saltwater barrier at Calcasieu pass make seeding and conservation of oysters in the estuary a temporary proposition at best.

[MathGeek]

Originally Posted by CharlieFoxtrot

MathGeek, with the ongoing increase in redfish population, do you feel that it affects the 80% theory ?

I have not seen recent stock assessment data on the redfish, do you have a link?

Further, redfish do not have high levels of generational fidelity to one estuary (like seatrout), so a dip in body condition (and fecundity) in one estuary does not have the same impact. Also, the number of redfish eggs depends both on the population of mature females and the fecundity of each. Reduced average fecundity in one estuary is thus balanced by higher numbers of mature females and also by migration of eggs, larvae, and fish between estuaries. Redfish in other areas of Louisiana (Barataria, Terrebonne, Sabine) are not experiencing the same declines in body condition as the mature redfish in Calcasieu.

[Gottogo49]

Plans to build a saltwater barrier at Calcasieu pass make seeding and conservation of oysters in the estuary a temporary proposition at best.

MathGeek When is this likely to happen? I can't wait to go bass fishing in Turner's.

[CharlieFoxtrot]

Originally Posted by MathGeek

I have not seen recent stock assessment data on the redfish, do you have a link?

Further, redfish do not have high levels of generational fidelity to one estuary (like seatrout), so a dip in body condition (and fecundity) in one estuary does not have the same impact. Also, the number of redfish eggs depends both on the population of mature females and the fecundity of each. Reduced average fecundity in one estuary is thus balanced by higher numbers of mature females and also by migration of eggs, larvae, and fish between estuaries. Redfish in other areas of Louisiana (Barataria, Terrebonne, Sabine) are not experiencing the same declines in body condition as the mature redfish in Calcasieu.

I have no link for stock assessment.

With numerous fishing reports of good catches, what are your thoughts of an estuary supporting x amount pounds of redfish similar to saying a freshwater lake supports a certain poundage of a particular species of fish ?

[Clampy]

Originally Posted by Gottogo49

Plans to build a saltwater barrier at Calcasieu pass make seeding and conservation of oysters in the estuary a temporary proposition at best.

MathGeek When is this likely to happen? I can't wait to go bass fishing in Turner's.

This is first I hear if this horse $&@;
I would not be happy.
Do you have a link ?


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[MathGeek]

Originally Posted by CharlieFoxtrot

I have no link for stock assessment.

With numerous fishing reports of good catches, what are your thoughts of an estuary supporting x amount pounds of redfish similar to saying a freshwater lake supports a certain poundage of a particular species of fish ?

Anecdotal reports of catch rates usually reflect the anglers being in the same place at the same time as the fish, especially in Big Lake, where the fish have lots of places to be where the anglers either can't or don't bother to look. Absolute population densities (or biomass densities) are very hard to assess in places like Big Lake.

The situation is further complicated by the openness of the system. There's a much greater flux of fish through the Calcasieu pass (plus the intracoastal waterway) than most freshwater lakes see to and from feeder streams.

It is obvious to all that Louisiana inshore waters are among the most productive in the world in terms of seafood production per unit area. Very few freshwater lakes come anywhere close. Choices about commercial and recreational harvest limits and management are mostly about resource partitioning. If tons and tons of shrimp are harvested, there will be less for the specks and juvenile redfish to eat. At some point in crab harvest numbers, there is less for the redfish and drum to eat. Harvesting all the pogeys probably had an impact higher in the food chain. However, most of the time, seafood production is highest at lower trophic levels, so if it is marketable, it makes economic sense to harvest 1000 lbs of shrimp even if it means producing 100 lbs less of spotted seatrout.

Oysters are different, however. The oysters are not only consumed by one species (black drum), oyster reefs provide essential hard bottom habitat and vertical relief to a whole array of benthic organisms. These benthic organisms contribute to ecosystem production in many ways. Further, the living oysters provide a variety of ecosystem services including improving water quality by filtering, serving as nurseries for fish, and buffering anthropogenic inputs.

While it is hard to know the actual biomass of a species in an estuary, it is easy to infer how much of the species are present relative to their food supply. If (on average) the fish are fat, the food supply could support additional fish, or the fish are underpopulated relative to the available food. If the fish are thin (on average), there are too many fish for the available food supply, which could mean an over abundance of fish or an under abundance of their preferred forage species.

The attached graph shows the relative condition factor for redfish in Calcasieu, analyzed by length class from 2011 to 2013. The statewide average is 100% based on analysis of large statewide data set measured from 1995 to 1999. Clearly, the adult redfish are having trouble finding sufficient forage to maintain body condition. The juveniles (16"-20") are doing better, but 2013 was the first year since 2011 that they were above the statewide average. A 2000 study (Jenkins 2004) found most fish sampled in Calcasieu were above the statewide body condition at about 103%.

[Clampy]

Originally Posted by MathGeek

Anecdotal reports of catch rates usually reflect the anglers being in the same place at the same time as the fish, especially in Big Lake, where the fish have lots of places to be where the anglers either can't or don't bother to look. Absolute population densities (or biomass densities) are very hard to assess in places like Big Lake.



The situation is further complicated by the openness of the system. There's a much greater flux of fish through the Calcasieu pass (plus the intracoastal waterway) than most freshwater lakes see to and from feeder streams.



It is obvious to all that Louisiana inshore waters are among the most productive in the world in terms of seafood production per unit area. Very few freshwater lakes come anywhere close. Choices about commercial and recreational harvest limits and management are mostly about resource partitioning. If tons and tons of shrimp are harvested, there will be less for the specks and juvenile redfish to eat. At some point in crab harvest numbers, there is less for the redfish and drum to eat. Harvesting all the pogeys probably had an impact higher in the food chain. However, most of the time, seafood production is highest at lower trophic levels, so if it is marketable, it makes economic sense to harvest 1000 lbs of shrimp even if it means producing 100 lbs less of spotted seatrout.



Oysters are different, however. The oysters are not only consumed by one species (black drum), oyster reefs provide essential hard bottom habitat and vertical relief to a whole array of benthic organisms. These benthic organisms contribute to ecosystem production in many ways. Further, the living oysters provide a variety of ecosystem services including improving water quality by filtering, serving as nurseries for fish, and buffering anthropogenic inputs.



While it is hard to know the actual biomass of a species in an estuary, it is easy to infer how much of the species are present relative to their food supply. If (on average) the fish are fat, the food supply could support additional fish, or the fish are underpopulated relative to the available food. If the fish are thin (on average), there are too many fish for the available food supply, which could mean an over abundance of fish or an under abundance of their preferred forage species.



The attached graph shows the relative condition factor for redfish in Calcasieu, analyzed by length class from 2011 to 2013. The statewide average is 100% based on analysis of large statewide data set measured from 1995 to 1999. Clearly, the adult redfish are having trouble finding sufficient forage to maintain body condition. The juveniles (16"-20") are doing better, but 2013 was the first year since 2011 that they were above the statewide average. A 2000 study (Jenkins 2004) found most fish sampled in Calcasieu were above the statewide body condition at about 103%.

I think it's mainly from lack of menhaden and mullet. Once they get that big they mainly eat mullet poggie and crab. The little ones eat a lot of shrimp and small crab. 7-8 years ago I would see huge rafts of mullet in the lake. I don't see that too much any more. Occasionally but not like back in the day.


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[ThePinkBanana]

All this oyster dredging and a dozen of Raw is $15 everywhere in lake charles. This blows my mind, I get a dozen for $5 in Baton Rouge. Anyone have any idea why prices are so steep in lake charles?

[MathGeek]

Most oysters are harvested on the east side of the state. Less supply near LC.

[capt coonassty]

Where are you getting them for 5 a dozen?

[silver_snipe]

MG I thought gafftops primarily fed in the water column on live bait like trout do. Versus the hard heads that are bottom feeders and primarily eat dead. I know when I catch large gafftops it has been under a popping cork same as trout.

[MathGeek]

Originally Posted by silver_snipe

MG I thought gafftops primarily fed in the water column on live bait like trout do. Versus the hard heads that are bottom feeders and primarily eat dead. I know when I catch large gafftops it has been under a popping cork same as trout.

Gafftops will occasionally pursue prey in the water column. We've caught them on shrimp under a cork and on live lined croaker. But we catch a lot more of them fishing crabs on the bottom for redfish. The only day we didn't catch any bull reds at the jetties in 2013, we got into a bunch of big gafftops and put a dozen or so in the box, including the 3rd and 7th place Louisiana records.

I've read several papers analyzing stomach contents, and while fish and shrimp are important parts of their diet, gafftops feed mainly on the bottom. Zoobenthos, benthic crustaceans, and crabs (mostly blue, but all kinds) make up the bulk of their diet. They have pharygeal teeth at the back of their throats that allow them to crush crabs, and thin shelled molluscs, but they probably cannot crush oysters.

Gafftops can definitely be fast and agile predators when they need to be, but their long barbels give away that they prefer to slowly cruise the bottom and eat the bottom critters that their barbels detect in their wide swath.

[ThePinkBanana]

5 dollars a dozen at chimes east on coursey during happy hour. Everywhere in LC is $15 a dozen and I give them hell about it every time. Therefore, I wait for my trips to BR to endulge.

[Smalls]

Originally Posted by Clampy

This is first I hear if this horse $&@;
I would not be happy.
Do you have a link ?


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http://www.coastalmasterplan.louisia...date-projects/

Check that out. Project ID 004.HR.06: "Salinity Control Structure in Calcasieu Ship Channel at Gulf of Mexico".

This has been in the plans for a few years now. I do not believe they have set in stone when work will begin, but it is in the First Implementation Period (2012-2032).

["W"]

Originally Posted by Smalls

http://www.coastalmasterplan.louisia...date-projects/

Check that out. Project ID 004.HR.06: "Salinity Control Structure in Calcasieu Ship Channel at Gulf of Mexico".

This has been in the plans for a few years now. I do not believe they have set in stone when work will begin, but it is in the First Implementation Period (2012-2032).

This will never happen in our life time, Do you know how many make a living off that lake and estuary!! Never will get approved ...NEVER

[Gottogo49]

Originally Posted by "W"

This will never happen in our life time, Do you know how many make a living off that lake and estuary!! Never will get approved ...NEVER

It didn't stop them from damming up almost all of the marsh drains on the East bank and arguably destroying the living of many small shrimpers. That happened in my lifetime. Never say never. I'm with you, hopefully we won't see it.

[Smalls]

Originally Posted by "W"

This will never happen in our life time, Do you know how many make a living off that lake and estuary!! Never will get approved ...NEVER

Hate to tell you, but Senate and House UNANIMOUSLY approved the Master Plan AFTER it went through the public comment period.

So, there is a good chance that it WILL happen.

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[meaux fishing]

Originally Posted by "W"

This will never happen in our life time, Do you know how many make a living off that lake and estuary!! Never will get approved ...NEVER

supposed to be completed by 2032 according to the site
http://www.coastalmasterplan.louisia...ject-Lists.pdf

[MathGeek]

Originally Posted by Smalls

Hate to tell you, but Senate and House UNANIMOUSLY approved the Master Plan AFTER it went through the public comment period.

So, there is a good chance that it WILL happen.

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Approving a "plan" and approving the money to pay for it in cash strapped times are two different things.

When it's time to put up the money, folks will make the case that it costs too much in terms of taxpayer money and negative economic impact. Future legislatures are never under any obligation to pay millions for hopes and intentions of past legislatures.

Someone is also bound to ask whether a saltwater barrier of this size and scope (and cost) has ever been implemented before. Where? Was it completed on budget? Was it successful in its ecological goals? What was the economic impact? Did it have a negative impact on shipping? Did it have a negative impact on recreational uses? Did it have a negative impact on commercial fisheries?

Once all the stakeholders have ample opportunity for input in a real funding and cost and risk analysis, it is unlikely to happen before 2032, unless someone can point to successful implementations in answer to the above questions.