[Goooh]

Originally Posted by MathGeek

Big Lake is not over fished.



There are a lot of fish and they are eating very well, especially the specks and redfish. Black drum and gafftops are not eating as well. There are plenty of gafftops (likely overpopulated), but the bulk of black drum population has moved out (lot to Sabine) in search of more oysters.



The absence of oyster beds and weir management has the specks and reds following different patterns than usual. However, we recently measured that specks are 106% of their expected weight and redfish are 102% of their expected weight, so they are not going hungry. Weir management, low crab stocks, and low shrimp numbers suggest redfish and specks are eating well on fish (menhaden, croaker, mullet, and small fish of many species).



If specks and reds have shifted to piscivory rather than eating crustaceans, then they are chasing schools of small fish and will be hard to catch using the techniques and locations that work when they are chasing mostly shrimp and crabs.



The attached graph shows a recent estimate for the interactions between species over the past 4 years. Note that each species has a 1.00 interaction with itself. Specks and reds have a measured 77% interaction (high, as expected). Specks and black drum have a 9% interaction, because their forage habits are so different.



What was somewhat unexpected was the 49% interaction between specks and gafftops. It seems that since the destruction of the oyster reefs that began in 2010, gafftops have turned much more piscivorous (fish eating) rather than eating bottom dwelling benthos. As a result, they are likely both competing strongly with the specks and also eating a lot of juvenile specks in the 4-8" range. I bet a lot more gafftops have been caught on topwater plugs and shallow diving crankbaits since 2010 than in the earlier years, since they show lots of evidence of feeding in schools of fish.

Great post