After my son's 1st place finish in the Colorado State Science Fair (
http://www.saltycajun.com/forum/show...=Bioindicators ), there's a lot of interest in a follow-up project this year focusing on the condition index in black drum, red drum, and spotted sea trout in the Calcasieu estuary. We'd be hoping to measure (length and weight) 200 spotted sea trout, 100 red drum, and 50 black drum. Since resources are limited compared with last year's project, we'd be hoping to get all the measurements done in one day rather than stretching them out over three weeks like last year.
As we plan, this post hopes to gauge angler willingness to retain all the legal fish of these species they catch on this day and bring them by to be measured to one of the teams stationed at Calcasieu Pt. and Hebert's Marina the Monday afternoon of Memorial day.
Here's what we're hoping to learn:
Black Drum are a valuable bioindicator of the oyster abundance available for forage. Last year, the average relative condition factor for black drum was 0.934 in Calcasieu, which was even lower than the areas directly impacted by the oil spill, suggesting the oysters in Calcasieu might be in even worse condition from overharvesting than the oysters in the Lafourche area were from the oil spill. The study this year would determine if the forage sources of black drum have rebounded or are still diminished.
Red Drum are a valuable bioindicator of the relative abundance of their food sources. Last year, the average relative condition factor of red drum was 0.965 in Calcasieu, which is significantly below the statewide long term average of 1.000 and about the same as areas impacted by the oil spill. The purpose of this year's study will be to see if the red drum's food sources have rebounded from last year.
Spotted Sea Trout can also be a bioindicator of the relative abundance of their food sources. If not enough spotted sea trout are being harvested (relative to their food sources), then they will have a relative condition factor below 1.000. Last year, the average relative condition factor of spotted sea trout was 0.971 in the Calcasieu estuary. This may have been because of increased shrimping pressure in 2010 due to oil spill related closures in other parts of the state, or it may have been because the sporting limits are keeping the local spotted sea trout population above what the available forage can optimally support. If the relative condition index remains below 1.000 in 2012, it would support the hypothesis that the number of spotted sea trout in the estuary is too high and that consideration should be given to raising the limit.
So, how easy do you think it would be to measure the needed numbers of fish given favorable conditions on Memorial Day? Are you willing to keep the legal fish you catch that day and wait a few minutes for one of our teams to weigh and measure the fish in your ice chest?