I'm pretty sure that lake is on the "do not eat" list. Might check with the TWD site.
It's not. You're thinking about Lake Worth which is very close, but they are not connected at all. Marine Creek is basically a pond and is not part of the Trinity at all. The only fish it has are what's been stocked.
Lake Worth and the river running from it up to it Eagle Mountain had a 2010 Consumption Advisory that recommended limiting consumption to 4 ounces a month of most fish. Crappie were never designated, but sand bass were, so I always avoided eating crappie from there as well. It seems to me that the scientists that did the study failed to examine crappie, and makes no sense why they wouldn't have been on the list.
Regardless, the Consumption Advisory still exists, but now says to limit to 8 ounces a month. I won't eat anything out of Lake Worth or the Nature Center because why bother. It's a shame because 10-mile bridge and the Nature Center offer such excellent crappie fishing, but it's just not worth the risk in my opinion. I'd have a guilty conscious feeding anyone fish from those waters.