Louisiana Seafood Stats The scientific story of what makes our waters so plentiful starts with our estuaries. And if you're lucky, it ends on your plate. ESTUARIES ARE A BIOLOGICAL ORCHESTRA Their harmonious combination of brackish water, shallow depths and high levels of nutrients form an ideal environment for microscopic marine organisms, which in turn form the base of the marine food chain by fostering healthy populations of fish, amphibians and shellfish. In an estuary, every species plays its part. The scientific story of what makes our waters so plentiful starts with our estuaries. And if you're lucky, it ends on your plate.