The gillnet sampling program was fully established in 2001 and is instrumental in management decisions for size and catch limit regulations. The sampling program is a stratified random sampling program that increases the precision of estimating population characteristics. "Small" and "large" mesh net are used to allow biologist to account for the varying sizes and shapes of finfish inhabiting the coastal waters of Alabama. The "small" mesh net consists of 5 panels of net in varying stretched mesh sizes (2"-4" mesh) and stretches out 750 feet. The "large" mesh net consists of 4 panels of net in varying stretched mesh sizes (4.5"-6" mesh) and stretches out 600 feet.
To ensure that all coastal Alabama waters are accounted for the Mississippi Sound, Mobile Bay, and Perdido System are divided into 4 major samples. Each major sample area is further broken down into 5 smaller sample areas. A total of 240 net sets per year, divided evenly between "small" and "large" mesh is the target number. Along with collecting finfish from each set hydrological data is also recorded. The hydrological data collected includes surface water temperature, surface salinity, and surface dissolved oxygen.
(click map to enlarge for better viewing)
All of the finfish caught are separated out by mesh and measured down their centerline. Target species are returned to the lab for further processing. Lab processing consists of recording length, weight, sex, ovary weight (if female), and otoliths are removed for ageing. A more in depth description of lab processing can be found on the Sample Processing page.
For further information regarding the Gillnet Sampling Program contact Jaime Miller.