Acoustic contacts with tagged fish by the hydrophone/data loggers system will be monitored by a dedicated computer and processed by software included with the tagging hardware.

The occurrence of tagged striped bass within the study area will be treated similar to conventional tag returns in that the contribution of fishes initially tagged within or outside the system will be calculated as a percent of stock contribution.

However, an important exception is that multiple records of individual fish will resolve such questions as to the regularity (variation) of participation in coastal migration, and depending on the participation of collaborative efforts, in the range or destination of migrants.

Where three or more hydrophones record the presence of tags simultaneously, the position of the fish will be triangulated. Tracks of fishes that stay within range of several hydrophones for extended periods may be displayed in Lagrangian fashion similar to progressive vector diagrams.

Otherwise, the frequency of occurrence of contacts with specific individuals will be calculated/plotted on a chart to show habitat preference (space use patterns) as a function of time of day, season, or year, and temperature, salinity, or bathymetry for those times when physical data can be concurrently collected, and movement extent calculated as a function of fish size and sex.

Mobile Tracking

Other details of habitat use will be determined by mobile tracking and these same habitat components will be recorded, but at more frequent intervals and with better spatial resolution. We anticipate that mobile tracking of striped bass will be able to locate individual fish within meters and thus identify specific habitat types.

Rates and range of movement during migration and seasonal estuarine or coastal ocean use from the fixed hydrophones/data logger system can be likewise displayed on a scale appropriate to the geographic and temporal scales over which contacts are recorded.

We expect at least a single contact with 100 percent initially and 30-60 percent annually of the tagged fishes, as found for similar tagging programs studying other anadromous fishes such as shad, salmon, and sturgeon.

We anticipate documenting the localization of putative overwintering sites in the Saco River estuary, the degree of return visitations by striped bass on a seasonal and interannual time scale (i.e. fidelity), patterns (sporadic or regular) of migratory passage or estuarine use of fish tagged in other systems, and the delineation of stock structure within the Saco River metapopulation. We also expect to advance our knowledge of telemetry technology towards its application to other coastal migratory species.