The goal of this web tool is to compare three hatchery release strategies in a simplified system comprised of two rivers with a salmonid hatchery on one of the rivers. The hatchery is assumed to produce 8 million smolts annually. The user specifies how those smolts should be distributed among 3 release strategies: in-river, SAFE, and (non-SAFE) bay releases. Based on fixed and user-specified parameter values (Table 1), the app calculates ocean harvest, terminal harvest (SAFE only), in-river harvest, hatchery returns, and hatchery-origin spawners (Figure 1).
Table 1. Parameter values used in this web tool for each release strategy. Some values are fixed to reduce the number of input sliders on the 'Application' tab.
| River | SAFE | Bay | |
|---|---|---|---|
| Release Proportion | user | ||
| Smolt-to-Adult Proportion | 0.01 | 0.03 | 0.03 |
| Mixed Stock Harvest Impact | user | ||
| Terminal Harvest Proportion | 0 | user | 0 |
| Straying Proportion | 0.05 | 0.5 | 0.5 |
| In-River Harvest Proportion | user |
Figure 1. Flowchart showing the order of calculations in this web tool. The display shapes (right column) indicate values that are returned as figures or text output.
Contact Brad Cavallo with questions.