Knowledge representation and qualitative simulation of salmon redd functioning. Part II: qualitative model of redds

Area of Science:

• Freshwater ecology
• Ecological modeling
• Salmonid biology

Background:

• Salmon spawning success is influenced by environmental factors within redds.
• Early-stage mortality in salmon is a critical factor for population dynamics.
• Qualitative modeling offers a flexible approach to complex ecological systems.

Purpose of the Study:

• To develop a qualitative model of salmon redd functioning.
• To assess the impact of redd conditions on early-stage salmon mortality.
• To introduce real-time dating and duration into qualitative ecological models.

Main Methods:

• Utilized Qsim, a qualitative simulator, to represent expert knowledge.
• Decomposed the model into two parts based on different time scales.
• Implemented a qualitative clock for simulating developmental stages and accumulated degree-days.
• Simulated sub-models to analyze variable evolutions under various scenarios.

Main Results:

• The qualitative model effectively represents salmon redd dynamics.
• Simulations generated insights into mortality rates influenced by oxygen flow and gravel plugging.
• The qualitative clock successfully integrated real-time dating and duration into the model.

Conclusions:

• Qualitative modeling with a qualitative clock is suitable for studying salmon redds and mortality.
• Environmental factors like water flow and gravel interstices significantly impact salmon early-stage survival.
• The model provides a framework for exploring various scenarios affecting salmon populations.