This glossary defines key terms used throughout this book.
Terms are organized alphabetically for clarity.
A
Acclimated Salinity
The salinity level a fish has gradually adjusted to and can tolerate without stress.
Agent
A virtual organism (e.g., fish) in the agent-based model that makes decisions and moves through space.
Allometric
A biological scaling relationship where physiological processes such as metabolism, growth, or filtration capacity scale nonlinearly with body size and/or age rather than proportionally (linearly).
Anadromous
Fish that hatch in freshwater, migrate to the ocean to grow, and return to freshwater to spawn.
Base Energy
The minimum energy required for basic physiological maintenance under resting conditions.
B
Benthic
Related to the bottom of a water body, where some fish feed or rest.
Bioaccumulation
The gradual buildup of contaminants like mercury in a fish over time.
Biomagnification
Increase in contaminant concentration as it moves up the food chain from prey to predator.
Bottom Feeding
A feeding strategy where fish forage along the riverbed or estuary floor.
Broadcast Spawning
A reproductive strategy where males and females release sperm and eggs freely into the water column.
M
Mercury
A toxic metal that accumulates in aquatic systems and organisms.
Methylmercury
A highly toxic, bioaccumulative form of mercury.
S
Salinity
Concentration of dissolved salts in water.
Salinity Stress
Energy strain caused when salinity deviates from a fish’s preferred range.
Salt Wedge
A dense layer of seawater intruding beneath freshwater in an estuary.
Seaward Migration
Movement from rivers or estuaries toward the ocean.
Selective Tidal Stream Transport (STST)
Behavior where fish exploit tidal currents to assist migration.
Semelparous
Species that spawn once and then die.
Spawning
Release of eggs and sperm for reproduction.
Staging
A temporary resting or holding phase in migration.
Suspended Particulate Matter (SPM)
Fine particles (sediment, organic matter) suspended in the water column.
Swimming Difficulty
Effort required to swim based on flow direction and strength.
Swimming Energy
Energy expenditure required for locomotion.
Swimming Speed (Velocity)
Rate of movement relative to water.
T
Temperature
Water temperature; major driver of metabolism and behavior.
Temperature Stress
Stress caused when water is too warm or too cold for optimal performance.
Thermal Tolerance
Range of temperatures within which a fish can survive and function.
Thermoregulation
Behavioral regulation of temperature by moving into warmer or cooler habitats.