SpawningBiomass: Spawning Biomass (SB)

In nmfs-fish-tools/data_dictionary: Collaborative tool to improve consistency in terminology and develop a framework of tools for fisheries science.

Spawning Biomass (SB)

Description

The mass of fish (males and females or females only) in the population that contribute to reproduction. Often conventionally defined as the product of weight at age and the proportion mature at age. Alternatively, it can be defined as the biomass of all individuals at or above “age at 50 percent maturity” or “size at 50 percent maturity” or the total biomass of fish of reproductive age during the breeding season of a population. Spawning biomass depends on the abundance of the various age classes composing the population and their past exploitation pattern, rate of growth, fishing and natural mortality rates, onset of sexual maturity, and environmental conditions. Most often used as a proxy for measuring egg production.

Usage

SpawningBiomass()

Format

Examples

female spawning biomass

Rationale

Spawning biomass and spawning stock biomass have both been used historically, though the former is shorter without sacrificing clarity. For single-sex models, spawning biomass often pertains only to females but text should be specific, e.g., female spawning biomass. The alternative, spawning output, is only viable for species that exhibit multiple spawning events per fish within a time period and have pelagic eggs.

Alternatives

spawning stock biomass, spawning output (eggs), spawning stock output (eggs)

Range of possible values

0–Inf

Units

mt

nmfs-fish-tools/data_dictionary documentation built on July 27, 2024, 12:20 p.m.