Single Species Assessment

Single-species assessment estimates the status and sustainable harvest of one stock in isolation, treating natural mortality and the environment as fixed inputs rather than modeling predator-prey links. It is the dominant operational approach: surplus-production models such as Schaefer, age-structured models, and integrated platforms like Stock Synthesis all run one stock at a time to produce biomass, fishing mortality, and reference points. The simplification keeps the model tractable and the data demands manageable, but it cannot capture trophic interactions or technical interactions between fisheries, which is what ecosystem and multispecies approaches add on top.