For Cod’s Sake: Implementation of Stage- Structured Ecological and Social Harvesting Models to Simulate Commercial Fishing Dynamics on the Cod Fishery in the Northwest Atlantic Marine System

Abstract

In recent decades, cod in the Northwest Atlantic have rapidly declined in abundance, causing fisheries to shut down across numerous coastal fishing communities. Alarmingly, management of these fisheries has been largely inadequate in terms of recovering the biomass that characterized the population for centuries. This paper represents the ecology of cod (Gadus morhua) and herring (Clupeus harengus) in two stage-structured ecological models and two stage-structured social harvesting models to show the effect of top-down regulation on the persistence and stability dynamics of cod and herring populations. Top-down fishing exploitation introduces various mortality effects to consumer and resource populations as a result of alternative stable states. The models show that indiscriminate, non-selective harvesting damages the stage-structured processes of reproduction and maturation. Therefore, management must account for critical ecological transitions in the life stage composition of exploited fish populations and create policies to incentivize sustainable, selective harvesting behavior.