Ecological‐economic modeling of nutrient enrichment in multispecies fisheries

• Published in: Natural resource modeling Vol. 38; no. 1
• Main Author: Nguyen, Thanh Viet
• Format: Journal Article
• Language: English
• Published: Hoboken John Wiley & Sons, Inc 01.02.2025
• Subjects: Aquatic environment; Aquatic sciences; Commercial fishing; ecological economic model; Economic models; Economics; Ecosystem dynamics; Ecosystem models; Ecosystem stability; Ecosystems; ecosystem‐based fishery management; Enrichment; eutrophication; Fisheries; Fisheries management; Fishery management; Fishing; Nutrient balance; Nutrient dynamics; Nutrient enrichment; Nutrient flow; Nutrients; Overfishing; Pontryagin principle; Predators; Prey; Species extinction; Stability; Sustainable fisheries; Sustainable practices
• ISSN: 0890-8575; 1939-7445
• DOI: 10.1111/nrm.12416

In fisheries economics, multispecies or ecosystem models typically focus on interactions among fish species, often overlooking the flow of nutrients. However, biologists widely acknowledge that nutrients–Âİsuch as nitrogen, phosphorus, potassium, and calcium–Âİare vital for organisms and play crucial roles in ecosystem dynamics. This paper delves into a bioeconomic predator‐prey model incorporating nutrient enrichment through Holling Type II and Michaelis–Menten functional forms. Initially, we examine the system's dynamics before formulating an optimal time‐dependent harvest policy using the Pontryagin maximum principle. Our findings reveal that heightened nutrient enrichment can lead to the breakdown of a positive stable equilibrium, resulting in the extinction of both prey and predator. The stability of the ecosystem may also be influenced by the interplay of nutrient enrichment and predator harvest. Recommendations for Resource Managers Implementing ecosystem‐based fishery management strategies can help address the complex interactions between species, nutrients, and fishing activities within an ecosystem context. Consider the impacts of nutrient enrichment on multispecies fisheries and incorporate them into management plans to ensure long‐term sustainability. Recognize the importance of maintaining a balance between predator and prey populations to maintain ecosystem stability. Promote sustainable fishing practices that minimize the negative effects of overfishing on predator‐prey dynamics and overall ecosystem health. Encourage the adoption of practices that reduce nutrient runoff into aquatic systems, as excessive nutrient enrichment can disrupt the delicate balance of predator‐prey relationships.