Dolphinfish Management Strategy Evaluation in the U.S. Atlantic

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Dolphinfish, or mahi mahi, is an iconic species in the eastern United States. These fish are in high demand, both commercially and recreationally. Recent concerns over increased user conflicts, highly variable availability, and international harvest have sparked the need for a more flexible and adaptive management approach.

We are conducting a management strategy evaluation (also called an MSE) to develop innovative ways to manage dolphinfish in the U.S. Atlantic. The goal is to design an approach that maximizes stakeholder objectives, reduces conflicts, and best fits the life history of dolphinfish. With this evaluation, we aim to:

• Predict the amount of dolphinfish that will be available each year
• Maximize the usage of dolphinfish across sectors and regions

What is a Management Strategy Evaluation?

A management strategy evaluation is a way to test fishery management strategies, which may include alternative regulations or harvest control rules, before implementing them. The approaches tested are called management procedures. These management procedures specify how different management actions will be adjusted based on the changing behavior of the stock. For example, in years where stock availability is high, the fishery can adapt and take advantage of the high abundance. Each management procedure defines:

• What data are collected
• How data are analyzed to inform us on stock status or stock behavior
• How management advice should be adjusted given the state of the stock
• How management advice is implemented for the fishery

Within a management strategy evaluation, management procedures are tested on their ability to respond to a variety of different environmental, data, and stock scenarios. This ensures that they are robust and appropriate for application to the real fishery. Each hypothesized scenario (including data quality and stock, fishery, and ecosystem dynamics) is quantified in an operating model. Candidate management procedures are tested across a suite of different operating models that collectively encompass the historical and future uncertainties about the system dynamics.

These management procedures are evaluated against:

• How well they meet certain objectives for the stock
• Trade-offs in their performance against those fishery objectives
• If they meet legal requirements of the Magnuson-Stevens Act to prevent overfishing

The management objectives are defined by stakeholders, and reflect what priorities they value in the fishery.

A management strategy evaluation may not reveal a specific outcome or strategy that meets every management goal for the stock. It allows us to compare different management options and evaluate their biological, social, and economic tradeoffs. This process is designed to test potential management procedures to see how they might perform under many possible conditions.  

Why Do Dolphinfish Need a Management Strategy Evaluation?

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Dolphinfish are a short-lived and highly productive stock. Such species can generally withstand more exploitation than less-productive stocks. Since their productivity is thought to be largely environmentally driven, dolphinfish abundance and availability is sporadic from year-to-year. 

As a highly migratory species, dolphinfish are harvested across international boundaries. This limits the capacity for the United States to manage the entire stock. It limits the available data that we are able to collect about these fish, since not all countries collect and report data on dolphinfish. 

Consequently, these traits and data limitations largely hinder the development of a comprehensive, traditional stock assessment. A more effective approach is to use a management strategy evaluation to identify management procedures that may work best to address management objectives for dolphinfish in the South Atlantic. 

Management Strategy Evaluation Process

1. Conduct stakeholder workshops to develop conceptual management objectives, identify relevant uncertainties, and collect input on the type of management procedures to explore
2. Continue stakeholder involvement by equitably selecting a small group of volunteers for iterative feedback
3. Build MSE framework and operating models based on stakeholder workshops
4. Build management procedures and refine the evaluation
5. Assess management procedure performance using metrics defined through stakeholder engagement
6. Iterate steps 4 and 5 based on small group feedback and performance
7. Select management procedure(s) with highest performance to recommend for dolphinfish management

Currently, we have accomplished steps 1 and 2. We will continue ongoing work on step 3 and will be engaging with our small stakeholder group to guide the evaluation and management procedure development in 2024. 

Throughout this process, we collaborate with the South Atlantic Fishery Management Council, NOAA Fisheries’ Southeast Regional Office, North Carolina State University, and the Beyond Our Shores Foundation.

Project Updates

• Presentation to South Atlantic Fishery Management Council - June 2023
• Presentation to South Atlantic Fishery Management Council - December 2023

Stakeholder Goals for the Dolphinfish Management Strategy Evaluation

Stakeholders along the U.S. Atlantic coast generally indicated a desire to ensure access to the fishery, preserve opportunities to catch dolphinfish, and prevent fishery closures. In most regions, stakeholders preferred stability in management regulations over maximizing allowable catch over the long term. Common conceptual management objectives included:

• Ensuring opportunity and access to fishery
• Preventing fishery closures
• Increasing size of dolphinfish caught 
• Stabilizing regulations 
• Balancing regional and sector differences in fishery goals and objectives

• Other objectives varied significantly by region and fishing sector.

If you are interested in learning more, or have questions about the dolphinfish management strategy evaluation process, please contact cassidy.peterson@noaa.gov.