Researchers Crack the Code on effective fisheries management — and the answer is fish larvae


September 13, 2022

Miniscule and underdeveloped, fish larvae don’t usually come to mind when considering ecologically important and complex marine animals. But marine scientists will tell you that there’s much more than meets the eye. 

In a recently published article in Marine Policy, Rare co-authors Courtney Cox, Stuart Campbell, and Raymond Jakub alongside leading scientists demonstrate how knowledge and data of fish larval movement are vital to selecting effective areas for small-scale fisheries management and closures. Their work details the impact of marine population dynamics and validates Fish Forever’s reserve design approach. 

What question were we trying to answer? 

The scientists sought to answer one primary question: Can the distribution of fish larvae in the ocean help researchers and management agencies identify the best locations to strengthen conservation efforts and improve fisheries management?  

What are fish larvae? 

Once fish eggs hatch, they become fish larvaethe second life cycle stage of fish. Measuring only a few millimeters in size, fish larvae receive nutrients from a yolk sac attached to their body and can’t swim fully on their own. They drift across the open ocean, transported by ocean currents until they grow large enough to settle into their preferred habitats, develop into adults, and provide invaluable ecosystem and fisheries benefits. This larval dispersal creates a network of fish populations that connects fishing zones and coastal fisheries across broad regions.

Study details:  

The team examined fish larval dispersal data across coral reefs in Indonesia, comparing total catch and fish biomass among various marine protected area designs. The objective was to demonstrate that simple larvae dispersal characteristics can help determine area-based management and contribute to fish recovery. 

Research findings 

The study confirms the importance of population connectivity through larval dispersal in area-based marine management. Maximizing larval export from the protected area network to fished areas proved to be an effective strategy for recovering fish populations while simultaneously increasing catch.  

Why it matters:  

This research identifies a simple metric for using larval dispersal data for decision-making, allowing researchers and fisheries managers to easily operationalize recommendations supported by previous studies. These research findings will support the global marine fisheries community in implementing and evaluating the impact of global marine conservation policies, especially in biodiverse hotspots where communities heavily rely on coral reefs and fisheries for their livelihoods 

Read the full report 

Explore Rare’s research to learn how our Fish Forever program is a global leader in managing and protecting the world’s territorial seas.