In a groundbreaking study published in the journal Ecological Applications, researchers have unveiled how the intricate dynamics of commercial fisheries mirror the principles of financial investment portfolios. The investigation centered on the Chesapeake Bay, revealing that biodiversity and seasonal variation, known as “asynchrony,” foster enhanced stability within fisheries. By tracking multiple finfish species and analyzing commercial catch data, scientists demonstrated that when species peak at different times throughout the year, the fishery as a whole becomes more resilient to the unpredictable boom-and-bust cycles that have long plagued watermen and ecosystem managers alike.
This pioneering research was spearheaded by Sean Hardison, formerly a doctoral student at the University of Virginia and a Virginia Sea Grant Fellow. Utilizing a comprehensive dataset collected from 2002 through 2018, compiled through the collaborative efforts of William & Mary’s Batten School of Coastal & Marine Sciences and the Virginia Institute of Marine Science’s (VIMS) Chesapeake Bay Multispecies Monitoring and Assessment Program (CHesMMAP), the study integrated ecological, economic, and fisheries science perspectives. The interdisciplinary team also included experts from the University of North Carolina at Chapel Hill, the University of Maryland Center for Environmental Science, and Canada’s Pacific Biological Station, providing a multifaceted view of fisheries dynamics in the Chesapeake Bay.
Hardison and colleagues’ work capitalized on CHesMMAP’s unique monitoring of juvenile-to-adult fish populations spanning the full length of the Chesapeake Bay—from Poole’s Island, Maryland, to just beyond the Chesapeake Bay Bridge Tunnel in Virginia. Unlike many fisheries surveys, this program tracks multiple species simultaneously, capturing the interconnected nature of the estuary’s ecosystem. Such fine-scale temporal and spatial resolution allowed researchers to quantify how asynchronous population peaks can buffer the entire fishery against volatility by reducing the likelihood that all species experience downturns simultaneously.
The researchers drew a compelling analogy between diversified fisheries portfolios and investment strategies used in finance to manage risk. When species abundance and harvest timing are out of sync, the variability in total landings and economic returns is diminished, providing a more consistent yield for fishermen and reducing the economic risk associated with reliance on any single species. This phenomenon has profound implications for fisheries management, suggesting that maintaining or enhancing species diversity and temporal separation in peak abundances can serve as natural insurance against environmental and market fluctuations.
However, management practices can significantly influence these natural dynamics. The study contrasted the fisheries of Maryland, where commercial striped bass fishing is seasonally closed to protect spawning stocks, to those in Virginia, which currently lacks such a closure. Maryland’s management approach, while aimed at conservation, inadvertently disrupted the natural asynchrony by reducing striped bass availability during harvest seasons. Because this species dominates the commercial portfolio and commands a high economic value, the closure fragmented the temporal diversification of landings. Although watermen temporarily compensated by targeting alternative species, such substitution did not fully stabilize revenue, underscoring the limitations of piecemeal diversification when high-value species are withheld.
In Virginia, the absence of seasonal closures initially allowed natural asynchrony to impart stabilizing effects on fisheries landings and economic returns. Yet, between 2002 and 2018, notable declines in key species such as Atlantic croaker and spot diminished population asynchrony. This decline, in turn, increased harvest volatility, revealing how changing species abundance trends can erode stability even in the absence of regulatory disruption. These contrasting state dynamics highlight the complexity of managing fisheries portfolios where ecological fluctuations, economic drivers, and regulatory frameworks intersect.
Dr. Max Castorani, an associate professor of Environmental Sciences at UVA and a coauthor of the study, emphasized the broad ecological principle that biodiversity enhances ecosystem stability. He explained that species diversity doesn’t merely promote healthier ecosystems; it fundamentally spreads risk over time—acting as a biological form of insurance when certain populations become scarce or collapse. By extension, this ecological insurance translates directly into economic stability for fisheries, which depend on predictable resources to sustain industries and rural communities.
Christopher Patrick, an ecologist and associate professor at William & Mary’s Batten School and VIMS, provided additional insights into how economic value distribution among species impacts portfolio stability. According to Patrick, systems with many species of roughly equal economic importance tend to be more stable, but asymmetric value distributions—as seen in Maryland’s striped bass-centric fishery—make such systems vulnerable to instability. The findings suggest that achieving both ecological and economic balance requires attentiveness to how heavily fisheries rely on dominant species.
One promising avenue to bolster fishery diversification is the emerging commercial harvest of invasive blue catfish in the Chesapeake Bay. Despite currently modest market prices, the study projects that even small increases in catfish valuation could incentivize greater participation, enhancing overall portfolio diversification and subsequent stability. This example illustrates how integration of novel species into fisheries could offset declines or closures affecting traditional target species, providing both ecological and economic resilience.
More broadly, the study underscores the necessity of incorporating both ecological and economic factors into fisheries management. Biodiversity alone does not guarantee stability; regulatory measures, market dynamics, and fishers’ behavior can either magnify or undermine the benefits diversity offers. Thus, managing fisheries as integrated socio-ecological systems becomes paramount in sustaining long-term fisheries productivity and economic viability.
While focused on the Chesapeake Bay—the United States’ largest and most economically significant estuary—the research findings resonate globally. Many fisheries worldwide grapple with the challenges of fluctuating species abundance and economic variability. The portfolio approach introduced here serves as a powerful conceptual and practical framework that can inform sustainable fisheries governance across diverse ecosystems.
Sean Hardison, now a postdoctoral researcher at the University of Alaska Fairbanks, reflected on the study’s significance by reiterating the synergy between natural fluctuations and human management. “Fisheries portfolios benefit from natural fluctuations in the ecosystem, but those benefits are mediated by management and human behavior. Our research shows the ecological and economic benefits of biodiversity,” he stated.
As the fisheries sector faces mounting pressures from climate change, habitat degradation, and shifting market demands, embracing portfolio diversification strategies informed by robust scientific data could prove essential. These strategies not only promote ecological resilience but also safeguard economic stability for fishing communities, ensuring the sustainable use of vital marine resources in the face of uncertainty.
For readers interested in delving deeper, the full manuscript is available through the journal Ecological Applications and provides a comprehensive account of the methodologies and analyses underpinning these important discoveries.
Subject of Research: Not applicable
Article Title: Seasonal asynchrony and harvest diversification contribute to demersal finfish fisheries stability in Chesapeake Bay
News Publication Date: 11-Sep-2025
Web References:
References:
DOI: 10.1002/eap.70097
Image Credits:
Credit: Matthew Farnham
Keywords:
Fisheries, Fisheries management, Economics
