About

Steven Gaines is a Distinguished Professor Emeritus at the Bren School of Environmental Science & Management at the University of California, Santa Barbara. His research focuses on marine ecology and conservation, sustainable fisheries, the design of marine reserves, and the impact of climate change on ocean ecosystems. He has served as director of the UC Santa Barbara Marine Science Institute, as well as acting Dean of Science and acting Vice Chancellor for Research at UCSB. Gaines currently serves as a strategic advisor for the Environmental Markets Lab (emLab), which advances economic research to deliver practical solutions for people and the planet.

Research topics

• Geography
• Ecology
• Environmental science
• Fishery
• Political Science
• Biology
• Environmental resource management
• Economics
• Business
• Computer Science
• Economic policy
• Optics
• Telecommunications
• Finance
• Market economy
• Atmospheric sciences
• Geology
• Macroeconomics
• Economic system
• Physics
• Oceanography
• Development economics
• Law
• Climatology

Selected publications

• Exploring pathways to the persistence of community engagement in co-management across social-ecological conditions

  Kent Academic Repository (University of Kent) · 2026-04-09

  article

  Evaluating sustained community engagement in co-management is critical for designing durable governance with conservation potential, yet such persistence remains rarely assessed. We analyze 750 co-management initiatives established under Chile’s Territorial Use Rights for Fishing policy (1998-2021), examining persistence across conditions theorized to shape collective action in social-ecological systems. Survival analysis shows that initiatives had a 75% probability of persisting beyond 15 years. Abandonment risk declined non-linearly with initial exploitable abundance and increased with monitoring distances. Exploring combinations of variables through cluster analysis reveals that, while initiatives starting with high abundance showed the highest persistence, some initiatives with lower initial abundance also endured at comparable rates when combined with shorter monitoring distances, proximity to large markets, higher poverty, and stronger upwelling. These findings suggest diverse pathways to sustained community engagement in co-management, generate hypotheses for future research, and show how tracking persistence can inform strategies for durable and equitable conservation.

• Trade and governance drive luxury seafood serial exploitation

  Research Square · 2026-02-12

  preprintOpen accessSenior author
  PublisherOA PDFDOI

• Enhancing the potential of children’s agency to achieve global sustainability

  AMBIO · 2025-02-19

  articleOpen accessSenior author

  Despite progress toward sustainability, it remains uncertain how we as a global society will make transformations needed at scale. We argue that intentionally involving children in sustainability efforts may catalyze promising changes in how we approach human-environmental crises. This involvement, however, entails much more than the traditional focus on exposing children to environmental education or sustainability learning. Here, we present a pathway where children move through incremental yet fluid stages, from rich experiences in nature in early childhood, to reflective activities, leadership development, and formal opportunities in sustainability governance in later childhood and adolescence. Each stage requires overcoming distinct barriers that vary across and within countries: we identify and discuss these main barriers, and suggest potential ways the sustainability sciences community can help to reduce them. We offer this proposed pathway as a first step toward ensuring young people's involvement, agency, and stewardship in achieving global sustainability.

  PublisherOA PDFDOI

• Marine fish trait interactions give rise to unique ontogenetic movement combinations

  Marine Ecology Progress Series · 2025-09-18

  articleOpen access

  Fish exhibit bipartite lifecycles, moving as both larvae and adults. Each life stage is influenced by diverse factors determining the structure of fish communities. While movement extents have known trade-offs, the factors affecting movement extents and their relationships between life stages are largely unknown. These interactions are vital to consider, for example, in designing conservation interventions and understanding species’ geographic distributions and ability to respond to change. Here, we created a Gaussian mixture model to organize 606 fish species into 6 distinct movement combinations based on their adult (home range size; HR) and larval (pelagic larval duration; PLD) movements. We then assessed key life-history characteristics as predictors of movement groupings. We found that (1) species generally exhibited a mid-range extent during at least 1 life stage, and (2) interactions between traits resulted in unique ontogenetic movement relationships, sometimes reversing expected outcomes; for example, in long-lived species, HR increased with length while PLD decreased, and in shorter-lived species, HR decreased with length while there was no relationship with PLD. Our findings highlight specific physiological and environmental contexts in which different movement combinations arise, leading to a better understanding of how different species groups may respond to their environments.

  PublisherDOI

• Aquaculture coupled with trade is sustaining growth and improving stability in global aquatic food supply

  Aquaculture · 2025-11-22 · 1 citations

  article
  PublisherDOI

• Exploring pathways to the persistence of fisheries co-management across social-ecological archetypes

  2025-08-06

  preprintOpen access

  Co-management can balance resource use with conservation, yet its persistence remains poorly understood. Identifying the extent and conditions of sustained co-management is critical for assessing progress toward conservation targets and designing scalable strategies. However, systematic evaluations of persistence across social and biophysical contexts remain scarce. We analyze 750 co-management initiatives established under Chile’s Territorial User Rights for Fishing policy between 1998 and 2021, assessing their persistence across conditions known to influence collective action. Using interpretable cluster analysis, we identified three social-ecological archetypes and applied survival analysis to evaluate their persistence. Nationally, initiatives had a 75% probability of persisting beyond 15 years. The archetype with the highest initial resource abundance showed the greatest persistence (84%), while another—despite low initial abundance—achieved similarly high persistence (78%) when coupled with low surveillance costs, high dependence, proximity to markets, and high ecosystem’s productivity. In contrast, the archetype characterized by low dependence, high surveillance costs, and low abundance and productivity persisted at much lower rates (54%). These results highlight multiple pathways to enduring co-management and offer novel insights to guide testable hypotheses. They also underscore the importance of tracking persistence and abandonment to inform adaptive, context-specific policies delivering lasting benefits for people and nature.

  PublisherDOI

• Exploring pathways to the persistence of community engagement in co-management across social-ecological archetypes

  2025-09-23 · 1 citations

  articleOpen access

  Evaluating when and under what conditions community engagement in co-management endures is critical for tracking conservation progress and sustaining impact. Yet assessments of initiatives persistence remain rare. We analyze 750 co-management initiatives under Chile’s Territorial Use Rights for Fishing policy (1998–2021), examining persistence across conditions theorized to shape collective action in social-ecological systems. Using cluster analysis, we identified three collective action archetypes and evaluated their persistence with survival analysis. Nationally, initiatives had a 75% probability of lasting beyond 15 years. Those with high initial resource abundance persisted longest (84%). Initiatives with low initial abundance still endured at similar rates under favorable collective action conditions (78%) but had greater abandonment rates when coupled with low poverty, low productivity, and high surveillance costs (54%). These results reveal multiple pathways to lasting co-management, refine hypotheses for future research, and show how tracking persistence supports adaptive, context-specific interventions for durable and equitable conservation.

  PublisherOA PDFDOI

• Revisiting Small‐Scale Aquaculture ( <scp>SSA</scp> )

  Reviews in Aquaculture · 2025-11-02 · 2 citations

  articleOpen accessSenior author

  ABSTRACT Aquatic foods are a vital source of nutrition, yet growing demand and stagnant wild‐capture fisheries have positioned aquaculture as essential to meeting global food needs. Despite this, aquaculture's diverse forms remain poorly understood, particularly small‐scale aquaculture (SSA). Unlike small‐scale fisheries (SSF), which are widely recognized in policy and research, SSA lacks consistent definitions and is often conflated with SSF or defined narrowly by physical metrics like farm size. This limits its visibility in policy and development efforts, overlooking critical social, economic, and governance dimensions such as ownership, labor, and market orientation. Through a systematic review of 83 studies across 24 countries, we analyze SSA across ecosystems (freshwater, brackish, marine) and species groups (finfish, invertebrates, seaweed) to identify trends in production characteristics, yield reporting, and social dimensions. We find freshwater SSA dominates the literature, while marine SSA, especially mollusk farming, is significantly underrepresented. SSA exhibits wide variation in yields, farm sizes, ownership, and management structures, indicating that existing classification frameworks are insufficient. We propose a context‐sensitive, social‐ecological classification system that integrates production metrics with governance and socioeconomic characteristics. To guide application, we offer two policy frameworks, one for regions with existing SSA definitions, recommending participatory revision and expanded data collection; and one for regions without definitions, advocating for a stepwise approach to characterization. Our findings underscore the need for more inclusive, adaptable classifications to improve SSA's visibility in global food policy and unlock its full contributions to sustainable development, equity, and local livelihoods.

  PublisherOA PDFDOI

• Aquaculture isn’t always the answer: rethinking blue transitions through justice and community experience

  Global Environmental Change · 2025-08-13 · 4 citations

  articleOpen accessSenior author

  • Critically examines the assumptions and outcomes of “blue transitions” from fishing to aquaculture in two small-scale coastal communities in Mexico, finding that aquaculture interventions often lead to fragmented and contested transformations. • Uses an exploratory mixed-methods approach to capture diverse community perspectives and experiences. • Introduces a justice-centered framework to evaluate the equity, recognition, and procedural dimensions of aquaculture policies in seafood system transitions. • Demonstrates the need for multiscale, context-sensitive governance that centers community agency and local realities to achieve more just and sustainable blue transitions. Aquaculture interventions and policies are now fundamental in sustainability agendas, particularly in supporting small-scale fisheries and coastal communities. These policies often rely on the “blue transitions” theory of change, which posits that an expansion of aquaculture will aid in recovering declining fish stocks and enhancing livelihoods. However, the blue transitions theory is relatively new, leaving many aspects uncertain, especially regarding how transition stages unfold and impact communities as they are expected to transform livelihoods. Frequently, these policies adopt a top-down approach driven by political and corporate interests at global or national levels, emphasizing environmental and economic benefits while neglecting local social, cultural, and historical contexts. This study aims to identify gaps in current blue transition policies at the local level through two empirical case studies in Baja California Sur, Mexico. Additionally, it evaluates the suitability of existing frameworks for incorporating justice in food system transitions for seafood system transitions and provides insights for developing more equitable blue food policies. Using an exploratory mixed methods approach from 2021 to 2023, including ethnography, interviews, surveys, and focus groups, this research delves into the complexities of aquaculture policies for communities going through blue transitions. Findings indicate that these policies often prioritize economic development over social, cultural, and historical considerations, leading to injustices within communities. The case studies reveal impacts and challenges such as intra-community conflict, illegal fishing, and threats to food security and resilience, as well as benefits like momentary economic gains. Applying a framework for just food system transitions, we advocate for flexible, community-centric policies that recognize local heterogeneity and empower communities to shape their transitions, including deciding whether a transition is appropriate. This study underscores the limitations of viewing aquaculture as a panacea for small-scale fisheries’ challenges, emphasizing the need for holistic, multiscale management approaches. Contextualizing blue transitions within local realities and prioritizing food justice can promote just and equitable outcomes that address the nuanced needs of diverse coastal communities amidst global pressures.

  PublisherDOI

• Natural climate solutions based on fish, fisheries, and marine mammals: Current evidence and assessment of readiness

  2025-03-25 · 1 citations

  preprintOpen access

  Several initiatives to conserve, restore or better manage fisheries, fishes, whales, and other marine mammals have been proposed as natural climate solutions to sequester carbon from the atmosphere or avoid new emissions. We reviewed the knowledge and uncertainties surrounding carbon fluxes and storage mediated by these organisms to evaluate their suitability to support climate mitigation interventions. Estimates of the carbon stored within fish and marine mammal biomass ranged from 0.1-1.9 Pg C for mesopelagic fishes, 0.0020-0.016 Pg C for great whales, and 0.0065-0.0113 Pg C for all marine mammals, compared to an estimated 1.5-3 Pg C stored in all ocean biota. Epipelagic fishes, mesopelagic fishes, and great whales contribute on the order of 0.03-0.2 Pg C yr-1, 1-3 Pg C yr-1, and 0.001-0.004 Pg C yr-1, respectively, to carbon export from the ocean’s surface to below the euphotic zone, compared to an estimated total marine biological export of 9-10 Pg C yr-1. The combined flux of carbon to the atmosphere from benthic trawling, biomass extraction, and fuel consumption during commercial fishing ranged from 0.05-0.25 Pg C yr-1. Substantial uncertainties were associated with nearly all fluxes and reservoirs. The contributions of whales to carbon export and the mobilization of carbon from sediments during benthic trawling were least certain, limiting the readiness of associated pathways to provide quantifiable, high-quality carbon credits. While substantial uncertainties also surrounded mesopelagic fishes, we found that even the most conservative estimates of these organisms’ contribution to ocean carbon export were large enough to justify precautionary conservation actions.

  PublisherDOI

Recent grants

• U.S.-Mexico Dissertation Enhancement: Marine Population Connectivity Across the U.S./Mexican Border: A Genetic Approach to Dispersal Dynamics in Kelp Bass

  NSF · $26k · 2004–2007

Frequent coauthors

• Benjamin S. Halpern

  University of California, Santa Barbara

  58 shared

• Robert R. Warner

  45 shared

• Christopher Costello

  University of British Columbia

  44 shared

• Jane Lubchenco

  39 shared

• Sarah E. Lester

  Florida State University

  34 shared

• Bruce A. Menge

  Oregon State University

  28 shared

• Elizabeth M. P. Madin

  University of Hawaiʻi at Mānoa

  24 shared

• Mark D. Bertness

  Brown University

  24 shared

Labs

• Gaines LabPI

Education

• Ph.D., Zoology

  Oregon State University

  1982

• B.Sc., Biology

  University of California Irvine

  1977