A recent study by researchers at the University of São Paulo (USP) has shed light on the structure and impact of Brazil’s “blue economy”—the collective term for economic activities that directly depend on the sea and its resources. Using an interregional input-output model, the researchers tracked both the direct and indirect effects, both direct and cascading, of marine-based industries throughout the Brazilian economy. The results underscore not only the significant economic contribution of coastal regions but also their intricate ties to inland areas, revealing a broad and often underappreciated geographical footprint of maritime activities.

The research, led by Professor Eduardo Haddad and postdoctoral researcher Inácio Araújo, both from USP’s School of Economics, Business, Accounting and Actuary (FEA-USP), was published in the journal Ocean Sustainability. According to the authors, one of their key innovations lies in the geographical mapping of the ocean economy’s productive structure. “What we brought as an innovation was the measurement of the so-called ocean economy, with emphasis on the geographical dimension and the interconnection of the productive structure,” explained Haddad. This methodological framework not only provides a more complete picture of the sector’s reach but also offers a tool that can be adapted for other regions and nations seeking to understand their marine economies.

In 2019, the blue economy directly contributed 2.91% to Brazil’s GDP and was responsible for 1.07% of the country’s employment. Within this economic structure, oil and natural gas extraction stood out as the dominant sector, accounting for over 60% of what the researchers term the “Blue GDP.” Other notable contributors included public administration and defence (7.4%) and storage and transport services (7.3%). Haddad notes that while offshore oil forms the financial backbone, the remaining 40% is spread across vital areas, including coastal tourism, fishing, maritime transport, and national defence, reflecting the sector’s diversity and multifaceted value.

The most striking revelation of the study is the extent of interdependence between coastal and inland regions. When indirect effects—such as supply chain connections and consumption spillovers—are considered, the blue economy’s contribution to GDP nearly doubles to 6.39%, with its share in employment rising to 4.45%. “It’s as if I pulled a plant out of the ground and along came the whole root, which had spread very far,” Haddad remarked. Using Minas Gerais—a landlocked state—as an example, he illustrates how inland territories are economically tied to the sea through supply chains in industries such as fishing and transportation. This connectivity paints a more complex picture of the blue economy, one that extends well beyond the coastline.

The study also delves into regional dynamics, revealing that while the Southeast (particularly Rio de Janeiro, São Paulo, and Espírito Santo) dominates blue economic output—contributing 82% of direct production—other regions have developed distinct specialisations. The Northeast, for example, is more focused on coastal tourism and artisanal fishing. These regional differences underscore the importance of developing locally tailored policies to foster sustainable marine development. As Haddad notes, “What we see are various regional nuances in coastal economies and this has important implications for the design of sustainable development policies.” This notion is reflected in the study’s evocative title, Shades of Blue, suggesting a spectrum of regional realities within Brazil’s marine economy.

Despite the sector’s breadth and importance, the study critiques Brazil’s fragmented approach to maritime policy. Although national frameworks, such as the National Policy for Sea Resources and the National Maritime Policy, exist, the authors argue that they fall short of effectively integrating ocean-related decision-making into broader development strategies. The methodology pioneered in this research has already found international applications in Portugal’s island territories and Peru, with promising implications for future policymaking. As Haddad concludes, “We aim to contribute to the formulation of more just, territorially sensitive, and effective environmental and economic decisions.” The study thus represents not only a significant academic contribution but also a potential blueprint for sustainable and inclusive economic planning around marine resources.

More information: Eduardo Haddad et al, Shades of blue: the regional structure of the ocean economy in Brazil, npj Ocean Sustainability. DOI: 10.1038/s44183-025-00112-x

Journal information: npj Ocean Sustainability Provided by Fundação de Amparo à Pesquisa do Estado de São Paulo