Date of Award
2026
Degree Type
Dissertation
Degree Name
Doctor of Philosophy in Biological and Environmental Sciences
Department
Fisheries, Animal and Veterinary Science
First Advisor
Melva Treviño Peña
Abstract
Fisheries dependency refers to the action of a person, community, or society linking their social, cultural, and economic actions to different ecosystem services (ES) for covering their food system with essential marine species, developing a governance system to conserve these fishing areas, their local ecological knowledge, and guaranteeing food security in the coastal areas. In Latin America, most fishing activities are practiced within three nautical miles of the shoreline, estuaries, lagoons, and mangrove forest channels, using small vessels and traditional gear such as hooks, trammel nets, and gill nets. Some coastal communities have developed their subsistence and livelihood activities in mangrove forests, dependent on mangrove resources, such as using the wood for timber and firewood, and capturing high-value marine species. Over the last 40 years, mangrove forests have become crucial protected areas worldwide, with a focus on maintaining their regulation and supporting ecosystem services to reduce deforestation and the degradation of mangrove forests. Although those processes have been reduced in some coastal areas of Latin America, other threats continue to affect mangrove forests and the communities that depend on mangrove resources, especially in their food provisioning and cultural ecosystem services, which should be included in ecosystem-based management plans. I argue that current mangrove forest management practices do not account for the dependency levels of coastal communities, setting aside real concerns for people, such as food systems and, consequently, their food provisioning.
This dissertation focuses on the impact of current management strategies in three Latin American countries - El Salvador, Honduras, and Peru - where most of the mangrove forests have been declared as Natural Protected Areas (NPAs) and have current management plans to avoid their deforestation, overfishing, and pollution. The purpose of this research is to interpret those strategies to conserve mangrove forests, how NPAs configurate the relationship with local coastal communities and external stakeholders (such as shrimp farmers, tuna fish industry and tourism industry), and the strong linkage between local fishers and gathers with mangrove forests and the estuaries, focused on their food provisioning and cultural values of seafood into their Local Ecological Knowledges (LEKs). To define and evaluate the impact of NPAs on mangrove forest coverage and accessibility, I worked with land cover metrics using Remote Sensing Analysis; to understand the perceptions of coastal communities and their relationships with mangrove forests and governance systems, I applied an ethnographic approach through focus groups and interviews. Finally, the implementation of quantitative analysis through questionnaires and the Marine Resource Dependence Index (MRDI) allowed metrics to evaluate fishing capacities and dependence on food provisioning in coastal communities in the areas of study.
Chapter 1 employs a mixed-methods approach to integrate remote sensing analysis and ethnographic research to understand the interactions between small-scale fishers and gatherers with mangrove forests in Tumbes, Peru. First, I evaluated changes in mangrove forest coverage and forest fragmentation over the last 40 years (1985 - 2024). I found that most of the original coverage has been maintained during that period, and the Natural Protected Area exhibits landscape connectivity. However, the surrounding coastal communities do not perceive that their original fishing areas or profitability have improved, and they remain threatened by shrimp farming encroaching on the mangrove forests. These perceptions were identified through participatory mapping exercises with coastal communities in Tumbes, Peru, which further demonstrated the reconfiguration and displacement of activities resulting from shrimp farming.
Considering the importance of conserving mangrove forest coverage, Chapter 2 of this dissertation analyzes historical land cover change from 1980 to 2024 in the Gulf of Fonseca (a shared estuary located in Central America), with the aim of examining the different threats in the area and how the conservation process is functional in maintaining and restoring coverage. This process was developed using Remote Sensing Analysis with Random Forest algorithms to determine the rate of change in mangrove and transitional ecosystems, including temporary lagoons and dry forests. Main findings demonstrate that mangrove forests in El Salvador and Honduras experienced deforestation, but that, with the implementation of environmental policies, most mangrove areas have recovered since 2000. Although transitional ecosystems show decreasing rates of settlement by shrimp farms, they threaten not only mangrove forests but also other human activities, such as access and reductions in fishing areas, which pose a threat to food availability and security.
The focus of Chapter 3 was to evaluate perceptions of the integrity of decision-making processes in the governance system for mangrove forest management, especially whether the challenges and environmental concerns of coastal communities in El Salvador, Honduras, and Peru are aligned with the aims of the Natural Protected Areas established within mangrove forests. Through interviews and focus groups, I found that communities are concerned about reduced fishing and the profitability of target marine species, especially due to shrimp farming, which affects access to traditional fishing areas, the pollution it promotes, and a weak governance system that does not include their aims.
Finally, Chapter 4 examines community concerns by employing a Marine Resource Dependence Index designed to evaluate potential food security risks through accessibility and profitability of fishing in mangrove forests in El Salvador, Honduras, and Peru. The findings show a significantly high dependence of specific communities, with different target marine species such as mangrove crab (Ucides occidentalis), mangrove cockle (Anadara tuberculosa), snapper (Lutjanus spp.), snook (Centropomus spp.), and shrimp (Litopenaeus vannamei). These species not only have high economic value, but are also of high nutritional importance. For example, 75% of the Honduran households in the study site and 50% of the households surveyed in El Salvador consume finfish at least three days per week. In Peru, 50% of households consume mangrove mussels at least twice per week, and 90% of them consume finfish at least twice per week. Relative to other animal proteins such as pork, chicken, beef, eggs, and milk, consumption levels are low, with less than 15% of households across the three countries reporting consumption three times per week.
Through a mixed-methods approach integrating remote sensing analysis, ethnography, and quantitative data analysis, this research reveals the importance of accounting for the potential impacts of food systems on the conservation of crucial Marine Protected Areas associated with mangrove forests. Food provisioning and cultural ecosystem services deserve special attention in further mangrove ecosystem-based management to avoid misrepresentation or underrepresentation of coastal communities.
Recommended Citation
Quintanilla Magana, Ariel Alexander, "ASSESSING FISHERIES DEPENDENCE OF COASTAL COMMUNITIES IN MANAGED MANGROVE FORESTS IN LATIN AMERICA" (2026). Open Access Dissertations. Paper 4604.
https://digitalcommons.uri.edu/oa_diss/4604