Mangrove Ecosystem Service Values and Coastal-Household Livelihood-Strategy Choices: A Systematic Review
Doan Ba Toai, Jianzhou YangMangrove ecosystems underpin the livelihoods of coastal and rural households across the tropics, yet how their ecosystem service (ES) values are associated with livelihood-strategy choices remains unevenly understood. Following a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided protocol, this systematic review searched Web of Science and Scopus for studies published between 2016 and 2026 (database search was run on 27 May 2026); of the 353 records identified and 207 screened after removing 146 duplicates, 133 unique studies were retained; 95 of these contributed evidence to one or more of seven outcome themes, while 38 were retained as contextual or background evidence. The seven themes were graded using a hybrid Grading of Recommendations Assessment, Development and Evaluation (GRADE)/Confidence in the Evidence from Reviews of Qualitative Research (CERQual) approach (zero, high certainty; two, moderate certainty; five, low certainty). A structured assessment of meta-analytic feasibility across six candidate outcome domains found that no domain met the operational requirement of at least three independent studies reporting one outcome construct on a harmonisable metric with usable variance information; therefore, this review reports the direction, consistency, and certainty of associations rather than pooled-effect magnitudes. The corpus shows a pronounced value-epistemology asymmetry, with monetary valuation forming the largest single evidence theme (45 studies, approximately one-third of the corpus) and relational or indigenous framings remaining a smaller but substantive theme (20 studies, about 15%), meaning that household decision-making is incompletely captured. Evidence for mangrove–fishery production linkages and the coastal-protection/ecosystem-based disaster-risk-reduction function was the most consistent and was rated as moderate certainty. However, the fishery evidence provides the more direct connection to livelihood dependence, whereas most coastal-protection estimates are biophysical or aggregate and do not directly demonstrate household livelihood-strategy responses. The five remaining themes rest on low-certainty evidence, with welfare estimates spanning orders of magnitude and value-to-behaviour pathways weakly tested. Asian settings account for roughly half of the evidence (Southeast and South Asia together 45%, 60/133), while African, Latin American, and Pacific Island settings remain under-represented, limiting transferability. Evidence on bundled payments for ecosystem services, blue-carbon governance, and secure community tenure should therefore be treated as context-dependent options for prospective evaluation rather than as established prescriptions. The clearest research priority is quasi-experimental and longitudinal work linking elicited values to observed livelihood behaviour.