Coral reef fish assemblages are shaped by management regimes and not reef location in the East African region

Patterns of reef fish assemblages are structured by a range of physical, biological, and anthropogenic drivers operating at different scales. The roles that these forces play in influencing community composition, biomass, size, density, diversity, and ecological function are increasingly being understood on a regional and global scales. In this study, we examined reef fish communities along the East African coastline (spanning over 1,500 km) to assess spatial and temporal variations in the abundance, density, size, biomass, and total weight of coral reef fish assemblages across different management regimes (marine parks, community-conserved areas, reserves, and fished areas). Among the four management regimes surveyed, government-controlled marine parks recorded the highest biomass (mean = 14.8 kg/ha), while reserves had the lowest (mean = 10 kg/ha). In contrast, fish density was highest in community-conserved areas (104 individuals/hectare) and lowest in reserves (66 individuals/hectare). Kruskal-Wallis One-Way ANOVA revealed significant differences in fish density (X² = 33.1, p < 0.05) and biomass (X² = 27.5, p < 0.05) across management regimes, with unprotected areas differing significantly from the other three different management regimes. However, no significant spatial or temporal variation was detected between sites in Tanzania and Kenya, suggesting that coral reef fish assemblages along the East African coastline are primarily influenced by management regimes rather than site location and temporal variations.