Modeling the influence of anthropogenic disturbances, territory quality, and biotic factors toward fitness of Mytella strigata (Hanley, 1843): Implications for biocontrol of an invasive species

The introduction of invasive species is often associated with functional traits that differ markedly from those of native communities. In urban coastal lagoons, elevated nutrient inputs and persistent human activities create conditions that facilitate invasion success; however, the long-term ecological consequences in these systems remain poorly understood. This study investigated the combined influence of anthropogenic disturbances, territory quality, and biotic factors on the fitness of the invasive mussel Mytella strigata in a reclaimed lagoon in Cebu City, Philippines. Field data were collected across 150 plots, where environmental, biotic, and disturbance variables were quantified, and their relationships with fitness indicators were analyzed. The lagoon exhibited relatively stable environmental conditions, with an average depth of 5 m, mean pH of 6.5, dissolved oxygen of 7.08 mg L⁻¹, and salinity of approximately 15 ppt. Path analysis revealed generally weak relationships between predictors and fitness, with low explanatory power (R² ≤ 0.151). Only dissolved oxygen significantly affected gonadosomatic index (β = −0.297, p = 0.035), while proximity to encroachment showed a positive effect on reproduction (β = 0.239, p = 0.004). Overall, the measured factors exerted limited influence on fitness, suggesting high physiological tolerance of M. strigata in disturbed environments. Management interventions should therefore prioritize integrated approaches targeting anthropogenic disturbances, complemented by mechanical or harvest-based control strategies to enhance effectiveness in urban coastal systems.