Population dynamics of the black mussel Mytella strigata (Hanley, 1843) across environmental gradients in Panguil Bay, Philippines: Implications for management

The effective management of a nonindigenous species with invasive potential hinges on a thorough understanding of its population dynamics. In Panguil Bay, Philippines, the black mussel Mytella strigata, an emerging invasive species in Asia, has recently established populations. Investigating the population dynamics of M. strigata in this estuarine mangrove ecosystem provides critical insights into its environmental adaptability and invasive potential. Thus, the present study investigated the spatial variability in physicochemical parameters and their influence on the growth, mortality, and recruitment patterns of the nonindigenous black mussel M. strigata across the inner, middle, and outer locations of the bay. Significant differences were observed in temperature, salinity, total dissolved solids, and pH across the bay, with the middle location exhibiting the highest temperature, whereas salinity and total dissolved solids increased from the inner to the outer locations. The growth parameters varied accordingly, with the middle location showing the highest asymptotic length but the lowest growth rate, resulting in a longer lifespan for mussels in this area. Conversely, the inner location had the highest growth rate but the shortest lifespan. The mortality rates were lowest in the inner location and highest in the outer location. Recruitment patterns also showed spatial variability, with peaks occurring in different months depending on the location. A linear model incorporating pH, dissolved oxygen, salinity, and temperature explained 59.32 % of the variance in recruitment, highlighting the complex environmental influences on recruitment. The yield-per-recruit analysis indicated that the middle and outer locations could sustain greater biomass production than the inner location, suggesting areas for targeted management for population collapse. These findings offer valuable insights for developing effective management strategies to mitigate the impact of M. strigata in Panguil Bay.