Relationship between biofouling abundance on wood and the recruitment and growth of the wood-boring bivalve Bankia martensi (Stempell, 1899) - Seasonal and bathymetric variations

Abstract

The marine wood-boring bivalve Bankia martensi (Stempell, 1899) is the primary agent responsible for wood degradation along the Chilean coast. However, there is limited understanding of its interactions with other marine wood-biofouling species. Previous studies have shown an inverse relationship between biofouling cover on wood and the recruitment and growth of B. martensi. These trends may vary over time and at different depths. Consequently, during the austral autumn and spring of 2024, pine wood panels (25 x 15 × 5 cm) were submerged at three different depths (1, 3, and 5 m below the water surface) in Metri Bay (41°36′S; 72°42′W). After five months, B. martensi recruitment and size were assessed, along with biofouler cover and biomass on the panels. The recruitment and size of B. martensi were higher in spring (1.7 ± 0.3 perforations∗cm⁻²) than in autumn (0.5 ± 0.2 perforations∗cm⁻²) and diminished with increasing depth (mainly at 5 m). Inverse associations were observed between the recruitment and size of B. martensi specimens and the cover and biomass of the main biofouler species. These results suggest that the presence of biofouling species influences larval settlement and growth of B. martensi. Furthermore, these potential interspecific competition relationships change depending on season and depth, thereby affecting the rate at which xylophagous species degrade wood. Manipulative experiments with biofouler species, as well as measurements of the reproductive traits of B. martensi, could help us understand the biological interactions between marine wood borers and biofouler species.