Estamos realizando la búsqueda. Por favor, espere...

Predicting coexistence and predominance patterns between the introduced Manila clam (Ruditapes philippinarum) and the European native clam (Ruditapes decussatus)

Abstract: In several European estuaries, the introduced Manila clam (Ruditapes philippinarum) has become a widespread and predominating species supplanting the native carpet shell clam (Ruditapes decussatus) whereas in other estuaries such as the Bay of Santander (Gulf of Biscay) this pattern has not been detected. Using this estuary as a case study, the potential coexistence/predominance patterns between these two species were explored with the objective of providing insight into the capacity of expansion of R. philippinarum. Firstly, the Ecological Niche Factor Analysis (ENFA) was applied to determine the niches of both species, using seven contemporary environmental variables, i.e. salinity, water depth, current velocity, and sediment sand, gravel, silt and organic matter content. Secondly, ENFA-derived habitatsuitability (HS) maps were simultaneously treated, using geospatial techniques and following HS indexbased criteria, to determine the potential distribution patterns. Both species models performed well according to the cross-validation evaluation method. The environmental variables that most determined the presence of both clams were depth, current velocity and salinity. ENFA factors showed that R. philippinarum habitat differs more from the mean environmental conditions over the estuary (i.e. higher marginality) and has less narrow requirements (i.e. lower specialization). R. philippinarum dominated areas, determined by relatively lower current velocities and percentages of sand, higher organic matter contents and slightly shallower depths, were very reduced (i.e. 2.0% of the bay surface) compared to coexistence (47%) and R. decussatus predominance areas (7.4%). These results suggest that HS may regulate the expansion of R. philippinarum. ENFA, together with geospatial analysis of HS index, seems to be a valuable approach to explore the expansion potential of estuarine invasive or introduced species and thus support conservation decisions regarding native species.

 Fuente: Estuarine, Coastal and Shelf Science 152 (2015) 162e172

 Editorial: Academic Press

 Año de publicación: 2015

 Nº de páginas: 11

 Tipo de publicación: Artículo de Revista

 DOI: http://dx.doi.org/10.1016/j.ecss.2014.11.018

 ISSN: 0272-7714,1096-0015

 Proyecto español: CGL2009-10620

 Url de la publicación: http://www.sciencedirect.com/science/article/pii/S0272771414003461