Differential benthic community response to increased habitat complexity mediated by an invasive barnacle

MARIA M MENDEZ; EVANGELINA SCHWINDT; ALEJANDRO BORTOLUS

AQUATIC ECOLOGY

SPRINGER

Lugar: Berlin; Año: 2015 vol. 49 p. 441 - 452

1386-2588

ABSTRACTInvasive species threaten native ecosystemsworldwide. However, these species can interactpositively with local communities, increasing theirrichness, or the abundance of some species. Manyinvasive species are capable of influencing the habitatitself, by ameliorating physical stress and facilitatingthe colonization and survival of other organisms.Barnacles are common engineer species that canchange the physical structure of the environment, itscomplexity, and heterogeneity through their ownstructure. Balanus glandula is a native barnacle of the rocky shores of the west coast of North America. InArgentina, this invasive species not only colonizesrocky shores but it also has successfully colonized softbottomsalt marshes, where hard substrata are alimiting resource. In these environments, barnaclesform three-dimensional structures that increase thestructural complexity of the invaded salt marshes. Inthis work, we compared the composition, density,richness, and diversity of the macroinvertebrateassemblages associated with habitats of differentstructural complexity in two Patagonian salt marsheswhere B. glandula is well established. Our resultsshowed differences in the relative distribution andabundances of the invertebrate species between habitatsof different complexities. Furthermore, theresponse of the communities to the changes in thestructural complexity generated by B. glandula wasdifferent in the two marshes studied. This highlightsthe fact that B. glandula facilitates other invertebratesand affect community structure, mainly where thesettlement substrata (Spartina vs. mussels) are notfunctionally similar to the barnacle. Thus, our workshows that the rocky shore B. glandula is currently acritical structuring component of the native invertebratecommunity of soft-bottom environments wherethis species was introduced along the coast of southernSouth America.