Can an invasive species compensate for the loss of a declining native species? Functional similarity of native and introduced oysters

Nadescha Zwerschke; Lawrence Eagling; Dai Roberts; Nessa O'Connor

doi:10.1016/j.marenvres.2019.104793

Can an invasive species compensate for the loss of a declining native species? Functional similarity of native and introduced oysters

Mar Environ Res. 2020 Jan:153:104793. doi: 10.1016/j.marenvres.2019.104793. Epub 2019 Sep 25.

Authors

Nadescha Zwerschke¹, Lawrence Eagling², Dai Roberts³, Nessa O'Connor⁴

Affiliations

¹ Queen's University Marine Laboratory, 12-13 the Strand, Portaferry, BT22 1PF, UK. Electronic address: nzwerschke01@qub.ac.uk.
² Queen's University Marine Laboratory, 12-13 the Strand, Portaferry, BT22 1PF, UK.
³ Queen's University Marine Laboratory, 12-13 the Strand, Portaferry, BT22 1PF, UK; Queen's University Belfast, School of Biological Science, Belfast, BT9 7BL, UK.
⁴ Queen's University Belfast, School of Biological Science, Belfast, BT9 7BL, UK.

PMID: 31582298
DOI: 10.1016/j.marenvres.2019.104793

Abstract

The widespread introduction of the Pacific oyster, Magallana gigas, has raised concerns regarding its potential impact on the functioning of invaded ecosystems. Concurrently, populations of the European oyster, Ostrea edulis, are in decline. We quantified the functional role of the native oyster, O. edulis, in terms of nutrient cycling and associated infaunal biodiversity and compared it directly to that of the invading oyster, M. gigas. The presence and density of both species were manipulated in the field and we tested for differences in concentration of ammonium, phosphate, total oxidised nitrogen and silicate in pore-water; total organic nitrogen and carbon in sediment; microbial activity; chlorophyll concentration; and the assemblage structure and richness of associated benthic taxa. No differences in nutrient cycling rates or associated benthic assemblages were identified between both oyster species. Nutrient concentrations were mostly affected by differences in oyster density and their significance varied among sampling events. Our findings suggest that M. gigas could compensate for the loss of ecosystem functions performed by O. edulis in areas where native oysters have been extirpated.

Keywords: Benthic-pelagic coupling; Biodiversity; Bioengineers; Functional traits; Intertidal; Invasive species; Nutrient cycling; Oysters; Temperate estuary.