Positive versus negative effects of an invasive ecosystem engineer on different components of a marine ecosystem

By P. Gribben, J. E. Byers, Jeffrey T. Wright, Tim Glasby. 2013

88 citations recorded by the source corpus.

Habitat-forming invasive species have complex impacts on native communities. Positive above ground and negative below ground impacts are reported, suggesting that habitat-forming invasive species may affect community components differently. Furthermore, such effects may vary depending on the density of the invader. We determined the responses of community components to different densities of the invasive green alga Caulerpa taxifolia in southeastern Australia. Initially we investigated differences in soft-sediment faunal communities (above and below ground) across a biomass gradient at two invaded sites. Caulerpa taxifolia biomass was positively associated with the composition and abundance of the epifaunal community, but negatively correlated with the abundance of infauna. To examine the response of common community members in more detail, we caged two species of mollusk (the infaunal bivalve, Anadara trapezia and the epifaunal gastropod, Batillaria australis) across the same biomass gradient to determine lethal and sublethal effects of C. taxifolia biomass on individuals. Survivorship of A. trapezia was low when C. taxifolia was above 300 g m22. Negative sublethal effects were also density-dependent with A. trapezia tissue weight being lowest above this same C. taxifolia biomass. The proportion of B. australis surviving was unaffected by C. taxifolia biomass. However, the total number of live B. australis recovered in cages increased as C. taxifolia biomass increased, providing further evidence of positive density dependent effects (in line with the survey data) of C. taxifolia on epifauna. Finally, we removed C. taxifolia from plots of differing C. taxifolia biomass and followed community change for 5 months. Community change following C. taxifolia removal was also density dependent as recovery 5 months post-removal depended on the initial biomass of C. taxifolia, suggesting a lag in the recovery of communities due to residual environmental effects post-removal (i.e. hysteresis). We have shown that the effects of a habitat-forming invasive species are biomass dependent and also affect community components differently, suggesting that, globally, the impact of these types of invaders may be context dependent.

Subfields: Global and Planetary Change, Oceanography

View Paper: https://www.semanticscholar.org/paper/52fd8d8953242988d9e366cfa594da54c97d58de

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Global and Planetary Change

1. D. Booth
2. Will Figueira
3. Jonathan D. Phillips
4. S. Ahyong
5. E. Johnston
6. P. Hutchings

In Oceanography

1. M. Mayer‐Pinto
2. Will Figueira
3. D. Booth
4. S. Ahyong
5. E. Johnston
6. P. Hutchings
7. Peter D. Steinberg
8. P. Gribben

Citations in the corpus

• Sydney Harbour: a review of anthropogenic impacts on the biodiversity and ecosystem function of one of the world’s largest natural harbours (2015, background): “C. taxifolia has large negative direct and indirect effects (by modifying habitat quality) on native biota (Wright and Gribben 2008; Gribben et al. 2009;Wright et al. 2012; Gribben et al. 2013).”
• Biogeomorphic Impacts of Invasive Species (2014, background): “Another is Gribben et al. (2012), who found the invasive seaweed Caulerpa taxifolia creates habitats with reduced water flow, siltier bed sediments, and lower dissolved oxygen.”