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The invasion and subsequent die-off of Mytilus galloprovincialis in Langebaan Lagoon, South Africa: effects on natural communities.
- Source :
-
Marine Biology . Aug2007, Vol. 152 Issue 2, p225-232. 8p. 1 Diagram, 1 Chart, 4 Graphs, 1 Map. - Publication Year :
- 2007
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Abstract
- The alien mussel Mytilus galloprovincialis invaded sand banks in Langebaan Lagoon on the west coast of South Africa in the mid-1990s. However, by 2001 these beds had completely died off, with only empty shells and anoxic sand remaining. In an effort to prevent the re-settlement of this aggressive invader, all dead mussel shells were then cleared. This study considered the impacts of the invasion and subsequent die-off on natural benthic communities. Community composition differed significantly between non-invaded and invaded areas (ANOSIM, R = 0.685 and P < 0.01) as the physical presence of mussel beds created a new habitat that promoted invasion by indigenous rocky-shore species. This dramatically increased faunal biomass from 1,132.9 g m−2 ± 3,454.7 SD to 53,262.4 g m−2 ± 23,052.6 SD and species richness from 38 to 49 species. Following the die-off of the mussel beds, communities remained significantly different between non-invaded areas and those in which mussel shells remained (ANOSIM, R = 0.663 and P < 0.01). Species richness was significantly greater in non-invaded areas (18 species) than in uncleared areas with remnant shells (four species) (Kruskal–Wallis ANOVA H 2,36 = 10.8964 and P = 0.032), as the previously dominant rocky-shore species became smothered by sediment and the compacted shells formed an impermeable layer excluding sandy-shore burrowing organisms. After the shells were cleared, 50% of the sandy-shore species associated with non-invaded areas returned within 5 months, but community structure still remained significantly different to non-invaded areas (ANOSIM, R = 0.235 and P > 0.05). Invasion thus dramatically altered natural communities and although the subsequent removal of the dead mussel shells appears to have aided recovery, community composition remained different from the pre-invasion state after 5 months. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00253162
- Volume :
- 152
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Marine Biology
- Publication Type :
- Academic Journal
- Accession number :
- 25811306
- Full Text :
- https://doi.org/10.1007/s00227-007-0697-x