Please cite this article in press as: Thurstan, R. H., et al. Oyster (Ostrea edulis) extirpation and ecosystem transformation in the Firth of Forth, Scotland. Journal for Nature Conservation (2013), http://dx.doi.org/10.1016/j.jnc.2013.01.004 ARTICLE IN PRESS G Model JNC-25284; No. of Pages 9 Journal for Nature Conservation xxx (2013) xxx–xxx Contents lists available at SciVerse ScienceDirect Journal for Nature Conservation jou rn al homepage: www.elsevier.de/jnc Oyster (Ostrea edulis) extirpation and ecosystem transformation in the Firth of Forth, Scotland Ruth H. Thurstan a,b,∗ , Julie P. Hawkins b , Lee Raby b , Callum M. Roberts b a School of Biological Sciences and ARC Centre of Excellence for Coral Reef Studies, University of Queensland, St Lucia, Queensland, 4072, Australia b Environment Department, University of York, Heslington, York, YO10 5DD, UK a r t i c l e i n f o Article history: Received 29 October 2012 Received in revised form 24 January 2013 Accepted 30 January 2013 Keywords: Benthic communities Bottom trawling Historical ecology a b s t r a c t Marine inshore communities, including biogenic habitats have undergone dramatic changes as a result of exploitation, pollution, land-use changes and introduced species. The Firth of Forth on the east coast of Scotland was once home to the most important oyster (Ostrea edulis Linnaeus, 1758) beds in Scotland. 19th and early 20th century fisheries scientists documented the degradation and loss of these beds, yet transformation of the wider benthic community has been little studied. We undertook archival searches, ecological surveys and shell community analysis using radioisotope dated sediment cores to investigate the history of decline of Forth oyster beds over the last 200 years and the changes to its wider biolog- ical communities. Quadrat analysis of the present day benthos reveal that soft-sediment communities dominate the Firth of Forth, with little remaining evidence of past oyster beds in places where abundant shell remains were picked up by a survey undertaken in 1895. Queen scallops (Aequipecten opercularis Linnaeus, 1758) and horse mussels (Modiolus modiolus Linnaeus, 1758) were once common within the Forth but have also markedly decreased compared to the earlier survey. Ouranalyses of shell remains sug- gest that overall mollusc biomass and species richness declined throughout the 19th century and early 20th century, suggesting broader-scale community change as human impacts increased and as habitats degraded. Inshore communities in the Firth of Forth today are less productive and less diverse compared to past states, with evidence suggesting that most of the damage was done by early bottom trawling and dredging activities. Given the pervasive nature of intensive trawling over the past 150 years, the kind of degradation we document for the Firth of Forth is likely to be commonplace within UK inshore communities. © 2013 Elsevier GmbH. All rights reserved. Introduction Healthy biogenic habitats such as oyster (Ostrea spp., Crassotrea spp.), maerl (Lithothamnion spp.) and horse mussel (Modiolus modi- olus Linnaeus, 1758) communities perform a variety of ecological functions including stabilisation of sediment, creation of feeding and nursery habitat for juvenile fish species, and water filtration (Holt et al. 1998). A reduction or loss of these organisms results in subsequent loss of ecosystem services (Jackson et al. 2001; Lotze et al. 2006; Roberts 2007). Yet many of these communities are under threat from a multitude of human impacts including destructive fishing methods, increased sediment loading, altered hydrodynamic regimes, disease and the introduction of non-native competitors and predators (Airoldi & Beck 2007; Hall-Spencer et al. ∗ Corresponding author at: School of Biological Sciences and ARC Centre of Excel- lence for Coral Reef Studies, University of Queensland, St Lucia, Queensland, 4072, Australia. Tel.: +61 450586263; fax: +61 733651655. E-mail addresses: r.thurstan@uq.edu.au, ruththurstan@yahoo.co.uk (R.H. Thurstan). 2003; Jackson et al. 2001; Lotze & Milewski 2004). Beck et al. (2011) estimated that globally, 85% of oyster reefs have been destroyed with many remaining beds degraded to the point where they have limited or no ecological function. In many cases the long time-interval over which degradation has occurred makes it difficult to determine the original extent and/or nature of biogenic habitats prior to large-scale human influence and hence determine the true degree of degradation (Lotze et al. 2006; Robinson & Frid 2008). It is likely that many estuarine or coastal seas have suffered from the ‘shifting baseline syndrome’ (Dayton et al. 1998; Pauly 1995), where current generations (and conse- quently current management) underestimate the extent of changes to coastal areas and therefore fail to manage areas for recovery. Exceptions do exist; the San Francisco Estuary Institute is an ini- tiative that aims to document and record past conditions and use the information to guide restoration management (Grossinger et al. 2005). However conservation-planning policies often make little or no reference to past conditions (Ban et al., in preparation). Native oysters (Ostrea edulis) were once plentiful in open sea environments and inshore estuaries around the UK (Royal Commission 1885). Yet today few wild populations of native 1617-1381/$ – see front matter © 2013 Elsevier GmbH. All rights reserved. http://dx.doi.org/10.1016/j.jnc.2013.01.004