MEPS 355:173-182 (2008)  -  DOI: https://doi.org/10.3354/meps07248

Piddocks (Mollusca: Bivalvia: Pholadidae) increase topographical complexity and species diversity in the intertidal

Eunice H. Pinn1,*, R. C. Thompson2, S. J. Hawkins3,4

1Joint Nature Conservation Committee, Dunnet House, 7 Thistle Place, Aberdeen AB10 1UZ, UK
2Marine Biology and Ecology Research Centre, School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
3Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
4School of Ocean Sciences, University of Wales Bangor, Menai Bridge, Anglesey LL59 5AB, UK

ABSTRACT: Bioerosion increases the topographic complexity of soft rock habitats, thereby increasing species diversity. This increase in species diversity may either be associated with an increase in complexity or may simply be a consequence of the increase in available surface area for colonisation. The influence of habitat modification by piddocks on intertidal species richness was investigated through field survey using fractal geometry to assess topographical complexity. The relationship between topographical complexity and species diversity was examined using the species spacing technique, which uses fractal dimensions to normalise the species richness data in relation to topographical complexity. Six sites were chosen, comprising either clay or chalk substratum, which had a range of rock hardness. Through their rock-boring activities, piddocks significantly increased the topographical complexity of the shore. Associated with this increase was an increase in species richness at all sites. Using species spacing, at 5 of the 6 sites, the increased species richness was found to be area-independent, with more species being observed than would be expected for a simple increase in surface area alone. However, piddocks are also known to significantly increase the erosion of soft rock habitats, many of which are regarded as being of particular conservation importance because of their rarity within Europe. Piddocks thus increase intertidal biodiversity while at the same time significantly contributing to erosion of the substratum.


KEY WORDS: Biodiversity · Burrow morphology · Ecosystem engineers · Fractal dimensions · Habitat complexity


Full text in pdf format 
Cite this article as: Pinn EH, Thompson RC, Hawkins SJ (2008) Piddocks (Mollusca: Bivalvia: Pholadidae) increase topographical complexity and species diversity in the intertidal. Mar Ecol Prog Ser 355:173-182. https://doi.org/10.3354/meps07248

Export citation
Mail this link - Contents Mailing Lists - RSS
- -