The University of Southampton
University of Southampton Institutional Repository

Grazing dynamics in intertidal rockpools: Connectivity of microhabitats

Noël, Laure M.-L.J., Hawkins, Steve J., Jenkins, Stuart R. and Thompson, Richard C. (2009) Grazing dynamics in intertidal rockpools: Connectivity of microhabitats Journal of Experimental Marine Biology and Ecology, 370, (1-2), pp. 9-17. (doi:10.1016/j.jembe.2008.11.005).

Record type: Article


Differences between rockpool and emergent rock communities are often attributed to their contrasting physical conditions. However, differences in grazing pressure between rockpools and open rock could also exert an important structuring role. Greater densities and/or the lack of tidal constraints on foraging may allow grazing intensity to be greater in rockpools. Here, wax discs were deployed to compare grazing intensity between rockpool and emergent rock habitats at each of three tidal heights on a moderately exposed shore in SW England. Grazing intensity was then examined in relation to herbivore density. Grazing intensity in pools was twice that on emergent rock, despite a lower density of herbivores in the rockpools. Of these herbivores, patellid limpets are the dominant grazers on rocky shores throughout the NE Atlantic and are recognised to have a major role in structuring intertidal communities. Thus, subsequent experiments focussed on the influence of limpets in determining the differences in consumer pressure between rockpools and emergent rock. Three alternative explanations were considered: (1) the effect of continuous immersion on grazing intensity in rockpools; (2) differences in limpet species abundance between the two habitats; (3) movement of limpets from emergent rock into pools to feed. The level of grazing pressure exerted by Patella ulyssiponensis (Gmelin), the predominant species living constantly immersed in rockpools, was similar to that of P. vulgata (Linnaeus) which is predominantly found on emergent rock. P. vulgata were observed moving from emergent rock into rockpools during high tide. Manipulative experiments confirmed that these foraging excursions resulted in a 2-fold increase in grazing intensity in the pools. Grazing activity of P. vulgata in rockpools was not consistent between sites and may be influenced by differences in wave exposure and/or the abundance of microbial resources. Elevated consumer pressure in rockpools may be an important factor influencing algal assemblages and probably explains the predominance of grazer resistant-species in these pools.

PDF Noel_etal_2009_JEMBE.pdf - Version of Record
Restricted to Repository staff only
Download (634kB)

More information

Published date: March 2009
Keywords: Foraging behaviour, Herbivory, Patellids, Rocky intertidal, Tidepool


Local EPrints ID: 187911
ISSN: 0022-0981
PURE UUID: 44072ea7-c98a-46dd-b034-289ca3683087

Catalogue record

Date deposited: 18 May 2011 15:30
Last modified: 18 Jul 2017 11:44

Export record



Author: Laure M.-L.J. Noël
Author: Stuart R. Jenkins
Author: Richard C. Thompson

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.