eCite Digital Repository

Using historical data to detect temporal changes in the abundances of intertidal species on Irish shores


Simkanin, C and Power, A and Myers, A and McGrath, D and Southward, A and Mieszkowska, N and Leaper, R and O'Riordan, R, Using historical data to detect temporal changes in the abundances of intertidal species on Irish shores, Marine Biological Association of The United Kingdom. Journal, 85, (2005) pp. 1329-1340. ISSN 0025-3154 (2005) [Refereed Article]

Not available

Copyright Statement

Copyright İ 2005 Cambridge University Press

Official URL:;jsessi...

DOI: doi:10.1017/S0025315405012506


An historical data set, collected in 1958 by Southward and Crisp, was used as a baseline for detecting change in the abundances of species in the rocky intertidal of Ireland. In 2003, the abundances of each of 27 species was assessed using the same methodologies (ACFOR [which stands for the categories: abundant, common, frequent, occasional and rare] abundance scales) at 63 shores examined in the historical study. Comparison of the ACFOR data over a 45-year period, between the historical survey and re-survey,showed statistically signi˘cant changes in the abundances of 12 of the 27 species examined. Two species(one classed as northern and one introduced) increased signi˘cantly in abundance while ten species (˘ve classed as northern, one classed as southern and four broadly distributed) decreased in abundance. The possible reasons for the changes in species abundances were assessed not only in the context of anthropogenic eĦects, such as climate change and commercial exploitation, but also of operator error. The error or diĦerences recorded among operators (i.e. research scientists) when assessing species abundance using ACFOR categories was quanti˘ed on four shores. Signi˘cant change detected in three of the 12 species fell within the margin of operator error. This eĦect of operator may have also contributed to the results of no change in the other 15 species between the two census periods. It was not possible to determine the eĦect of operator on our results, which can increase the occurrence of a false positive (Type 1) or of a false negative (Type 2) outcome.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Adaptation to climate change
Objective Field:Climate change adaptation measures (excl. ecosystem)
UTAS Author:Leaper, R (Dr Rebecca Leaper)
ID Code:70552
Year Published:2005
Web of Science® Times Cited:70
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2011-06-28
Last Modified:2011-07-05

Repository Staff Only: item control page