|The intertidal system: Sustainability and long-term indicators of system status|
Wilson, J.G. (2005). The intertidal system: Sustainability and long-term indicators of system status, in: Wilson, J.G. (Ed.) (2005). The intertidal ecosystem: the value of Ireland’s shores. pp. 165-178
In: Wilson, J.G. (Ed.) (2005). The intertidal ecosystem: the value of Ireland’s shores. Royal Irish Academy: Dublin. ISBN 1-904890-09-1. 206 pp., more
The intertidal system provides the classic control paradigm of physical control at the landward extreme to biological control at the seaward. Consequently, stability is an unlikely property, yet many intertidal systems display remarkable consistency in character and community type or biotope, if not in individual species’ abundances or biomass. There are several barriers to sustainability, as outlined by the OECD. Principal among these are sea level rise under climate change, habitat loss, habitat degradation (including over-exploitation) and pollution. Selection of long-term indicators of intertidal system status is limited both by the characteristics of the system, and in particular its susceptibility to physical disturbance, and by the lack of long-term data by which the noise of natural variation can be distinguished from that of anthopogenically induced change. Community measures such as H’ or SAB curves, which again have reference conditions, can be used to assess status, although they operate under the restrictions of both species’ impoverishment and variability in community structure. However these approaches can yield false positives, in that departures from reference condition are the norm rather than the exception. The final approach is long-term monitoring of selected ‘key’ species such as Tellina tenuis, Cerastoderma edule or Macoma balthica. Results suggest that several species are needed for an overall picture.