HARBOUR MONITORING

Beach Monitoring Programme

In the fall of 2005, the beach monitoring survey was designed and initiated for St Ann’s Harbour. This survey is based on the premise that major changes in the sublittoral ecosystem of the Harbour, whether they be due to mussel aquaculture or not, will eventually also be manifested in the intertidal zones and on beaches around the Harbour. In addition, the programme provides an opportunity for community education, involvement and direct stewardship with regard to the environmental condition of the area.

Educational activities included two preparatory workshops in November 2005 and April 2006 (Fig. 10a-b) with interested members of the community. During these workshops, participants visited various shoreline sites in the Harbour. Jointly, and under the guidance of Dr. Chapman, participants became familiarized with the local marine flora and fauna, acquired monitoring skills for the long-term programme and discussed all aspects of the environmental history and future of the region. Monthly monitoring commenced in April 2006. As the monitoring focuses on the low intertidal zone, in addition to beaches, monitoring became limited to the summer months (April – October), as there are no sufficiently low tides occurring in St Ann’s Harbour during the daytime throughout the winter (Pentcheff, 2007).

Methods

Three sites around St. Ann’s Harbour were identified for the ongoing beach monitoring (Fig. 2), one east of Munro Point in the south-western region of St Ann’s Harbour (CS-Site), one on the eastern side (Englishtown) below the MacAskill museum (MU-Site), and one near Jersey Cove on the sand spit at the north-western tip of Harbour (FE-Site).

At each site, three permanent monitoring stakes were placed in the lower intertidal zone, marking the ends and the centre of a line running parallel to the low tide line, approximately 100 m in length. Monthly monitoring of benthic biota has been carried out in relation to this line (using six randomly placed 0.25m2 quadrats), following an established protocol, assessing percent surface cover and abundances of species >0.5cm length. In addition, a description of the strandline with categorical quantification of dominant components complemented intertidal quadrat samples. Data recordings have been complemented by digital images of quadrats and strandline. Identification sheets, developed from the species found abundantly in St. Ann’s Harbour, served as visual aids during the monitoring and may be used in future production of a more general brochure on St. Ann’s Harbour natural history.

Results

As a direct result of the commitment of the Stewards of St Ann’s Harbour Association, data records are almost entirely complete, i.e. include almost the full set of quadrat and image records for all three monitoring sites. Also, in most months, data were recorded within two days of one another at all three sites (ensuring comparability). Overall, the range of characteristics encountered at the different sites is consistent throughout the monitoring period. Hence, the CS-site is characterised by a mudflat with a few rocky outcrops, the FE-site is dominated by pebbles interspersed with mussels, and the MU-site is dominated by rocks with attached vegetation (especially rockweeds) and associated fauna. Abundance patterns of species as well as debris, both in the strandline and in the low intertidal zone (quadrats), remain fairly consistent at each site across the monitoring period. In some cases, seasonal effects are detectable, e.g. the increase of seaweeds at the FE-site throughout the summer. No dramatic events or changes were recorded at the monitored sites, and as expected at this point in time, no indication of the mussel aquaculture affecting the species distribution in the intertidal zone in any specific way. Also, within our monitoring period, we did not find significant evidence for materials associated with the mussel farm accumulating on beaches. In view of the long-term prospects of this monitoring programme, the past year of recordings will provide an invaluable baseline for future comparisons.