1.                  Monitoring Requirements

1.1               Section 6.2.5 of the approved EM&A Manual for the Project requires that potential work disturbance to inter-tidal bird communities is monitored during the construction phase. Appendix 1 shows the requirements and Event and Action Plan for monitoring works.

2.                  Monitoring Equipment

2.1               Equipment used for monitoring included a 20-60x spotting scope, 10x42 binoculars, and Hand-held GPS.

3.                  Monitoring Locations

3.1               Monitoring was conducted at two locations, Ngau Hom Shek (NHS) and Sheung Pak Nai (SPN), as shown in Figure 3.1. Monitoring at NHS was adjacent to the works area, and provides a record of potential construction phase disturbance. The SPN site is relatively distant from the works area, and was used as a control site.

 

4.                  Monitoring Methodology

Intertidal Mudflat Monitoring

4.1               Bird species and abundance within a 100m quadrat of exposed mudflat were recorded at low tide (>100m of mudflat exposed) on 16th September 2005. Records were made at both NHS and SPN (Figure 3.1).

4.2               Bird abundance and species composition were compared with baseline data recorded from September/October 2001 to May 2002, as presented in the Shenzhen Western Corridor EIA Report. 

Tideline Monitoring

4.3               Bird species and abundance within a 100m quadrat of exposed mudflat were recorded at low tide (>100m of mudflat exposed) on 16th September 2005. Records were made at both NHS and SPN (Figure 3.1).

4.4               Surveys were also conducted at a 500m belt transect established at SPN (Fig. 3.1), on the same date using the same methodology adopted at NHS.

4.5               Bird density within the tideline transects at NHS and SPN was compared using the non-parametric Mann-Whitney test, where:

HO = There are no differences in bird densities along the tidelines at NHS and SPN.

4.6               Additionally, bird abundance and species composition were compared with baseline data recorded from September 2001 to May 2002, as presented in the Shenzhen Western Corridor EIA Report.

 

5.                  Monitoring Results

Intertidal Mudflat Monitoring

5.1               Two species, Little Egret (Egretta garzetta) and Whimbrel (Numenius phaeopus), were recorded from exposed mudflats during recent surveys, with a Little Egret and two Whimbrels recorded from SPN, and a single Little Egret recorded from NHS (Figure 5.1).

5.2               Compared to the results of September 2005 surveys, the EIA Report recorded a mean of 1.5 birds/ha and 0.9 species and 3.9 birds/ha and 1.5 species on exposed mudflats at NHS and SPN respectively.

 

Figure 5.1     Comparison of Bird Abundance and Species Composition on Exposed Mudflats: Ngau Hom Shek and Sheung Pak Nai, September, 2005

Tideline

5.3               Bird densities recorded along tidelines were 66 birds/ha at NHS and 68 birds/ha at SPN, with 3 species recorded at NHS (Chinese Pond Heron, Ardeola bacchus; Little Egret, Egretta garzetta and Great Egret, Casmerodius albus) and only one species (Little Egret) recorded from SPN (Figure 5.2).

5.4               A Mann-Whitney test found no statistically significant difference between bird densities recorded at NHS and SPN (P = 0.970).

5.5               At NHS, bird density recorded during recent surveys (66 birds/ha) was greatly higher than mean values presented in the EIA Report (23.2 birds/ha), whereas bird density at SPN (68 birds/ha) was slightly higher than values presented in the EIA Report (58.2 birds/ha). At both sites, species richness recorded during recent surveys (3 species at NHS and 1 species at SPN) was similar to mean values presented in the EIA Report (1.8 species and 2 species recorded at NHS and SPN respectively).

Figure 5.2     Comparison of Bird Abundance and Species Composition Along Tidelines: Ngau Hom Shek and Sheung Pak Nai, September 2005

 

6.                  Discussion and Conclusion

Intertidal Mudflats

6.1               Bird densities on mudflats at both the potential impact site and the control site were low during September 2005 surveys. There was no evidence of construction phase disturbance at NHS, the potential impact site.

Tideline

6.2               During surveys conducted in September 2005, bird densities along tidelines at NHS (the potential impact site) and SPN (the control site) were almost the same. No statistically significant difference in tideline densities at NHS and SPN was observed, and there was no evidence of construction phase disturbance at NHS, the potential impact site.

References

Carey, G.J., Chalmers, M.L., Diskin, D.A., Kennerley, P.R., Leader, P.J., Leven, M.R., Lewthwaite, R.W., Melville, D.S., Turnbull, M., and Young, L. (2001): The Avifauna of Hong Kong. Hong Kong Bird Watching Society, Hong Kong.