State of the Bay Report 2011-Final.pdf - Anchor Environmental

State of Saldanha Bay & Langebaan Lagoon 2011
List of Figures
Figure 6.27.
Figure 6.28.
Figure 6.29.
Figure 7.1.
Figure 7.2.
Figure 7.3.
Figure 7.4.
Figure 8.1.
Figure 8.2.
Figure 8.3
Figure 8.4
Figure 8.5.
Figure 8.6.
Figure 8.7.
Figure 8.8.
Figure 8.9.
Concentrations of Nickel (Ni) in mg/kg recorded at six sites in Saldanha Bay
between 1980 and 2011. Dotted lines indicate Effects Range Low values for
sediments ............................................................................................................... 118
Concentrations of Iron (Fe) in mg/kg recorded at five sites in Saldanha Bay between
2004 and 2011. ....................................................................................................... 120
Geographic representation of the results of a PRIMER analysis showing significant
clustering of sites based on the similarity of trace metal concentrations. Group A
generally had the highest concentrations for all metals and group E the lowest
(SIMPER analysis) .................................................................................................... 122
Seagrass (black) and saltmarsh (green) near Bottelary in Langebaan Lagoon.
Source: Google Earth. ............................................................................................. 124
Width of the Zostera beds and density of Siphonia at Klein Oesterwal and Bottelary
in Langebaan Lagoon, 1972-2006. .......................................................................... 126
Change in saltmarsh area over time in Langebaan Lagoon. (Data from Gerricke
2008) ....................................................................................................................... 127
Change in the number of discrete saltmarsh patches over time in Langebaan
Lagoon. (Data from Gerricke 2008) ........................................................................ 127
Sites sampled for benthic macrofauna between 1975 and 2011 in Saldanha Bay and
Langebaan Lagoon. ................................................................................................. 130
Dendrogram representing the similarity of sites (Bray Curtis Similarity) based on
the benthic macrofaunal community composition sampled at Small Bay (SB), Big
Bay (BB), Salamander Bay (S), Donkergat (D) and Langebaan Lagoon (LL) in 2011.
The 30% level of similarity is indicated by the slice. Clusters of sites significantly
similar are represented by the red dotted lines (SIMPROF). ................................. 134
Geographic representation of the results of a PRIMER analysis showing significant
clustering of sites based on the similarity of trace metal concentrations (Euclidean
Distance). Group A generally had the highest concentrations for all metals and
group E the lowest (SIMPER analysis) .................................................................... 136
Variation in the percentage mud in sediments in Saldanha Bay and Langebaan
Lagoon as indicated by the 2011 survey results. .................................................... 136
Geographic representation of the results of a PRIMER analysis showing significant
clustering of sites based on the similarity of benthic macrofaunal community
composition (Bray-Curtis coefficient) ..................................................................... 138
Overall trends in the biomass and abundance of benthic macrofauna in Small Bay
as shown by taxonomic and functional groups. ..................................................... 144
Overall trends in the biomass and abundance of benthic macrofauna in Big Bay as
shown by taxonomic and functional groups. ......................................................... 145
Overall trends in the biomass and abundance of benthic macrofauna in Langebaan
Lagoon as shown by taxonomic and functional groups. ........................................ 146
Variation in the diversity of the benthic macrofauna in Saldanha Bay and
Langebaan Lagoon as indicated by the 2010 survey results. (H’ = 1.5 indicates low
diversity, H’ = 3.5 indicates high diversity) ............................................................. 148
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