State of the Bay Report 2010-Final - Anchor Environmental

State of the Bay 2010: Saldanha Bay and Langebaan Lagoon
Anchor Environmental
concentrations of mud in the sediments of Big Bay and Langebaan Lagoon are well below those of
Small Bay. The average concentration of fine grained particles has decreased at both Big Bay and
Langebaan Lagoon between 2009 and 2010 (Figure 6.5). The mud content in the lagoon is lower
than the level recorded in 2004, while that in Big Bay still exceeds the levels recorded in 2004 (Figure
6.5). The increase and subsequent reduction of fine grained particles in the Lagoon may be
indicative of variable flows and current strengths in this environment. The decreasing trend in the
concentration of mud in Big Bay may be due to a reduction the deposition of fine particles or the
increased flushing of the Bay. The reduction of fine grained particles in both Small Bay and Big Bay
since 2008 is an indication of improved environmental health.
Table 6.2. Concentrations of metals (mg/kg) surface sediments collected from Small Bay (SB), Big Bay
(BB) and Langebaan Lagoon in 2010 (Sediment analyzed by Scientific Services)
Al Fe Cd Cu Ni Pb Zn
SB1 8180 8049 1 34.3 10.2 18.4 78.3
SB2 1405 1876 0 2.3 1.7 2.0 6.0
SB3 1596 1749 0 3.5 1.0 11.0 6.4
SB8 1677 1835 0 2.0 1.4 1.4 5.3
SB9 2951 4093 0 3.7 3.1 3.3 11.6
SB10 824 1295 0 1.5 0.6 0.8 3.9
SB14 4976 6747 0 13.9 7.6 44.8 32.1
SB15 4013 5577 0 8.5 5.4 23.4 24.1
SB16 2178 2849 0 3.7 2.5 2.4 9.3
BB20 2032 1985 0 2.8 2.4 0 6.3
BB21 2222 2554 0 2.3 2.4 0.7 10.2
BB22 2917 3365 0 3.0 2.9 2.4 12.1
BB25 698 866 0 1.2 0.4 0 2.3
BB26 2254 2387 0 2.2 2.1 0 8.6
BB29 2637 2256 0 2.7 3.0 0 7.3
BB30 579 691 0 1.0 0 0 2.1
LL31 2316 3460 0 2.8 3.7 0.6 4.6
LL32 1996 4293 0 2.7 3.1 0.9 4.3
LL33 1381 3215 0 3.2 4.1 0 1.8
LL34 2356 2764 0 2.6 3.8 0 6.7
LL37 1367 2562 0 2.7 3.2 0 4.4
LL38 3691 4717 0 3.7 5.6 2.0 9.1
LL39 892 1620 0 1.7 1.1 0 1.5
LL40 780 1601 0 2.1 1.4 0 2.1
LL41 652 930 0 1.9 1.1 0 0.4