State of the Bay Report 2010-Final - Anchor Environmental

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Amonia (mg/l as N) Nitrate(mg/l as N) Orthophosphorus (mg/l as P) Free Active Chlorine (mg/l) 70 60 50 40 30 20 10 0 16 14 12 10 8 6 4 2 0 16 14 12 10 8 6 4 2 0 4 3 3 2 2 1 1 0 May-09 May-09 May-09 May-09 Aug-09 Aug-09 Aug-09 Aug-09 Dec-09 Dec-09 Dec-09 Dec-09 Anchor Environmental Figure 4.22. Monthly trends in the volume of Ammonia Nitrate, Ortho Phosphorus and Nitrate Nitrogen present in effluent from Langebaan WWTW, June 2009-February 2011. Allowable limits as specified in terms of a General Authorisation under the National Water Act 1998 (red line). State of the Bay 2010: Saldanha Bay and Langebaan Lagoon 76 Mar-10 Mar-10 Mar-10 Mar-10 Jun-10 Jun-10 Jun-10 Jun-10 Sep-10 Sep-10 Sep-10 Sep-10 Jan-11 Jan-11 Jan-11 Jan-11
4.3.7 Storm water Anchor Environmental Storm water runoff, which occurs when rain flows over the impervious surfaces into waterways, is one of the major sources of non-point pollution in Saldanha (CSIR 2002). Sealed surfaces such as driveways, streets and pavements prevent rainwater from soaking into the ground and the runoff is typically directed directly into rivers, estuaries or coastal waters. Storm water running over these surfaces accumulates debris and chemical contaminants, which then enter water bodies untreated and may eventually lead to environmental degradation. Contaminants that are commonly introduced into coastal areas via storm water runoff include metals (Lead and Zinc in particular), fertilizers, hydrocarbons (oil and petrol from motor vehicles), debris (plastics), bacteria and pathogens and hazardous household wastes such as insecticides, pesticides and solvents (EPA, 2003). It is very difficult to characterise and treat storm water runoff prior to discharge, and this is due to the varying composition of the discharge as well as the large number of discharge points. The best way of dealing with contaminants in storm water runoff is to target the source of the problem by finding ways that prevent contaminants from entering storm water systems. This involves public education as well as effort from town planning and municipalities to implement storm water management programmes. The volume of storm water runoff entering waterways is directly related to the catchment characteristics and rainfall. The larger the urban footprint and the higher rainfall, the greater the runoff will be. At the beginning of a storm a “first flush effect” is observed, in which accumulated contaminants are washed from surfaces resulting in a peak in the concentrations of contaminants in the waterways (CSIR 2002). Several studies have shown degradation in aquatic environments in response to an increase in the volume of storm water runoff (Booth and Jackson 1997, Bay et al. 2003). Storm water runoff can be divided into two categories, namely urban and rural runoff. Storm water runoff that could potentially impact the marine environment in Saldanha and Langebaan originates from the Saldanha Bay industrial area (36 ha), the Saldanha Bay residential area (398 ha), the Port of Saldanha and surrounding industrial sites (323 ha) and Langebaan to Club Mykonos (711 ha). All residential and industrial storm water outlets drain into the sea. There are approximately 15 outlets in the Saldanha Bay residential area. Historically, storm water from the Port of Saldanha and ore terminal was allowed to overflow into the Bay but now most of this is diverted to storm water evaporation ponds and any material settling in these ponds is trucked to a landfill site. The number of storm water outlets in Saldanha Bay industrial zone (along the western margin of Small Bay) is not known, nor is the number of drains between Langebaan and Club Mykonos (CSIR 2002). The CSIR (2002) estimated the monthly flow of storm water entering Saldanha Bay and Langebaan Lagoon using rainfall data and runoff coefficients for residential and industrial areas. In this report, these estimates have been updated by obtaining more recent area estimates of industrial and residential developments surrounding Saldanha Bay and Langebaan Lagoon using Google Earth and acquiring longer term rainfall data (Table 4.6 and Figure 4.23). Runoff coefficients used to calculate storm water runoff from rainfall data were 0.3 for residential areas and 0.45 for industrial areas (CSIR 2002). Note that runoff from the Port of Saldanha and ore terminal have been excluded from these calculations. State of the Bay 2010: Saldanha Bay and Langebaan Lagoon 77
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State of the Bay 2010: Saldanha Bay
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TABLE OF CONTENTS Anchor Environmen
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11 BIRDS 234 Anchor Environmental 1
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LIST OF FIGURES Anchor Environmenta
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Anchor Environmental Figure 4.27. O
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Anchor Environmental Figure 7.3. Ch
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Anchor Environmental Figure 9.10. C
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Anchor Environmental Figure 12.1. N
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Anchor Environmental samples were c
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EXECUTIVE SUMMARY Anchor Environmen
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Anchor Environmental matter in the
Page 25 and 26: Anchor Environmental considered mos
Page 27 and 28: Anchor Environmental again in 2004,
Page 29 and 30: Anchor Environmental Populations of
Page 31 and 32: GLOSSARY Alien species An introduce
Page 33 and 34: 1 INTRODUCTION Anchor Environmental
Page 35 and 36: 2 STRUCTURE OF THIS REPORT Anchor E
Page 37 and 38: Anchor Environmental complicates ma
Page 39 and 40: Anchor Environmental observed deter
Page 41 and 42: Anchor Environmental 4 ACTIVITIES A
Page 43 and 44: Fish factories Small craft harbour
Page 45 and 46: Anchor Environmental Aerial photogr
Page 47 and 48: Anchor Environmental interferes wit
Page 49 and 50: Anchor Environmental Figure 4.7. Nu
Page 51 and 52: o Decrease in oxygen concentrations
Page 53 and 54: Anchor Environmental Upgrades to th
Page 55 and 56: Anchor Environmental Figure 4.9. A)
Page 57 and 58: Anchor Environmental (possibly link
Page 59 and 60: Anchor Environmental Prestedge Reti
Page 61 and 62: Anchor Environmental the constructi
Page 63 and 64: Number and types of vessels enterin
Page 65 and 66: Anchor Environmental is contained b
Page 67 and 68: Anchor Environmental include the be
Page 69 and 70: o 33 3’S o 33 10’S Saldanha Bay
Page 71 and 72: Anchor Environmental (1956) UNDER T
Page 73 and 74: Free ACtive Chlorine (mg/l) Amonia
Page 75: Faecal coliforms (org/100 ml) Chemi
Page 79 and 80: Anchor Environmental sites (concent
Page 81 and 82: Anchor Environmental Discharges fro
Page 83 and 84: Anchor Environmental Table 4.9. Det
Page 85 and 86: 5 WATER QUALITY Anchor Environmenta
Page 87 and 88: Anchor Environmental Stander (1977)
Page 89 and 90: Anchor Environmental coast, result
Page 91 and 92: Anchor Environmental likely as a re
Page 93 and 94: Anchor Environmental Construction o
Page 95 and 96: Anchor Environmental Table 5.2. Per
Page 103 and 104: Counts per 100ml of sample Counts p
Page 105 and 106: Counts per 100ml of sample 10000 10
Page 107 and 108: 5.6 Trace Metal Contaminants in the
Page 109 and 110: State of the Bay 2010: Saldanha Bay
Page 111 and 112: Lead(mg/kg) Mercury (mg/kg) Cadmium
Page 113 and 114: 6 SEDIMENTS 6.1 Sediment particle s
Page 115 and 116: 6.1.2 Sediment Particle size result
Page 119 and 120: 100% 90% 80% 70% 60% 50% 40% 30% 20
Page 125 and 126: % POC 18 16 14 12 10 8 6 4 2 0 % PO
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Percentage Percentage 1.8 1.6 1.4 1
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o 33 3’S o 33 10’S Yacht Club B
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Figure 6.12. Variation in the conce
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The concentrations of metals in sed
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concentrations are 56 and 29 times
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threshold of 1.2 mg/kg established
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Cadmium (mg/kg) 8 7 6 5 4 3 2 1 0 C
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Copper (mg/kg) 45 40 35 30 25 20 15
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16000 14000 12000 10000 8000 6000 4
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In summary, elevated trace metal co
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6.5 Summary of sediment health stat
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7.1 Long term changes in seagrass i
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7.2 Long term changes in Saltmarshe
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Figure 8.1. Benthic macrofauna samp
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Table 8.1. Depth at each of the sit
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these species usually provide the l
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(clustering of similar groups) (Meg
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The Big Bay samples BB 25 and BB29
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2007/08 dredging. Other signs of th
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Wet mass per m² Wet mass per m² 4
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Big Bay Crustaceans and polychaetes
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Average number of individuals per m
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Number Individuals per m² Number I
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8.4.2 Abundance Biomass Indices 8.4
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and percentage organic nitrogen (PO
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Table 8.5. W statistics at all stat
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Figure 8.15: Variation in the diver
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percentage of mud compared to Lange
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Cu (mg/kg) Cd (mg/kg) Ni (mg/kg) Pb
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contaminants. Furthermore dredging
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areas even 5 months after the clear
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Brittle star ( Ophiuroidea spp) Sea
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9.2 Approach and Methodology 9.2.1
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cover data for both mobile and sess
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9.2.3 Data Analysis The similaritie
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40%, co-occurring with sponges espe
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stands of the kelp Ecklonia maxima
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Plocamium spp. Ecklonia maxima Scut
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20 40 A Group 1 B 60 Similarity C G
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Percentage Cover 80 70 60 50 40 30
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Evenness Shannon Wiener 0.9 0.8 0.7
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2005 2008 2009 2010 Dive School Jet
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Table 9.5. Results from the SIMPER
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In general, the inter-annual differ
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The temporal distribution of M. gal
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Consistent with the previous years,
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Saldanha and Langebaan. Results fro
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The average abundance of the four m
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Anchor Environmental Figure 10.5. A
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Anchor Environmental Figure 10.7. A
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Anchor Environmental Within Big Bay
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Anchor Environmental 2008 and 2009
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Anchor Environmental the islands, b
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Anchor Environmental at Saldanha ar
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their main prey species, sardines a
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Anchor Environmental 2009). The eff
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Anchor Environmental attributed to
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Number of breeding pairs 800 700 60
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11.3 Birds of Langebaan Lagoon 11.3
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Anchor Environmental Figure 11.11.
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Anchor Environmental for the gannet
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Taxon Anchor Environmental Occurren
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Taxon Anchor Environmental Occurren
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Anchor Environmental 13 MANAGEMENT
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Anchor Environmental their operatio
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Anchor Environmental concentrations
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Anchor Environmental changes that p
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Anchor Environmental and slight imp
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Birdlife International. 2010. URL w
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Anchor Environmental penguins Sphen
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Anchor Environmental Game, E.T., Gr
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Anchor Environmental Kerwath, S. E.
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Anchor Environmental Moldan, A. 197
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Anchor Environmental Robinson, T.B.
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Anchor Environmental Tunley KL, Att
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State of the Bay Report 2010-Final - Anchor Environmental

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