WEST COAST – To adhere to the regulations set by the Government regarding the Covid 19 pandemic, the Saldanha Bay Water Quality Forum Trust (SBWQFT) delivered the yearly State of the Bay report via webinar on Thursday even- ing from Juffroushoogte Guest Farm just out- side Vredenburg.
Only a few role players, some Trust members and members of the media were present in per- son while dr Barry Clark presented the findings of the past year as well as comparing statistics over the past few decades, availability permit- ting.
Barry told that it was an amazing experience collecting samples on the beach in Langebaan during the lockdown period with not a sole in sight.
What the report essentially is is an annual assessment of anthropogenic impacts to and ecological health of Saldanha Bay and Langebaan Lagoon, composed of 3 broader components:
1) Anthropogenic impact:
– Activities and discharges affecting the
health of the bay;
2) Physical health:
– Water quality parameters, temperature, sa- linity, oxygen, nutrients, currents and waves and groundwater inflow;
– Concentrations of contaminants (eg trace metals, bacteria) in seawater, sediments and liv- ing organisms in the bay;
3) Ecological health:
– Organisms themselves, the animals that live in the bay that are affected by the health of the bay, using a number of indicators through sedi- ments to living organisms, all operating on dif- ferent time scales, giving an indication how the health is changing over time;
– Changes in community structure and abun- dance of living organisms (macrophytes, inverte- brates, fish and birds).
Activities and discharge
In previous years huge growth in popula- tion and urban and industrial development was observed in and around the bay. This year, how- ever, little progress was made on some of the larger developments proposed by the IDZ, LPG/ LNG imports, export of iron ore and manganese, phosphate mining, fish processing and desilina- tion, although some exceptions (Aquaculture Development Zone and Powership) does exist.
A few other factors also contributed to lesser
activities impacting the health of the bay:
– Unfortunately, some industries, like Arcelor
Mittal, has closed down;
– Shipping traffic and ballast water discharges
are both down;
– Numbers of visitors to West Coast National Park are down;
The exception here is at the Saldanha Waste Water Treatment Works, where discharge is up again due to the fact that waste water was historically taken up by ArcelorMittal and is not used at this stage, which is an unfortunate set- back. This might change soon as other industries has shown interest in making use of the waste water.
A second exception is the government spon- sored ADZ, with mussel production growing
since 2012 and thirdly new initiatives that are coming in line now, eg Powership (the production of electricity proposed for Saldanha Bay).
Aquaculture Development Zone The aquaculture footprint in the area grew from 464ha to 884ha, but all has not been taken up yet, as only 36% of the new lease area has been taken up. Around 60% of this 36% is actually being utilized to date, which means about an 11% increase in aquaculture production in the last year.
The ADZ is subject to environmental authorization and fairly strict conditions provided by Environmental Affairs (EA). These include EMP, CF and AMC programs to monitor environmental impacts. They can only continue expanding as long as indications show the impact on the bay is not significant.
The ADZ does a lot of additional independent monitoring, including monitoring of the water quality in the bay.
Reef area in Big Bay One of the most surprising findings through the ADZ’s monitoring program was the identification of some extensive reef areas in Big Bay, that was not picked up during the Environmental Impact Assessment process. Knowledge of the reefs has however been in place since the 1970`s when Bogart Fleming highlighted this fact in a publication in 1977.
From Barry`s perpective this is a bit of a concern as reef areas tend to harbour high bio- diversity . Another concern is that the monitor- ing program for the ADZ was structured around soft sediment impact, habitats and how these might change when affected by mari-culture operations. Monitoring programs currently in place are however not really appropriate for assessing impact on the kinds of habitat surrounding reef areas. The Department of Environment, Fisheries and Forestry already started taking action to address the matter.
Not much time was spent on groundwater in the past, although it is an incredibly important commodity in the area, particularly the West Coast that is quite an arid area with not much surface water around.
A new partner, GEOSS (Ground Water and Earth Sciences) came on board the State of of the Bay program. GEOSS is a company special- izing in groundwater assessment and work and have contributed a new chapter to the State of the Bay report this year, providing some context for the groundwater resources in the area, the sensitivity of these resources and the impor- tance there-of and highly contributed to the equality of the lagoon.
Groundwater in the area is classified as a con- trolled area by the Department of Water and Sanitation.
GEOSS reported that the total usable ground- water exploitation potential in the area is 15.2 cubic meters per annum without compromis- ing other habitats or fauna and flora that are dependant on it. This includes groundwater outflow to Langebaan Lagoon.
Commodities utilizing groundwater are ag- riculture and three well-field developments, Langebaan Road Aquifer, Hopefield Well-field and Elandsfontein Well-field.
Elandsfontein Well-field is associated with Elandsfontein Phosphate Mine, where ground- water abstraction is designed to enable mining. Essentially they are de-watering a mining pit and re-injecting that water back downstream. Groundwater flow typically is coming from the aquifer system down towards the lagoon and is sustaining plant and animal communities around the lagoon.
GEOSS recommended these well-fields only to be used during times of severe drought and kept as full as possible in non-drought times and in fact should be recharged during non-drought times if at all possible to ensure that the water supply to the lagoon and ecosystems along the aquifers are not compromised.
As part of the State of the Bay monitoring work Elandsfontein Phosphate Mine has funded some monitoring of water quality parameters at the head of the lagoon, specifically temperature and salinity. Monitoring at this stage is focused on baseline data collection, establishing a base- line of what conditions are like in the lagoon.
Data produce really interesting trends with graphs showing changing temperatures through the seasons, also touching on tidal variation and spring leap cycles. Salinity (salt content in the la- goon) also show clear seasonal patterns. Normal seawater is about 34,5g per 1000l in winter and rising up to quite a high level of 40g per 1000l in summer.
Microbial data – recreational limits
This data gives an indication of the safety for recreational use of the bay. The method to collect this data is used all over the world.
Data for recreational limits has been collected by the SBWQFT since its inception in 1999 at a series of sites in the parameter of the bay. Studying the graph clearly indicates that the water quality in the bay has improved dramatically. Towards the beginning of the 2000`s conditions were mostly poor and unsuitable for recreation due to high inputs of treated waste water and problems with the waste treated works in Saldanha. The breakpoint came in 2005/6 where a dramatic improvement started and is largely sustained to the present day.
There are however a few problem areas, for instance near Hoedjiesbaai Hotel and in Pepper Bay, but by enlarge conditions in Langebaan Lagoon are safe for recreational use.
This success story is testament to information sharing and information made available to authorities and taking the necessary steps to address any problems.
Trace metals in shoreline mussels
Trace metals, sometimes known as heavy metals, are sometimes toxic to people and animals. Data collected from shoreline mussels in Small Bay suggest it is not safe for human consumption as levels are mostly above safety levels, although things have improved in recent years.
Cadmium levels are slightly better, although data shows times and places where levels exceed safety levels.
Data on manganese was included for inter- est sake because of a recent program to export manganese from the Multi Purpose Terminal.
Manganese levels have increased in mussels in the bay.
Importantly there is no safety or maximum permissible level for consumption of manganese in seafoods.
Trace metals in farmed mussels and oysters
Looking at graphs from data collected by mariculture farmers, it is encouraging that trace metal levels are much lower than those on the shoreline.
To view the full 2020 State of the Bay presentation with graphs visit the Saldanha Bay Water Quality Forum Trust website at www.sbwqft.org. za
Any comments of the report will be attended