otherwise known as the WETLANDS. Welcometo our little corner of learning, to matters that
are close to our pocketsand hearts.
Port Alfred is renowned for its wetlands, these have been the subjectof many a controversial discussion for so many years. To spoil or not tospoil, dat is da question? How do these affect our daily lives? Well, that, like the question of development, dunes and growth, willnever really be resolved. What we can hope for, is that the peoplein charge, when making decisions regarding the developments, can weighthe facts against greed. If this is too harsh a statement, then wecan only hope that they look years ahead and ask themselves whether ornot what they decided in the heat of excitement, when proposals are putbefore them, is 'how will this affect the future?'
In tourism, we constantly beg the 'powers-that-be' to think before theystamp, to understand the dire consequences of making decisions for peopleyet to take their place amongst us...
Our estuaries are dwindling. They are not being cared for. Withthe upsurge of tourism, more and more people are buying anything that willrace them over the waters. Little thought is given to the river banks,the life under the water and the effects that these motorized modes ofpleasure will do to the waters..
Just out of town, the largest of our wetlands, are being suffocatedunder the garbage that people throw away, supposedly from gardens.
In town, the area known as 'the duck pond' is being developed, witha fair
amount of thought, it is up to us the concerned, to ensure thatthe careless
people who throw litter, the builders who have no thoughtof preservation and
the buildings that will try to sneak their waste, willbe monitored.
meeting places of the rivers and the sea, and are
characterized by theinteraction between the two. Conditions in
an estuary are alwayschanging, and this instability or variability
is one of the mostimportant features of estuaries.
The salinity of
estuarinewater varies depending on the tide and
the strength of theinflowing river. In addition, a river also brings
silt and nutrientsto the estuary in varying quantities, depending
on conditions in thecatchment (drainage basin) of the river
WHY ARE ESTUARIES
Conditions in estuariesare very different from those in the sea.
Estuaries are usuallycalm, sheltered and shallow, and vary
greatly in temperature,salinity and turbidity (murkiness). As a
result they are specializedenvironments.
A nursery for
marinespecies: Over 100 species of fishes, prawns
and crabs in SouthAfrican off-shore waters use estuaries as
nurseries and/or feedinggrounds. The life cycle of most of these
species involves eggproduction at sea, often close inshore and
near an estuary mouth.Eggs and larvae develop at sea, but the
larvae and juvenilesmigrate to estuaries in great numbers. In fish,
this migration takesplace mainly during late winter, spring and
early summer whenmillions of juveniles swim into estuaries.
Estuaries are goodnurseries
because they offer protection from
most marine predators,and their high temperatures and rich food
supplies favour rapidgrowth of the juveniles. The source of this
food supply is estuarineplants growing in the water, as well as
the plants of theneighbouring wetlands, e.g. mangroves and
reeds. These plantssupply most of the detritus (fragmented
remains of dead plantsand animals) which, together with bacteria
responsible for decomposingdetritus, forms the basis of the
estuarine food web.
Most juvenile fishmigrate
back to sea at an age of about one
year. These sub-adultstend to live close to the shore, where they
join adult spawningpopulations once they become mature.
ESTUARIES AND PEOPLE
Estuaries are favouritesites for human settlement, urban
development and recreation(boating, fishing etc.). Many cities
and towns along thecoast depend on estuaries for harbour
facilities, tourismand recreation, e.g. Durban, Richard's Bay and
Estuaries are particularlypopular with anglers when adult fish
enter seasonally tofeed. At these times fish are easier to catch
and are importantas a source of both food and recreation. An
example of this isthe famous spotted grunter "run" into
KwaZulu/Natal andCape estuaries. Of the 81 fish species which
depend on estuariesin South Africa, 29 are sport angling species
and an additional21 species are used for human food.
THREATS TO ESTUARIES
Anything that happensto a river in its catchment can have an
impact on the estuary.A river flowing through farmlands can
become polluted bypesticides, herbicides and nutrients from
fertilizer. Soil erodedfrom badly farmed or overgrazed lands will
also be washed intoestuaries after heavy rains. This excessive silt
load has the effectof filling up the estuary and in some cases
resulting in the estuarymouth closing. Silt smothers animals and
reduces light penetrationso that plants are unable to grow except
in very shallow water.
Damming of rivers andthe
use of water for irrigation or industry
can lead to freshwaterstarvation of an estuary. This upsets the
ratio of freshwaterto sea water in the estuary which in turn
affects the plantsand animals living there.
WHAT YOU CAN DO
* Get to know theestuaries in your area by walking along their
shoreline or canoeingthroughout their length. Report signs of
damage to the localauthority.
* List the plants
andanimals living in these estuaries. Photograph
the upper, middleand lower reaches of the estuary from fixed
vantage points andmonitor change between seasons and from
year to year.
* Find out what theestuary
is used for, which local authority is
responsible for itsmanagement and what strategies have been
prepared to controldevelopment alongside it.
DID YOU KNOW?
* Bad catchment managementis the major cause of estuarine
damage in southernAfrica.
* The numbers of
manyimportant commercial (e.g. prawns) and
angling species (e.g.kob, grunter, perch) which rely upon
estuaries are dwindlingas a result of disturbed estuarine
The coast of SouthAfrica
runs in a great arc of over 3000
kilometres from theOrange River on the west coast to Kosi Bay
on the east coast.The west coast is influenced by the cold
Benguela current andthe east coast by the warm Agulhas
current. These currentsgive rise to different communities of
marine life alongthe west, south and east coast.
This coast supportsa rich fishing industry. Inshore there are large
kelp forests and manylimpets, mussels, perlemoen and rock
lobsters. Large concentrationsof seabirds breed on the offshore
islands. Seals breedboth on the islands and the mainland.
Langebaan lagoon isthe only national park and an important
feeding ground forbirds that migrate to the Northern Hemisphere
to breed. Sanctuarieshave been established to protect bird islands
and rock lobsters.
This section of thecoast extends from the Cape Peninsula to
East London, and experiencesmuch pressure from land usage
and tourism. The CapePoint nature reserve is of special interest
for comparison ofthe west coast and south coast communities.
Smaller protectedareas occur in False Bay and at Betty's Bay
where perlemoen areabundant. De Hoop nature reserve, north
of Cape Agulhas, hasa magnificent stretch of coastline with a
combination of rockyshore and extensive dune fields. The
Southern Right whalescan be seen breeding in the sheltered
bays. Trails go throughthe reserve which is also used as an
education centre forschool camps. Tsitsikamma coastal national
park is a well-managedwild stretch of coast which boasts an
underwater divingtrail and the famous Otter Hiking Trail.
Knysna lagoon is theonly estuary given any protection.
If one travels northfrom East London to Kosi Bay, the coast
becomes more tropicaland mangroves line the river banks.
Dwesa, Hluleka andMkambati nature reserves protect part of the
beautiful and gentlecoast of the Transkei. They provide a stark
contrast to the heavilyexploited neighbouring shores where the
local population harveststhe edible shellfish and also the seaweed
Gelidium which isused commercially as a source of agar. In
KwaZulu/Natal, a largearea of northern Zululand from Lake St
Lucia to Ponto daOuro is set aside for conservation. This area
contains the onlycoral reefs in the country. Access to these
beaches is strictlycontrolled as they are the breeding grounds of
the loggerhead andleatherback turtles which come ashore in
early summer to laytheir eggs.
Sharks are plentifulon the
east coast of KwaZulu/Natal and
bathing beaches areprotected by shark nets. These have been so
effective in catchingsharks that there is now concern over the
removal of so manyof the top predators of the seas. Shark nets
also catch dolphins,skates, rays and turtles and this is another
source of concern.
WHY ARE MARINE
Marine reserves protecta selection of ecosystems from:
* Human pressure andurban development.
* Pollution which maybe
caused by sewage, industrial effluent,
thermal effluent frompower stations, oil pollution from ships,
plastic and rubbish.
activities,e.g. boating, fishing, bait collecting and
harvesting for thepot.
* Commercial ventures,e.g.
fishing and harvesting rock lobsters,
perlemoen, kelp andother seaweeds - overfishing will disturb the
delicate balance ofnature.
ventures,especially diamond mining and the mining of
sand dunes for heavymetals.
* The use of beachvehicles
which damage sand dunes, compact
the sand and destroythe sand-dwelling plants and animals.
THE COAST OF SOUTHERNAFRICA.
J Kench. Struik,
THE NATIONAL PARKSOF SOUTH
Bannister and R. Gordon.Struik, Cape Town, 1983.
LIVING SHORES OF
SOUTHERNAFRICA. G. and M.
Branch. Struik, 1984.
EXPLORE THE SEASHOREOF
SOUTH AFRICA. M.
Branch. Struik, CapeTown,1987.
A GUIDE TO THE COASTAND
NATURE RESERVES OF
THE TRANSKEI. DuncanButchart. The Wildlife Society,
Linden and Durban,1989.
Department of EnvironmentAffairs and Tourism; and the Dept.
Environment and CulturalAffairs (previously Cape Nature
PARADISE UNDER PRESSURE.A.
OCEANS OF LIFE OFFSOUTHERN
AFRICA. A. Payne
and R. Crawford (eds).Vlaeberg, Cape Town, 1989.
A FIELD GUIDE TO THEEASTERN
CAPE COAST. R.
Lubke, F. Gess andM. Bruton (eds). Wildlife Society,
All books availablefrom
Russel Friedman Books, PO Box 73,
Halfway House, 1685.Tel. 011-7022300/1.
Natal Parks Board.PO Box
662, Pietermaritzburg 3200. Tel.
National Parks Board.PO Box
787, Pretoria 0001. Tel.
andCultural Affairs (previously Cape
Nature Conservation).Private Bag X9086, Cape Town 8000.
Tel. 021-483 4227.
NatureConservation. Private Bag X98,
Ulundi 3838. Tel.0358-700552.
There is clear waterup to
your ankles and a dragonfly zips past
your head as you watchsome ducks fly off the water - welcome
to the soggy worldof the wetland!
Wetlands are difficultto
define because of their great variation in
size and location.The most important features of wetlands are:
Waterlogged soilsor soils covered with a shallow layer of water
(permanently or seasonally),unique types of soil, and distinctive
plants adapted towater-saturated soils. Marshes, bogs, swamps,
vleis and spongesare examples of wetlands.
WHY ARE WETLANDS IMPORTANT?
* Flood busters:
Wetlands associatedwith streams and rivers slow floodwaters by
acting as giant, shallowbowls. Water flowing into these bowls
loses speed and spreadsout. Plants in the wetland play an
important role inholding back the water. The wetland acts as a
sponge as much ofthe flood water is then stored in the wetland
and is slowly releasedto downstream areas, instead of it all
rushing to the seawithin a few days. This greatly reduces flood
damage, particularlyerosion, and ensures a more steady supply
of water throughoutthe year.
Wetlands improve waterquality as they are very good natural
filters, trappingsediments, nutrients (e.g. nitrogen and
phosphorus), and evenpathogenic (disease-causing) bacteria. In
addition, pollutantssuch as heavy metals (e.g. mercury, lead) and
pesticides, may betrapped by chemical and biological processes.
In other words, thewater leaving the wetland is cleaner than the
water entering it.
* Wetlands and wildlife:
Wetlands are filterswhere sediments and nutrients accumulate,
so many plants growthere, e.g. bulrushes, grasses, reeds,
waterlilies, sedgesand trees. The plants, in turn, provide food
and a place for attachmentand shelter for many creatures. There
is more life, hectarefor hectare, in a healthy wetland than in
almost any other habitat.These productive places support huge
numbers of insects,fish, birds and other animals. Some animals
are completely dependanton wetlands, whilst others use
wetlands for onlypart of their lives. The wattled crane, for
example, is dependanton wetlands for breeding. The rich
diversity of waterbedsin southern Africa (totalling 130 species) is
possible because ofthe many wetlands spread across the
sub-continent. Thewetlands of southern Africa are of
international importanceas they are the southern destination for
many migratory wadingbirds.
* People and wetlands:
Wetlands have beenused for centuries as grazing for domestic
stock, and as a sourceof reeds used for thatching, hut
construction and basketweaving. They are provide fishing,
hunting and the opportunityto observe wildlife, especially birds.
Wetlands are appreciatedfor their beauty as open spaces and
also for their educationalvalue.
WETLANDS IN TROUBLE
To most people wordssuch as "marsh, swamp, bog and vlei",
conjure up littlemore than the "four D's" - dampness, disease,
difficulty and danger.Because of this wetlands have been seen as
wastelands to be convertedto alternative uses such as cropland,
dams, plantationsof exotic trees, waste disposal sites and
pastures. Many wetlandshave been "reclaimed" for industry and
the construction ofairports, harbours and sewage treatment
plants. Historicallywetlands have been drained in attempts to
All wetlands in
southernAfrica are threatened. Botswana's
magnificent OkavangoDelta is threatened by the possible
canalization of theBoro river to supply water for both domestic
and industrial use.In KwaZulu/Natal, debate rages over the
mining of the duneson the eastern shores of St. Lucia because of
the unknown consequencesto the water table in the area.
St. Lucia is a
Ramsarrecognized site. The Ramsar Convention
on Wetlands of InternationalImportance recognizes such
wetlands and worksto conserve them. South Africa has 12 sites
recognized by theRamsar Convention, including Langebaan on
the west coast, Barberspanin Gauteng and De Hoop vlei in the
WHAT YOU CAN DO
* The Department ofEnvironment Affairs and Tourism runs a
wetland conservationprogramme and all interested people are
invited to participate.
* Get to know the
wetlandsin your area and list the plants and
animals growing there.Draw a map of the wetland's position,
size and usage. Takephotographs of the wetlands from fixed
vantage points andat different seasons of the year to compare
the changes betweenseasons and from year to year.
* Report the abuseof
wetlands to your local nature conservation,
agricultural extensionofficer or Department of Environment
Affairs. Always makeyour report in writing to ensure that the
officer concernedhas to investigate.
* Read "The Biologyand
Conservation of South Africa's
Vanishing Waters"(see below) which has a very useful chapter
titled "What you cando".
DID YOU KNOW?
* In KwaZulu/Natal,58% of the wetlands associated with the
Mfolozi River catchmenthave disappeared as a result of siltation
caused by erosionof overgrazed lands.
WETLANDS.Newsletter on the activities
relating to the RamsarConvention in South Africa. Department
of Environment Affairs.
THE WETLANDS OF NATAL(PARTS 1-4). Natal Town and
Regional PlanningCommission. Private Bag 9038,
ECOLOGY AND CONSERVATIONOF
SOUTH AFRICA. CSIRoccasional report no.56. CSIR 1982.
Waterlogged Wealth.E. Maltby, Earthscan,1986.
WETLANDS. C. Gaigher.Dept.
Environment and Cultural
Affairs (previouslyCape Nature Conservation).
THE BIOLOGY AND
AFRICA'S VANISHINGWATERS. B.R. Davies and J.A.Day.
CEMS, University ofCape Town and The Wildlife Society of
Southern Africa, CapeTown, 1986.
The Department of
EnvironmentAffairs and Tourism.
Private Bag X447,Pretoria 0001. Tel. 012-310 3425.
All provincial natureconservation authorities.
Universities of CapeTown,
Orange Free State, KwaZulu/Natal,
In conclusion, PLEASE try to ensure, that every precautionis taken, when even thinking of throwing out a bucket of dirt, itcan and will spoil life forever!