NFEPA Atlas 5.3_20111025_FINAL.indd - Biodiversity GIS - SANBI

1.2 Guiding principles for managingfreshwater ecosystemsBelow are eight principles that should guide the management of freshwater ecosystemsin support of sustainable development. These principles informed the identification ofFEPAs.Principle 1: Fresh water flowing out to sea is not wastedFreshwater inputs to estuaries and the sea are necessary to maintain importantecological processes that keep our marine resources healthy. For example, fresh waterprovides an important environmental cue that helps fish and other marine animalsfind their way to estuary mouths to breed. Nutrients in fresh water also form thefoundation of marine food webs. These ecological processes are vital for maintainingcommercial and recreational fish stocks, as well as for providing a source of foodto poor coastal communities that depend directly on marine resources for food.A certain amount of water is also required to flush and scour the mouth of mostestuaries. Without the scouring effect, sediments build up at the mouth and the riskof back-flooding during storms increases. Artificial breaching of an estuary mouthto minimise this risk is expensive and damages estuarine ecosystems. Apart fromthe scouring effect, fresh water helps to flush estuaries of organic matter and otherpollutants, which otherwise smell unpleasant. If too much water is taken out of a riveralong its length, not enough fresh water reaches the estuary and the sea to maintainthese vital ecological processes.Principle 2: Freshwater ecosystems are connectedsystems that require a source-to-seaapproachNo single ecosystem component can be meaningfully managed in isolation from itsconnected aquatic ecosystems – be they rivers, wetlands, groundwater, estuaries ormarine ecosystems. What happens upstream or in the surrounding landscape affectsdownstream ecosystems and their ability to provide ecosystem services. The nowcommonly acknowledged whole-catchment approach should be taken further tobecome a source-to-sea approach, because freshwater inputs impact significantly onestuarine and marine environments, and the ecosystem services they deliver.Principle 3: Healthy tributaries and wetlands support thesustainability of hard-working riversFreshwater ecosystems in a catchment can be designed to support different levels of use,with natural rivers and wetlands that are minimally-used supporting the sustainability ofheavily-used rivers and wetlands that often form the economic hub of the catchment. Inmany catchments, the desired condition of the estuary (as agreed on through negotiationsbetween stakeholders) will be a determining factor in the management of upstream waterresources connected to the estuary. To ensure that some tributaries and wetlands stay healthy,a catchment can be zoned for varying degrees of use and impact. For example, FEPAs shouldbe zoned for low impact activities; surrounding secondary zones can allow moderate impactactivities; and heavily impacting activities such as high-intensity agriculture, plantation forestryand mining, can be restricted to high impact zones. In addition, buffers of natural vegetationaround all freshwater ecosystems support the maintenance of healthy freshwater ecosystems(see principle 4).Principle 4: Healthy riparian, wetland and estuary buffersreduce the impact of land-based activitiesFreshwater ecosystems are generally the lowest point in the landscape, making them thereceivers of wastes, sediment and pollutants in runoff. This, combined with the strongconnectivity of freshwater ecosystems, means that they are highly susceptible to upstream,downstream and upland impacts. Managing land-based impacts is therefore essential. Whileit is seldom feasible for entire catchments to be ‘locked away’ from human use, catchmentscan be designed to incorporate varying levels of use and impacts on freshwater ecosystemsas discussed in principle 3. Buffers of natural vegetation around all freshwater ecosystems,even heavily-used ones, go a long way to reducing the effects of damaging land-use practices(such as agricultural activities close to river banks). The effective width of the buffer shouldbe determined on a site-specific basis. The Implementation Manual for FEPAs (available on theNFEPA DVD) provides some recommendations for delineating management buffers.Principle 5: Groundwater sustains river flows, particularly indry seasonsGroundwater abstracted from boreholes in or close to rivers, streams or wetlands has avery direct influence on river flow, and should be not be viewed as an additional waterresource. Such groundwater plays an important role in sustaining river flows (‘base flows’)and supporting refuge pools in the dry season. Apart from the human benefits of maintainingriver flows in the dry season, refuge pools in seasonal rivers support water-dependent animalsthat would otherwise not survive when the rivers dry up. Healthy riparian zones (riverbanks and their surrounds), which filter pollutants that drain from the land, are also oftenmaintained by groundwater. When groundwater has very weak links to surface water (such asin deep, confined aquifers) it may be possible to abstract it without significantly impacting onfreshwater ecosystems; however, long term impacts are not well understood.Principle 6: Rivers provide ecological corridors in anincreasingly fragmented landscapeRivers form important ecological corridors from water source areas all the way down tothe sea. These river corridors support land and water-based ecosystem processes andbiodiversity that depend on connectivity. The loss of connectivity between different partsof a catchment fundamentally alters ecosystem processes and associated services, andnegatively affects biodiversity. Such landscape connectivity provides social and ecologicalresilience, especially within a changing climate. This contributes to ecosystem-basedadaptation to climate change.Principle 7: Managing freshwater ecosystems requiresstrong cooperation across multiple sectorsThe effective protection of freshwater ecosystems requires close coordination andcooperation among the sectors responsible for protection and management of waterresources, biodiversity conservation, land-use management (including agriculturalresources), and integrated development planning. Coordination and cooperation can begreatly enhanced through a skilled facilitating organisation that can play an intermediaryrole between the water user, science and policy domains. SANBI, provincial conservationauthorities and Catchment Management Agencies are well-placed to play such a role infreshwater ecosystem conservation.Principle 8: A strategic and systematic approach toconserving freshwater ecosystems is neededThe intensity of the pressures on freshwater ecosystems means that we cannot manageimpacts just on a river-by-river or wetland-by-wetland basis. A strategic approach toplanning and setting priorities is essential, to focus conservation efforts where theywill have the greatest impact. Systematic biodiversity planning provides a spatialplanning tool for achieving this. With its overarching goal of planning for the longtermpersistence of biodiversity, systematic biodiversity planning identifies those areasthat are essential for conserving biodiversity. Spatial priorities are based on achievingrepresentation of the full spectrum of freshwater ecosystems and associated biodiversitywithin the region of concern. A systematic biodiversity planning approach was used inthe development of the NFEPA maps (see Section 1.4 below).Introduction- 4 -