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Water SA
versão On-line ISSN 1816-7950
versão impressa ISSN 0378-4738
Water SA vol.34 no.3 Pretoria Mar. 2008
Water temperature and riverine ecosystems: An overview of knowledge and approaches for assessing biotic responses, with special reference to South Africa
Helen Dallas
Freshwater Research Unit, Department of Zoology, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa
ABSTRACT
Available information pertaining to water temperature in riverine ecosystems is examined and consolidated into an overview that describes the spatial and temporal variation in water temperature, the importance of water temperature in lotic ecosystems, the measurement and modelling of water temperature, anthropogenic factors that modify water temperature, the effects of temperature changes on the physical and chemical characteristics of water; and on aquatic organisms and ecosystems. Methods for assessing the effects of temperature changes on aquatic organisms are discussed and current water temperature guidelines for the protection of aquatic ecosystems are outlined. This paper highlights the complexity of water temperature in the aquatic environment and the importance of understanding the spatio-temporal variability in water temperature and the variable responses of aquatic organisms to thermal stress. Anthropogenic modifiers of the thermal regime, which include heated discharges, flow modifications, riparian vegetation removal and global climate change; present ongoing threats to aquatic ecosystems. Whilst Northern Hemisphere information on water temperature is plentiful, this overview has identified the huge gap that exists in temperature-related data in South Africa. Without baseline data on water temperature and the thermal requirements of aquatic organisms, it is extremely difficult to adequately manage aquatic ecosystems. The risk of increasingly harsh conditions caused by greater water demands and climate change accentuates the need for a greater understanding of the thermal conditions in aquatic ecosystems in South Africa and the requirements and triggers of the associated aquatic biota. Future directions for thermal research are described.
Keywords: water temperature, riverine ecosystems, rivers, thermal regimes, biotic responses, aquatic organisms
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References
ALLANSON B (1961) Investigations into the ecology of polluted inland waters in the Transvaal. Hydrobiol. 18 1-76. [ Links ]
APPLETON C (1976) Observations on the thermal regime of a stream in the eastern Transvaal with reference to certain aquatic Pulmonata. S. Afr. J. Sci. 72 20-23. [ Links ]
ARSCOTT D, TOCKNER K and WARD J (2001) Thermal heterogeneity along a braided floodplain river (Tagliamento River, northeastern Italy). Can. J. Fish. Aquat. Sci. 58 2359-2373. [ Links ]
BAIRD D (1976) Aspects of the growth and reproduction of Labeo capensis in the Caledon River. J. Limnol. Soc. South. Afr. 2 25-28. [ Links ]
BEAMISH F (1981) Swimming performance and metabolic rate of three tropical fishes in relation to temperature. Hydrobiol. 83 245-254. [ Links ]
BEITINGER T, BENNET W and McCAULEY R (2000) Temperature tolerances of North American freshwater fishes exposed to dynamic changes in temperature. Environ. Biol. Fish. 58 237-275. [ Links ]
BELL J (2006) The Assessment of Thermal Impacts on Habitat Selection Growth Reproduction and Mortality in Brown Trout (Salmo trutta L.): A Review of the Literature Rep. No. EPA GRANT #WS 97512701-0. Applied Ecological Services Inc Minnesota. [ Links ]
BERMAN C and QUINN T (1991) Behavioural thermoregulation and homing by spring chinook salmon (Oncorhynchus tshawytscha Walbaum) in the Yakima River. J. Fish Biol. 39 301-321. [ Links ]
BILLS R (2007) Personal communication. South African Institute of Aquatic Biodiversity (SAIAB) Grahamstown, South Africa. [ Links ]
BOK A and HEARD H (1982) Induced spawning of Barbus trevelyani (Pisces Cyprinidae). S. Afr. J. Wild. Res. 12106-108. [ Links ]
BOUBEE J, SCHICKER K and STANCLIFF A (1991) Thermal avoidance in inanga Galaxias maculatus (Jenyns) from the Waikato River New Zealand. N. Z. J. Mar. Freshwater Res. 25 177-180. [ Links ]
BRITTAIN J (1975) The life cycle of Baetis macani Kimmins (Ephemeridae) in a Norwegian mountain biotope. Ent. Scan. 6 47-51. [ Links ]
BRITTAIN J (1991) Effect of temperature on egg development in the Australian stonefly genus Austrocercella Illies (Plecoptera: Notonemouridae). Aust. J. Mar. Freshwater Res. 42 107-114. [ Links ]
BRITTAIN J and CAMPBELL I (1991) The effect of temperature on egg development in the Australian mayfly genus Coloburiscoides (Ephemeroptera: Coloburiscidae) and its relationship to distribution and life history. J. Biogeog. 18 231-235. [ Links ]
BRUNGS W (1971) Chronic effects of constant temperature on the fathead minnow, Pimephales promelas rafinesqe. American Fisheries Society 100 659-664. [ Links ]
BRUTON M and ALLANSON B (1974) The growth of Tilapia mossambica Peters (Pisces: Cichlidae) in Lake Sibaya, South Africa. J. Fish Biol. 6701-715. [ Links ]
CAISSIE D (2006) The thermal regime of rivers: a review. Fresh. Biol. 51 1389-1406. [ Links ]
CAMBRAY J, KING J and BRUWER C (1997) Spawning behaviour and early development of the Clanwilliam Yellowfish (Barbus capensis: Cyprinidae) linked to experimental dam releases in Olifants River South Africa. Reg. Rivers Res. Manag. 13 579-602. [ Links ]
CAMPBELL I (1986) Life histories of some Australian Siphlonurid and Oligoneurid mayflies (Insecta: Ephemeroptera). Aust. J. Mar. Freshwater Res. 37 261-288. [ Links ]
CCREM (1999) A Protocol for the Derivation of Water Quality Guidelines for the Protection of Aquatic Life. Canadian Council of Ministers of the Environment, Canada. [ Links ]
CECH J, MITCHELL S, CASTLEBERRY D and MCENROE M (1990) Distribution of California stream fishes: influence of environmental temperature and hypoxia. Environ. Biol. Fish. 29 95-105. [ Links ]
CHERRY D and CAIRNS J (1982) Biological monitoring - Part V: preference and avoidance studies. Water Res. 16263-301. [ Links ]
CHUTTER F (1970) Hydrobiological studies in the catchment of Vaal Dam South Africa. Part 1: River zonation and the benthic fauna. Int. Rev. ges Hydrob. 55 445-494. [ Links ]
CINCOTTA D and STAUFFER J (1984) Temperature preference and avoidance studies of six North American freshwater fish species. Hydrobiol. 109173-177. [ Links ]
CLARK E, WEBB B and LADLE M (1999) Microthermal gradients and ecological implications in Dorset rivers. Hydrol. Process. 13 423-438. [ Links ]
COCKRELL B (1984) Effects of temperature and oxygenation on predator-prey overlap and prey choice of Notonecta glauca. J. Anim. Ecol. 53 519-532. [ Links ]
COLEMAN M and HYNES H (1970) Life histories of some Plecoptera and Ephemeroptera in a southern Ontario stream. Can. J. Zool. 48 1333-1339. [ Links ]
COLLIER K and SMITH B (2000) Interactions of adult stoneflies (Plecoptera) with riparian zones. I Effects of air temperature and humidity on longevity. Aquat. Insects 22 275-284. [ Links ]
CONSTANZ J, THOMAS C and ZELLWEGER G (1994) Influence if diurnal variations in stream temperature on streamflow loss and groundwater recharge. Water Resour. Res. 30 3253-3264. [ Links ]
COUTANT C (1987) Thermal preference: when does an asset become a liability? Environ. Biol. Fish. 18 161-172. [ Links ]
CRISP D (1990) Water temperature in a stream gravel bed and implications for salmonid incubation. Freshwater Biol. 23 601-612. [ Links ]
DALLAS H (2007) The Effect of Water Temperature on Aquatic Organisms: A Review of Knowledge and Methods for Assessing Biotic Responses to Temperature. WRC Report for Project K8-690. Water Research Commission, Pretoria, South Africa. [ Links ]
DALLAS H and DAY J (2004) The Effect of Water Quality Variables on Aquatic Ecosystems: A Review. WRC Technical Report No. 224/04, Water Research Commission, Pretoria, South Africa. [ Links ]
DALLAS H and RIVERS-MOORE N (2008) Water Temperatures and the Ecological Reserve. WRC Project No. K5/1799. Water Research Commission, Pretoria, South Africa. [ Links ]
DALLAS H, DAY J, MUSIBONO D and DAY E (1998) Water quality for aquatic ecosystems: tools for evaluating regional guidelines. WRC Technical Report No. 626/1/98. Water Research Commission, Pretoria, South Africa. [ Links ]
DALLAS H, JANSSENS M and DAY J (1999) An aquatic macroinvertebrate and chemical database for riverine ecosystems. Water SA 25 1-8. [ Links ]
DAVIES B, THOMS M and MEADOR M (1992) Viewpoint: an assessment of the ecological impacts of inter-basin water transfers and their threats to river basin integrity and conservation. Aquat. Cons. Mar. Fresh. Ecosys. 2 325-349. [ Links ]
DENICOLA D (1996) Periphyton responses to temperature at different ecological levels. In: Algal Ecology in Freshwater Benthic Ecosystems. Academic Press New York. [ Links ]
DEPARTMENT OF WATER AFFAIRS AND FORESTRY (2008) Water Affairs Water Quality Monitoring Points. (http://www.dwaf.gov.za/IWQS/wms/WebInventory/Others/PointInventory.HTML). [ Links ]
DICKENS C and GRAHAM M (2006) In connection with the ecological impacts of reverse hydrograph water releases from Albert Falls Dam on in-stream processes. Water Research Commission, Pretoria, South Africa. [ Links ]
DUFFUS J (1980) Environmental Toxicology. Edward Arnold Publishers, London. [ Links ]
DWAF (1996) South African Water Quality Guidelines Volume 7: Aquatic Ecosystems. Department of Water Affairs and Forestry, Pretoria, South Africa. [ Links ]
EATON J and SCHELLER R (1996) Effects of climate warming on fish thermal habitat in streams of the United States. Limnol. Oceonogr. 41 1109-1115. [ Links ]
EBERSOLE J, LISS W and FRISSELL C (2001) Relationship between stream temperature thermal refugia and rainbow trout Oncorhynchus mykiss abundance in arid-land streams in the northwestern, United States. Ecol. Fresh. Fish 10 1-10. [ Links ]
EBERSOLE J, LISS W and FRISSELL C (2003) Cold water patches in stream: Physicochemical characteristics and the influence of shading. J. Amer. Wat. Res. Ass. 39 355-368. [ Links ]
ELLIOTT J (1972) Effect of temperature on the time of hatching in Baetis rhodani (Ephemeroptera: Baetidae). Oecologia 9 47-51. [ Links ]
ELLIOTT J (1987a) Egg hatching and resource partitioning in stone-flies: The six British Leuctra spp. (Plecoptera: Leuctridae). J. Animal Ecol. 56 415-426. [ Links ]
ELLIOTT J (1987b) Temperature-induced changes in the life cycle of Leuctra nigra (Plecoptera: Leuctridae) from a Lake District stream. Fresh. Biol. 18 177-184. [ Links ]
ELLIOTT J (2000) Pools as refugia for brown trout during two summer droughts: trout responses to thermal and oxygen stress. J. Fish Biol. 56 938-948. [ Links ]
ERICKSON T and STEFAN H (2000) Linear air/water temperature correlations for streams during open water periods. J. Hydrol. Eng. 5 317-321. [ Links ]
ERIKSEN C (1964) Evidence of a spring rise in metabolic rate in the burrowing mayfly Ephemera simulans Walker. Hydrobiol. 23506-510. [ Links ]
ERNST M, BEITINGER T and STEWART K (1984) Critical maxima of nymphs of three plecoptera species from an Ozark foothill stream. Freshwater Invertebrate Biol. 3 80-85. [ Links ]
EVANS E and PETTS G (1997) Hyperheic temperature patterns within riffles. J. Hydrol. Sci. 42199-213. [ Links ]
EWART-SMITH J, DALLAS H and JANSSENS M (2000) Rivers Database: Version 1A User Manual Rep. No. 11. Institute for Water Quality Studies, Department of Water Affairs and Forestry, Pretoria, South Africa. [ Links ]
GARDNER B, SULLIVAN P and LEMBOR A (2003) Predicting stream temperatures: geostatistical model comparison using alternative distance metrics. Can. J. Fish. Aquat. Sci. 60 344-351. [ Links ]
GEALD G and SPEZZANO C (2005) The influence of chemical cues and conspecific density on the temperature selection of a freshwater snail (Melanoides tuberculata). Journal of Thermal Biology 20 237-245. [ Links ]
GU R, MONTGOMERY S and AUSTIN T (1998) Quantifying the effects of stream discharge on summer river temperature. J. Hydrol. Sci. 43 885-904. [ Links ]
HARPER P (1973) Life histories of Nemouridae and Leuctridae in Southern Ontario (Plecoptera). Hydrobiol. 41 309-356. [ Links ]
HARRISON A (1965) River zonation in Southern Africa. Arch. Hydrobiol. 61 380-386. [ Links ]
HARRISON A and ELSWORTH J (1958) Hydrobiological studies on the Great Berg River Western Cape province. Part I: General description chemical studies and main features of the flora and fauna. Trans. Royal Soc. South Africa 35 125-226. [ Links ]
HART R (1985) Seasonality of aquatic invertebrates in low-latitude and Southern Hemisphere inland waters. Hydrobiol. 25 151-178. [ Links ]
HART R (2001) Rapid estimation of in situ growth rates of Caridina nilotica (Crustacea: Decapoda) in Lake Victoria: Description and pilot application of a simple field-compatible technique. Limnology and Oceanography 46 692-698. [ Links ]
HAWKINS C, HIGUE J, DECKER L and FEMINELLA J (1997) Channel morphology water temperature and assemblage structure of stream insects. J. North Am. Benthol. Soc. 16 728-749. [ Links ]
HECHT T (1980) A comparison between otolith and scale methods of ageing and the growth of Sarotherodon mossambicus (Pisces: Cich-lidae) in a Venda impoundment (Southern Africa). S. Afr. J. Zool. 15 222-228. [ Links ]
HELLAWELL J (1986) Biological Indicators of Freshwater Pollution and Environmental Management. Elsevier Applied Science, London. [ Links ]
HOCKEY J, OWENS I and TAPPER N (1982) Empirical and theoretical models to isolate the effect of discharge on summer water temperatures in the Hurunui river. J. Hydrol. 21 1-12. [ Links ]
HOGG I, WILLIAMS D, EADIE J and BUTT S (1995) The consequences of global warming for stream invertebrates: a field simulation. J. Thermal Biol. 20 199-206. [ Links ]
HOPKINS C (1971) The annual temperature regime of a small stream in New Zealand. Hydrobiol. 37 397-408. [ Links ]
HUFF D, HUBLER S and BORISENKO A (2005) Using field data to estimate the realised thermal niche of aquatic vertebrates. N. Am. J. Fish. Manage. 25 346-360. [ Links ]
HUMPESCH U (1980) Effect oftemperature on the hatching time of eggs of five Ecdyonurus spp. (Ephemeroptera) from Austrian streams and English streams rivers and lakes. J. Anim. Ecol. 49 317-333. [ Links ]
HUMPHRIES P, KING A and KOEHN J (1999) Fish flows and flood plains: links between freshwater fishes and their environment in the Murray-Darling system Australia. Environ. Biol. Fish. 56 129-151. [ Links ]
HURYN A (1996) Temperature-dependent growth and life cycle of Deleatidium (Ephemeroptera: Leptophlebiidae) in two high-country streams in New Zealand. Fresh. Biol. 36 351-361. [ Links ]
HYNES H and HYNES M (1975) The life histories of many of the stoneflies (Plecoptera) of South-eastern Mainland Australia. Aust. J. Mar. Freshwater Res. 26 113-153. [ Links ]
JACKSON P and COETZEE P (1982) Spawning behaviour of Labeo umbratus (Smith) (Pisces: Cyprinidae). S. Afr. J. Sci. 78 293-295. [ Links ]
JAMES N and BRUTON M (1992) Alternative life-history traits associated with reproduction in Orechromis mossambicus (Pisces: Cichlidae) in small water bodies of the eastern Cape South Africa. Environ. Biol. Fish. 34 379-392. [ Links ]
JOOSTE S and ROSSOUW J (2002). Hazard-Based Water Quality EcoSpecs For The Ecological Reserve In Fresh Surface Water Resources Rep. No. N/0000/REQ0000. Institute for Water Quality Studies Department of Water Affairs and Forestry, Pretoria, South Africa. [ Links ]
KELEHER C and RAHEL F (1996) Thermal limits to salmonid distributions in the rocky mountain region and potential habitat loss due to global warming: A Geographic Information System (GIS) approach. Trans. Amer. Fish. Soc. 125 1-13 [ Links ]
KING J (1981) The distribution of invertebrate communities in a small South African river. Hydrobiol. 83 43-65. [ Links ]
KING J, CAMBRAY J and IMPSON N (1998) Linked effects of dam-released floods and water temperature on spawning of the Clanwilliam yellowfish Barbus capensis. Hydrobiol. 384 245-265. [ Links ]
KING J, DAY J, HURLEY P, HENSHALL-HOWARD M and DAVIES B (1988) Macroinvertebrate communities and environment in a southern African mountain stream. Can. J. Fish. Aquat. Sci. 45 2168-2181. [ Links ]
KISHI D, MURAKAMI M, NAKANO S and MAEKAWA K (2005) Water temperature determines strength of top-down control in a stream food web. Freshwater Biol. 50 1315-1322. [ Links ]
KOLAR C and RAHEL F (1993) Interaction of a biotic factor (predator presence) and an abiotic factor (low oxygen) as an influence on benthic invertebrate communities. Oecologia 95 210-219. [ Links ]
LAKE J (1967) Rearing experiments with five species of Australian freshwater fishes: I. Inducement to spawning. Aust. J. Mar. Freshwater Res. 18 137-154. [ Links ]
LAKE P, BARMUTA L, BOULTON A, CAMPBELL I and CLAIR R (1985) Australian streams and northern hemisphere stream ecology: comparisons and problems. Proc. Ecol. Soc. Aust. 14 61-82. [ Links ]
LANGFORD T (1990) Ecological Effects of Thermal Discharges. Elsevier Applied Science London and New York. [ Links ]
MACKEY A and BERRIE A (1991) The prediction of water temperatures in chalk streams from air temperatures. Hydrobiol. 210 183-189. [ Links ]
MADIKIZELA B and DYE A (2003) Community composition and distribution of macroinvertebrates in the Umzimvubu River South Africa: a pre-impoundment study. Afr. J. Aquat. Sci. 28 137-149. [ Links ]
MAGNUSON J, CROWDER L and MEDVICK P (1979) Temperature as an ecological resource. Am. Zool. 19 331-343. [ Links ]
MANN K (1965) Heated effluents and their effects on the invertebrate fauna of rivers. Proc. Soc. Water Treat. Exam. 14 45-53. [ Links ]
MARINE K and CECH J (2004) Effects of high water temperature on growth smoltification and predator avoidance in juvenile Sacramento River Chinook salmon. N. Am. J. Fish. Manage. 24 198-210. [ Links ]
MARKARIAN R (1980) A study of the relationship between aquatic insect growth and water temperature in a small stream. Hydrobiol. 75 81-95. [ Links ]
MATTHEWS H and BERG N (1997) Rainbow trout responses to water temperature and dissolved oxygen stress in two southern California stream pools. J. Fish Biol. 50 50-67. [ Links ]
MATTHEWS W and ZIMMERMAN E (1990) Potential effects of climate change on native fish of the southern Great Plains and Southwest. Fish. 15 26-32. [ Links ]
McKIE B, CRANSTON P and PEARSON R (2004) Gondwanan mesotherms and cosmopolitan eurytherms: effects of temperature on the development and survival of Australian Chironomidae (Diptera) from tropical and temperate populations. Mar. Freshwater Res. 55 759-767. [ Links ]
MEISNER J (1990) Potential loss of thermal habitat for brook trout due to climatic warming in two Southern Ontario streams. Trans. Am. Fish. Soc. 119 282-291. [ Links ]
MITCHELL S (1999) A simple model for estimating mean monthly stream temperatures after riparian canopy removal. Environ. Manage. 24 77-83. [ Links ]
MOHSENI O, ERICKSON T and STEFAN H (1999) Sensitivity of stream temperatures in the United States to air temperatures projected under a global warming scenario. Water Resour. Res. 35 3723-3733. [ Links ]
HSENI O and STEFAN H (1999) Stream temperature/air temperature relationship: a physical interpretation. J. Hydrol. 218 128-141. [ Links ]
MOHSENI O, STEFAN H and ERICKSON T (1998) A nonlinear regression model for weekly stream temperatures. Water Resour. Res. 34 2685-2692. [ Links ]
MOSLEY M (1983) Variability of water temperatures in the braided Ashley and Rakaia rivers. N. Z. J. Mar. Freshwater Res. 17 331-342. [ Links ]
NEBEKER A (1971a) Effect of water temperature on nymphal feeding rate emergence and adult longevity of the stonefly Pteronarcys dorsata. J. Kansas Entomol. Soc. 44 21-26. [ Links ]
NEBEKER A (1971b) Effect of high winter water temperatures on adult emergence of aquatic insects. Water Res. 5 77-783. [ Links ]
NEBEKER A (1972) Effect of low oxygen concentration on survival and emergence of aquatic insects. Trans. Am. Fish. Soc. 4 675-679. [ Links ]
NEBEKER A and LEMKE A (1968) Preliminary studies on the tolerance of aquatic insects to heated water. J. Kansas Entomol. Soc. 41 413-418. [ Links ]
NEBEKER A, ONJUKKA S, STEVENS D and CHAPMAN G (1996) Effect of low dissolved oxygen on aquatic life stages of the caddis-fly Clistoronia magnified (Limnephilidae). Arch. Environ. Contam. Toxicol. 31 453-458. [ Links ]
NORDLIE K and ARTHUR J (1981) Effect of elevated water temperature on insect emergence in outdoor experimental channels. Environ. Pollut. 25 53-65. [ Links ]
NWQMS (2000) National water quality management strategy: Australian and New Zealand Guidelines for Fresh and Marine Water Quality Rep. No. 4A. Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand Australia. [ Links ]
OGBEIBU A and ORIBHABOR B (2002) Ecological impact of river impoundment using benthic macro-invertebrates as indicators. Water Res. 36 2427-2436. [ Links ]
OLIFF W (1960) Hydrobiological studies on the Tugela System Part II: Organic pollution in the Bushmans River. Hydrobiol. 16 137-196. [ Links ]
PALLER M and SAUL B (1996) Effects of temperature gradients resulting from reservoir discharge on Dorsoma cepedianum spawning in the Savannah River. Environ. Biol. Fish. 45 151-160. [ Links ]
PAXTON (2008) Personal communication. Freshwater Research Unit, University of Cape Town, South Africa. [ Links ]
PALMER R AND O'KEEFFE J (1989) Temperature characteristics of an impounded river. Archiv. Hydrobiol. 116 471-485. [ Links ]
PETTS G and GREENWOOD M (1985) Channel changes and invertebrate faunas below Nant-Y-Moch dam River Rheidol Wales UK. Hydrobiol. 122 65-80. [ Links ]
PITCHFORD R and VISSER P (1975) The effect of large dams on river water temperature below the dams with special reference to bilharzia and the Verwoerd Dam. S. Afr. J. Sci. 71 212-213. [ Links ]
POOLE G and BERMAN C (2001) An ecological perspective on in-stream temperature: natural heat dynamics and mechanisms of human-caused thermal degradation. Environ. Manage. 27 787-802. [ Links ]
POOLE G, RISLEY J and HICKS M (2001) Issue paper 3 - Spatial and temporal patterns of stream temperature Rep. No. Issue Paper 3. EPA-910-D-01-003 United States Environmental Protection Agency. United States Environmental Protection Agency. [ Links ]
QUINN J, WILLIAMSON R, SMITH R and VICKERS M (1992) Effects of riparian grazing and channelisation on streams in Southland New Zealand. 2. Benthic invertebrates. N. Z. J. Mar. Freshwater Res. 26 259-273. [ Links ]
RICHARDSON J, BOUBEE J and WEST D (1994) Thermal tolerance and preference of some native New Zealand freshwater fish. N. Z. J. Mar. Freshwater Res. 28 399-407. [ Links ]
RIVERS-MOORE N and JEWITT G (2004) Intra-annual thermal patterns in the main rivers of the Sabie Catchment Mpumalanga South Africa. Water SA 30 445-452. [ Links ]
RIVERS-MOORE N, JEWITT G and WEEKS D (2005) Derivation of quantitative management objectives for annual instream water temperatures in Sabie River using a biological index. Water SA 31 473-480. [ Links ]
RIVERS-MOORE N, JEWITT G, WEEKS D and O'KEEFFE J (2004) Water Temperature and Fish Distribution in the Sabie River System: Towards the Development of an Adaptive Management Tool. WRC Report No. 1065/1/04. Water Research Commission, Pretoria, South Africa. [ Links ]
RIVERS-MOORE N, MOOR F.D, MORRIS C and O'KEEFFE J (2006) Effect of flow variability modification and hydraulics on invertebrate communities in the Great Fish River (Eastern Cape province South Africa) with particular reference to critical hydraulic thresholds limiting larval densities of Simulium chutteri Lewis (Diptera Simuliidae). River Res. Applic. 23 201-222. [ Links ]
ROOS J and PIETERSE A (1994) Light temperature and flow regimes of the Vaal River at Balkfontein South Africa. Hydrobiol. 277 1-15. [ Links ]
RUTHERFORD J, BLACKETT S, BLACKETT C, SAITO L and DAVIES-COLLEY R (1997) Predicting the effects of shade on water temperature in small streams. N. Z. J. Mar. Freshwater Res. 31 707-721. [ Links ]
SINOKROT B and GULLIVER J (2000) In-stream flow impact on river water temperatures. J. Hydraul. Res. 38 339-349. [ Links ]
SKELTON P (1993) A Complete Guide to the Freshwater Fishes of Southern Africa. Southern Book Publishers, Johannesburg. [ Links ]
SMITH K (1972) River water temperatures - An environmental review. Scottish Geographical Magazine 88 211-220. [ Links ]
SMITH K (1981) The prediction of river water temperatures. Hydrobiol. Sci. Bull. 26 19-32. [ Links ]
SNADDON C, DAVIES B and WISHART M (2000) A global overview of inter-basin water transfer schemes: ecological socio-economic and socio-political implications and recommendations for their management. WRC Report No. TT 120/00. Water Research Commission, Pretoria, South Africa. [ Links ]
STEFAN H and PREUD'HOMME E (1993) Stream temperature estimation from air temperature. Water Resour. Bull. 29 27-45. [ Links ]
STEFAN H and SINOKROT B (1993) Projected global climate change impact on water temperatures in five north central U.S streams. Clim. Change 24 353-381. [ Links ]
STOREY A, EDWARD D and GAZEY P (1991) Recovery of aquatic macroinvertebrate assemblages downstream of the canning dam Western Australia. Reg. Rivers Res. Manage. 6 213-224. [ Links ]
SULLIVAN K, MARTIN D, CARDWELL R, TOLL J and DUKE S (2000) An Analysis of the Effects of Temperature on Salmonids of the Pacific Northwest with Implications for Selecting Temperature Criteria. Sustainable Ecosystems Institute, Portland, Oregon, USA. [ Links ]
TATE K, LANCASTER D and LILE D (2006) Assessment of thermal stratification within stream pools as a mechanism to provide refuge for native trout in hot arid rangelands. Environ. Mon. Assess. 124 289-300. [ Links ]
THORUP J (1973) Interpretation of growth-curves for animals from running waters. Verh. Internat. Verein. Limnol. 181512-1520. [ Links ]
TOMASSON T, CAMBRAY J and JACKSON P (1984) Reproductive biology of four large riverine fishes (Cyprinidae) in a man-made lake Orange River South Africa. Hydrobiol. 112 179-195. [ Links ]
TORGERSEN C, PRICE D, LI H and MCINTOSH B (1999) Multiscale thermal refugia and stream habitat associations of chinook salmon in north-Eastern Oregon. Ecolog. App. 9 301-319. [ Links ]
VANNOTE R and SWEENEY B (1980) Geographic analysis of thermal equilibria: A conceptual model for evaluating the effect of natural and modified thermal regimes on aquatic insect communities. Am. Nat. 115 667-695. [ Links ]
WARD J (1982) Ecological aspects of stream regulation: responses in downstream lotic reaches. Water Pollut. Manage. Rev. 2 1-26. [ Links ]
WARD J (1985) Thermal characteristics of running waters. Hydrobiol. 125 31-46. [ Links ]
WARD J and STANFORD J (1982) Thermal responses in the evolutionary ecology of aquatic insects. Ann. Rev. Entomol. 2797-117. [ Links ]
WEATHERLEY N and ORMEROD S (1990) Forests and the temperature of upland streams in Wales: a modelling exploration of the biological effects. Freshwater Biol. 24109-122. [ Links ]
WEBB B (1996) Trends in stream and river temperature. Hydrol. Process. 10 205-226. [ Links ]
WEBB B, CLACK P and WALLING D (2003) Water-air temperature relationships in a Devon river system and the role of flow. Hydrol. Process. 17 3069-3084. [ Links ]
WEBB B and NOBILIS F (1997) Long-term perspective on the nature of the air-water temperature relationship: a case study. Hydrol. Process. 11137-147. [ Links ]
WEBB B and WALLING D (1993) Temporal variability in the impact of river regulation on thermal regime and some biological implications. Freshwater Biol. 29167-182. [ Links ]
WEBB B and WALLING D (1997) Complex summer water temperature behaviour below a UK regulating reservoir. Reg. Rivers Res. Manage. 13 463-477. [ Links ]
WELLBORN G and ROBINSON J (1996) Effects of a thermal effluent on macroinvertebrates in a central Texas reservoir. Am. Midl. Nat. 136 110-120. [ Links ]
WHITNEY R (1939) The thermal resistance of mayfly nymphs from ponds and streams. J. Exp. Biol. 16 374-385. [ Links ]
Correspondence:
+2721 650-3631
Fax: +2721 650-3301
E-mail: Helen.Dallas@uct.ac.za
Received 22 June 2007;
Accepted in revised form 10 June 2008.