Dr Martyn Lucas, PhD, BSc Hons (I)
My group's principal interests are in the behavioural ecology and physiological ecology of aquatic animals; conservation biology of aquatic animals; introduced and invasive species in aquatic systems; and fisheries ecology, as outlined below. See personal web page for further details (link given below).
(i) Spatial behaviour and migration of fishes, using techniques such as biotelemetry. Studies are at species and assemblage level and include variations in habitat use and life history strategy. Evaluation of anthropogenic effects on fish migration and the performance of fish passes. Studies of energy expenditure and ecophysiology of fishes, using physiological approaches such as heart rate telemetry.
(ii) Fisheries ecology and conservation. Ecology of exploited fish and shellfish populations in marine and freshwater systems; fisheries management; fate of stocked fish. Conservation biology of aquatic species and habitats e.g. lamprey, crayfish, endemic fauna. Interspecific competition and resource use by fish and invertebrates, including effects of invasive species such as exotic crayfish species.
(iii) Energetics and cardio-respiratory physiology of fishes. Factors affecting intraspecific and intraindividual variation in metabolism of fishes and relationship to life history, swimming performance and migration.
(iv) Effects of pollutants and environmental stress on aquatic animals. Sublethal responses of fishes in the natural environment. Effects on fish and invertebrate communities. Effects on growth, behaviour and energetics of aquatic animals.
This research is carried out in freshwater, brackish and marine environments and involves collaborations within the UK and abroad (e.g. Europe, USA, Korea, W. Africa), mostly funded by research councils and government agencies. The group currently comprises 8 postdoctoral, doctoral and graduate researchers and opportunities for graduate students are available.
Indicators of Esteem
- 2013: Corvallis, Oregon - invited plenary: Invited plenary speaker at 4th international Conference on Fish Passage and Ecohydraulics, July 2013. Corvaliis, Oregon, US.
- 2013: Grahamstown, South Africa - invited plenary: Invited plenary speaker, Advances in fish telemetry, International conference and workshop, Grahamstown, South Africa. July 2013.
- 2013: Invited author - research methods textbook: Invited author for 'Biotelemetry and Biologging' (pp.819-881) in the Third Edition of 'Fisheries Techniques' (eds Zale, A.V., Parrish, D.L. & Sutton, T.M.), the 1070 page standard reference work textbook for research level understanding of the subject. Published in Jan. 2013, ISBN 978-1-934874-29-5).
- 2012: Feature interviewee, BBC1 Countryfile: Interviewee for a feature on conservation of lamprey, BBC1 television Countryfile, ca. 5 million viewers. June 2012.
- 2012: Iguassu Falls, Brazil - Invited plenary and panel: Invited plenary speaker and discussion panel member, Iguassu Falls, Brazil. Nov. 2012
- 2012: Tasmania and Denmark - thesis examiner: Examiner of research theses in Tasmania and Denmark. July, Aug 2012.
- 2012: Vienna - Invited speaker: Invited speaker, downstream fish migration, at Ecohydraulics Symposium, Vienna. Sept. 2012.
- 2011: Oxford - Invited speaker: Invited speaker, migration and passage of fishes. Symposium on Fish Migration and Passage, Oxford, UK. March 2011.
- 2010: Lund - Invited speaker: Invited speaker and workshop contributor. Partial Migration symposium and workshop, Lund, Sweden. Sept. 2010.
- 2008: Taiwan - invited research course leader: Invited course leader in telemetry methods and applications for aquatic reseacrh, National Marine University, Kaosiung, Taiwan. Dec 2008.
- 2008: Taiwan - invited research seminar: Invited research seminar, National Marine University, Kaosiung, Taiwan. Dec. 2008
- Biology of introduced and invasive aquatic animals
- Conservation biology of aquatic animals
- Ecology, behaviour and respiratory physiology of fish
- Effects of pollution on fish and macro invertebrates (particularly in freshwater ecosystems)
- Fisheries management
- Migration and space use of fish and aquatic invertebrates
- Telemetry and radiotracking
- Lucas, M.C. & Baras, E. (2001). Migration of Freshwater Fishes. Oxford: Blackwell Science.
- Cooke, S.J., Hinch, S.G., Lucas, M.C. & Lutcavage, M. (2012). Biotelemetry and biologging. In Fisheries Techniques, 3rd edition. Zale, A.V., Parrish, D.L. & Sutton, T.M. (Eds) American Fisheries Society, Bethesda, Maryland. 819-881.
- Lucas, MC & Marmulla, G (2000). An assessment of anthropogenic activities on and rehabilitation of river fisheries: current state and future direction. In Management and Ecology of River Fisheries. Cowx, IG Oxford: Blackwell Science. 261-278.
- Lucas MC, Mercer, T, McGinty, S & Armstrong, JD (2000). Development and evaluation of a flat-bed passive integrated transponder detection system for recording movement of lowland river fishes through a baffled pass. In Advances in Fish Telemetry. Moore, A & Russell, I Lowestoft, UK: Centre for Environment, Fisheries and Aquaculture Science (CEFAS). 117-127.
- Lucas, MC, Mercer, T, Peirson, G & Frear, P (2000). Seasonal movements of coarse fish in lowland rivers and their relevance to fisheries management. In Management and Ecology of River Fisheries. Cowx, IG Oxford: Blackwell Science. 87-100.
Journal papers: academic
- Cooke, S.J., Martins, E.G., Struthers, D.P., Gutowsky, L.F.G., Power, M., Doka, S.E., Dettmers, J.M., Crook, D.A., Lucas, M.C., Holbrook, C.M. & Krueger, C.C. (2016). A moving target - incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations. Environmental Monitoring and Assessment 188(4): 239.
- Rosten, C.M., Gozlan, R.E. & Lucas, M.C. (2016). Allometric scaling of intraspecific space use. Biology Letters 12(3): 20150673.
- Tummers, J.S., Winter, E., Silva, S., O'Brien, P., Jang, M-H. & Lucas, M.C. (2016). Evaluating the effectiveness of a Larinier super active baffle fish pass for European river lamprey Lampetra fluviatilis before and after modification with wall-mounted studded tiles. Ecological Engineering 91: 183-194.
- Hawley, K.L., Rosten, C.M., Christensen, G. & Lucas, M.C. (2016). Fine-scale behavioural differences distinguish resource use by ecomorphs in a closed ecosystem. Scientific Reports 6: 24369.
- Barry, J., Newton, M., Dodd, J.A., Hooker, O.E., Boylan, P., Lucas, M.C. & Adams, C.E. (2016). Foraging specialisms influence space use and movement patterns of the European eel Anguilla anguilla. Hydrobiologia 766(1): 333-348.
- Barry, J., Newton, M., Dodd, J.A., Lucas, M.C., Boylan, P. & Adams, C.E. (2016). Freshwater and coastal migration patterns in the silver-stage eel Anguilla anguilla. Journal of Fish Biology 88(2): 676-689.
- Winter, E.R., Tummers, J.S., Aarestrup, K., Baktoft, H. & Lucas, M.C. (2016). Investigating the phenology of seaward migration of juvenile brown trout (Salmo trutta) in two European populations. Hydrobiologia 775(1): 139-151.
- Forty, M., Spees, J. & Lucas, M.C. (2016). Not just for adults! Evaluating the performance of multiple fish passage designs at low-head barriers for the upstream movement of juvenile and adult trout Salmo trutta. Ecological Engineering 94: 214-224.
- Gauld, N.R., Campbell, R.N.B. & Lucas, M.C. (2016). Salmon and sea trout spawning migration in the River Tweed: telemetry-derived insights for management. Hydrobiologia 767(1): 111-123.
- Moser, M.L., Jackson, A.D., Lucas, M.C. & Mueller, R.P. (2015). Behavior and potential threats to survival of migrating lamprey ammocoetes and macrophthalmia. Reviews in Fish Biology and Fisheries 25(1): 103-116.
- Bracken, F.S.A., Hoelzel, A.R., Hume, J.B. & Lucas, M.C. (2015). Contrasting population genetic structure among freshwater-resident and anadromous lampreys: the role of demographic history, differential dispersal, and anthropogenic barriers to movement. Molecular Ecology 24(6): 1188-1204.
- Silva, S., Gooderham, A., Forty, M., Morland, B. & Lucas, M.C. (2015). Egg drift and hatching success in European river lamprey Lampetra fluviatilis: is egg deposition in gravel vital to spawning success?. Aquatic Conservation: Marine and Freshwater Ecosystems 25(4): 534-543.
- Findlay, J.D.S., Riley, W.D. & Lucas, M.C. (2015). Signal crayfish (Pacifastacus leniusculus) predation upon Atlantic salmon (Salmo salar) eggs. Aquatic Conservation: Marine and Freshwater Ecosystems 25(2): 250-258.
- Bolland, J.D., Nunn, A.D., Lucas, M.C. & Cowx, I.G. (2015). The habitat use of young-of-the-year fishes during and after floods of varying timing and magnitude in a constrained lowland river. Ecological Engineering 75: 434-440.
- Jepsen, N., Thorstad, E.B., Havn, T. & Lucas, M.C. (2015). The use of external electronic tags on fish: an evaluation of tag retention and tagging effects. Animal Biotelemetry 3(1): 49.
- Louca, V., Ream, H.M., Findlay, J.D., Latham, D.M. & Lucas, M.C. (2014). Do culverts impact the movements of the endangered white-clawed crayfish?. Knowledge and Management of Aquatic Ecosystems 414: 14.
- Lucas, M.C. & Bubb, D.H. (2014). Fish in space: local variations of home range and habitat use of a stream-dwelling fish in relation to predator density. Journal of Zoology 293(2): 126-133.
- Foulds, W,L. & Lucas, M.C. (2014). Paradoxical exploitation of protected fishes as bait for anglers: evaluating the lamprey bait market in Europe and developing sustainable and ethical solutions. PLoS ONE 9(6): e99617.
- Foulds, W.L. & Lucas, M.C. (2013). Extreme inefficiency of two conventional, technical fishways used by European river lamprey (Lampetra fluviatilis). Ecological Engineering 58: 423-433.
- Bracken, F.S.A. & Lucas, M.C. (2013). Potential impacts of small-scale hydroelectric power generation on downstream moving lampreys. River Research and Applications 29(9): 1073–1081.
- Gauld, N.R, Campbell, R.N.B & Lucas, M.C (2013). Reduced flow impacts salmonid smolt emigration in a river with low-head weirs. Science of The Total Environment 458-460: 435-443.
- Cooke, S.J., Midwood, J.D., Thiem, J.D., Klimley, P., Lucas, M.C., Thorstad, E.B., Eiler, J., Holbrook, C. & Ebner, B.C. (2013). Tracking animals in freshwater with electronic tags: past, present and future. Animal Biotelemetry 1: 5.
- Genner, M.J., Hillman, R.J., McHugh, M., Hawkins, S.J. & Lucas, M.C. (2012). Contrasting demographic histories of European and North American sea lamprey (Petromyzon marinus) populations inferred from mitochondrial DNA sequence variation. Marine and Freshwater Research 63(9): 827-833.
- Bolland, J. D., Nunn, A. D., Lucas, M. C. & Cowx, I. G. (2012). The importance of variable lateral connectivity between artifical floodplain waterbodies and river channels. River Research and Applications 28(8): 1189-1199.
- Corrigan, L. J., Winfield, I. J., Hoelzel, A. R. & Lucas, M. C. (2011). Dietary plasticity in Arctic charr (Salvelinus alpinus) in response to long-term environmental change. Ecology of Freshwater Fish 20(1): 5-13.
- Corrigan, L.J., Lucas, M.C., Winfield, I.J. & Hoelzel, A.R. (2011). Environmental factors associated with genetic and phenotypic divergence among sympatric populations of Arctic charr (Salvelinus alpinus). Journal of Evolutionary Biology 24(9): 1906-1917.
- Russon, I. J., Kemp, P. S. & Lucas, M. C. (2011). Gauging weirs impede the upstream migration of adult river lamprey Lampetra fluviatilis. Fisheries Management and Ecology 18(3): 201-210.
- Kemp, P. S., Russon, I. J., Vowles, A. S. & Lucas, M. C. (2011). The influence of discharge and temperature on the ability of upstream migrant adult river lamprey (Lampetra fluviatilis) to pass experimental overshot and undershot weirs. River Research and Applications 27(4): 488-498.
- Bolland, J. D., Bracken, L. J., Martin, R. & Lucas, M. C. (2010). A protocol for stocking hatchery reared freshwater pearl mussel Margaritifera margaritifera. Aquatic Conservation: Marine and Freshwater Ecosystems 20(6): 695-704.
- Louca, V., Lindsay, S. W., Piyapong, C. & Lucas, M. C. (2010). Habitat associations, reproduction and diet of the Guinean tilapia Tilapia guineensis of the Gambia River floodplain. Journal of Fish Biology 76: 2469-2485.
- Baras, E. & Lucas, M. C. (2010). Individual growth trajectories of sibling Brycon moorei raised in isolation since egg stage, and their relationship with aggressive behaviour. Journal of Fish Biology 77: 985-997.
- Bolland, J. D., Cowx, I.G. & Lucas, M.C. (2010). Retention of Panjet-applied alcian blue by cyprinids. Journal of Fish Biology 76: 1015-1018.
- Lucas, M. C., Bubb, D. H., Jang, M.-H., Ha, K. & Masters, J. E. G. (2009). Availability of and access to critical habitats in regulated rivers: effects of low-head barriers on threatened lampreys. Freshwater Biology 54(3): 621-634.
- Bolland, J. D., Cowx, I. G. & Lucas, M. C. (2009). Dispersal and survival of stocked cyprinids in a small English river: comparison with wild fishes using a multi-method approach. Journal of Fish Biology 74: 2313-2328.
- Louca, V., Lindsay, S. W. & Lucas, M. C. (2009). Factors triggering floodplain fish emigration: importance of fish density and food availability. Ecology of Freshwater Fish 18: 60-64.
- Louca, V., Lindsay, S. W., Majambere, S. & Lucas, M. C. (2009). Fish community characteristics of the lower Gambia River floodplains: a study in the last major undisturbed West African river. Freshwater Biology 54(2): 254-271.
- Knight, C. M., Kenward, R. E., Gozlan, R. E., Hodder, K. H., Walls, S. S. & Lucas, M. C. (2009). Home-range estimation within complex restricted environments: importance of method selection in detecting seasonal change. Wildlife Research 36: 213-224.
- Bubb, D. H., O'Malley, O. J., Gooderham, A. C. & Lucas, M. C. (2009). Relative impacts of native and non-native crayfish on shelter use by an indigenous benthic fish. Aquatic Conservation: Marine and Freshwater Ecosystems 19(4): 448-455.
- Louca, V., Lucas, M. C., Green, C., Majambere, S., Fillinger, U. & Lindsay, S. W. (2009). Role of fish as predators of mosquito larvae on the floodplain of the Gambia River. Journal of Medical Entomology 46: 546-556.
- Knight, C. M., Gozlan, R. E. & Lucas, M. C. (2008). Can seasonal home-range size in pike Esox lucius predict excursion distance? Journal of Fish Biology 73: 1058-1064.
- Bolland, J. D., Cowx, I. G. & Lucas, M. C. (2008). Movements and habitat use of wild and stocked juvenile chub, Leuciscus cephalus (L.) in a small lowland river. Fisheries Management and Ecology 15(5-6): 401-407.
- Bubb, D. H., Thom, T. J. & Lucas, M. C. (2008). Spatial ecology of the white-clawed crayfish in an upland stream and implications for the conservation of this endangered species. Aquatic Conservation - Marine and Freshwater Ecosystems 18(5): 647 - 657.
- Jang, M.-H., Joo, G.-J. & Lucas, M.C. (2006). Diet of introduced largemouth bass in Korean rivers and potential interactions with native fishes. Ecology of Freshwater Fish 15: 315-320.
- Gaudron, SM & Lucas, MC (2006). First evidence of attraction of adult river lamprey in the migratory phase to larval odour. Journal of Fish Biology 68(2): 640-644.
- Bubb, D. H., Thom, T. J. & Lucas, M. C. (2006). Movement patterns of the invasive signal crayfish determined by PIT telemetry. Canadian Journal of Zoology 84: 1202-1209.
- Bubb, D.H., Thom, T.J. & Lucas, M.C. (2006). Movement, dispersal and refuge use of co-occurring introduced and native crayfish. Freshwater Biology 51(7): 1359-1368.
- Masters, JEG, Jang, MH, Ha, K, Bird, PD, Frear, PA & Lucas, MC (2006). The commercial exploitation of a protected anadromous species, the river lamprey (Lampetra fluviatilis (L.), in the tidal River Ouse, north-east England. Aquatic Conservation - Marine and Freshwater Ecosystems 16(1): 77-92.
- Jang, MH & Lucas, MC (2005). Reproductive ecology of the river lamprey. Journal of Fish Biology 66(2): 499-512.
- Svendsen, JC, Koed, A & Lucas, MC (2005). The angle of attack of the body of common bream while swimming at different speeds in a flume tank. Journal of Fish Biology 66(2): 572-577.
- Scott, DM, Lucas, MC & Wilson, RW (2005). The effect of high pH on ion balance, nitrogen excretion and behaviour in freshwater fish from an eutrophic lake: A laboratory and field study. Aquatic Toxicology 73(1): 31-43.
- Bubb, DH, Thom, TJ & Lucas, MC (2005). The within-catchment invasion of the non-indigenous signal crayfish Pacifastacus leniusculus (Dana), in upland rivers. Bulletin Francais de la Peche et de la Pisciculture (376-37): 665-673.
- Jang, MH, Ha, K, Lucas, MC, Joo, GJ & Takamura, N (2004). Changes in microcystin production by Microcystis aeruginosa exposed to phytoplanktivorous and omnivorous fish. Aquatic Toxicology 68(1): 51-59.
- Bubb, DH, Thom, TJ & Lucas, MC (2004). Movement and dispersal of the invasive signal crayfish Pacifastacus leniusculus in upland rivers. Freshwater Biology 49(3): 357-368.
- Timchenko, VM, Oksiyuk, OP & Lucas, MC (2004). Oxygen regime improvement in large, lowland reservoirs during the winter period for the reduction of fish suffocation: the example of the Dnieper reservoirs. Ecohydrology and Hydrobiology 4: 17-25.
- Aarestrup, K, Lucas, MC & Hansen, JA (2003). Efficiency of a nature-like bypass channel for sea trout (Salmo trutta) ascending a small Danish stream studied by PIT telemetry. Ecology of Freshwater Fish 12(3): 160-168.
- Jang, MH, Lucas, MC & Joo, GJ (2003). The fish fauna of mountain streams in South Korean national parks and its significance to conservation of regional freshwater fish biodiversity. Biological Conservation 114(1): 115-126.
- Lyons, J & Lucas, MC (2002). The combined use of acoustic tracking and echosounding to investigatethe movement and distribution of common bream (Abramis brama) in the River Trent, England. Hydrobiologia 483(1-3): 265-273.
- Bubb, DH, Lucas, MC, Thom, TJ & Rycroft, P (2002). The potential use of PIT telemetry for identifying and tracking crayfish in their natural environment. Hydrobiologia 483(1-3): 225-230.
- Bubb, DH, Lucas, MC & Thom, TJ (2002). Winter movements and activity of signal crayfish Pacifastacus leniusculus in an upland river, determined by radio telemetry. Hydrobiologia 483(1-3): 111-119.
- Baras E & Lucas MC (2001). Impacts of man's modification of river hydrology on freshwater fish migration: a mechanistic perspective. Ecohydrology and Hydrobiology 1: 291-304.
- Liao, YY & Lucas, MC (2000). Diet of the common wolffish Anarhichas lupus in the North Sea. Journal of the Marine Biological Association Of The United Kingdom 80(1): 181-182.
- Liao, YY & Lucas, MC (2000). Growth, diet and metabolism of common wolf-fish in the North Sea, a fast-growing population. Journal of Fish Biology 56(4): 810-825.
- Lucas, M.C. & Baras, E. (2000). Methods for studying the spatial behaviour of freshwater fishes in the natural environment. Fish and Fisheries 1: 283-316.
- Robinson, CA, Thom, TJ & Lucas, MC (2000). Ranging behaviour of a large freshwater invertebrate, the white-clawed crayfish Austropotamobius pallipes. Freshwater Biology 44(3): 509-521.
- Lucas, MC (2000). The influence of environmental factors on movements of lowland-river fish in the Yorkshire Ouse system. Science of the Total Environment 251/252: 223-232.
- Lucas, MC, Mercer, T, Armstrong, JD, McGinty, S & Rycroft, P (1999). Use of a flat-bed passive integrated transponder antenna array to study the migration and behaviour of lowland river fishes at a fish pass. Fisheries Research 44(2): 183-191.
- Lucas, MC, Mercer, T, Batley, E, Frear, PA, Peirson, G, Duncan, A & Kubecka, J (1998). Spatio-temporal variations in the distribution and abundance of fish in the Yorkshire Ouse system. Science of the Total Environment 210(1-6): 437-455.
- Whitton, BA & Lucas, MC (1997). Biology of the Humber rivers. Science of the Total Environment 194: 247-262.
- Lucas, MC & Frear, PA (1997). Effects of a flow-gauging weir on the migratory behaviour of adult barbel, a riverine cyprinid. Journal of Fish Biology 50(2): 382-396.
- Lucas, MC & Batley, E (1996). Seasonal movements and behaviour of adult barbel Barbus barbus, a riverine cyprinid fish: Implications for river management. Journal of Applied Ecology 33(6): 1345-1358.
- Altimiras, J, Johnstone, ADF, Lucas, MC & Priede, IG (1996). Sex differences in the heart rate variability spectrum of free-swimming Atlantic salmon (Salmo salar L) during the spawning season. Physiological Zoology 69(4): 770-784.
- Lucas, MC (1994). Heart rate as an indicator of metabolic rate and activity in adult Atlantic salmon, Salmo salar. Journal of Fish Biology 44(5): 889-903.
- Lucas, MC, Johnstone, ADF & Tang, J (1993). An annular respirometer for measuring aerobic metabolic rates of large schooling fishes. Journal of Experimental Biology 175: 325-331.
- Hansen, MJ, Boisclair, D, Brandt, SB, Hewett, SW, Kitchell, JF, Lucas, MC & Ney, JJ (1993). Applications of bioenergetics models to fish ecology and management - where do we go from here? Transactions of the American Fisheries Society 122(5): 1019-1030.
- Lucas, MC (1993). Food interrelationships between brown trout, Salmo trutta L., and rainbow trout, Oncorhynchus mykiss (Walbaum), in a small put-and-take stillwater fishery. Aquaculture and Fisheries Management 24: 355-364.
- Lucas, MC, Johnstone, ADF & Priede, IG (1993). Use of physiological telemetry as a method of estimating metabolism of fish in the natural environment. Transactions of the American Fisheries Society 122(5): 822-833.
- Armstrong, JD, Johnstone, ADF & Lucas, MC (1992). Retention of intragastric transmitters after voluntary ingestion by captive cod Gadus morhua L. Journal of Fish Biology 40(1): 135-137.
- Lucas, MC (1992). Spawning activity by male and female pike, Esox lucius L. determined by acoustic tracking. Canadian Journal of Zoology 70(1): 191-196.
- Armstrong, JD, Priede, IG & Lucas, MC (1992). The link between respiratory capacity and metabolic demands during growth of northern pike, Esox lucius L. Journal of Fish Biology 41(Supplement B): 65-75.
- Lucas, MC & Priede, IG (1992). Utilization of metabolic scope in relation to feeding and activity by individual and grouped zebrafish, Brachydanio rerio (Hamilton-Buchanan). Journal of Fish Biology 41(2): 175-190.
- Lucas, MC, Priede, IG, Armstrong, JD, Gindy, ANZ & De Vera, L (1991). Direct measurements of metabolism, activity and feeding behaviour of pike, Esox lucius L., in the wild, by the use of heart rate telemetry. Journal of Fish Biology 39(3): 325-345.
- Lucas, MC & Armstrong, JD (1991). Estimation of meal energy intake from heart rate records of pike, Esox lucius L. Journal of Fish Biology 38: 317-319.
- Lucas, MC & Johnstone, ADF (1990). Observations on the retention of intragastric transmitters, and their effects on food consumption, in cod, Gadus morhua L. Journal of Fish Biology 37: 647-649.
- Armstrong, JD, Lucas, MC, Priede, IG & De Vera, L (1989). An acoustic telemetry system for monitoring the heart rate of pike, Esox lucius L., and other fish in their natural environment. Journal of Experimental Biology 143: 549-552.
- Lucas MC (1989). Effects of implanted dummy transmitters on mortality, growth and tissue reaction in rainbow trout, Salmo gairdneri Richardson. Journal of Fish Biology 35: 577-587.
- Armstrong JD, Lucas M, French J, Vera L & Priede IG (1988). A combined radio and acoustic transmitter for fixing direction and range of freshwater fish (RAFIX). Journal of Fish Biology 33: 879-884.