Hyperbenthic and pelagic predators regulate alternate key planktonic copepods in shallow temperate estuaries
R. J. Wasserman A C , T. J. F. Vink B , R. Kramer A and P. W. Froneman A
+ Author Affiliations
- Author Affiliations
A Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown, 6140, South Africa.
B Department of Botany, Coastal and Marine Research Unit, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031, South Africa.
C Corresponding author. Email: ryanwas21@gmail.com
Marine and Freshwater Research 65(9) 791-801 https://doi.org/10.1071/MF13233
Submitted: 6 September 2013 Accepted: 28 November 2013 Published: 16 June 2014
Abstract
Although predation has been identified as an important community driver, the role of predator diversity in structuring estuarine zooplankton has not been assessed. As such, we investigated the effects of two different zooplanktivorous fish species on the estuarine zooplankton community during a 12-day mesocosm study. Three experimental treatments were established, whereby natural zooplankton communities were subject to either (1) no predatory pressure, (2) predation by a pelagic predator (Monodactylus falciformis) or (3) predation by a hyper-benthic predator (Glossogobius callidus). The pelagic feeding M. falciformis fed largely on the numerically dominant mid-water copepod species, Paracartia longipatella. In contrast, the hyper-benthic fish had a greater predatory impact on the less numerically dominant copepod, Pseudodiaptomus hessei, which demonstrates strong diel vertical migration. Variations in prey-population regulation are ascribed to the distinct behavioural differences of the predators, and mediated by the differences in behaviour of the copepod species.
Additional keywords: copepod prey, diel vertical migration, niche partitioning, trophic interactions, zooplanktivorous fish.
References
Amarasekare, P., Hoopes, M. F., Mouquet, N., and Holyoak, M. (2004). Mechanisms of coexistence in competitive metacommunities. American Naturalist 164, 310–326.| Mechanisms of coexistence in competitive metacommunities.Crossref | GoogleScholarGoogle Scholar | 15478087PubMed |
Anderson, M. J. (2001). A new method for non-parametric multivariate analysis of variance. Austral Ecology 26, 32–46.
Anderson, M. J., Gorley, R. N., and Clarke, K. R. (2008). ‘PERMANOVA+ for PRIMER: a Guide to Software and Statistical Methods.’ (Primer-e: Plymouth, UK.)
Banse, K. (1995). Zooplankton: pivotal role in the control of ocean production: I. Biomass and production. ICES Journal of Marine Science: Journal du Conseil 52, 265–277.
| Zooplankton: pivotal role in the control of ocean production: I. Biomass and production.Crossref | GoogleScholarGoogle Scholar |
Bate, G. C., and Heelas, B. V. (1975). Studies on the nitrite nutrition of two indignenous Rhodesian grasses. Journal of Applied Ecology 12, 941–952.
| Studies on the nitrite nutrition of two indignenous Rhodesian grasses.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2sXhsFCmt7c%3D&md5=83fc611fb39723a6c882f1e6ac30760eCAS |
Beddington, J. R., Free, C. A., and Lawton, J. H. (1976). Concepts of stability and resilience in predator–prey models. Journal of Animal Ecology 45, 791–816.
| Concepts of stability and resilience in predator–prey models.Crossref | GoogleScholarGoogle Scholar |
Boltovskoy, D. (1999). ‘South Atlantic Zooplankton.’ (Backhuys: Leiden, The Netherlands.)
Brooks, J. L., and Dodson, S. I. (1965). Predation, body size, and composition of plankton. Science 150, 28–35.
| Predation, body size, and composition of plankton.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3cvltlWqsA%3D%3D&md5=a7d722c83b89d9c1ca55c6d23a7dce02CAS | 17829740PubMed |
Burks, R. L., Lodge, D. M., Jeppesen, E., and Lauridsen, T. L. (2002). Diel horizontal migration of zooplankton: costs and benefits of inhabiting the littoral. Freshwater Biology 47, 343–365.
| Diel horizontal migration of zooplankton: costs and benefits of inhabiting the littoral.Crossref | GoogleScholarGoogle Scholar |
Buskey, E. J., Lenz, P. H., and Hartline, D. K. (2012). Sensory perception, neurobiology, and behavioral adaptations for predator avoidance in planktonic copepods. Adaptive Behavior 20, 57–66.
| Sensory perception, neurobiology, and behavioral adaptations for predator avoidance in planktonic copepods.Crossref | GoogleScholarGoogle Scholar |
Chalcraft, D. R., and Resetarits, W. J. (2003). Mapping functional similarity of predators on the basis of trait similarities. American Naturalist 162, 390–402.
| Mapping functional similarity of predators on the basis of trait similarities.Crossref | GoogleScholarGoogle Scholar | 14582003PubMed |
Chave, J., Muller‐Landau, H. C., and Levin, S. A. (2002). Comparing classical community models: theoretical consequences for patterns of diversity. American Naturalist 159, 1–23.
| Comparing classical community models: theoretical consequences for patterns of diversity.Crossref | GoogleScholarGoogle Scholar | 18707398PubMed |
DeWitt, T. J., Sih, A., and Wilson, D. S. (1998). Costs and limits of phenotypic plasticity. Trends in Ecology & Evolution 13, 77–81.
| Costs and limits of phenotypic plasticity.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3M7itFygsQ%3D%3D&md5=e7a612b9b6fdc1164bf2122e88e3b5dbCAS |
Estes, J. A., Terborgh, J., Brashares, J. S., Power, M. E., Berger, J., Bond, W. J., Carpenter, S. R., Essington, T. E., Holt, R. D., Jackson, J. B., Marquis, R. J., Oksanen, L., Oksanen, T., Paine, R. T., Pikitch, E. K., Ripple, W. J., Sandin, S. A., Scheffer, M., Schoener, T. W., Shurin, J. B., Sinclair, A. R., Soule, M. E., Virtanen, R., and Wardle, D. A. (2011). Trophic downgrading of planet Earth. Science 333, 301–306.
| Trophic downgrading of planet Earth.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXos1ylur0%3D&md5=7efdfef8632bb1e1a9f2ef8abd51222cCAS | 21764740PubMed |
Fancett, M. S., and Kimmerer, W. J. (1985). Vertical migration of the demersal copepod Pseudodiaptomus as a means of predator avoidance. Journal of Experimental Marine Biology and Ecology 88, 31–43.
| Vertical migration of the demersal copepod Pseudodiaptomus as a means of predator avoidance.Crossref | GoogleScholarGoogle Scholar |
Fey, K., Banks, P. B., Oksanen, L., and Korpimäki, E. (2009). Does removal of an alien predator from small islands in the Baltic Sea induce a trophic cascade? Ecography 32, 546–552.
| Does removal of an alien predator from small islands in the Baltic Sea induce a trophic cascade?Crossref | GoogleScholarGoogle Scholar |
Fretwell, S. D. (1987). Food chain dynamics: the central theory of ecology? Oikos 50, 291–301.
| Food chain dynamics: the central theory of ecology?Crossref | GoogleScholarGoogle Scholar |
Froneman, P. W. (2000). Feeding studies on selected zooplankton in a temperate estuary, South Africa. Estuarine, Coastal and Shelf Science 51, 543–552.
| Feeding studies on selected zooplankton in a temperate estuary, South Africa.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXjtFylsg%3D%3D&md5=24698d6e1a7e1848d3392e5c1660be54CAS |
Froneman, P. W. (2002). Response of the plankton to three different hydrological phases of the temporarily open/closed Kasouga Estuary, South Africa. Estuarine, Coastal and Shelf Science 55, 535–546.
| Response of the plankton to three different hydrological phases of the temporarily open/closed Kasouga Estuary, South Africa.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xot1KmsLc%3D&md5=bc6aa92527d3258ee3f83cc5f16b38a2CAS |
Froneman, P. W. (2004). Zooplankton community structure and biomass in a southern African temporarily open/closed estuary. Estuarine, Coastal and Shelf Science 60, 125–132.
| Zooplankton community structure and biomass in a southern African temporarily open/closed estuary.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXjtlCjsbc%3D&md5=9dce60511d3d4b448ade145ff9ed3d24CAS |
Gilbert, B., Srivastava, D. S., and Kirby, K. R. (2008). Niche partitioning at multiple scales facilitates coexistence among mosquito larvae. Oikos 117, 944–950.
| Niche partitioning at multiple scales facilitates coexistence among mosquito larvae.Crossref | GoogleScholarGoogle Scholar |
Gobler, C. J., Cullison, L. A., Koch, F., Harder, T. M., and Krause, J. W. (2005). Influence of freshwater flow, ocean exchange, and seasonal cycles on phytoplankton – nutrient dynamics in a temporarily open estuary. Estuarine, Coastal and Shelf Science 65, 275–288.
| Influence of freshwater flow, ocean exchange, and seasonal cycles on phytoplankton – nutrient dynamics in a temporarily open estuary.Crossref | GoogleScholarGoogle Scholar |
Griffen, B. D. (2006). Detecting emergent effects of multiple predator species. Oecologia 148, 702–709.
| Detecting emergent effects of multiple predator species.Crossref | GoogleScholarGoogle Scholar | 16568277PubMed |
Hart, R. C., and Allanson, B. R. (1976). The distribution and diel vertical migration of Pseudodiaptomus hessei (Mrázek) (Calanoida: Copepoda) in a subtropical lake in southern Africa. Freshwater Biology 6, 183–198.
| The distribution and diel vertical migration of Pseudodiaptomus hessei (Mrázek) (Calanoida: Copepoda) in a subtropical lake in southern Africa.Crossref | GoogleScholarGoogle Scholar |
Henninger, T. O., Froneman, P. W., and Hodgson, A. N. (2008). The population dynamics of the estuarine isopod Exosphaeroma hylocoetes (Barnard, 1940) within three temporarily open/closed southern African estuaries. African Zoology 43, 202–217.
| The population dynamics of the estuarine isopod Exosphaeroma hylocoetes (Barnard, 1940) within three temporarily open/closed southern African estuaries.Crossref | GoogleScholarGoogle Scholar |
Heyns, E., and Froneman, P. W. (2010). Spatial and temporal patterns in the hyperbenthic community structure in a warm temperate southern African permanently open estuary. Estuarine, Coastal and Shelf Science 88, 105–115.
| Spatial and temporal patterns in the hyperbenthic community structure in a warm temperate southern African permanently open estuary.Crossref | GoogleScholarGoogle Scholar |
Holzmueller, E. J., Gibson, D. J., and Suchecki, P. F. (2012). Accelerated succession following an intense wind storm in an oak-dominated forest. Forest Ecology and Management 279, 141–146.
| Accelerated succession following an intense wind storm in an oak-dominated forest.Crossref | GoogleScholarGoogle Scholar |
Houde, E. D., and Rutherford, E. S. (1993). Recent trends in estuarine fisheries: predictions of fish production and yield. Estuaries 16, 161–176.
| Recent trends in estuarine fisheries: predictions of fish production and yield.Crossref | GoogleScholarGoogle Scholar |
Humes, A. G. (1994). How many copepods? Hydrobiologia 292–293, 1–7.
| How many copepods?Crossref | GoogleScholarGoogle Scholar |
Iglesias, C., Goyenola, G., Mazzeo, N., Meerhoff, M., Rodó, E., and Jeppesen, E. (2007). Horizontal dynamics of zooplankton in subtropical Lake Blanca (Uruguay) hosting multiple zooplankton predators and aquatic plant refuges. Hydrobiologia 584, 179–189.
| Horizontal dynamics of zooplankton in subtropical Lake Blanca (Uruguay) hosting multiple zooplankton predators and aquatic plant refuges.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXlsVeqtb4%3D&md5=f8bacf72334910f3ef519edfffb56644CAS |
Isla, J. A., and Perissinotto, R. (2004). Effects of temperature, salinity and sex on the basal metabolic rate of the estuarine copepod Pseudodiaptomus hessei. Journal of Plankton Research 26, 579–583.
| Effects of temperature, salinity and sex on the basal metabolic rate of the estuarine copepod Pseudodiaptomus hessei.Crossref | GoogleScholarGoogle Scholar |
Jerling, H. L., and Wooldridge, T. H. (1989). The developmental stages of Pseudodiaptomus hessei (Copepoda: Calanoida). South African Journal of Zoology 24, 139–145.
Jerling, H. L., and Wooldridge, T. H. (1995). Plankton distribution and abundance in the Sundays River Estuary, South Africa, with comments on potential feeding interactions. South African Journal of Marine Science 15, 169–184.
| Plankton distribution and abundance in the Sundays River Estuary, South Africa, with comments on potential feeding interactions.Crossref | GoogleScholarGoogle Scholar |
Kabacoff, R. I. (2011). ‘R in Action: Data Analysis and Graphics with R.’ (Manning Publications Co.: New York.)
Kibirige, I., and Perissinotto, R. (2003). The zooplankton community of the Mpenjati Estuary, a South African temporarily open/closed system. Estuarine, Coastal and Shelf Science 58, 727–741.
| The zooplankton community of the Mpenjati Estuary, a South African temporarily open/closed system.Crossref | GoogleScholarGoogle Scholar |
Kouassi, E., Pagano, M., Saint-Jean, L., Arfi, R., and Bouvy, M. (2001). Vertical migrations and feeding rhythms of Acartia clausi and Pseudodiaptomus hessei (Copepoda: Calanoida) in a tropical lagoon (Ebrié, Côte d’Ivoire). Estuarine, Coastal and Shelf Science 52, 715–728.
| Vertical migrations and feeding rhythms of Acartia clausi and Pseudodiaptomus hessei (Copepoda: Calanoida) in a tropical lagoon (Ebrié, Côte d’Ivoire).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXltlGhsbo%3D&md5=5b1ce6fb6a03fd8199673c0a67d19684CAS |
Lampert, W. (1989). The adaptive significance of diel vertical migration of zooplankton. Functional Ecology 3, 21–27.
| The adaptive significance of diel vertical migration of zooplankton.Crossref | GoogleScholarGoogle Scholar |
Lorenzen, C. J. (1966). A method for the continuous measurement of in vivo chlorophyll concentration. Deep Sea Research and Oceanographic Abstracts 13, 223–227.
| A method for the continuous measurement of in vivo chlorophyll concentration.Crossref | GoogleScholarGoogle Scholar |
Mehner, T., and Thiel, R. (1999). A review of predation impact by 0+ fish on zooplankton in fresh and brackish waters of the temperate northern hemisphere. Environmental Biology of Fishes 56, 169–181.
| A review of predation impact by 0+ fish on zooplankton in fresh and brackish waters of the temperate northern hemisphere.Crossref | GoogleScholarGoogle Scholar |
Møller, E. F. (2005). Sloppy feeding in marine copepods: prey-size-dependent production of dissolved organic carbon. Journal of Plankton Research 27, 27–35.
| Sloppy feeding in marine copepods: prey-size-dependent production of dissolved organic carbon.Crossref | GoogleScholarGoogle Scholar |
Møller, E. F. (2007). Production of dissolved organic carbon by sloppy feeding in the copepods Acartia tonsa, Centropages typicus, and Temora longicornis. Limnology and Oceanography 52, 79–84.
| Production of dissolved organic carbon by sloppy feeding in the copepods Acartia tonsa, Centropages typicus, and Temora longicornis.Crossref | GoogleScholarGoogle Scholar |
Montoya-Maya, P. H., and Strydom, N. A. (2009). Description of larval fish composition, abundance and distribution in nine south and west coast estuaries of South Africa. African Zoology 44, 75–92.
| Description of larval fish composition, abundance and distribution in nine south and west coast estuaries of South Africa.Crossref | GoogleScholarGoogle Scholar |
Mos, B., Cowden, K. L., Nielsen, S. J., and Dworjanyn, S. A. (2011). Do cues matter? Highly inductive settlement cues don’t ensure high post-settlement survival in sea urchin aquaculture. PLoS ONE 6, e28054.
| Do cues matter? Highly inductive settlement cues don’t ensure high post-settlement survival in sea urchin aquaculture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhs1KhtL%2FM&md5=1ed6bb97de9f33003512a10d6194d5b9CAS | 22162755PubMed |
Muška, M., Tušer, M., Frouzová, J., Draštík, V., Čech, M., Jůza, T., Kratochvíl, M., Mrkvička, T., Peterka, J., Prchalová, M., Říha, M., Vašek, M., and Kubečka, J. (2013). To migrate, or not to migrate: partial diel horizontal migration of fish in a temperate freshwater reservoir. Hydrobiologia 707, 17–28.
| To migrate, or not to migrate: partial diel horizontal migration of fish in a temperate freshwater reservoir.Crossref | GoogleScholarGoogle Scholar |
Nemec, A. F. L. (1996). ‘Analysis of Repeated Measures and Time Series: an Introduction with Forestry Examples.’ 6th edn. (Province of British Columbia, Ministry of Forests Research Program: Victoria, Canada.)
O’Connor, N. E., Grabowski, J. H., Ladwig, L. M., and Bruno, J. F. (2008). Simulated predator extinctions: predator identity affects survival and recruitment of oysters. Ecology 89, 428–438.
| Simulated predator extinctions: predator identity affects survival and recruitment of oysters.Crossref | GoogleScholarGoogle Scholar | 18409432PubMed |
Pagano, M., Kouassi, E., Saint-Jean, L., Arfi, R., and Bouvy, M. (2003). Feeding of Acartia clausi and Pseudodiaptomus hessei (Copepoda: Calanoida) on natural particles in a tropical lagoon (Ebrié, Côte d’Ivoire). Estuarine, Coastal and Shelf Science 56, 433–445.
| Feeding of Acartia clausi and Pseudodiaptomus hessei (Copepoda: Calanoida) on natural particles in a tropical lagoon (Ebrié, Côte d’Ivoire).Crossref | GoogleScholarGoogle Scholar |
Parsons, T. R., Maita, Y., and Lalli, C. M. (1984). ‘A Manual of Chemical and Biological Methods for Seawater Analysis.’ (Pergamon Press: Oxford, UK.)
Perissinotto, R., Nozais, C., Kibirige, I., and Anandraj, A. (2003). Planktonic food webs and benthic–pelagic coupling in three South African temporarily-open estuaries. Acta Oecologica 24, S307–S316.
| Planktonic food webs and benthic–pelagic coupling in three South African temporarily-open estuaries.Crossref | GoogleScholarGoogle Scholar |
Persson, L. (1999). Trophic cascades: abiding heterogeneity and the trophic level concept at the end of the road. Oikos 85, 385–397.
| Trophic cascades: abiding heterogeneity and the trophic level concept at the end of the road.Crossref | GoogleScholarGoogle Scholar |
Polis, G. A. (1994). Food webs, trophic cascades and community structure. Australian Journal of Ecology 19, 121–136.
| Food webs, trophic cascades and community structure.Crossref | GoogleScholarGoogle Scholar |
R Development Core Team (2013). ‘R: a Language and Environment for Statistical Computing.’ Available at http://www.R-project.org/ [accessed 25 August 2013].
Saba, G. K., Steinberg, D. K., and Bronk, D. A. (2011). The relative importance of sloppy feeding, excretion, and fecal pellet leaching in the release of dissolved carbon and nitrogen by Acartia tonsa copepods. Journal of Experimental Marine Biology and Ecology 404, 47–56.
| The relative importance of sloppy feeding, excretion, and fecal pellet leaching in the release of dissolved carbon and nitrogen by Acartia tonsa copepods.Crossref | GoogleScholarGoogle Scholar |
Schmitz, O. J. (2007). Predator diversity and trophic interactions. Ecology 88, 2415–2426.
| Predator diversity and trophic interactions.Crossref | GoogleScholarGoogle Scholar | 18027743PubMed |
Schmitz, O. J., Krivan, V., and Ovadia, O. (2004). Trophic cascades: the primacy of trait-mediated indirect interactions. Ecology Letters 7, 153–163.
| Trophic cascades: the primacy of trait-mediated indirect interactions.Crossref | GoogleScholarGoogle Scholar |
Sih, A., Englund, G., and Wooster, D. (1998). Emergent impacts of multiple predators on prey. Trends in Ecology & Evolution 13, 350–355.
| Emergent impacts of multiple predators on prey.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3M7itF2lsQ%3D%3D&md5=339fe0d72cfcf0aaefc278a163ee6c61CAS |
Sokol-Hessner, L., and Schmitz, O. J. (2002). Aggregate effects of multiple predator species on a shared prey. Ecology 83, 2367–2372.
| Aggregate effects of multiple predator species on a shared prey.Crossref | GoogleScholarGoogle Scholar |
Sommer, U. (2008). Trophic cascades in marine and freshwater plankton. International Review of Hydrobiology 93, 506–516.
| Trophic cascades in marine and freshwater plankton.Crossref | GoogleScholarGoogle Scholar |
Strydom, N. A., Whitfield, A. K., and Wooldridge, T. H. (2003). The role of estuarine type in characterizing early stage fish assemblages in warm temperate estuaries, South Africa. African Zoology 38, 29–43.
Vumazonke, L. U., Mainoane, T. S., Bushula, T., and Pakhomov, E. A. (2008). A preliminary investigation of winter daily food intake by four small teleost fish species from the Igoda Estuary, Eastern Cape, South Africa. African Journal of Aquatic Science 33, 83–86.
| A preliminary investigation of winter daily food intake by four small teleost fish species from the Igoda Estuary, Eastern Cape, South Africa.Crossref | GoogleScholarGoogle Scholar |
Walter, T. C. (1987). Review of the taxonomy and distribution of the demersal copepod genus Pseudodiaptomus (Calanoida: Pseudodiaptomidae) from southern Indo-West Pacific waters. Marine and Freshwater Research 38, 363–396.
| Review of the taxonomy and distribution of the demersal copepod genus Pseudodiaptomus (Calanoida: Pseudodiaptomidae) from southern Indo-West Pacific waters.Crossref | GoogleScholarGoogle Scholar |
Warfe, D. M., and Barmuta, L. A. (2004). Habitat structural complexity mediates the foraging success of multiple predator species. Oecologia 141, 171–178.
| Habitat structural complexity mediates the foraging success of multiple predator species.Crossref | GoogleScholarGoogle Scholar | 15300485PubMed |
Warlen, S. M., and Burke, J. S. (1990). Immigration of larvae of fall/winter spawning marine fishes into a North Carolina estuary. Estuaries 13, 453–461.
| Immigration of larvae of fall/winter spawning marine fishes into a North Carolina estuary.Crossref | GoogleScholarGoogle Scholar |
Wasserman, R. J. (2012). Feeding ecology of the early life-history stages of two dominant gobiid species in the headwaters of a warm-temperate estuary. Estuarine, Coastal and Shelf Science 109, 11–19.
| Feeding ecology of the early life-history stages of two dominant gobiid species in the headwaters of a warm-temperate estuary.Crossref | GoogleScholarGoogle Scholar |
Wasserman, R. J., and Froneman, P. W. (2013). Risk effects on copepods: preliminary experimental evidence for the suppression of clutch size by predatory early life-history fish. Journal of Plankton Research 35, 421–426.
| Risk effects on copepods: preliminary experimental evidence for the suppression of clutch size by predatory early life-history fish.Crossref | GoogleScholarGoogle Scholar |
Wasserman, R. J., and Strydom, N. A. (2011). The importance of estuary head waters as nursery areas for young estuary- and marine-spawned fishes in temperate South Africa. Estuarine, Coastal and Shelf Science 94, 56–67.
| The importance of estuary head waters as nursery areas for young estuary- and marine-spawned fishes in temperate South Africa.Crossref | GoogleScholarGoogle Scholar |
Wasserman, R. J., Strydom, N. A., and Wooldridge, T. H. (2010). Larval fish dynamics in the Nxaxo–Ngqusi Estuary complex in the warm temperate–subtropical transition zone of South Africa. African Zoology 45, 63–77.
| Larval fish dynamics in the Nxaxo–Ngqusi Estuary complex in the warm temperate–subtropical transition zone of South Africa.Crossref | GoogleScholarGoogle Scholar |
Wasserman, R. J., Noyon, M., Avery, T. S., and Froneman, P. W. (2013). Trophic level stability-inducing effects of predaceous early juvenile fish in an estuarine mesocosm study. PLoS ONE 8, e61019.
| Trophic level stability-inducing effects of predaceous early juvenile fish in an estuarine mesocosm study.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXmtVehtb8%3D&md5=7af0df7e1cf5f91326438af8ff5b1e1aCAS | 23565294PubMed |
Wheeler, B. (2010a). ‘lmPerm: Permutation Tests for Linear Models. R Package Version 1.1–2.’ Available at http://CRAN.R-project.org/package=lmPerm [accessed 25 August 2013].
Wheeler, R. E. (2010b). ‘Permutation Tests for Linear Models in R.’ Available at http://cran.r-project.org/web/packages/lmPerm/vignettes/lmPerm.pdf [accessed 10 September 2013].
Wheeler, R. E. (2010c). ‘Permutation Tests for Linear Models in R.’ Available at http://cran.r-project.org/web/packages/lmPerm/vignettes/lmPerm.pdf [accessed 25 August 2013].
Whitfield, A. K. (1992). A characterization of southern African estuarine systems. Southern African Journal of Aquatic Sciences 18, 89–103.
| A characterization of southern African estuarine systems.Crossref | GoogleScholarGoogle Scholar |
Whitfield, A. K. (1998). ‘Biology and Ecology of Fishes in South African Estuaries.’ Ichthyological Monographs of the J.L.B. Smith Institute of Ichthyology, Vol. 2.
Wooldridge, T. H., and Melville-Smith, R. (1979). Copepod succession in two South African estuaries. Journal of Plankton Research 1, 329–341.
| Copepod succession in two South African estuaries.Crossref | GoogleScholarGoogle Scholar |
