Vertical distribution and trophic structure of the macrozooplankton in a shallow temperate estuary (Ria de Aveiro, Portugal)


  • Fernando M. Morgado Departamento de Biologia, Universidade de Aveiro, Portugal
  • Ramiro Pastorinho Departamento de Biologia, Universidade de Aveiro, Portugal
  • Carla Quintaneiro Departamento de Biologia, Universidade de Aveiro, Portugal
  • Pedro Ré Departamento de Biologia Animal. Faculdade de Ciências da Universidade de Lisboa.



macrozooplankton, vertical distribution, trophic structure, temperate estuary


The zooplankton of the lower part of Canal de Mira (Ria de Aveiro) was sampled during one lunar month. The sampling programme consisted of nine 25 hour fixed-cycles, separated weekly. In each cycle, samples were collected every two hours at three depths (surface, mid-water and above the bottom) with a 500 µm mesh net. The overall effect of the tidal phase was analyzed, taking into account the day and depth of the vertical position of the organisms through a 3-way analysis of variance (ANOVA). The zooplankton densities were, in general, higher at the surface during the night and near the bottom during the day, mainly at spring tide. The variation in the number of species followed a similar pattern to that observed for abundance. Significant differences (p<0.01) between diel and tidal phases were observed. Interaction between phase of the day and depth was also significant (p<0.05), with higher organism densities observed during night periods near the bottom. From a trophic point of view the zooplankton community of Canal de Mira was mainly composed of carnivorous and omnivorous species. Carnivores were significantly more abundant around the new and full moon (p<0.001), the omnivores at the new moon (p<0.001) and the herbivores and detritivores at the first quarter of the moon cycles (p<0.001). The density of carnivores was significantly higher at the surface at night and near the bottom during the day (p<0.05). Significant differences in the abundance of omnivores were observed between phases of the day and between depths, with higher values near the bottom during the day. The herbivores and detritivores had significantly higher densities during flood tides (p<0.001).


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Alldredge, A.L. and W.M. Hamner. – 1980. Recurring aggregation of zooplankton by a tidal current. Estuar. Coast. Mar. Sci., 10: 31-37. doi:10.1016/S0302-3524(80)80047-8

Bachelet, G. and M. Yacine-Kassab. – 1987. Intégration de la phase post-recrutée dans la dynamique des populations du gastéropode intertidal Hydrobia ulvae (Pennant). J. Exp. Mar. Biol. Ecol., 111: 37-60. doi:10.1016/0022-0981(87)90019-0

Barnes, R.S.K. – 1994. The Brackish-Water Fauna of Northwestern Europe. An identification guide to brackish-water habitats, ecology and macrofauna for field workers, naturalists and students. Cambridge University Press, Cambridge.

Bollens, S.M. and B.W. Frost. – 1989a. Zooplanktivorous fish and variable diel vertical migration in the marine planktonic copepod Calanus pacificus. Limnol. Oceanogr., 34: 1072-1083.

Bollens, S.M. and B.W. Frost. – 1989b. Predator-induced diel vertical migration in a planktonic copepod. J. Plankton Res., 11 (Suppl. 5): 1047-1065. doi:10.1093/plankt/11.5.1047

Bollens, S.M. and B.W. Frost. – 1991. Diel vertical migration in zooplankton: rapid individual response to predators. J. Plankton Res., 13 (Suppl. 6): 1359-1365. doi:10.1093/plankt/13.6.1359

Brookins, K.G. and C.E. Epefanio. – 1985. Abundance of brachyuran larvae in a small coastal inlet over six consecutive tidal cycles. Estuaries, 8 (Suppl. 1): 60-67. doi:10.2307/1352122

Chase, M.E. and M.L.H. Thomas. – 1995. The effect of the rate and onset of temperature increase on spawning of the periwinkle, Littorina littorea (L.). J. Exp. Mar. Biol. Ecol., 186: 277-287. doi:10.1016/0022-0981(94)00165-A

Christy, J.H. – 1982. Adaptive significance of semilunar cycles of larval release in fiddler crabs (genus Uca): test of an hypothesis. Biol. Bull., 163: 251-263. doi:10.2307/1541264

Costello, J. and S.E. Stancyk. – 1983. Tidal influence upon appen dicularian abundance in North Inlet estuary, South Carolina. J. Plankton Res., 5 (Suppl. 2): 263-277. doi:10.1093/plankt/5.2.263

Decoursey, P.J. – 1983. Biological timing. In: D.E. Bliss (ed.), The Biology of Crustacea, Vol 7. Behaviour and ecology, pp. 107-162. Academic Press, New York.

De Stasio Jr., B.T. – 1993. Diel vertical and horizontal migration by zooplankton: populations budgets and the diurnal deficit. Bull. Mar. Sci., 53 (Suppl. 1): 44-64.

Dias J.M., J.F. Lopes and I. Dekeyser. – 2003. A numerical system to study the transport properties in the Ria de Aveiro lagoon. Ocean Dynam., 53: 220–231. doi:10.1007/s10236-003-0048-5

Dodson, S. – 1988. The ecological role of chemical stimuli for the zooplankton: predator-avoidance behaviour in Daphnia. Limnol. Oceanogr., 33: 1431-1439.

Enright, J.T. – 1965. Entrainment of a tidal rhythm. Science, 147: 864–8867. doi:10.1126/science.147.3660.864

Enright, J.T. – 1970. Ecological aspects of endogenous rhythmicity. Annu. Rev. Ecol. Syst., 1: 221-238. doi:10.1146/

Enright, J.T. – 1977. Diurnal vertical migration: adaptive significance and timing. Part I. selective advantage: a metabolic method. Limnol. Oceanogr., 22: 856-872.

Epifanio, C.E. – 1988. Transport of crab larvae between estuaries and the continental shelf. Lecture Notes on Coastal and Estuarine Studies, 22: 291-305.

Esnal, G.B., C. Sankarankutty and R.J. Castro. – 1985. Diurnal and seasonal fluctuations of Oikopleura dioica Fol, 1872 (Tunicata, Appendicularia) in the mouth of the river Potengi (North Brazil). Physis (Buenos Aires), Secc. A, 43 (Suppl. 105): 65-71.

Fenaux, R. – 1967. Les Appendiculaires des mers d’Europe et du Bassin Méditerranéen. Faune de l’Europe et du Bassin Méditerranéen. Masson et Cie., Paris.

Fincham, A.A. – 1977. Larval development of British prawns and shrimps (Crustacea: Decapoda: Natantia). 1. Laboratory methods and a review of Palaemon (Paleander) elegans Rathke, 1837. Bull. Br. Mus. Nat. Hist. (Zool.), 32 (Suppl. 1): 1-28.

Fincham, A.A. and A.J. Figueras. – 1986. Larval keys and diagnoses for the subfamily Palaemoninae (Crustacea Decapoda: Palaemonidae) in the north-east Atlantic and aspects of functional morphology. J. Nat. Hist., 20: 203-224. doi:10.1080/00222938600770171

Fish, J.D. – 1979. The rhythmic spawning behaviour of Littorina littorea (L.). J. Mollus. Stud., 45: 172-177.

Forward, R.B., Jr. – 1988. Diel vertical migration: zooplankton photobiology and behaviour. Oceanogr. Mar. Biol., 26, 361–393.

Fragopoulu, N. and J.J. Lykakis. – 1990. Vertical distribution and nocturnal migration of zooplankton in relation to the development of the seasonal thermocline in Patraikos Gulf. Mar. Biol., 104: 381-387. doi:10.1007/BF01314340

Gagnon, M. and G. Lacroix. – 1981. Zooplankton sample variability in a tidal estuary: an interpretative model. Limnol. Oceanogr., 26 (Suppl. 3): 401-413.

Gajbhiye, S.N., V.R. Nair and B.N. Desai. – 1984. Diurnal variation of zooplankton in Malad Creek, Bombay. Indian J. Mar. Sci., 13: 75-79.

Giske, J., D.L. Aksnes, B.M. Baliño, S. Kaartvedt, U. Lie, J.T. Nordeide, A.G.V. Salvanes, S.M. Wakili and A. AaDnesen. – 1990. Vertical distribution and trophic interactions of zooplankton and fish in Masjforden, Norway. Sarsia, 75: 65-81.

Gliwicz, M.Z. – 1986. Predation and the evolution of vertical migration in zooplankton. Nature, 320: 746-748. doi:10.1038/320746a0

Guerney, A.R. – 1982. The larval development of Crangon crangon (Fabricius, 1795) (Crustacea: Decapoda). Bull. Br. Mus. Nat. Hist. (Zool.), 42 (Suppl. 4): 247-262.

Hammer, R.M. – 1981. Day-night influences in the emergence of demersal zooplankton from a sand substrate in a Kelp Forest. Mar. Biol., 62: 275-280. doi:10.1007/BF00397694

Hansson, S., U. Larsson and S. Johansson. – 1990. Selective predation by herring and mysids, and zooplankton community structure in a Baltic Sea coastal area. J. Plankton Res., 12 (Suppl. 5): 1059-1116. doi:10.1093/plankt/12.5.1099

Harding, G.C., W.C. Vass, B.T. Hargrave and S. Pearre Jr. – 1986. Vertical movements and feeding activity of zooplankton in St. Georges Bay, N.S., using net tows and a newly developed passive trap. Can. J. Fish. Aquat. Sci., 43: 952-967.

Hays, G.C. – 2003. A review of the adaptive significance and ecosystem consequences of zooplankton diel vertical migrations. Hydrobiologia, 503: 163-170. doi:10.1023/B:HYDR.0000008476.23617.b0

Hill, A.E. – 1991a. Advection-diffusion-mortality solutions for investigating pelagic larval dispersal. Mar. Ecol. Prog. Ser., 70: 117-128. doi:10.3354/meps070117

Hill, A.E. – 1991b. A mechanism for horizontal zooplanktonic transport by vertical migration in tidal currents. Mar. Biol., 111: 485-492. doi:10.1007/BF01319422

Hill, A.E. – 1991c. Vertical migration in tidal currents. Mar. Ecol. Progr. Ser., 75: 39-54.

Hill, A.E. – 1995. The kinematical principles governing horizontal transport induced by vertical migration in tidal flows. J. Mar. Biol. Assoc. U.K., 75: 3-13.

Ingle, R.W. – 1987. The first zoea of three Pachygrapsus species and the Cataleptodius floridianus (Gibbes) from Bermuda and Mediterranean (Crustacea: Decapoda: Brachyura). Bull. Br. Mus. Nat. Hist. (Zool), 52: 31-41.

Jagger, Z. – 1999. Selective stream transport of the flounder larvae (Platichthys flesus L.) in the Dolard (Ems Estuary). J. Mar. Biol. Assoc. U.K., 75: 3-13.

Jerling, H.L. and T.H. Wooldridge. – 1992. Lunar influence on distribution of a calanoid copepod in the water column of a shallow temperate estuary. Mar. Biol., 112: 309-312. doi:10.1007/BF00702476

Lampert, W. – 1989. The adaptive significance of diel vertical migration of zooplankton. Funct. Ecol., 3: 21-27. doi:10.2307/2389671

Land, M.F. – 1992. Locomotion and visual behaviour of mid-water crustaceans. J. Mar. Biol. Ass. U.K., 72: 41-60.

Laprise, R. and J.J. Dodson. – 1993. Nature of environmental variability xperienced by benthic and pelagic animals in the St. Lawrence Estuary, Canada. Mar. Ecol. Prog. Ser., 94: 129-139. doi:10.3354/meps094129

Lazzaro, X., R.W. Drenner, R.A. Stein and J.D. Smith. – 1992. Planktivores and plankton dynamics: effects of fish biomass and planktivore type. Can. J. Fish. Aquat. Sci., 49: 1466-1473.

Magnesen, T. – 1989. Vertical distribution of size-fractions in the zooplankton community in Lindaspollene, Western Norway. I. Seasonal variations. Sarsia, 74: 59-68.

Magnesen, T., L. Aknes and H.R. Skojoldal. – 1989. Fine-scale vertical structure of a summer zooplankton community in Lindaspollene, Western Norway. Sarsia, 74: 115-126.

Marine Zooplankton Colloquium. – 2001. Future marine zooplankton research-a perspective. Mar. Ecol-Prog. Ser., 222: 297-308. doi:10.3354/meps222297

Mauchline, J. – 1980. The biology of mysids and euphausiids. In: Blaxter, J.H.S., Russell, F. and M. Young. (eds.), Advances in Marine Biology, vol. 18., pp. 681. Academic Press, London, New York, Toronto, Sydney, S. Francisco.

McEwen, G.F., M.W. Johanson and T.R. Folsom. – 1954. A statistical analysis of the performance of the Folsom plankton splitter, based upon test observations. Arch. Meteor. Geophy. Bioklimatol., 7: 502-527. doi:10.1007/BF02277939

Mees, J., A. Dewicke and O. Hamerlynck. – 1993. Seasonal composition and spatial distribution of hyperbenthic communities along estuarine gradients in the Westerschelde. Nether. J. Aquat. Ecol., 27 (Suppl. 2-4): 359-376.

Morgado, F.M., R. Melo, H. Queiroga and J.C. Sorbe. – 2003. Zooplankton abundance in a coastal station off the Ria de Aveiro inlet (north-western Portugal): relation with tidal and day/night cycles. Acta Oecol., 24: 175-181. doi:10.1016/S1146-609X(03)00037-7

Morgado, F.M., C. Antunes and M.R. Pastorinho. – 2003. Distribution and patterns of emergence of suprabenthic and pelagic crustaceans from a shallow temperate estuary (Ria de Aveiro, Portugal). Acta Oecol., 24: 205-217. doi:10.1016/S1146-609X(03)00035-3

Neil, W.E. – 1990. Induced vertical migration in copepods as a defense against invertebrate predation. Nature, 345: 524-526. doi:10.1038/345524a0

Neilson, J.D. and R.I. Perry. – 1990. Diel vertical migrations of juvenile fish: an obligate or facultative process?. Adv. Mar. Biol., 26: 115-168. doi:10.1016/S0065-2881(08)60200-X

Neumann, D. – 1981. Tidal and lunar rhythms. In: J. Aschoff (ed.), Biological Rhythms (Handbook of Behavioral Neurobiology), vol. 4, pp. 351–380. Plenum Press, New York.

Norcross, B.L. and R.F. Shaw. – 1984. Oceanic and estuarine transport of fish eggs and larvae. A review. T. Am. Fish. Soc., 113: 153-165. doi:10.1577/1548-8659(1984)113<153:OAETOF>2.0.CO;2

Okemwa, E. – 1989. Analysis of six 24-hour series of zooplankton samplings across a tropical creek, the Port Reitz, Mombasa, Kenya. Trop. Zool., 2: 123-138.

Orsi, J.J. – 1986. Interactions between diel vertical migration of a mysidacean shrimp and two-layered estuarine flow. Hydrobiologia, 137: 79-87. doi:10.1007/BF00004175

Paffenhoper, G.A. – 1983. Vertical zooplankton distribution on the northeastern Florida shelf and its relation to temperaure and food abundance. J. Plankton Res., 5 (Suppl. 1): 15-33. doi:10.1093/plankt/5.1.15

Patriti, G., G. Champalbert and R. Arfi. – 1984. Eulerian sampling of zooplankton from Marseilles’ Vieux Port over a 24 h period. Mar. Biol., 82: 135-142. doi:10.1007/BF00394097

Paula, J. – 1993. Ecologia da Fase Larvar e Recrutamento de Crustáceos Decápodes no Estuário do Rio Mira. Ph. D. thesis, Faculdade de Ciências da Universidade de Lisboa, Lisboa.

Pereira, F., R. Pereira and H. Queiroga. -2000. Flux of decapod and juvenils at a station in the lower Canal de Mira (Ria de Aveiro, Portugal) during a lunar month. Invertebr. Reprod. Dev., 38 (Suppl. 3): 183-206.

Queiroga, H. – 1995. Processos de Dispersão e Recrutamento das larvas do Caranguejo Carcinus maenas (L.) na Ria de Aveiro. Ph. D. thesis, Departamento de Biologia da Universidade de Aveiro, Aveiro.

Queiroga, H., J.D. Cstlow Jr. and M.H. Moreira. – 1997. Vertical migration of the crab Carcinus maenas first zoea in an estuary: implications for tidal stream transport, Mar. Ecol. Prog. Ser., 149: 121-132. doi:10.3354/meps149121

Ré, P. – 1984a. Ictioplâncton da região central da costa Portuguesa e do estuário do Tejo. Ecologia da postura e da fase planctónica de Sardina pilchardus (Walbaum, 1792) e de Engraulis encrasicolus (Linné, 1758). Ph. D. thesis, Universidade de Lisboa, Lisboa.

Ré, P. – 1984b. Evidence of daily and hourly growth in pilchard larvae based on otolith growth increments, Sardina pilchardus (Walbaum, 1792). Cybium, 8 (Suppl.1): 33-38.

Ré, P. – 1987. Ecology of the planktonic phase of the anchovy, Engraulis encrasicolus (L.), within Mira estuary (Portugal). Inv. Pesq., 51 (Suppl. 4): 581-598.

Ré, P. – 1990. Tidal transport and retention of anchovy eggs and larvae within Mira estuary (Portugal). Portugaliae Zoologica, 1 (Suppl. 2): 7-13.

Rice, A.L. and R.W. Ingle. – 1975a. The larval development of Carcinus maenas (L.) and C. mediterraneus Czerniavsky (Crustacea, Brachyura, Portunidae) reared in the laboratory. Bull. Br. Mus. Nat. Hist. (Zool.), 28 (Suppl. 3): 101-119.

Rice, A.L. and R.W. Ingle. – 1975b. A comparative study of the larval morphology of the British portunid crabs Macropipus puber (L.) and M. holsatus (Fabricius), with a discussion of generic and sub-familial larval characters within the Portunidae. Bull. Br. Mus. Nat. Hist. (Zool.), 28 (Suppl. 4): 121-151.

Rose, M. – 1933. Faune de France. Copépodes pélagiques. Ed. Fédération Française des Societés de Sciences Naturelles, Paris.

Russell, F.S. – 1953. The Medusae of the British Isles. Cambridge University Press, London.

Saigusa, M. – 1985. Tidal timing of larval release activity in nontidal environment. Jpn. J. Ecol., 35: 243–251.

Saigusa, M. and T. Akiyama. – 1995. The tidal rhythm of emergence, and the seasonal variation of this synchrony, in an intertidal midge. Biol. Bull., 188: 166-178. doi:10.2307/1542082

Saint-Jean, L. and M. Pagano. – 1990. Variation nycthémerale de la répartition verticale et de l’efficacité de collecte du zooplancton en lagune Ebrié (Côte d’Ivoire). Hydrobiologia, 194: 247-265.

Schwassmann, H.O. – 1971. Biological rhythms. In: Fish Physiology, vol. 6, Academic Press (ed.), pp. 371-427.

Sekino, T. and N. Yamamura. – 1999. Diel vertical migration of zooplankton: optimum migrating schedule based on energy accumulation. Evol. Ecol., 13: 267-282. doi:10.1023/A:1006797101565

Sekino, T. and T. Yoshioka. – 1995. The relationship between nutritional condition and diel vertical migration of Daphnia galeata. Jpn. J. Limnol., 56: 145–150.

Simard, Y., G. Lacroix and L. Legendre. – 1986. Diel migrations and nocturnal feeding of a dense coastal krill scattering layer (Thysanoessa raschi and Meganyctiphanes norvegica) in stratified surface waters. Mar. Biol., 91: 93-105. doi:10.1007/BF00397575

Stuart, V. and H.M. Verheye. – 1991. Diel migration and feeding patterns of the chaetognath Sagitta friderici, off the west coast of South Africa. J. Mar. Res., 49: 493-515. doi:10.1357/002224091784995819

Stubblefield, C.L., C.M. Lascara and M. Vecchione. – 1984. Vertical distribution of zooplankton in a shallow turbid estuary. Contrib. Mar. Sci., 27: 93-104.

Totton, A.K. and H.E. Bargmann. – 1965. A Synopsis of the Syphonophora. Trustees of the British Museum of Natural History, London.

Trégouboff, G. and M. Rose. – 1957. Manuel de Planctonologie Méditerranéenne. Centre National de la Recherche Scientifique, 1st ed., Paris.

Williams, A.B. and N.R. Collins. – 1984. Distribution and variability in abundance of Schistomysis spiritus (Crustacea: Mysidacea) in the Bristol Channel in relation to environmental variables, with comments on other mysids. Mar. Biol., 80: 197-206. doi:10.1007/BF02180187

Wooldridge, T. and T. Erasmus. – 1980. Utilization of tidal currents by estuarine zooplankton. Estuar. Coast. Shelf Sci., 2: 107-114.

Yamaguchi, A., T. Ikeda, Y. Watanabe and J. Ishizaka. -2004. Vertical Distribution Patterns of Pelagic Copepods as Viewed from the Predation Pressure Hypothesis. Zool. Stud., 43 (Suppl. 2): 475-485.

Zaret, T.M. and J.S. Suffern. – 1976. Vertical migration in zooplankton as a predator avoidance mechanism. Limnol. Oceanogr., 21 (Suppl. 6): 804-813.

Zar, J.H. – 1984. Biostatistical Analysis. Prentice-Hall, Inc., New Jersey.




How to Cite

Morgado FM, Pastorinho R, Quintaneiro C, Ré P. Vertical distribution and trophic structure of the macrozooplankton in a shallow temperate estuary (Ria de Aveiro, Portugal). scimar [Internet]. 2006Jun.30 [cited 2022Nov.29];70(2):177-88. Available from: