In this paper we describe the invasion history of benthic crustacean species that have recently invaded the Estonian coastal sea. Physical characteristics of their habitat and communities associated with the invasive species were explored. The crustaceans Gammarus tigrinus, Chelicorophium curvispinum, Pontogammarus robustoides, and Paramysis intermedia are the most recent newcomers in the Estonian coastal sea. All these species have formed permanent populations and more aggressive species have likely caused significant shifts in the community structure and functioning. Besides the true invasive species, some native amphipod species have significantly expanded their range in the Baltic Sea. This group consists of rare or previously not spotted benthic invertebrate species in the northern Baltic Sea range such as Echinogammarus stoerensis, Calliopius laeviusculus, and Melita palmata.
Barnes, R. S. K. 1994. The Brackish-water Fauna of Northwestern Europe: A Guide to Brackish-water Habitats, Ecology, and Macrofauna for Field Workers, Naturalists, and Students. Cambridge University Press, Cambridge.
Bellan-Santini, D. & Costello, M. J. 2001. Amphipoda. In European Register of Marine Species:
A Check-list of the Marine Species in Europe and a Bibliography of Guides to Their Identification (Costello, M. J. et al., eds). Collection Patrimoines Naturels, 50, 295–308.
Berezina, N. A. 2007. Expansion of the North American amphipod Gammarus tigrinus Sexton, 1939 to the Neva Estuary (easternmost Baltic Sea). Oceanologia, 49, 129–135.
Bij de Vaate, A., Jazdzewski, K., Ketelaars, H. A. M., Gollasch, S. & Van der Velde, G. 2002. Geographical patterns in range extension of Ponto-Caspian macroinvertebrate species in Europe. Can. J. Fish. Aquat. Sci., 59, 1159–1174.
doi:10.1139/f02-098
Birshteina, Ya. A., Vinogradova, L. G., Kondakova, N. N., Kun, M. S., Astahoboj, T. V. & Romanovoj, N. N. 1968. Atlas of Invertebrates of the Caspian Sea. Moscow (in Russian).
Carlton, J. T. 1996. Pattern, process, and prediction in marine invasion ecology. Biol. Conserv., 78, 97–106.
doi:10.1016/0006-3207(96)00020-1
Chambers, M. R. 1977. The population ecology of Gammarus tigrinus (Sexton) in the reed beds of the Tjeukemeer. Hydrobiologia, 53, 155–164.
doi:10.1007/BF00029294
Grabowski, M., Konopacka, A., Jazdzewski, K. & Janowska, E. 2006. Invasions of alien gammarid species and retreat of natives in the Vistula Lagoon (Baltic Sea, Poland). Helgoland Mar. Res., 60, 90–97.
doi:10.1007/s10152-006-0025-8
Grabowski, M., Jaždžewski, K. & Konopacka, A. 2007. Alien Crustacea in Polish waters – Amphipoda. Aquat. Invasions, 2, 25–38.
doi:10.3391/ai.2007.2.1.3
Gumuliauskaitė, S. & Arbačiauskas, K. 2008. The impact of the invasive Ponto-Caspian amphipod Pontogammarus robustoides on littoral communities in Lithuanian lakes. Hydrobiologia, 599, 127–134.
doi:10.1007/s10750-007-9209-8
Hansson, H. G. 1998. NEAT (North East Atlantic Taxa): South Scandinavian marine Crustacea check-list. http://www.tmbl.gu.se/libdb/taxon/neat_pdf/NEAT*Crustacea.pdf (accessed 2008-05-01).
HELCOM. 2006. Manual for Marine Monitoring in the COMBINE Programme of HELCOM. http://sea.helcom.fi/Monas/CombineManual2/CombineHome.htm (accessed 2008-05-01).
Herkül, K. & Kotta, J. 2007. New records of the amphipods Chelicorophium curvispinum, Gammarus tigrinus, G. duebeni, and G. lacustris in the Estonian coastal sea. Proc. Estonian Acad. Sci. Biol. Ecol., 56, 290–296.
Herkül, K., Kotta, J., Kotta, I. & Orav-Kotta, H. 2006. Effects of physical disturbance, isolation and key macrozoobenthic species on community development, recolonisation and sedimentation processes. Oceanologia, 48, 267–282.
Jazdzewski, K. 1976. Notes on the occurrence and ecology of Chaetogammarus stoerensis (Reid, 1938) (Amphipoda) in the Baltic Sea. Crustaceana, 30, 33–38.
doi:10.1163/156854076X00369
Jazdzewski, K., Konopacka, A. & Grabowski, M. 2002. Four Ponto-Caspian and one American gammarid species (Crustacea, Amphipoda) recently invading Polish waters. Contrib. Zool., 71, 115–122.
Jazdzewski, K., Konopacka, A. & Grabowski, M. 2005. Native and alien malacostracan Crustacea along the Polish Baltic Sea coast in the twentieth century. Ocean. Hydrobiol. Stud., 34, Suppl. 1, 175–193.
Kangur, K., Timm, H. & Timm, T. 2004. Zoobenthos. In Lake Võrtsjärv (Haberman, J., Pihu, E. & Raukas, A., eds), pp. 265–279, Estonian Encyclopaedia Publishers, Tallinn.
Kotta, J., Herkül, K., Kotta, I. & Orav-Kotta, H. 2006. Invasion history and distribution of the key benthic alien invertebrate species in the Estonian coastal sea. EMI Rep. Ser., 14, 13–19.
Kurashov, E. A. & Barbashova, M. A. 2008. First record of the invasive Ponto-Caspian amphipod Pontogammarus robustoides G.O. Sars, 1894 from Lake Ladoga, Russia. Aquat. Invasions, 3, 253–256.
doi:10.3391/ai.2008.3.2.18
Leineweber, P. 1985. The life-cycles of four amphipod species in the Kattegat. Holarct. Ecol., 8, 165–174.
Malyavin, S. A., Berezina, N. A. & Khvang, D. S. 2008. Finding of Chelicorophium curvispinum (Amphipoda, Crustacea) in the Gulf of Finland, Baltic Sea. Zool. Zh., 87, 643–649 (in Russian).
Orav-Kotta, H., Kotta, J., Herkül, K., Kotta, I. & Paalme, T. 2009. Seasonal variability in the grazing potential of the invasive amphipod Gammarus tigrinus and the native amphipod Gammarus salinus in the northern Baltic Sea. Biol. Invasions, 11, 597–608.
doi:10.1007/s10530-008-9274-6
Panov, V. E., Bychenkov, D. E., Berezina, N. A. & Maximov, A. A. 2003. Alien species introductions in the eastern Gulf of Finland: current state and possible management options. Proc. Estonian Acad. Sci. Biol. Ecol., 52, 254–267.
Pienimäki, M., Helavuori, M. & Leppäkoski, E. 2004. First findings of the North American amphipod Gammarus tigrinus Sexton, 1939 along the Finnish coast. Mem. Soc. Fauna Flora Fenn., 80, 17–19.
Pinkster, S., Scheepmaker, M., Platvoet, D. & Broodbakker, N. 1992. Drastic changes in the amphipod fauna (Crustacea) of Dutch inland water during the last 25 years. Bijdr. Dierk., 61, 193–204.
Sala, O. E., Chapin, F. S., III, Armesto, J. J., Berlow, E., Bloomfield, J., Dirzo, R., Huber-Sanwald, E., Huenneke, L. F., Jackson, R. B., Kinzig, A., Leemans, R., Lodge, D. M., Mooney, H. A., Oesterheld, M., Poff, N. L., Sykes, M. T., Walker, B. H., Walker, M. & Wall, D. H. 2000. Global biodiversity scenarios for the year 2100. Science, 287, 1770–1774.
doi:10.1126/science.287.5459.1770
Szaniawska, A., Łapucki, T. & Normant, M. 2003. The invasive amphipod Gammarus tigrinus Sexton, 1939, in Puck Bay. Oceanologia, 45, 507–510.
Timm, T., Kangur, K., Timm, H. & Timm, V. 2001. Zoobenthos. In Lake Peipsi. Flora and Fauna (Pihu, E. & Haberman, J., eds), pp. 82–99. Sulemees Publishers, Tallinn.
Vitousek, P. M., Mooney, H. A., Lubchenco, J. & Melillo, J. M. 1997. Human domination of Earth’s ecosystems. Science, 277, 494–499.
doi:10.1126/science.277.5325.494
Yarvekyulg, A. 1979. The Benthic Fauna in the Eastern Part of the Baltic Sea. Valgus, Tallinn (in Russian).
