Seagrasses are marine angiosperms fulfilling important ecological functions in coastal ecosystems worldwide. Out of the 66 known seagrass species only two inhabit the Baltic Sea and only one, Zostera marina L., is found in its NE part. In the coastal waters of Estonia, where eelgrass grows at its salinity tolerance limit, only scarce information exists on the Z. marina community and there are no data on eelgrass growth. In the current study the community characteristics and growth of eelgrass were studied at four sites: Ahelaid, Saarnaki, and Sõru in the West-Estonian Archipelago Sea and Prangli in the Gulf of Finland. Fieldwork was carried out from May to September in 2005. The results showed that eelgrass grew between 1.8 and 6 m with main distribution at 2–4 m. The eelgrass bed had a considerably higher content of sediment organic matter compared to the adjacent unvegetated areas, but this difference was statistically significant only in areas where the movement of soft sediments is higher. The results also showed that altogether 19 macrophytobenthic and 23 invertebrate taxa inhabited the eelgrass stand. The prevailing vascular plants were Stuckenia pectinata and Potamogeton perfoliatus. Besides attached macrophytes, drifting algae were recorded within the eelgrass communities throughout the study period. Most common invertebrate species inhabiting eelgrass stands were Peringia ulvae, Cerastoderma glaucum, Mytilus trossulus, Macoma balthica, Mya arenaria, Theodoxus fluviatilis, and Idotea chelipes. Irrespective of the studied basin, the increasing eelgrass density supported an elevated diversity and abundance of benthic invertebrates. The eelgrass shoot biomass showed a constant increase from May to September. The overall growth pattern was similar for all studied areas but varied among depth strata. The average shoot density of eelgrass was 50–1300 shoot per m2, average biomass ranged from (0.75) 7.8 to 37.31 g dw m–2 in spring and from 18.42 to 68.59 g dw m–2 in autumn.
Bäck, S., Lehvo, A., and Blomster, J. 2000. Mass occurrence of unattached Enteromorpha intestinalis on the Finnish Baltic Sea coast. Annales Botanici Fennici, 37, 155–161.
Bintz, J. C., Nixon, S. W., Buckley, B. A., and Granger, S. L. 2003. Impacts of temperature and nutrients on coastal lagoon plant communities. Estuaries, 26, 765–776.
http://dx.doi.org/10.1007/BF02711987
Boström, C. and Bonsdorff, E. 1997. Community structure and spatial variation of benthic invertebrates associated with Zostera marina (L.) beds in the northern Baltic Sea. Journal of Sea Researsch, 37, 153–166.
http://dx.doi.org/10.1016/S1385-1101(96)00007-X
Boström, C. and Bonsdorff, E. 2000. Zoobenthic community establishment and habitat complexity – the importance of seagrass shoot density, morphology and physical disturbance for faunal recruitment. Marine Ecology Progress Series, 205, 123–138.
http://dx.doi.org/10.3354/meps205123
Boström, C., Baden, S. P., and Krause-Jensen, D. 2003. The seagrasses of Scandinavia and the Baltic Sea. In The World Atlas of Seagrasses (Green, P. and Short, F. T., eds), pp. 27–37. University of California Press, Berkeley, USA.
Boström, C., Roos, C., and Roennberg, O. 2004. Shoot morphometry and production dynamics of eelgrass in the northern Baltic Sea. Aquatic Botany, 79, 145–161.
http://dx.doi.org/10.1016/j.aquabot.2004.02.002
Boström, C., O’Brien, K., Roos, C., and Ekebom, J. 2006. Environmental variables explaining structural and functional diversity of seagrass macrofauna in an archipelago landscape. Journal of Experimental Marine Biology and Ecology, 335, 52–73.
http://dx.doi.org/10.1016/j.jembe.2006.02.015
Boström, C., Baden, S., Bockelmann, A.-C., Dromph, K., Fredriksen, S., Gustafsson, C., et al. 2014. Distribution, structure and function of Nordic eelgrass (Zostera marina) ecosystems: implications for coastal management and conservation. Aquatic Conservation: Marine and Freshwater Ecosystems,
http://dx.doi.org/10.1002/aqc.2424
Burdick, D. M., Kaldy, J. E., and Short, F. T. 1994. Nuisance algal blooms in estuarine waters are a major disturbance to eelgrass communities. In Proceedings of the International Association for Great Lakes Research, p. 166. Buffalo, NY, USA.
Clarke, K. R. 1993. Non-parametric multivariate analysis of changes in community structure. Australian Journal of Ecology, 18, 117–143.
http://dx.doi.org/10.1111/j.1442-9993.1993.tb00438.x
Clarke, K. R. and Ainsworth, M. 1993. A method of linking multivariate community structure to environmental variables. Marine Ecology Progress Series, 92, 205–219.
http://dx.doi.org/10.3354/meps092205
Clarke, K. R. and Green, R. H. 1988. Statistical design and analyses for a “biological effects” study. Marine Ecology Progress Series, 46, 213–226.
http://dx.doi.org/10.3354/meps046213
Clarke, K. R. and Warwick, R. M. 2001. Change in Marine Communities: An Approach to Statistical Analysis and Interpretation. Plymouth Marine Laboratory, Plymouth, 2nd edn.
Clausen, K. K., Krause-Jensen, D., Olesen, B., and Marba, N. 2014. Seasonality of eelgrass biomass across gradients in temperature and latitude. Marine Ecology Progress Series, in press.
http://dx.doi.org/10.3354/meps10800
Costanza, R., d’Arge, R., Groots, R., Farber, S., Grasso, M., Hannon, B., et al. 1997. The value of the world’s ecosystem services and natural capital. Nature, 387, 253–260.
http://dx.doi.org/10.1038/387253a0
den Hartog, C. 1970. The Seagrasses of the World. North Holland Publ. Co, Amsterdam.
Dennison, W. C. and Alberte, R. S. 1986. Photoadaptation and growth of Zostera marina L. (eelgrass) transplants along a depth gradient. Journal of Experimental Marine Biology and Ecology, 98, 265–282.
http://dx.doi.org/10.1016/0022-0981(86)90217-0
Drury, D. M. 2004. Effects of grass shrimp (Palaemonetes spp.) density manipulations and nutrient enrichment on widgeongrass (Ruppia maritima) condition, epiphyte load, and epiphyte functional groups. Dissertations. Paper 1971. http://aquila.usm.edu/theses_dissertations/1971 (accessed 03.04.2014).
Duarte, C. M. 1989. Temporal biomass variability and production/biomass relationships of seagrass communities. Marine Ecology Progress Series, 51, 269–276.
http://dx.doi.org/10.3354/meps051269
Duarte, C. M., Fourqurean, J. W., Krause-Jensen, D., and Olesen, B. 2006. Dynamics of seagrass stability and change. In Seagrasses: Biology, Ecology and Conservation (Larkum, A. W. D., Orth, R. J., and Duarte, C., eds), Chapter 11, pp. 271–294. Springer, Dordrecht.
http://dx.doi.org/10.1007/1-4020-2983-7_11
Gacia, E., Duarte, C. M., Marba, N., Terrados, J., Kennedy, H., Fortes, M. D., and Huang, N. 2003. Sediment deposition and production in SE Asia seagrass meadows. Estuarine, Coastal and Shelf Science, 56, 909–919.
http://dx.doi.org/10.1016/S0272-7714(02)00286-X
Gil, M., Armitage, A. R., and Fourqurean, J. W. 2006. Nutrient impacts on epifaunal density and species composition in a subtropical seagrass bed. Hydrobiologia, 569, 437–447.
http://dx.doi.org/10.1007/s10750-006-0147-7
Gustafsson, C. and Boström, C. 2009. Effects of plant species richness and composition on epifaunal colonization in brackish water angiosperm communities. Journal of Experimental Marine Biology and Ecology, 382, 8–17.
http://dx.doi.org/10.1016/j.jembe.2009.10.013
Heck, K. L. Jr., Hays, G., and Orth, R. J. 2003. Critical evaluation of the nursery role hypothesis for seagrass meadows. Marine Ecology Progress Series, 253, 123–136.
http://dx.doi.org/10.3354/meps253123
Hemminga, M. A. and Duarte, C. M. 2000. Seagrass Ecology. Cambridge University Press.
http://dx.doi.org/10.1017/CBO9780511525551
Herkül, K. and Kotta, J. 2009. Effects of eelgrass (Zostera marina) canopy removal and sediment addition on sediment characteristics and benthic communities in the Northern Baltic Sea. Marine Ecology, 30, 74–82.
http://dx.doi.org/10.1111/j.1439-0485.2009.00307.x
Herkül, K., Kotta, J., Kotta, I., and Orav-Kotta, H. 2006. Effects of physical disturbance, isolation and key macrozoobenthic species on community development, recolonisation and sedimentation processes. Oceanologia, 48S, 267–282.
Homziak, J., Fonseca, M. S., and Kenworthy, W. J. 1982. Macrobenthic community structure in
a transplanted eelgrass (Zostera marina ) meadow. Marine Ecology Progress Series, 9, 211–221.
http://dx.doi.org/10.3354/meps009211
Isæus, M. 2004. Factors structuring Fucus communities at open and complex coastlines in the Baltic Sea. PhD Thesis. Department of Botany, Stockholm University, Sweden.
Kiirikki, M. and Blomster, J. 1996. Wind induced upwelling as a possible explanation for mass occurrences of epiphytic Ectocarpus siliculosus (Phaeophyta) in the northern Baltic Proper. Marine Biology, 127, 353–358.
http://dx.doi.org/10.1007/BF00942120
Kotta, J., Paalme, T., Martin, G., and Mäkinen, A. 2000. Major changes in macroalgae community composition affect the food and habitat preference of Idotea baltica. International Review of Hydrobiology, 85, 697–705.
http://dx.doi.org/10.1002/1522-2632(200011)85:5/6<697::AID-IROH697>3.0.CO;2-0
Kotta, J., Lauringson, V., Martin, G., Simm, M., Kotta, I., Herkül, K., and Ojaveer, H. 2008a. Gulf of Riga and Pärnu Bay. In Ecology of Baltic Coastal Waters (Schiewer, U., ed.), pp. 217–243. Ecological Studies, 197. Springer.
Kotta, J., Paalme, T., Püss, T., Herkül, K., and Kotta, I. 2008b. Contribution of scale-dependent environmental variability on the biomass patterns of drift algae and associated invertebrates in the Gulf of Riga, northern Baltic Sea. Journal of Marine Systems, 74, S116–S123.
http://dx.doi.org/10.1016/j.jmarsys.2008.03.030
Krause-Jensen, D., Middelboe, A. L., Sand-Jensen, K., and Christensen, P. B. 2000. Eelgrass, Zostera marina, growth along depth gradients: upper boundaries of the variation as a powerful predictive tool. Oikos, 91, 233–244.
http://dx.doi.org/10.1034/j.1600-0706.2001.910204.x
Krause-Jensen, D., Pedersen, M. F., and Jensen, C. 2003. Regulation of eelgrass (Zostera marina) cover along depth gradients in Danish coastal waters. Estuaries, 26, 866–877.
http://dx.doi.org/10.1007/BF02803345
Larkum, A. W. D., Orth, R. J., and Duarte, C. (eds). 2006. Seagrasses: Biology, Ecology and Conservation. Springer, Dordrecht, Netherlands.
Lauringson, V., Kotta, J., Kersen, P., Leisk, Ü., Orav-Kotta, H., and Kotta, I. 2012. Use case of biomass-based benthic invertebrate index for brackish waters in connection to climate and eutrophication. Ecological Indicators, 12, 123–132.
http://dx.doi.org/10.1016/j.ecolind.2011.04.009
Lotze, H. K., Schramm, W., Schories, D., and Worm, B. 1999. Control of macroalgal blooms at early developmental stages: Pilayella littoralis versus Enteromorpha spp. Oecologia, 119, 46–54.
http://dx.doi.org/10.1007/s004420050759
Marba, N., Cebrian, J., Enriquez, S., and Duarte, C. M. 1996. Growth patterns of Western Mediterranean seagrasses: species-specific responses to seasonal forcing. Marine Ecology Progress Series, 133, 203–215.
http://dx.doi.org/10.3354/meps133203
Martin, G., Kotta, J., Möller, T., and Herkül, K. 2013. Spatial distribution of marine benthic habitats in the Estonian coastal sea, northeastern Baltic Sea. Estonian Journal of Ecology, 62, 165−191.
http://dx.doi.org/10.3176/eco.2013.3.01
McGlathery, K. J. 2001. Macroalgal blooms contribute to the decline of seagrass in nutrient-enriched coastal waters. Journal of Phycology, 37, 453–456.
http://dx.doi.org/10.1046/j.1529-8817.2001.037004453.x
Middelboe, A. L., Sand-Jensen, K., and Krause-Jensen, D. 2003. Spatial and interannual variations with depth in eelgrass populations. Journal of Experimental Marine Biology and Ecology, 291, 1–15.
http://dx.doi.org/10.1016/S0022-0981(03)00098-4
Möller, T. and Martin, G. 2007. Distribution of the eelgrass Zostera marina L. in the coastal waters of Estonia, NE Baltic Sea. Proceedings of the Estonian Academy of Sciences. Biology, Ecology, 56, 270–277.
Moore, K. A. and Short, F. T. 2006. Zostera: biology, ecology, and management. In Seagrasses: Biology, Ecology and Conservation (Larkum, A. W. D., Orth, R. J., and Duarte, C., eds), pp. 361–386. Springer, Dordrecht, Netherlands.
http://dx.doi.org/10.1007/978-1-4020-2983-7_16
Nelson, T. A. and Lee, A. 2001. A manipulative experiment demostrates that blooms of the macroalga Ulvaria obscura can reduce eelgrass shoot density. Aquatic Botany, 71, 149–154.
http://dx.doi.org/10.1016/S0304-3770(01)00183-8
Olesen, B. and Sand-Jensen, K. 1994. Demography of shallow eelgrass (Zostera marina) populations – shoot dynamics and biomass development. Journal of Ecology, 82, 379–390.
http://dx.doi.org/10.2307/2261305
Orth, R. J. 1977. Effect of nutrient enrichment on growth of the seagrass Zostera marina in the Chesapeake Bay, Virginia, USA. Marine Biology, 44, 187–194.
http://dx.doi.org/10.1007/BF00386958
Orth, R. J. 1992. A perspective on plant–animal interactions in seagrasses: physical and biological determinants influencing plant and animal abundance. In Plant–Animal Interactions in the Marine Benthos (John, D. M., Hawkins, S. J., and Price, J. H., eds), pp. 147–164. Systematics Association Special Volume 46. Clarendon Press, Oxford.
Paalme, T., Martin, G., Kotta, J., Kukk, H., and Kaljurand, K. 2004. Distribution and dynamics of drifting macroalgal mats in Estonian coastal waters during 1995–2003. Proceedings of the Estonian Academy of Sciences. Biology, Ecology, 53, 260–268.
Peralta, G., Perez-Llorens, J. L., Hernandez, I., and Vergara, J. J. 2002. Effects of light availability on growth, architecture and nutrient content of the seagrass Zostera noltii Hornem. Journal of Experimental Marine Biology and Ecology, 269, 9–26.
http://dx.doi.org/10.1016/S0022-0981(01)00393-8
Perez-Llorens, J. L. and Niell, F. X. 1993. Temperature and emergence effects on the net photosynthesis of 2 Zostera noltii Hornem. morphotypes. Hydrobiologia, 254, 53–64.
http://dx.doi.org/10.1007/BF00007765
Philippart, C. J. M. 1995. Effect of periphyton grazing by Hydrobia ulvae on the growth of Zostera noltii on a tidal flat in the Dutch Wadden Sea. Marine Biology, 122, 431–437.
http://dx.doi.org/10.1007/BF00350876
Pihl, I., Isaksson, I., Wennhage, H., and Moksnes, P.-O. 1995. Recent increase of filamentous algae in shallow Swedish bays, effects on the community structure of epibenthic fauna and fish. Netherlands Journal of Aquatic Ecology, 29, 349–358.
http://dx.doi.org/10.1007/BF02084234
Pitkänen, H., Kiirikki, M., Savchuk, O., Räike, A., Korpinen, P., and Wulff, F. 2007. Searching efficient protection strategies for the eutrophicated Gulf of Finland: the combined use of 1D and 3D modeling in assessing long-term state scenarios with high spatial resolution. Ambio, 36, 272−279.
http://dx.doi.org/10.1579/0044-7447(2007)36[272:SEPSFT]2.0.CO;2
Pitkänen, H., Lehtoranta, J., and Peltonen, H. 2008. The Gulf of Finland. In Ecology of Baltic Coastal Waters (Schiewer, U., ed.), pp. 285–308. Springer, Berlin.
http://dx.doi.org/10.1007/978-3-540-73524-3_13
Puttman, R. J. 1986. Grazing in Temperate Ecosystems: Large Herbivores and the Ecology of the New Forest. Croom Helm, London.
http://dx.doi.org/10.1007/978-94-011-6081-0
Rasmussen, J. R., Pedersen, M. F., Olesen, B., Nielsen, S. L., and Pedersen, T. M. 2013. Temporal and spatial dynamics of ephemeral drift-algae in eelgrass, Zostera marina, beds. Estuarine, Coastal and Shelf Science, 119, 167–175.
http://dx.doi.org/10.1016/j.ecss.2013.01.006
Rumohr, H., Brey, T., and Ankar, S. 1987. A compilation of biometric conversion factors for benthic invertebrates of the Baltic Sea. BMB Publication, No. 9.
Sand-Jensen, K. 1975. Biomass, net production and growth dynamics in an eelgrass (Zostera marina L.) population in Vellerup Vig, Denmark. Ophelia, 14, 185–201.
http://dx.doi.org/10.1080/00785236.1975.10422501
Sand-Jensen, K. and Borum, J. 1983. Regulation of growth of eelgrass (Zostera marina L.) in Danish coastal waters. Marine Technology Society Journal, 17, 15–21.
StatSoft, Inc. 2006. STATISTICA (data analysis software system), version 7.1. www.statsoft.com (accessed 30.03.2014).
Suursaar, Ü., Astok, V., and Otsmann, M. 1998. The front of Väinameri. EMI Report Series, 9, 23–33.
Terrados, J. and Duarte, C. M. 2000. Experimental evidence of reduced particle resuspension within a seagrass (Posidonia oceanica L.) meadow. Journal of Experimental Marine Biology and Ecology, 243, 45–53.
http://dx.doi.org/10.1016/S0022-0981(99)00110-0
Touchette, B. W. and Burkholder, J. M. 2000. Overview of the physiological ecology of carbon metabolism in seagrasses. Journal of Experimental Marine Biology and Ecology, 250,
169–205.
http://dx.doi.org/10.1016/S0022-0981(00)00196-9
Trei, T. 1973. Lääne-Eesti rannikuvete fütobentos [The phytobenthos of West-Estonian coastal water]. Dissertation. Eesti Mereihtüoloogia laboratoorium, Tallinn (in Estonian).
Trei, T. 1991. Taimed Läänemere põhjal [Plants in the Baltic Sea]. Tallinn, Valgus (in Estonian).
Turner, S. J., Hewitt, J. E., Wilkinson, M. R., Morrisey, D. J., Thrush, S. F., Cummings, V. J., and Funnell, G. 1999. Seagrass patches and landscapes: the influence of wind–wave dynamics and hierarchical arrangements of spatial structure on macrofaunal seagrass communities. Estuaries, 22, 1016–1032.
http://dx.doi.org/10.2307/1353080
Vahteri, P., Maekinen, A., Salovius, S., and Vuorinen, I. 2000. Are drifting algal mats conquering the bottom of the Archipelago Sea, SW Finland? Ambio, 29, 338–343.
http://dx.doi.org/10.1639/0044-7447(2000)029[0338:ADAMCT]2.0.CO;2
Viaroli, P., Bartoli, M., Fumagalli, I., and Giordani, G. 1997. Relationship between benthic fluxes and macrophyte cover in a shallow brackish lagoon. Water, Air, & Soil Pollution, 99, 533–540.
http://dx.doi.org/10.1007/BF02406893
Wallentinus, I. 1984. Partioning of nutrient uptake between annual and perennial seaweeds in a Baltic archipelago area. Hydrobiologia, 116/117, 363–370.
http://dx.doi.org/10.1007/BF00027703
Witman, J. D., Etter, R. J., and Smith, F. 2004. The relationship between regional and local species diversity in marine benthic communities: a global perspective. Proceedings of the National Academy of Sciences, 101, 15664–15669.
http://dx.doi.org/10.1073/pnas.0404300101
Wium-Andersen, S. and Borum, J. 1984. Biomass variations and autotrophic production of an epiphyte–macrophyte community in a coastal Danish area: I. Eelgrass (Zostera marina L.) biomass and net production. Ophelia, 23, 33–46.
http://dx.doi.org/10.1080/00785236.1984.10426603
Worm, B. and Sommer, U., 2000. Rapid direct and indirect effects of a single nutrient pulse in a seaweed–epiphyte–grazer system. Marine Ecology Progress Series, 202, 283–288.
http://dx.doi.org/10.3354/meps202283
Wortmann, J., Hearne, J. W., and Adams, J. B. 1997. A mathematical model of an estuarine seagrass. Ecological Modelling, 98, 137–149.
http://dx.doi.org/10.1016/S0304-3800(96)01910-2
Zajac, R. N., Lewis, R. S., Poppe, L. J., Twichell, D. C., Vozarik, J., and DiGiacomo-Cohen, M. L. 2003. Responses of infaunal populations to benthoscape structure and the potential importance of transition zones. Limnology and Oceanography, 48, 829–842.
http://dx.doi.org/10.4319/lo.2003.48.2.0829
