Seasonal Response and Recovery of Eelgrass (Zostera marina) to Short-Term Reductions in Light Availability

  • Melisa C. WongEmail author
  • Gwendolyn Griffiths
  • Benedikte Vercaemer


Anthropogenic activities in the marine nearshore, such as dredging and construction, can significantly reduce light availability for seagrasses through increased turbidity. Seagrass resilience to such shading depends on the seasonal timing of the event, as water temperature and photoperiod strongly influence plant response to disturbance. We examined the response and recovery of Zostera marina to 9 weeks of low and moderate light reduction (35 and 64% reduction) implemented in situ during the spring/mid-summer growth and late summer/fall senescence periods. Fall shading had the most severe impacts, with shoot densities of both low and moderate shade plants decreasing faster to lower densities relative to controls (unshaded plants), than observed during spring shading. Moderate shade plants in the fall also had high leaf loss, reduced growth and chlorophyll content, and utilized stored rhizome water-soluble carbohydrates, whereas in the spring, they had lower leaf loss, increased growth and chlorophyll content, and did not utilize stored carbohydrates. Although most physiological aspects of both spring and fall shaded plants recovered rapidly with restoration of ambient light, shoot density did not, remaining lower than unshaded plants into the next growing season. The stronger impact of fall shading resulted from the decreased photoperiod and daily light saturation, which caused plants to drastically alter their morphology and density to maintain carbon balance. Our study shows that Z. marina resilience to light reduction depends on its seasonal timing, suggesting that nearshore activities affecting light availability should be conducted during periods of maximum plant resilience.


Carbohydrate reserves HSat Morphology Overwintering PAR Sheath length 



We thank A. Campbell, J. Hogenbom, D. Krug, B. Roethlisberger, M. Scarrow, and C. Siong for assistance in the field and laboratory. Anonymous reviewers provided helpful comments that improved the manuscript.

Funding Information

Funding was provided by Fisheries and Oceans Canada.


  1. Abal, E.G., N. Loneragan, P. Bowen, C.J. Perry, J.W. Udy, and W.C. Dennison. 1994. Physiological and morphological responses of the seagrass Zostera capricorni Aschers, to light intensity. Journal of Experimental Marine Biology and Ecology 178: 113–129.CrossRefGoogle Scholar
  2. Ainsworth, E.A., and K.M. Gillespie. 2007. Estimation of total phenolic content and other oxidation substrates in plant tissues using Folin-Ciocalteu reagent. Nature Protocols 2: 875–878.CrossRefGoogle Scholar
  3. Alcoverro, T., R.C. Zimmerman, D.G. Kohrs, and R.S. Alberte. 1999. Resource allocation and sucrose mobilization in light-limited eelgrass Zostera marina. Marine Ecology Progress Series 187: 121–131.CrossRefGoogle Scholar
  4. Boese, B.L., J.E. Kaldy, P.J. Clinton, P.M. Eldridge, and C.L. Folger. 2009. Recolonization of intertidal Zostera marina L.(eelgrass) following experimental shoot removal. Journal of Experimental Marine Biology and Ecology 374: 69–77.CrossRefGoogle Scholar
  5. Brock, T.D. 1981. Calculating solar radiation for ecological studies. Ecological Modelling 14: 1–97.CrossRefGoogle Scholar
  6. Bulthuis, D.A. 1983. Effects of in situ light reduction on density and growth of the seagrass Heterozostera tasmanica (Martens ex Aschers.) den Hartog in Western Port, Victoria, Australia. Journal of Experimental Marine Biology and Ecology 67: 91–103.CrossRefGoogle Scholar
  7. Burke, M.K., W.C. Dennison, and K.A. Moore. 1996. Non-structural carbohydrate reserves of eelgrass Zostera marina. Marine Ecology Progress Series 137: 195–201.CrossRefGoogle Scholar
  8. Burkholder, J.M., D.A. Tomasko, and B.W. Touchette. 2007. Seagrasses and eutrophication. Journal of Experimental Marine Biology and Ecology 350: 46–72.CrossRefGoogle Scholar
  9. Bush, E., and D.S. Lemmen, eds. 2019. Canada’s changing climate report, 444pp. Ottawa: Government of Canada.Google Scholar
  10. Chartrand, K.M., C.V. Bryant, A.B. Carter, P.J. Ralph, and M.A. Rasheed. 2016. Light thresholds to prevent dredging impacts on the Great Barrier Reef seagrass, Zostera muelleri ssp. capricorni. Frontiers in Marine Science 3: 1–17.CrossRefGoogle Scholar
  11. Clausen, K.K., D. Krause-Jensen, B. Olesen, and N. Marbà. 2014. Seasonality of eelgrass biomass across gradients in temperature and latitude. Marine Ecology Progress Series 506: 71–85.CrossRefGoogle Scholar
  12. Close, D.C., and C. McArthur. 2002. Rethinking the role of many plant phenolics–protection from photodamage not herbivores? Oikos 99: 166–172.CrossRefGoogle Scholar
  13. Collier, C.J., P.S. Lavery, P.J. Ralph, and R.J. Masini. 2009. Shade-induced response and recovery of the seagrass Posidonia sinuosa. Journal of Experimental Marine Biology and Ecology 370.CrossRefGoogle Scholar
  14. Dalla Via, J., C. Sturmbauer, G. Schönweger, E. Sötz, S. Mathekowitsch, M. Stifter, and R. Rieger. 1998. Light gradients and meadow structure in Posidonia oceanica: ecomorphological and functional correlates. Marine Ecology Progress Series 163: 267–278.CrossRefGoogle Scholar
  15. Dennison, W.C., and R.S. Alberte. 1982. Responses of Zostera marina L . ( Eelgrass ) to in situ manipulations of light intensity. Oecologia 55 (2): 137–144.CrossRefGoogle Scholar
  16. Dennison, W.C., and R.S. Alberte. 1985. Role of daily light period in the depth distribution of Zostera marina (eelgrass). Marine Ecology Progress Series 25: 51–61.CrossRefGoogle Scholar
  17. Duarte, C.M. 1989. Temporal biomass variability and production/biomass relationships of seagrass communities. Marine Ecology Progress Series 51: 269–276.CrossRefGoogle Scholar
  18. Duarte, C.M. 1991. Allometric scaling of seagrass form and productivity. Marine Ecology Progress Series 77: 289–300.CrossRefGoogle Scholar
  19. Enríquez, S., and N.I. Pantoja-Reyes. 2005. Form-function analysis of the effect of canopy morphology on leaf self-shading in the seagrass Thalassia testudinum. Oecologia 145 (2): 235–243.CrossRefGoogle Scholar
  20. Erftemeijer, P.L.A., and R.R. Robin Lewis. 2006. Environmental impacts of dredging on seagrasses: A review. Marine Pollution Bulletin 52 (12): 1553–1572.CrossRefGoogle Scholar
  21. Fitzpatrick, J., and H. Kirkman. 1995. Effects of prolonged shading stress on growth and survival of seagrass Posidonia australis in Jervis Bay, New South Wales, Australia. Marine Ecology Progress Series 127: 279–289.CrossRefGoogle Scholar
  22. Giesen, W.B.J.T., M.M. van Katwijk, and C. den Hartog. 1990. Eelgrass condition and turbidity in the Dutch Wadden Sea. Aquatic Botany 37: 71–85.CrossRefGoogle Scholar
  23. Govers, L.L., W. Suykerbuyk, J.H.T. Hoppenreijs, K. Giesen, T.J. Bouma, and M.M. Van Katwijk. 2015. Rhizome starch as indicator for temperate seagrass winter survival. Ecological Indicators 49: 53–60.CrossRefGoogle Scholar
  24. Harrison, P.G., and C. Durance 1989. Seasonal variation in phenolic content of eelgrass shoots. Aquatic Botany 35: 409–413.CrossRefGoogle Scholar
  25. Jarvis, J.C., and K.A. Moore. 2010. The role of seedlings and seed bank viability in the recovery of Chesapeake Bay, USA, Zostera marina populations following a large-scale decline. Hydrobiologia 649: 55–68.CrossRefGoogle Scholar
  26. Kim, Y.K., S.H. Kim, and K.-S. Lee. 2015. Seasonal growth responses of the seagrass Zostera marina under severely diminished light conditions. Estuaries and Coasts 38: 558–568.CrossRefGoogle Scholar
  27. Kirk, J.T. 2011. Light and photosynthesis in aquatic ecosystems. Cambridge University Press.Google Scholar
  28. Lavery, P.S., K. McMahon, M. Mulligan, and A. Tennyson. 2009. Interactive effects of timing, intensity and duration of experimental shading on Amphibolis griffithii. Marine Ecology Progress Series 394: 21–33.CrossRefGoogle Scholar
  29. Lee, K.S., S.R. Park, and Y.K. Kim. 2007a. Effects of irradiance, temperature, and nutrients on growth dynamics of seagrasses: A review. Journal of Experimental Marine Biology and Ecology 350: 144–175.CrossRefGoogle Scholar
  30. Lee, K.S., J.I. Park, Y.K. Kim, S.R. Park, and J.H. Kim. 2007b. Recolonization of Zostera marina following destruction caused by a red tide algal bloom: the role of new shoot recruitment from seed banks. Marine Ecology Progress Series 342: 105–115.CrossRefGoogle Scholar
  31. Longstaff, B.J., and W.C. Dennison. 1999. Seagrass survival during pulsed turbidity events: The effects of light deprivation on the seagrasses Halodule pinifolia and Halophila ovalis. Aquatic Botany 65: 105–121.CrossRefGoogle Scholar
  32. Madden, C.J., and W.M. Kemp. 1996. Ecosystem model of an estuarine submersed plant community: calibration and simulation of eutrophication responses. Estuaries 19: 457.CrossRefGoogle Scholar
  33. Marsh, J.A., W.C. Dennison, and R.S. Alberte. 1986. Effects of temperature on photosynthesis and respiration in eelgrass (Zostera marina L.). Journal of Experimental Marine Biology and Ecology 101: 257–267.CrossRefGoogle Scholar
  34. Masuko, T., A. Minami, N. Iwasaki, T. Majima, S.I. Nishimura, and Y.C. Lee. 2005. Carbohydrate analysis by a phenol–sulfuric acid method in microplate format. Analytical Biochemistry 339: 69–72.CrossRefGoogle Scholar
  35. McMahon, K., P.S. Lavery, and M. Mulligan. 2011. Recovery from the impact of light reduction on the seagrass Amphibolis griffithii, insights for dredging management. Marine Pollution Bulletin 62 (2): 270–283.CrossRefGoogle Scholar
  36. McMahon, K., C. Collier, and P.S. Lavery. 2013. Identifying robust bioindicators of light stress in seagrasses: A meta-analysis. Ecological Indicators 30: 7–15.CrossRefGoogle Scholar
  37. Moore, K.A., R.L. Wetzel, and R.J. Orth. 1997. Seasonal pulses of turbidity and their relations to eelgrass (Zostera marina L.) survival in an estuary. Journal of Experimental Marine Biology and Ecology 215: 115–134.CrossRefGoogle Scholar
  38. Moore, K.A., E.C. Shields, D.B. Parrish, and R.J. Orth. 2012. Eelgrass survival in two contrasting systems: role of turbidity and summer water temperatures. Marine Ecology Progress Series 448: 247–258.CrossRefGoogle Scholar
  39. Nejrup, L.B., and M.F. Pedersen. 2008. Effects of salinity and water temperature on the ecological performance of Zostera marina. Aquatic Botany 88: 239–246.CrossRefGoogle Scholar
  40. Ochieng, C.A., F.T. Short, and D.I. Walker. 2010. Photosynthetic and morphological responses of eelgrass (Zostera marina L.) to a gradient of light conditions. Journal of Experimental Marine Biology and Ecology 382: 117–124.CrossRefGoogle Scholar
  41. Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. Fourqurean, K.L. Heck, A.R. Hughes, et al. 2006. A global crisis for seagrass ecosystems. Bioscience 56: 987–996.CrossRefGoogle Scholar
  42. Platt, T., A. Prakash, and B. Irwin. 1972. Phytoplankton, nutrients and flushing of inlets on the coast of Nova Scotia. Naturaliste Canadien 99: 253–261.Google Scholar
  43. Priestley, M.B. 2004. Spectral analysis and time series, 877. London: Academic Press.Google Scholar
  44. Ralph, P.J., M.J. Durako, S. Enríquez, C.J. Collier, and M.A. Doblin. 2007. Impact of light limitation on seagrasses. Journal of Experimental Marine Biology and Ecology 350: 176–193.CrossRefGoogle Scholar
  45. Ritchie, R.J. 2006. Consistent sets of spectrophotometric chlorophyll equations for acetone, methanol and ethanol solvents. Photosynthesis Research 89: 27.CrossRefGoogle Scholar
  46. Serrano, O., M.A. Mateo, and P. Renom. 2011. Seasonal response of Posidonia oceanica to light disturbances. Marine Ecology Progress Series 423: 29–38.CrossRefGoogle Scholar
  47. Shoaf, W.T., and B.W. Lium. 1976. Improved extraction of chlorophyll a and b from algae using dimethyl sulfoxide. Limnology and Oceanography 21: 926–928.CrossRefGoogle Scholar
  48. Short, F.T., and S. Wyllie-Echeverria. 1996. Natural and human-induced disturbance of seagrasses. Environmental Conservation 23: 17–27.CrossRefGoogle Scholar
  49. Short, F., T. Carruthers, W. Dennison, and M. Waycott. 2007. Global seagrass distribution and diversity: A bioregional model. Journal of Experimental Marine Biology and Ecology 350: 3–20.CrossRefGoogle Scholar
  50. Smith, T.M., P.H. York, P.I. Macreadie, M.J. Keough, D.J. Ross, and C.D. Sherman. 2016. Recovery pathways from small-scale disturbance in a temperate Australian seagrass. Marine Ecology Progress Series 542: 97–108.CrossRefGoogle Scholar
  51. Staehr, P.A., and J. Borum. 2011. Seasonal acclimation in metabolism reduces light requirements of eelgrass (Zostera marina). Journal of Experimental Marine Biology and Ecology 407: 139–146.CrossRefGoogle Scholar
  52. Touchette, B.W., and J.M. Burkholder. 2000. Overview of the physiological ecology of carbon metabolism in sea grasses. Journal of Experimental Marine Biology and Ecology 250: 169–205.CrossRefGoogle Scholar
  53. Vergeer, L.H.T., T.L. Aarts, and J.D. de Groot. 1995. The “wasting disease” and the effect of abiotic factors (light-intensity, temperature, salinity) and infection with Labyrinthula zosterae on the phenolic content of Zostera marina shoots. Aquatic Botany 52: 35–44.CrossRefGoogle Scholar
  54. Vichkovitten, T., M. Holmer, and M.S. Frederiksen. 2007. Spatial and temporal changes in non-structural carbohydrate reserves in eelgrass (Zostera marina L.) in Danish coastal waters. Botanica Marina 50: 75–87.CrossRefGoogle Scholar
  55. Vollenweider, R.A. 1965. Calculation models of photosynthesis-depth curves and some implications regarding day rate estimates in primary production measurements. Memorie dell'Istituto Italiano di Idrobiologia 18: 425–457.Google Scholar
  56. Walker, D.I., and A.J. McComb. 1992. Seagrass degradation in Australian coastal waters. Marine Pollution Bulletin 25: 191–195.CrossRefGoogle Scholar
  57. Waycott, M., C.M. Duarte, T.J.B. Carruthers, R.J. Orth, W.C. Dennison, S. Olyarnik, A. Calladine, et al. 2009. Accelerating loss of seagrasses across the globe threatens coastal ecosystems. Proceedings of the National Academy of Sciences of the United States of America 106 (30): 12377–12381.CrossRefGoogle Scholar
  58. Wong, M.C. 2018. Secondary production of macrobenthic communities in seagrass (Zostera marina, eelgrass) beds and bare soft sediments across differing environmental conditions in Atlantic Canada. Estuaries and Coasts 41: 536–548.CrossRefGoogle Scholar
  59. Wong, M.C., M.A. Bravo, and M. Dowd. 2013. Ecological dynamics of Zostera marina (eelgrass) in three adjacent bays in Atlantic Canada. Botanica Marina 56: 413–424.CrossRefGoogle Scholar
  60. Wu, P.P.Y., K. Mengersen, K. McMahon, G.A. Kendrick, K. Chartrand, P.H. York, et al. 2017. Timing anthropogenic stressors to mitigate their impact on marine ecosystem resilience. Nature Communications 8: 1263.CrossRefGoogle Scholar
  61. Zapata, O., and C. McMillan. 1979. Phenolic acids in seagrasses. Aquatic Botany 7: 307–317.CrossRefGoogle Scholar

Copyright information

© Crown 2019

Authors and Affiliations

  1. 1.Bedford Institute of Oceanography, Fisheries and Oceans CanadaDartmouthCanada

Personalised recommendations