Growth dynamics of the seagrass, Zostera marina in Jindong Bay on the southern coast of Korea

Abstract

Growth dynamics of the seagrass, Zostera marina were examined at the two stations (Myungju and Dagu) in Jindong Bay on the southern coast of Korea. Eelgrass leaf productivities, underwater irradiance, water temperature, dissolved inorganic nitrogen (DIN) in water column and sediments, and tissue carbon (C) and nitrogen (N) content were monitored monthly from March 2002 to January 2004. Underwater irradiance fluctuated highly without a clear seasonal trend, whereas water temperature showed a distinct seasonal trend at both study stations. Water column DIN concentrations were usually less than 5 μM at both study sites. Sediment pore water NH 4 + and NO 3 -+ NO 2 -concentrations were higher at the Myungju site than at the Dagu site. Eelgrass leaf productivity at both study sites exhibited a distinct seasonality, increasing during spring and decreasing during summer. Seasonal variation of eelgrass productivity was not consistent with seasonal patterns of underwater irradiance, or water temperature. Eelgrass tissue C and N content at both study sites also showed significant seasonal variations. Relationships between tissue C and N content and leaf productivities exhibited usually negative correlations at both study sites. These negative correlations implied that the growth of Z. marina at the study sites was probably limited by C and N supplies during the high growth periods.Key Words: growth dynamics; irradiance; nutrient availability; seagrass; temperature; tissue C and N content; Zostera marina INTRODUCTIONSeagrasses are known to play an important role as a primary producer in coastal and estuarine ecosystems (McRoy and McMillan 1977, Zieman and Wetzel 1980, Lee and Dunton 1996. Seagrasses can affect the coastal and estuarine environment by enhancing sedimentation and reducing current and wave energy (Fonseca 1989). Seagrasses also improve water qualities of coasts and estuaries by removing over-enriched inorganic nutrients through leaf uptake McRoy 1984, Lee andDunton 1999). Moreover, seagrass meadows provide habitats for commercially and ecologically valuable marine organisms (Holmquist et al. 1989, Montague andLey 1993). Since seagrass production is essential to support coastal and estuarine ecosystems, examination of seagrass growth dynamics is critical to understand functions and values of seagrass at a certain area in coastal and estuarine ecosystems.The primary productivity of seagrass is usually controlled by underwater irradiance, water temperature, and inorganic nutrient availabilities (Wetzel and Penhale Received July 20, 2012, Accepted August 14, 2012 *Corresponding Author E-mail: klee@pusan.ac.kr Tel: +82-51-510-2255+82-51-510- , Fax: +82-51-581-2962 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 216 be important factors for estimation of whole ...

Carbon stable isotope ratios of new leaves of Zostera marina in the mid-latitude region: Implications of seasonal variation in productivity

“…In this study, the productivities of Z. marina at both study sites exhibited significant seasonality (p b 0.001), increasing during the spring and summer and decreasing during the fall and winter. Similar trends in the biomass and productivity of Z. marina have been reported by several studies (Kim et al, 2012, Lee et al, 2004, Lee et al, 2005. The irradiance at the Dongdae Bay and Ojiri seagrass beds did not change significantly between March and June (Fig.…”

Effects of elevated CO2 and nutrients on the community metabolismof a Cymodocea nodosa bed

“…In all treatments, NCP increases during the morning were more pronounced than during the afternoon, just after the photoinhibition process, as shown by the differences in the slopes of NCP versus irradiance obtained from the morning and the afternoon incubations. It is important to note that NCP values may vary seasonally, since the length of the day, irradiance, and temperature, which are factors known to affect metabolic rates (MacLeod and Barton, 1988;Lee et al, 2007;Kim et al, 2012), will all vary as there is variation in hours of light, light intensity, and temperature. Therefore, future studies assessing the net community production and community metabolism of seagrass meadows should include the seasonal variation.…”

Deep-water Zostera marina meadows in the Mediterranean

“…N levels in Z. marina belowground compartments from Belyounech bay meadow (0.74 %DW, average of root and rhizome values) are low when compared to other places (Supplementary material Table S5). Kim et al (2012) reported a seasonal variation of N levels in Z. marina belowground compartment, with levels ranging from 5.50 %DW in winter to 0.50 %DW in summer and spring. However, the primary production of seagrass compartments can be high despite low N concentration in the plant (Pedersen and Borum, 1992;Gobert et al, 2002;Cabaço et al, 2013).…”