Seagrass litter decomposition: an additional nutrient source to shallow coastal waters (original) (raw)
Related papers
Leaching of dissolved organic matter from seagrass leaf litter and its biogeochemical implications
Acta Oceanologica Sinica, 2018
Dissolved organic matter (DOM) represents a significant source of nutrients that supports the microbial-based food web in seagrass ecosystems. However, there is little information on how the various fractions of DOM from seagrass leaves contributed to the coastal biogeochemical cycles. To address this gap, we carried out a 30-day laboratory chamber experiment on tropical seagrasses Thalassia hemprichii and Enhalus acoroides. After 30 days of incubation, on average 22% carbon (C), 70% nitrogen (N) and 38% phosphorus (P) of these two species of seagrass leaf litter was released. The average leached dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) of these two species of seagrass leaf litter accounted for 55%, 95% and 65% of the total C, N and P lost, respectively. In the absence of microbes, about 75% of the total amount of DOC, monosaccharides (MCHO), DON and DOP were quickly released via leaching from both seagrass species in the first 9 days. Subsequently, little DOM was released during the remainder of the experiment. The leaching rates of DOC, DON and DOP were approximately 110, 40 and 0.70 μmol/(g•d). Leaching rates of DOM were attributed to the nonstructural carbohydrates and other labile organic matter within the seagrass leaf. Thalassia hemprichii leached more DOC, DOP and MCHO than E. acoroides. In contrast, E. acoroides leached higher concentrations of DON than T. hemprichii, with the overall leachate also having a higher DON: DOP ratio. These results indicate that there is an overall higher amount of DOM leachate from T. hemprichii than that of E. acoroides that is available to the seagrass ecosystem. According to the logarithmic model for DOM release and the in situ leaf litter production (the Xincun Bay, South China Sea), the seagrass leaf litter of these two seagrass species could release approximately 4×10 3 mol/d DOC, 1.4×10 3 mol/d DON and 25 mol/d DOP into the seawater. In addition to providing readily available nutrients for the microbial food web, the remaining particulate organic matter (POM) from the litter would also enter microbial remineralization processes. What is not remineralized from either DOM or POM fractions has potential to contribute to the permanent carbon stocks.
Seagrass: A Store House of Carbon
We analyzed stored carbon in the Above Ground Biomass (AGB) and Below Ground Biomass (BGB) of three seagrass species in Koswari, Kariyachalli and Vilanguchalli during March, 2014 at Gulf of Mannar. Soil Organic Carbon (SOC) was also monitored simultaneously to evaluate the amount of stored carbon in the underlying soil of the intertidal mud flat in the study area. In the selected quadrate, the order of abundance of the seagrass species was Cymodocea serrulata > Thalassia hemprichii > Halophila ovalis. Pronounced variation was observed between AGB and BGB in all the three species. The ratio of AGB and BGB ranged from 1:1.25-1:1.30. The Above Ground Carbon (AGC) and Below Ground Carbon (BGC) also exhibited significant variation with highest value in Cymodocea serrulata followed by Thalassia hemprichii and Halophila ovalis.
Journal of Energy, Environment & Carbon Credits Seagrass: A Store House of Carbon
We analyzed stored carbon in the Above Ground Biomass (AGB) and Below Ground Biomass (BGB) of three seagrass species in Koswari, Kariyachalli and Vilanguchalli during March, 2014 at Gulf of Mannar. Soil Organic Carbon (SOC) was also monitored simultaneously to evaluate the amount of stored carbon in the underlying soil of the intertidal mud flat in the study area. In the selected quadrate, the order of abundance of the seagrass species was Cymodocea serrulata > Thalassia hemprichii > Halophila ovalis. Pronounced variation was observed between AGB and BGB in all the three species. The ratio of AGB and BGB ranged from 1:1.25-1:1.30. The Above Ground Carbon (AGC) and Below Ground Carbon (BGC) also exhibited significant variation with highest value in Cymodocea serrulata followed by Thalassia hemprichii and Halophila ovalis.
Applied Environmental Research
Examining how seagrass decomposition contributes to trophic pathways in marine ecosystems is crucial in understanding seagrass production. Decomposition rates of seagrasses may depend on many factors such as chemical composition and microbial colonization. In this study, microbial colonization and changes in chemical composition of decomposing material (necromass) of Smooth Ribbon Seagrass, Cymodocea rotundata of Bogtong Bay, Lahuy Island, Caramoan, Philippines were monitored. Seagrass litter were placed in litterbags and incubated in the seagrass meadow in situ for 56 d. Serial dilution, viable plate counts and microbial oxygen consumption analyses were done and gravimetry, Kjeldahl method and acid hydrolysis were used respectively to measure the change in carbohydrate, protein and nitrogen content of the decomposing necromass. Results showed that the decomposition processing rate was 0.27 to 2.51% biomass (g dw) loss per day with a half-life of 2.36 to 2.88 d. Growth of bacteria w...
Carbon storage by seagrass community.pdf
We analyzed stored carbon in the Above Ground Biomass (AGB) and Below Ground Biomass (BGB) of three seagrass species in Koswari, Kariyachalli and Vilanguchalli during March, 2014 at Gulf of Mannar. Soil Organic Carbon (SOC) was also monitored simultaneously to evaluate the amount of stored carbon in the underlying soil of the intertidal mud flat in the study area. In the selected quadrate, the order of abundance of the seagrass species was Cymodocea serrulata > Thalassia hemprichii > Halophila ovalis. Pronounced variation was observed between AGB and BGB in all the three species. The ratio of AGB and BGB ranged from 1:1.25-1:1.30. The Above Ground Carbon (AGC) and Below Ground Carbon (BGC) also exhibited significant variation with highest value in Cymodocea serrulata followed by Thalassia hemprichii and Halophila ovalis.
We analyzed stored carbon in the Above Ground Biomass (AGB) and Below Ground Biomass (BGB) of three seagrass species in Koswari, Kariyachalli and Vilanguchalli during March, 2014 at Gulf of Mannar. Soil Organic Carbon (SOC) was also monitored simultaneously to evaluate the amount of stored carbon in the underlying soil of the intertidal mud flat in the study area. In the selected quadrate, the order of abundance of the seagrass species was Cymodocea serrulata > Thalassia hemprichii > Halophila ovalis. Pronounced variation was observed between AGB and BGB in all the three species. The ratio of AGB and BGB ranged from 1:1.25-1:1.30. The Above Ground Carbon (AGC) and Below Ground Carbon (BGC) also exhibited significant variation with highest value in Cymodocea serrulata followed by Thalassia hemprichii and Halophila ovalis.
Biodiversitas Journal of Biological Diversity
Husodo T, Palabbi SDG, Abdoellah OS, Nurzaman M, Fitriani N, Partasasmita P. 2017. Seagrass diversity and carbon sequestration: Case study on Pari Island, Jakarta Bay, Indonesia. Biodiversitas 18: 1596-1601. Pari Island is located in Kepulauan Seribu chain. As a tourist destination, the seagrass ecosystem at the island is constantly under pressure from time to time. An effort to prevent widespread damage is to designate parts of the coastline as a limited access research centre. Efforts to study seagrass ecosystem on Pari Island are ongoing, including studies on seagrass' ability to sequestrate carbon. This quantitative study was conducted in December 2014. Surveys are done on the abundance and density of seagrass in 122 plots (area = 50 × 50 cm2) which spread in 6 research stations. Biomass measurements were performed by extractive method on 4 types of seagrass (Cymodocea serrulata, Halophila ovalis, Halodule uninervis and Syringodium isoetifolium). The assessment of seagrass ...