There are many different and even controversial results concerning the effects of Tamarisk on the physicochemical properties of soil. A year-round monitoring of soil salinity, pH and moisture is conducted beneath the Tamarisk shrub in a coastal wetland in the Bohai Sea in China, to ascertain the effects of Tamarisk on the physicochemical properties of soil in coastal wetland. Compared with the control area, the soil moisture content is lower around the area of the taproot when there is less precipitation in the growing season because of water consumption by Tamarisk shrub. However, the soil moisture content is higher around the taproot when there is more precipitation in the growing season or in the non-growing period because of water conservation by the rhizosphere. The absorption of salt by the Tamarisk shrub reduces the soil salinity temporarily, but eventually salt returns to the soil by the leaching of salt on leaves by rainfall or by fallen leaves. The annual average soil moisture content beneath the Tamarisk shrub is lower than the control area by only 6.4%, indicating that the Tamarisk shrub has little effect on drought or water conservation in soils in the temperate coastal wetland with moderate annual precipitation. The annual average salinity beneath the Tamarisk shrub is 18% greater than that of the control area, indicating that Tamarisk does have an effect of rising soil salinity around Tamarisk shrubs. The soil pH value is as low as 7.3 in summer and as high as 10.2 in winter. The pH of soil near the taproot of the Tamarisk shrubs is one pH unit lower than that in the control area during the growing season. The difference in pH is less different from the control area in the non-growing season, indicating that the Tamarisk shrub does have the effect of reducing the alkalinity of soil in coastal wetland.

Recent studies have highlighted the valuable role played by mangrove forests in carbon sequestration and storage. Although Indonesia accounts for a large proportion of global mangrove area, knowledge on the carbon stock and sources in the Indonesian mangrove is still limited. In this study, we quantified the ecosystem organic carbon (OC) stock and its spatial variation at an oceanic mangrove in Wori, North Sulawesi, Indonesia. The sources of soil OC were also investigated. The results showed that the mangrove soil had a substantial OC stock containing 15.4 kg/m² (calculated by carbon) in the top 50 cm soil, and represented the majority of the ecosystem OC stock at the Wori mangrove. The mangrove biomass and ecosystem OC stock were 8.3 kg/m² and 23.7 kg/m², respectively. There was no significantly difference in the soil OC stock among the stations with difference distances offshore, while the highest mangrove biomass OC stock was found at the seaward station. Isotope mixing calculations showed that the rich OC in mangrove soils was attributed to the accumulated autochthonous mangrove source while the suspended organic matter in tidal water and the mangrove-adjacent seagrass contributed less than 20% to the soil OC. The results further demonstrated the importances of the oceanic mangrove in carbon storage and the mangrove plants in contributing OC to their soils.

The present paper is based on the results of experiments on the adsorption of sulfide of bottom soil, which were carried out in 1979-1981, and gives special emphasis on the problem of the occurrence of the harm caused by hydrogen sulfide (H₂S) to the shrimps cultured in the high-production earthen pond. The scientific basis of prevention and control of the harm caused by hydrogen sulfide occurring in the pond and a simple effective measure for high, stable production of penaeid shrimp culture are proposed accordingly.

This paper deals with the reaction of the contents of carbohydrate and nitrogenous compound in leaves of mangroves (Kandelia candel and Aegiceras corniculatum) to the change of seabeach soil salinity (range:3-12) in the tidal swamp of Jiulongjiang River,Fujian Province,China.
Results obtained show that:(ⅰ) contents of total sugar,starch and soluble sugar in the leaves of those mangrove plants would increase with increase in the soil salinity; (ⅱ) with increase in the soil salinity,contents of total nitrogen and soluble protein in their leaves would decrease,but fluctuate at the soil salinity more than 10.

The purpose of this study was to investigate the accumulation behavior of two typical PAHs, phenanthrene (PHE) and fluoranthene (FLA), uptaken by the mangrove Kandelia candel in various treated sandy soils. The experiment lasted for three months. Soil and plant samples were collected after 3, 6, 9 and 13 weeks of the incubation and the levels of PAHs were analyzed using a GC/MS (HP6890-5975B). The results showed that the root accumulations of PHE and FLA were elevated with the increase of the PAH concentrations in the soil. With prolonged exposure time, PHE and FLA concentrations of the roots increased significantly in comparison with the control. PHE and FLA concentrations of root after 13 weeks of treatment ranged from 0.28 to 4.36 μg·g^-1 and 0.79 to 35.76 μg·g^-1, respectively. The calculated mean values of the root concentration factors were 0.58 for PHE and 0.71 for FLA. This indicated that root accumulation of FLA was greater than PHE, which would result from the higher octanol-water partition coefficient (K_ow) of FLA. These results underline the ability of mangroves to remove PAHs from contaminated marine substrates and hence their potential use in bioremediation and the removal of PAHs from the marine food chain.

Piezocone penetration test (CPTu), the preferred in-situ tool for submarine investigation, is significant for soil classification and soil depth profile prediction, which can be used to predict soil types and states. However, the accuracy of these methods needs to be validated for local conditions. To distinguish and evaluate the properties of the shallow surface sediments in Chengdao area of the Yellow River Delta, seabed CPTu tests were carried out at ten stations in this area. Nine soil classification methods based on CPTu data are applied for soil classification. The results of classification are compared with the in-situ sampling to determine whether the method can provide sufficient resolution. The methods presented by Robertson (based on soil behavior type index I_c), Olsen and Mitchell are the more consistent and compatible ones compared with other methods. Considering that silt soils have potential to liquefy under storm tide or other adverse conditions, this paper is able to screen soil classification methods suitable for the Chengdao area and help identify the areas where liquefaction or submarine landslide may occur through CPTu investigation.

This paper shows that the use of sea soil extract instead of vitamin and biotin to culture Chaet.muelleri is possible.The effect of the different nitrogen sources on Chaetoceros muelleri was studied in order to suggest a more simple and better fertilizer for the mass culture of this species.

Mangrove forests are under the stress of sea level rise (SLR) which would affect mangrove soil biogeochemistry. Mangrove soils are important sources of soil-atmosphere greenhouse gas (GHG) emissions, including carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). Understanding how SLR influences GHG emissions is critical for evaluating mangrove blue carbon capability. In this study, potential effects of SLR on the GHG emissions were quantified through static closed chamber technique among three sites under different intertidal elevations, representing tidal flooding situation of SLR values of 0 cm, 40 cm and 80 cm, respectively. Compared with Site SLR 0 cm, annual CO₂ and N₂O fluxes decreased by approximately 75.0% and 27.3% due to higher soil water content, lower salinity and soil nutrient environments at Site SLR 80 cm. However, CH₄ fluxes increased by approximately 13.7% at Site SLR 40 cm and 8.8% at Site SLR 80 cm because of lower salinity, higher soil water content and soil pH. CO₂-equivalent fluxes were 396.61 g/(m²·a), 1423.29 g/(m²·a) and 1420.21 g/(m²·a) at Sites SLR 80 cm, SLR 40 cm and SLR 0 cm, respectively. From Site SLR 0 cm to Site SLR 80 cm, contribution rate of N₂O and CH₄ increased by approximately 7.42% and 3.02%, while contribution rate of CO₂ decreased by approximately 10.44%. The results indicated that warming potential of trace CH₄ and N₂O was non-negligible with SLR. Potential effects of SLR on the mangrove blue carbon capability should warrant attention due to changes of all three greenhouse gas fluxes with SLR.

Along with the reduction of sediment yield of the Huanghe (Yellow) River, the erosion of the Huanghe River Delta aggravates, which has becomes an important factor that threatens the coastal protection structures. Starting from the study of the erosion resistibility of the sediment, this paper explores the internal mechanism of erosion phenomenon. This paper takes Diaokou as the study area and takes soils as samples which are mixed with clay into reconstructed samples whose ratio of clay content are 5%, 10%, 15%, 20% respectively, then dynamic tri-axial apparatus is applied to simulate wave loads of different intensity; then the resistibility of soil to erosion is determined via concentrated flow test and the structural property is determined via the disintegration test. Finally, the resistibility to erosion and the structural property of the non-compressed soil samples are compared with the compressed data. The results indicates that liquefaction failure exerts significant influence on the resistibility to erosion and the structural property of the silty soil in the Huanghe River Delta. Therefore, in the future erosion studies, the liquefaction phenomenon shall be fully considered.

Using sea surface salinity (SSS) observation from the soil moisture active passive (SMAP) mission, we analyzed the spatial distribution and seasonal variation of SSS around Changjiang River (Yangtze River) Estuary for the period of September 2015 to August 2018. First, we found that the SSS from SMAP is more accurate than soil moisture and ocean salinity (SMOS) mission observation when comparing with the in situ observations. Then, the SSS signature of the Changjiang River freshwater was analyzed using SMAP data and the river discharge data from the Datong hydrological station. The results show that the SSS around the Changjiang River Estuary is significantly lower than that of the open ocean, and shows significant seasonal variation. The minimum value of SSS appears in July and maximum SSS in December. The root mean square difference of daily SSS between SMAP observation and in situ observation is around 3 in both summer and winter, which is much lower than the annual range of SSS variation. In summer, the diffusion direction of the Changjiang River freshwater depicted by SSS from SMAP is consistent with the path of freshwater from in situ observation, suggesting that SMAP observation may be used in coastal seas in monitoring the diffusion and advection of freshwater discharge.