Mariculture tailwater requires treatment technologies that can operate under saline, low-strength conditions. This study evaluated a deep-bed filter inoculated with the salt-tolerant yeast Meyerozyma guilliermondii. The system was operated for 20 days to quantify removal of total nitrogen (TN), inorganic nitrogen (IN), and the permanganate index (CODMn).,Average removal efficiencies were 34.0% for TN, 30.0% for IN, and 34.9% for CODMn. Mean effluent concentrations were 4.05 mg/L TN, 2.73 mg/L IN, and 9.7 mg/L CODMn. The tested filter therefore achieved the study targets under the evaluated influent and operating conditions. Correlation analysis associated TN removal mainly with organic nitrogen removal, whereas nitrate and nitrite were the principal inorganic nitrogen species removed.,Because this study did not include an uninoculated control or direct measurements of yeast abundance, the observed performance cannot be attributed exclusively to M. guilliermondii. The results provide an operational assessment of the inoculated deep-bed filter and identify the need for controlled microbial validation in future work.

To investigate the relationship between fishery resources community structure (mainly fish and crustaceans) and environmental factors in the artificial reef waters off Nanri Island, surveys were conducted in November 2021, 2022, and 2023. Shannon-Wiener diversity index (H '), Margalef richness index (D), Pielou evenness index (J '), and resource density index (RD) were employed to characterize the community structure. From 2021 to 2023, DO and petroleum hydrocarbons exhibited significant interannual variation (p < 0.05), whereas DIP, DIN, and SS showed highly significant interannual variation (p < 0.01). Spatially, DO, COD, DIN, and petroleum hydrocarbons varied more than other factors. Both diversity and richness indices rose over the study period, with mean H ' rising from 1.693 to 1.942 and mean D from 2.107 to 2.474. The evenness index (J ') declined in 2022 but then increased to 0.787. In contrast, the resource density index (RD) dropped sharply in 2022 (107.2) and partially recovered in 2023 (155.4), though it remained below the 2021 level (218.5). Redundancy analysis revealed that five environmental variables (DIP, DIN, petroleum hydrocarbons, SS, and DO) primarily shaped the fishery resource community structure in the artificial reef area. This study provided reference data for artificial reef management and sustainable fishery development.

Aquaculture expansion to meet global protein demand has intensified concerns over nutrient pollution and greenhouse gas (GHG) emissions. While floating treatment wetlands (FTWs) are proven for water quality improvement, their potential to mitigate GHG emissions in marine aquaculture remains poorly understood. This study quantitatively evaluated the dual capacity of Sesuvium portulacastrum FTWs to (a) regulate dissolved inorganic nitrogen (DIN) and (b) reduce CO2/N2O emissions in grouper aquaculture systems. DIN speciation (NH4+, NO2−, NO3−) and CO2/N2O fluxes of six controlled ponds (three FTW and three control) were monitored for 44 days. DIN in the FTW group was approximately 90 μmol/L lower than that in the control group, and the water in the plant group was more “oxidative” than that in the control group. The former groups were dominated by NO3−, with lower dissolved inorganic carbon (DIC) and N2O concentrations, whereas the latter were dominated by NH4+ during the first 20 days of the experiment and by NO2− at the end of the experiment, with higher DIC and N2O concentrations on average. Higher primary production may be the reason that the DIC concentration was lower in the plant group than in the control group, whereas efficient nitrification and uptake by plants reduced the availability of NH4+ in the plant group, thereby reducing the production of N2O. A comparison of the CO2 and N2O flux potentials in the plant group and control group revealed that, in the presence of FTWs, the CO2 and N2O emissions decreased by 14% and 36%, respectively. This showed that S. portulacastrum FTWs effectively couple DIN removal with GHG mitigation, offering a nature-based solution for sustainable aquaculture. Their low biomass requirement enhances practical scalability.

Aquaponic systems are sustainable and environmentally friendly, primarily through the recycling of nutrients. However, identifying feasible combinations that achieve favorable economic and environmental performance in a win-win mariculture system can be challenging. A novel aquaponic mariculture system was established by combining sea purslane (Sesuvium portulacastrum) with hybrid grouper (Epinephelus sp.), and its performance was assessed. Triplicate experimental fish ponds assembled with floating plant beds of sea purslane (SP group) were compared with the control (without phytotreatment, CK group) over a 56-day experimental period. The changes in major pollutants in the system and the growth performance of the plants and groupers were analyzed. The results showed that the removal rates of pollutants in the sea purslane aquaponic system were 98.1 %, 97.5 %, 89.9 % and 50.6 % for total ammonia nitrogen (TAN), nitrite nitrogen, total suspended solids (TSS) and chemical oxygen demand (COD), respectively. Furthermore, the removal rates of total nitrogen (TN), total phosphorus (TP), dissolved inorganic nitrogen (DIN), and dissolved inorganic phosphorus (DIP) were 19.6 %, 12.0 %, 18.4 % and 16.2 %, respectively, in the SP group. With respect to growth performance, the specific growth rate (SGR) of groupers in the SP group increased by 43 % compared with that in the CK group. Grouper growth in the SP group showed strong negative allometric growth, whereas isometric growth was observed in the CK group. The net growth of sea purslane increased by 4.32 +/- 1.64 kg/m2, with a relative growth rate of 0.90 +/- 0.28 %/d, showing considerable incorporation of carbon via photosynthesis. Moreover, the sea purslane-grouper aquaponics system can be maintained at a low cost and is easily managed. In conclusion, the potential of this innovative marine aquaponic system was demonstrated, and the findings will contribute to enhancing the performance of environmentally friendly mariculture techniques in the future.

Constructed wetlands represent an eco-friendly approach for mariculture wastewater treatment, yet the mechanistic role of substrates, particularly their "biological influence" under high-salinity conditions (i.e., shaping and modulating functional microbial communities) remains poorly understood. To address this gap, horizontal flow simulated wetlands were established using Sesuvium portulacastrum L. combined with bay mud (BM), fine sand (FS), oyster shells (OS), volcanic rock (VR), and composite substrate (CS) to treat Epinephelus spp. breeding tailwater. Results demonstrated that the metabolic pathways of functional species rarely varied across habitats in the CWs, however, the functional bacterial community structure of the rhizosphere which,mainly contribute to the cycling of nitrogen, phosphorus and organic matters was significantly shaped by the characteristics of substrates. For example, substrates FS and VR demonstrated the highest COD removal efficiencies but poorly supported the growth of Sesuvium portulacastrum L. root systems, as well as the rhizosphere functional bacterial community structure. In contrast, the large voidage of OS resulted in lower removal efficiency (e.g., 45.6 % of COD removal), however, OS was suggested to favor the growth of plant roots, promoting the enrichment of keys functional species-Flavobacteriaceae, and "amino acid metabolism" and "energy metabolism" genes in both rhizosphere and water column, realizing the synergistic bacterial cooperation between aquatic and root niches for nutrient removal. Under high-salinity conditions, substrates with higher porosity were supposed to mainly regulate the accumulation of aerobic functional genera in the substrate and water column, while, substrates that could provide enough growth space for the root system prefer to exhibit optimal "biological role" in shaping functional flora in the CWs. This study provides critical insights into substrate-driven microbial selection in high-salinity wetlands, facilitating informed substrate design for enhanced pollutant remediation.

This study aims to address the suboptimal performance of conventional denitrifying strains in treating mariculture tail water (MTW) containing inorganic nitrogen (IN). The concentration of inorganic nitrogen in the mariculture tail water is about 5-20 mg center dot L -1 . A biofilm treatment process was developed and evaluated using an anoxic -anoxic -aerobic biofilter composite system inoculated with the denitrifying strain Meyerozyma guilliermondii Y8. The removal effect of total nitrogen (TN), IN, and Chemical Oxygen Demand (COD M n ) from MTW was investigated. The results indicate that the A 2 O composite biological filter has excellent pollutant removal efficiency within 25 days of operation, after the acclimation of the denitrifying microorganisms. The initial concentrations of TN, IN, and COD Mn ranged between 10.24 and 12.89 mg center dot L -1 , 7.84-10.49 mg center dot L -1 , and 9.44-11.52 mg center dot L -1 , respectively, and the removal rates of these indexes reached 38-68 %, 45-70 %, and 55-70 %, respectively. The experiments with different hydraulic retention times (HRT = 6 h, 8 h, 10 h) demonstrated that longer HRT was more conducive to the removal of inorganic nitrogen. Moreover, scanning electron microscopy observations revealed that the target strain successfully grew and attached to the filler in large quantities. The findings of this study provide practical guidance for the development of efficient biofilm processes for the treatment of MTW.

Sesuvium portulacastrum floating treatment wetlands (FTWs) are effective at removing nitrogen and phosphorus, adsorbing heavy metals, and removing organic pollutants from aquaculture wastewater, and thus improve fish farming productivity. In this study, an S. portulacastrum FTW was used in a simulated grouper aquaculture experiment for 40 days. The FTW removed 1~3 mg/L of dissolved inorganic nitrogen (DIN) throughout the experimental period as well as the following toxic nitrogen species: 88% NO2−-N in the middle stage and 90% TAN (total ammonia nitrogen) in the middle stage. The health of the groupers was promoted and the weight of each grouper was 8% higher than those in the control group in the end. Compared with that of the control group, the carbon sequestration of the aquaculture ecosystem was also increased by S. portulacastrum FTW because more carbon was held in the biomass, including through the growth of the plant mass of the FTW, 109 g C/pond, and a reduction in fishing catch losses, 442 g C/pond. Therefore, S. portulacastrum FTW can serve as a potential technology for improving the water environment quality of feeding ponds and contributing to carbon sequestration in aquaculture systems.

Cage farming is an important means of aquacultural production, while its potential environmental pollution needs to be further investigated. In this study, Dongshan Bay was taken as an example to investigate whether long-term cage farming in a semi-closed bay would cause environmental pollution via vertical distribution assessment. The four sediment cores (YB1, YB2, B1, and B2) were collected from two cage farming areas. Total nitrogen (TN), total organic carbon (TOC), and total phosphorus (TP) were measured. The results showed a negative correlation between TN and TOC and the sediment depth at four sampling sites, and TP was also negatively correlated with the depth at three sites. The average TN (1,405.8, 1,413.8, 1,115.7, and 936.1 mgkg −1 ) and TP (1,206, 1,141.6, 1,064.6, and 932.8 mgkg −1 ) values of the four sites were markedly higher than the safety level, with the indexes S TN , S TP , FF , and ON of the four sites indicating moderate to severe pollution of nitrogen and phosphorus. Particularly, the YB1 and YB2 sites in the area with lower current speed have more severe pollution. The C/N ratio uncovered that the organic matter (OM) might mainly derived from the phytoplankton and nonfibrous plants as a result of excessive fish feed and feces. Collectively, the results indicated that long-term (more than 10 years) cage farming activity in a semi-closed bay such as Dongshan Bay had a negative impact on the environmental quality. Despite limitations in sample size and the absence of stable isotopic analyses, this study enhances our understanding of environmental changes and endogenous pollution risks in shallow marine aquaculture areas. Moreover, it suggests practical approaches such as implementing alternative farming and fallowing periods, should be conducted to mitigate the pollution.

联苯菊酯是一种广泛应用的拟除虫菊酯类农药,但有关联苯菊酯对海水鱼类的毒性机理研究较少.为研究亚急性暴露下联苯菊酯对真鲷的毒性效应,在急性毒性试验基础上,选取5个浓度梯度对真鲷进行半静置暴露试验,测定不同暴露时间体内酶活性变化,并开展暴露25 d后肝细胞彗星试验.结果表明,亚急性暴露下真鲷血清中乙酰胆碱酯酶(AChE)、血细胞中Na+-K+-ATP酶(Na+-K+-ATPase)、肝和鳃中谷胱甘肽硫转移酶(GST)等酶活性先后出现了诱导或抑制现象.暴露浓度低于0.10μg·L-1,联苯菊酯对真鲷血清中AChE、血细胞中Na+-K+-ATPase和肝中GST等酶活性主要表现为诱导作用(P＜0.05).暴露浓度高于0.10 μg·L-1,AChE活性受到显著抑制(P＜0.05);暴露浓度高于020μg·L-1,Na+-K+-ATPase、GST活性均受到显著抑制(P＜0.05).与对照组相比,各暴露浓度组肝细胞DNA均有不同程度损伤,彗星拖尾率、彗星尾长、彗尾DNA相对含量、Olive尾距与对照组之间均差异显著(P＜0.02).回归分析显示,暴露浓度与各试验指标数据呈线性关系,R2值范围在0.906～0.984之间.暴露浓度高于0.10 μg·L-1时,联苯菊酯可显著影响真鲷体内酶活性,并对肝细胞DNA产生不同程度损伤,具有一定遗传毒性和潜在生态风险.

通过单因素试验优化盐渍海马齿的制作工艺参数,为海马齿的精深加工利用提供数据参考.经前处理、3次烘干、加盐揉搓、高温蒸煮等工序制作盐渍海马齿,其中,第1次烘干工艺流程的温度、时间和加盐量等参数直接影响盐渍海马齿成品的品质.因此,以感官评价和含水率为指标,优化烘干温度、烘干时间和加盐量等参数.结果表明:选择第1次烘干最适温度为60℃,烘干时间8 h,加盐量为4％,制得的盐渍海马齿呈光泽的茶褐色,具特有滋味和气味,组织鲜嫩,纯正爽口,展开后叶形完整,含水量为10.39％,氯化物11.3％,亚硝酸盐物质未检出,大肠菌群<0.3 MPN·g-1,金黄色葡萄球菌、沙门氏菌等致病菌均未检出.

为了评价联苯菊酯的遗传毒性,研究了不同浓度联苯菊酯对菲律宾蛤仔肝胰腺细胞DNA的损伤作用.研究分别在0.05、0.10、0.15、0.20 mg/L联苯菊酯暴露25 d后,取菲律宾蛤仔肝胰腺细胞并用单细胞凝胶电泳(彗星实验) 进行分析,以彗尾DNA相对含量( TDNA%)、彗星尾长(TL) 、Olive尾矩(OTM) 和拖尾率(TR) 作为DNA损伤的指标,实验结果表明: 与空白对照组相比,各处理组菲律宾蛤仔肝胰腺细胞DNA均有不同程度的损伤且各检测指标值均显著增加(P<0.05);随着联苯菊酯浓度的增加,各检测指标均呈规律性的增长趋势,具有高度的相关性(r>0.99),表现出良好的剂量效应关系.评价彗星实验较好的检测指标为彗尾DNA相对含量和Olive矩,实验获得的多元回归方程具有显著的统计学意义(P<0.01),可以有效地推断联苯菊酯对菲律宾蛤仔的染毒毒性浓度.

通过构建海马齿(S.portulacastrum L.)-石斑鱼封闭式海水生态养殖实验系统,模拟研究海马齿生态浮床对石斑鱼生长及养殖效益的影响,探索并优化浮床-水体面积覆盖比.结果显示,经22 d培养,海马齿成活率组间无明显差异(P>0.05),植株增重率与浮床覆盖率呈线性正相关(R2=0.994,P=0.0485).浮床处理组石斑鱼成活率、特定生长率(SGR)、饵料转化率和产出投入比均显著高于对照组(P<0.05),而浮床处理组间无显著差异(P>0.05).T2、T3组石斑鱼平均增重率和残饵粪便产量均高于对照组(P<0.05),与T1组无显著差异(P>0.05).各处理组的投饵量大小顺序为T3>(T2、T1)>CK,T3组残饵粪便氮含量低于其他处理组(P<0.05),而磷含量无组间差异(P>0.05).结果表明,海马齿生态浮床对石斑鱼存活、生长和养殖产出均具有明显的促进作用;15％的浮床覆盖率即可有效促进石斑鱼存活、提高经济效益;覆盖率为30％时,石斑鱼产量得到显著提高;当覆盖率升高至45％时,石斑鱼对饵料蛋白利用效率得到显著提升;其中以30％覆盖率综合养殖效益最佳.

本文根据2016年东山湾渔业统计基础资料,选取养殖面积、养殖结构等关键指标,赋予阈值参数,计算养殖面积指数、养殖结构指数和养殖综合指数,构建了东山湾养殖承载力评价指标体系.采用辅助指标和关键指标综合评价方法,对东山湾水产养殖承载力进行评价.结果 表明:东山湾养殖面积指数(yS)为0.89,养殖结构指数(YJ)为0.02,养殖综合指数(yZ)为0.91.东山湾水产养殖承载水平为临界超载,超载特征为布局不合理、局部海域投饵型养殖规模过大,主要管控措施为限养区退养、合理布局、控制鱼类等投饵型养殖生物养殖规模.

针对规模化网箱养殖的自身污染问题,在东山湾八尺门鱼类养殖海区开展海马齿(Sesuvium portulacastrum)生态浮床原位修复研究.经过一年的生长,八尺门修复区海马齿平均茎长1.28 m,平均根须长0.52 m,生物量达152.5×103 g/m2,通过生长吸收对C、N、P的积累量分别为5214.0、378.5、22.9 g/m2.经过两年的原位修复,浮床修复区海水的DO比对照区高11.9％;浮床对石油类、 悬浮物和COD的去除率分别为42.3％、14.9％和10.0％,对TN的去除率为11.7％,对NH4-N、NO3-N和PO4-P的去除率分别为19.9％、16.4％和9.2％;由于海水的流动性和影响因素的复杂性,浮床对TOC、NO2-N和TP的去除效果不理想.综上,海马齿生态浮床能够在一定程度上改善修复区海水水质,减轻网箱养殖水体的营养负荷.

通过水培实验模拟生态浮床,研究海马齿(Sesuvium portulacastrum)在不同盐度条件下的生长及生理生化响应特征,探讨海马齿盐度适应性和海马齿生态浮床修复技术推广的适宜盐度范围.结果表明:在中、低盐度(0～20)条件下,海马齿生长几乎不受影响,而在高盐度(25～35)水体中,其生长受到明显胁迫,其中最高盐度(35)处理组中部分海马齿茎节出现腐烂溃败的现象,苗种成活率下降;新根数为低盐度(0～10)处理组>中盐度(15和20)处理组>高盐度(25～35)处理组,且高盐度处理组新根呈现粗、短特征;培养40 d后,海马齿植株鲜质量、干质量、相对生长量、水分含量、根系活力和根质量随盐度升高均呈现先上升后下降的趋势,各指标最大值均落在盐度5～15范围内,其中根质量和根系活力的最大值均出现在盐度15处理组,表明适当的盐度可以促进水培海马齿的根系发育;除可溶性糖外,海马齿叶片中丙二醛和叶绿素含量受盐度变化的影响较小,不同盐度组间无显著差异(p>0.05),暗示海马齿可利用渗透压调节机制抵抗环境盐胁迫,以保证细胞内其他生理生化指标维持较稳定的状态.综合比较可初步确定海马齿的适宜生长盐度范围为0～15.

针对福建等海域养殖皱纹盘鲍度夏死亡率高的现象,试验研究了不同盐度、温度和溶解氧条件,对皱纹盘鲍幼鲍和1龄鲍死亡率的影响,并根据试验结果设定了皱纹盘鲍海上养殖盐度、温度和溶解氧预警阈值.结果表明:低盐胁迫对皱纹盘鲍的死亡率影响显著,在水温24～27℃时,盐度20是幼鲍和1龄鲍试验组和对照组死亡率有显著差异的临界点,盐度预警阈值为22;高温胁迫对皱纹盘鲍的死亡率影响显著,温度28℃是幼鲍和1龄鲍试验组和对照组死亡率有显著差异的临界点,温度预警阈值为27℃;皱纹盘鲍有较强的耐低氧能力,在水温26℃,盐度为30,溶解氧低于2.0 mg/L时,开始大量死亡,溶解氧预警阈值为3.5 mg/L;高温胁迫和低盐胁迫对皱纹盘鲍的死亡率有显著的交互作用,温度升高,低盐耐受能力下降.

[Objective]To study the acute toxicity effect and safe concentration of bifenthrin and ethofenprox to Pagrosomus major.[Method]The acute toxicity of bifenthrin and ethofenprox on P.major was studied by semi-static bioassay test,and their safety evaluation was made.[Result]At water temperature of (20.4 ±0.3)℃,24 h LC50 ,48 h LC50 ,72 h LC50 and 96 h LC50 values of bifenthrin on P.major were 2.50,1.36,0.96 and 0.84 μg/L,respectively,and those of ethofenprox on P.major were 17.80,2.81,1.04,0.54 mg/L,respectively.The safe concentrations (SC) of bifenthrin and ethofenprox on P.major were estimated as 0.12 μg/L and 0.02 mg/L,respectively.Bifenthrin and ethofenprox belonged to ex-tremely high toxicity grade and high toxicity grade on P.major, respectively.[Conclusion]When bifenthrin was used for fishery drugs,its dose and duration should be cautiously adjusted.

The detection of volatile phenol in sea water was optimized by continuous flow analyzer method.The results of this study could provide scientific basis for the determination of volatile phenol in sea water for scientific and technical personnel of testing agencies,and provide a scientific basis for the standardization of this method.The experimental results showed that this method had high precision and accuracy in the linear range of 0~0.100 mg/L,the minimum detection limit was 0.002 mg/L.The range of relative standard deviation was 2.21%~4.65%,which were all less than 5%(standard requirement).There was no significant difference between continuous flow analysis method and classical method.The method was fast,simple and environmental protection,and it would be worth to further study and application.

In order to study the toxic effect of deltamethrin on the hepatopancreas of Pagrosomus major with sub-acute exposure, Pagrosomus major were divided into 5 groups with different doses of semi-static exposure. The damage of the hepatopancreas tissue of Pagrosomus major was analyzed by microscopy observation and the DNA damage of the cells was analyzed by comet assay technique after 25 days exposure. The results showed that different degrees of congestion, nuclear enrichment and cell necrosis appeared in hepatopancreas of 0.025, 0.125, 0.250, 0.375 Μg·L-1 exposure concentrations. The higher the exposure concentration, the variations of tissue and cell were more significant. DNA damages in the hepatopancreas cells of all exposed group were observed. The co-met rate, percentage of tail DNA and the olive moment were significantly different from the control group (P<0.05). Linear regression analysis showed that the exposure concentration was significantly positively correlated with the tailing rate and the tail length (P<0.01). The indexes were significantly related to the concentration of deltamethrin exposure with the coefficient of determination between 0.909-0.996. It was suggested that deltamethrin could cause various degree of damage to the tissue and cellular DNAs in the hepatopancreas of Pagrosomus major in a linear responsive manner.

The acute toxicity and bioaccumulation of deltamethrin was studied in four species of mariculture organisms including the crustaceans Portunus pelagicus and Marsupenaeus japonicus, and the bivalve Meretrix meretrix and Ruditapes philippinarum. The results indicated that there were significant positive correlations between the mortality rate of the mariculture organisms and the concentration and exposure time of deltamethrin. The LC50values at 24 h, 48 h and 96 h for the crustacean P.pelagicus were 2.07×10-4, 1.70×10-4and 1.10×10-4mg/L respectively, and the values for M.japonicas were 7.32×10-4, 3.90×10-4and 1.43×10-4mg/L. The safe concentrations for these two species were 3.44×10-5mg/L and 3.32×10-5mg/L respectively. The LC50values at the 3 time points for the bivalves M.meretrix were 1.52,0.30 and 0.27 mg/L respectively,and for R.philippinarum they were 0.67, 0.11 and 0.06 mg/L respectively. The safe concentrations for these two species were 3.51× 10-3mg/L and 9.50×10-4mg/L respectively. Obviously the two crustacean species were more sensitive to deltamethrin than the bivalves.Next,the bivalves M.meretrix and R.philippinarum were exposed to the seawater containing deltamethrin at average concentrations of 0.86–0.05 mg/L and 0.37–0.03 mg/L respectively for 24–96 h, and we found that the accumulation coefficients of deltamethrin in these two species were 2.57–12.40 and 3.03–27.85 respectively. The accumulation rate of deltamethrin in the two bivalve species was positively corelated with the exposure time of deltamethrin, but negatively correlated with the concentration of deltamethrin. There were significant differences in sensitivity and accumulation rate of deltamethrin between different species of marine aquaculture organisms.