Abstract:In order to investigate the cytogenetic characters of Parabramis and Megalobrama, their karyotype polymorphisms were studied through cell culture in vivo. The DNA contents of M. amblycephala and M. amblycephala and P. pekinensis were measured for the first time. The karyotype of M. amblycephala is 2n=24m+20sm+4st, NF=92, DNA content is 2.66 pg. The karyotype of M. hoffmanni is 2n=26m+18sm+4st, NF=92, DNA content is 2.57 pg. The karyotype of M. pellegrini is 2n=26m+18sm+4st, NF=92, DNA content is 2.81 pg. The karyotype of M. amblycephala is 2n=24m+20sm+4st, NF=92, DNA content is 2.60 pg. The karyotype of P. pekinensis is 2n=26m+22sm, NF=96, DNA content is 2.34 pg. The chromosomal karyotypes of Megalobrama genus had convergence during evolution and obviously different from that of P. pekinensis. Both DNA content and fundamental arm number (NF) are significantly different between Parabramis and Megalobrama. In terms of the fundamental arm number (NF), the P. pekinensis should belong to specialization group, while Megalobrama species belong to primitive classification. Collectively, our results could provide essential data for chromosome set manipulation and genome research of Parabramis and Megalobrama.

Abstract:Cyclin M2(CNNM2) is one of the regulatory transport genes involved in zebrafish Mg²⁺ homeostasis. We generated CNNM2 gene knockout zebrafish by CRISPR/Cas9 system which has been developed into a novel gene targeting system in recent years.First, we constructed the sgRNA expression vector targeting zebrafish CNNM2 gene. Then, after in vitro transcription of sgRNA and Cas9 vectors, we co-injected them into one-cell fertilized eggs of zebrafish to generate zebrafish with targeted mutation. After 24-48 h, injected embryos were collected and used to conduct mutation analysis with restriction endonuclease and sequencing. To further verify the stability of genetic mutations, we selected mutated founder to outcross with wild type zebrafish. A knockout and wild-type outcross F₀ efficiency were obtained, and then F₁ were analyzed by PCR and sequencing of the caudal fin. The results showed F₀ and F₁ were introduced insertion, deletion and frameshift mutations to some extent, and F₀ mutation efficiency was 88%. The CNNM2 gene knockout zebrafish generated in this study can be transmitted by germline and provide a basis for further study of CNNM2 and Mg²⁺ homeostasis.

Abstract:In this study, we selected Coilia nasus as the research object, and we studied the effect of transport response on mRNA level of hypothalamus-pituitary-interrenal axis (HPI) genes and liver oxidative indices, using qRT-PCR and biochemistry method. Meanwhile, Coilia nasus were soaked with a certain concentration of glycyrrhizin (GL) to investigate the regulation of the above indices during transportation. The results showed that corticotropin releasing hormone (CRH) mRNA, proopiomelanocortin (POMC) mRNA and urotensin I (UI) mRNA expression in brain were significantly suppressed after transportation. Glucocorticoid receptor (GR) mRNA expression in head kidney decreased significantly at 2 h and reached the minimum at 4 h, then increased obviously at 8h. After transportation, Catalase (CAT) activities in liver decreased significantly, the level of malonaldehyde (MDA) in liver rose dramatically, glutathione peroxidase (GSH-PX) activities and the lipid peroxide (LPO) content of liver had no significant change. After 6 h, glycyrrhizin suppressed distinctly the level of GR mRNA in head kidney, and inversely stimulated CRH mRNA and POMC mRNA expression of brain with significant difference, but UI mRNA expression in brain had no obvious change. Moreover, glycyrrhizin had no significant effect on the activities of CAT and GSH-PX and the content of MDA and LPO. All the results above indicated that levels of HPI genes expression were changed to different extent after transportation. Transport response reduced hepatic anti-oxidative capacity and caused oxidative stress in Coilia nasus. Likewise, glycyrrhizin can regulate the expression of HPI genes, but it can't effectively relieve oxidative stress caused by transport stress.

Abstract:In laboratory culture conditions, a high proportion of gynogenic Pengze crucian carp (Carassius auratus var. Pengze, Pcc) male fish occurred in F₁ progenies compared with pond culture conditions. All these F₁ progenies were bred from the same parents and obtained via artificial gynogenic method. In order to find the accurate relationship between this variant sex ratio and the culture density, gynogenic PccF₂ progenies were obtained from female PccF₁ offspring and activated by the sperm of red carp (Cyprinus carpio var. red style). They were maintained in different culture densities. Then we chose the male ones from the high-density culture groups, and the female ones from the low-density culture groups. Ovarian gene expression profiles were detected and compared between the male and female F₂ progenies respectively. Results showed that ovarian transcripts of dmrt1c, anti-Mullerian hormone (amh), aromatase (cyp19a1a) were higher than those corresponding transcripts in the testis of PccF₂ offspring both in low-density and high-density culture groups. Ovarian dmrt1a, dmrt1b, 3β-hydroxysteroid dehydrogenase (3bhsd), 11β-hydroxysteroid dehydrogenase 2(11bhsd2), 17α-hydroxylase/17,20-lyase 1(cyp17a1) and steroidogenic acute regulator protein (star) were lower than those corresponding transcripts in the testis of PccF₂ offspring both in low-density and high-density culture groups. The gene expression profiles for steroidogenic genes of PccF₂ progenies differed from different genders and densities in laboratory culture conditions, which may cause the phenomenon of high proportion of the existing male ones.

Abstract:Impacts of different Na⁺ and K⁺ concentrations and Na⁺/K⁺ ratios on the hatching rate of fertilized eggs, deformity rate of newly hatched larvae and survival time of larvae of Anguilla japonica were studied in this paper. There were three experiments1) maintaining normal Na⁺ concentrations, while changing the concentration of K⁺; 2) maintaining normal K⁺ concentrations, while changing the concentration of Na⁺; and 3) maintaining stable Na⁺/K⁺ at 28, while changing both Na⁺ and K⁺ concentrations. The results showed thatWhen the concentration of K⁺ was 538 mg/L and Na⁺ 10760 mg/L, the highest hatching rate (44.0%) and the lowest deformity rate (23.8%) as well as the longest survival time were achieved. When Na⁺ to K⁺ ratio maintained at 28, with Na⁺ and K⁺ concentrations at 8400 mg/L and 300 mg/L respectively, the hatching rate was the highest among the five groups. Hatching rates would decline if the concentrations of Na⁺, K⁺ were too high (19500 mg/L and 1076 mg/L respectively). These results indicated that appropriate Na⁺, K⁺ concentrations and R values are required with optimum Na⁺, K⁺ concentrations varying between 7800-11700 mg/L and 360-540 mg/L respectively and R values 20-30.

Abstract:The key technologues of Brachymystax lenok tsinlingensis were studied on parent fish domestication, artificial breeding and hatching. The appropriate varieties and dosages of exogenous hormones were explored for promoting maturation and spawning of parent fish. 580 five-to-nine -year -old parental fish were primarily acquired in the wild from March 2011 to March 2014. The results showed that through a 30-day-domesticated feeding Tenebrio molitor, the wild parental fish was totally accustomed to artificial food. And according to the results, treating the fish with exogenous hormone DOM (2.5 mg/kg) and S-GnRHa (3μg/kg) would accelerate the maturation of the parent fish. 4.56×10⁴ eggs and 8×10⁴ eggs were harvested artificially in 2013 and 2014 respectively. The average hatching rate was 63%, and the fertilization rate was 82.5% in 2013. The average hatching rate was 62.5%, and the fertilization rate was 85.5% in 2014. The periods when the fish-fry floated during initial food intake and feed conversion are critical. Based on the gonad development, a postulate-"protecting in winter, propagating in spring, growing in summer, cultivating in autumn" was proposed for the improvement of the quality of sperms and eggs during the artificial cultivation. Artemia was the better choice as initial feed during the period of critical artificial cultivation. Feeding high protein diets would improve survival rate during the period of food conversion after the complete maturation of the digestive and immune systems of the juvenile fish.

Abstract:Coilia nasus is a dominant species in the fish community of Dianshan Lake and investigation on its diet composition contributes to understanding interspecific relationship and ecosystem structure of this lake. A total of 387 stomach specimens of C. nasus were collected in Dianshan Lake from August 2009 to July 2010. Based on those specimens, the diet composition of this fish was conducted using the traditional method of stomach contents. C. nasus preyed all year round with the highest index of fullness in summer and the lowest in winter, and with the highest rate of empty stomach in antumn and the lowest in spring. The diet composition of C. nasus covered 13 large and 30 small categories. Cluster analysis showed that numerical percentage (N%), occurrance rate (F%), and percent index of relative importance (IRI%) are consistent in measuring importance of each food category to C. nasus, all indicating that Cladocera and Copepoda were the main food sources for C. nasus; However, there were significant differences in measuring the contribution between gravimetric percentage (W%) and each of the three above mentioned indices. The W% displayed that the shrimp, Cladocera, and fish were the main food sources for C. nasus. The N% of the food composition of C. nasus did not significantly differ among seasons, but the W% of food composition did. Combining the results of all the four indices, we concluded that C. nasus in Dianshan Lake mainly feeds on crustacean zooplankton, fish and shrimp. The information on diets of C. nasus suggests that this fish may promote the growth of phytoplankton by top-down effect, implying that reduction of C. nasus' biomass would contribute to the ecological restoration of Dianshan Lake.

Abstract:Artificial propagation techniques of the grey mullet including brood stock culture and spawning induction were investigated. When the water temperature was 22-25℃, the response time and incubation period was 36 h and 52 h, respectively, after injecting HCG 1000 IU/kg and LRH-A₂ 10μg/kg into mature brood stock. The egg was pelagic and spherical, egg size and yolk diameter was (316.4±6.9) μm, and (190.8±5.4)μm. respectively. The process of embryonic development in grey mullet could be divided into seven stagesthe placenta formation stage, cleavage stage, blastula stage, gastrula stage, neural embryo stage, organ formation stage, and bitching stage. The present study indicates that response time and incubation period shortened with the rise of temperature in a certain temperature range. Hatching rate was 82%, when the temperature is 18-21℃.

Abstract:In order to explore the effect and mechanism of non-starch polysaccharides (NSPs) on growth and feed utilization of Chinese mitten crab, Eriocheir sinensis, soluble pectin (SP), insoluble pectin (ISP), soluble xylan (SX) and insoluble xylan (ISX) were included in test diets at 12% and were fed to juvenile Chinese mitten crab with initial body weight of (1.6±0.7) g for 13 weeks. Diet viscosity, special growth rate, feed conversion ratio, energy and nutrients retention, body composition, serum cholesterol and triglyceride, activities of lipase and amylase in hepatopancreas were measured. The results showed that dietary viscosity varied greatly, and SP diet had the highest viscosity, followed by ISP diet, and ISX diet had the lowest value. No significant difference was observed in special growth rate, body composition and digestive enzyme activity among groups (P > 0.05). Feed conversion ratio of group SP was higher than that of group ISP and group SX (P < 0.05) while no significant difference was detected between group ISX and other groups (P > 0.05). Retentions of protein, lipid and energy of group SP were lower than those of group ISP (P < 0.05), however, protein retention of group SX was higher than that of group ISX (P < 0.05) and no significant difference was detected between group ISP and group SX. No significant difference was observed in serum cholesterol between soluble and insoluble NSPs (P > 0.05). However, it was lower in group ISP than in group SX and ISX (P < 0.05). These results suggested that tested NSPs influenced the nutrients utilization of Chinese mitten crab, which might attribute to their viscosity but not the solubility. Both high and low viscosity of diet would reduce feed utilization. NSPs might decrease the resorption of bile acid but not lipid utilization

Abstract:Referring to the 96 h-LC₅₀ values of Perfluorooctane sulfonate (PFOS) on Danio rerio, four groups with concentration of 0, 1, 5 and 10 mg/L were set to explore the toxic effect of PFOSon fish. Indices of the physiological and biochemical parameters, such as the activities of alkaline phosphatase(ALP), lactate dehydrogenase(LDH), and acetylcholinesterase (AchE) in the fish head, the superoxide dismutase(SOD), catalase(CAT), malondialdehyde (MDA) and ALP in the fish visceral were analyzed. ALP, SOD and MDA in the muscle of Danio rerio were also determined. The results showed that the activities of ALP and AchE in the head would be inhibited at the beginning of the experiment, then recover gradually. PFOS with medium-low concentration(1mg/L and 5 mg/L)induced LDH activity in the head to rise remarkably. ALP in the visceral mass was significantly induced and showed dose-effect relationship with PFOS concentration. After being significantly induced at 0.5-1 h, the activity of SOD and CAT declined later, but no significant inhibition was found. The content of MDA was significantly induced. In the muscle, the activity of ALP was significantly inhibited by PFOS(P < 0.05), but SOD activity and MDA content were not affected.

Abstract:The dewatered sludge samples were collected in one wastewater treatment plant and the content of Cu was 116.04-316.68 mg/kg and Pb was 13.13-37.02 mg/kg. The influence of temperature, salinity and pH on Cu, Pb solubility in excess sludge was researched. It could be obtained that the release amount(average=0.567 mg/L) of Pb in acid conditions(pH=6.5)was less than that(average=0.641 mg/L) in alkaline conditions(pH=8.5),which was different from Cu(0.063>0.061), but the total release amount of Pb was greater. Temperature had obvious effect on Cu, Pb release, the heavy metals were easier to release along with the temperature increase, and at high temperature it could be quicker to reach the equilibrium concentration. Salinity had significant effect on heavy metal release in excess sludge, the release amount of Cu, Pb increased along with the salinity increase, and the equilibrium concentration was sooner to reach at higher salinity.

Abstract:The abundance and distribution characteristics of Synechococcus in the East China Sea(26°~30°N, 120°~127.5°E)in summer were investigated by epifluorescence microscopy. The average abundances of Synechococcus and CB/PB were 1.65×10⁴ cells/mL and 4.85μgC/L respectively.The abundance of Synechococcus decreased from coastal waters to external waters in horizontal direction. In vertical distribution the abundance of Synechococcus shows obvious difference among four depths, and decreases with depth from surface to bottom.The average value of CB/PB was 22.65% in the investigated area. In horizontal direction,the CB/PB increased from coastal waters to external waters. Pearson correlation analysis between Synechococcus or CB/PB on the one hand,Chl.a, water temperature, salinity, turbidity on the other,showed that there was a positive correlation between Synechococcus and Chl.a and water temperature, while there was a negative correlation between CB/PB and NO₃^--N, TIN, PO₄^3--P, salinity and TU.

Abstract:A coupled ECOM-si/N₂P₂ZD model with real-time solar radiation and sea surface heat flux was applied to evaluate the impact of thermal discharge from two coastal power plants (Guohua and Wushashan) on the plankton biomass in Xiangshan Bay. The simulated results show that thermal discharge and its mechanical entanglement and residual chlorine significantly decrease the plankton biomass and change the seasonal and spatial distribution of the biomass. In the warming season, spring and early summer, thermal water makes the occurrence of algal bloom occur earlier than normal. In summer, high water temperature exceeds the optimum growth temperature and leads to a decline of the phytoplankton biomass, and a risk reduction of the red tide. In the cool autumn and cold winter, when the water temperature is lower than the optimum growth temperature, thermal water can increase the primary productivity during this period. In addition to seasonal variation of phytoplankton and zooplankton biomass, annual average biomass of plankton is decreased by the damage of thermal water. The increased amount of detritus decrease the loss of total organism in the sea water, but the changes of annual average total organic matter damaged by thermal water is still negative. The thermal discharge of Guohua power plant impacts greater than Wushashan power plant. Both the range of area with temperature increased and plankton biomass variation, the Guohua power plant impacts the sea area in Tie Port greater than in Huangtun Port.

Abstract:In order to find out the composition and seasonal changes of zooplankton in the surf zone of sandy beach in Sijiao Island,zooplankton were collected at the 8 stations by a zooplankton net (0.3 cm mouth-diameter,0.2 mm mesh-aperture) each month during the spring tide from August 2010 to August 2011. During the study period,67 species and 10 kinds of planktonic larvae were collected. They included 56 crustacean species(43 copepod species,3 cladoceran species and 10 other species),4 chaetognath species,7 medusa species. There were 13 dominant species in total,such as Paracalanus parvus,Paracalanus crassirostris and Centropages dorsispinatus. The zooplankton in the surf zone of sandy beach in Sijiao Island could be divided into four ecotypes:estuarine low salinity group(2 species),offshore warm temperate group(2 species), offshore warm water group(52 species), and eurytopic group(5 species). The results indicated that zooplankton community in surf zone of sandy beach were mostly offshore warm water group. Affected by salinity,water temperature,ocean current and other environmental factors,seasonal changes were obvious. In spring,the mean density of zooplankton was the highest,while it was the lowest in winter.

Abstract:Jiuduansha wetland is a typical shoal in Yangtze River estuary, which has a very important influence on fishery resources of Yangtze River and East China Sea. In order to comprehend community diversity and its variation trend, 16 surveys from 2009 to 2012 were made, and the results showed that(1)A total number of 12477 individuals were collected belonging to 96 species including 15 new records. (2) Combining with historical data, there were 158 fish species in Jiuduansha wetland, the Order Perciformes was at a dominant position, whose species were 54, the Order Cypriniformes ranked only second to the order Perciformes, comprising 27 species. (3)The dominant species were Acanthogobius hasta, Liza haematocheila, Liza carinatus, Coilia ectenes, Coilia mystus and Lateolabrax maculates. (4)Differences of fish?composition existed in Shangsha, Zhongsha and Xiasha, which revealed that salinity was a very import factor resulting of the difference in fish composition. This research showed that fishery resources of Jiuduansha wetland are abundant, and its fish composition has the typical ichthyofauna trait of Yangtze River estuary.But the diversity of fish species has declined year by year, and changes happened in its fish composition year by year.

Abstract:White shrimp,Exopalaemon modestus,is the important economic species in freshwater lakes. As one of the economic sources for fishermen, studying morphometric traits will help to improve the survival rate of artificial breeding, and benefit the sustainable development of wild white shrimp in Dianshan Lake. 140 individuals were randomly sampled in Dianshan Lake. The body weight was 0.6-3.1 g. Seven morphometric traits including the body length(X₁), length of upper frontal eminence(X₂), carapace length(X₃), carapace width(X₄), abdominal length(X₅), abdominal width(X₆), tail length(X₇) and body weight (Y) were measured. The effects of morphometric traits on body weight were analyzed by using multivariate analysis methods including correlation analysis, path analysis and multiple regression analysis based on taking morphometric traits as independent variables, and the body weight as dependent variable. The results showed that all seven correlation coefficients were at very significant levels (P < 0.01) between each morphometric trait and the body weight. The path analysis revealed that the path coefficients of the body length, length of upper frontal eminence, and abdominal length to the body weight reached a significant level(P < 0.05). Among three attributes above, direct effects of body length on body weight were greater than that of indirect effect. Body length was the key factor to the body weight. High multiple correlation index (0.855) indicated that the main variables have been selected. Body length, carapace length, and abdominal length were used to establish the multiple regression equation, which was Y=-3.195+0.060X₁+0.038X₂+0.041X₅. The selected morphometric traits can provide theoretical measure target for selective breeding of white shrimps.

Abstract:The water flow patterns around hollow trapezoidal reef and hollow square reef in unsteady flow effect were investigated based on CFD numerical simulation, the scale and intensity of upwelling and wake vortex region were revealed, and the flow field differences of monomer reef and combination reef were analyzed. The numerical results show that for trapezoidal reef,the maximum and average velocities of upwelling were about 0.58 to 0.67 and 0.15 to 0.19 times of incoming velocity, the maximum height of upwelling was about 2.12 to 2.49 times of reef height, the average velocities of wake vortex region was about 0.35 to 0.36 times of incoming velocity, the width of wake vortex region was about 1.40 to 1.61 times of reef width, and the length of wake vortex region was about 4.06 to 4.17 times of reef height. For square reef, the maximum and average velocities of upwelling were about 0.56 to 0.61 and 0.15 to 0.17 times of incoming velocity, the maximum height of upwelling was about 2.22 to 2.63 times of reef height, the average velocities of wake vortex region was about 0.30 to 0.35 times of incoming velocity, the width of wake vortex region was about 1.75 to 2.00 times of reef width, and the length of wake vortex region is about 3.90 to 4.06 times of reef height. From the point of flow field control effect, under the same simulation conditions, the square reef could perform better environmental and resources repair functions than trapezoidal reef.

Abstract:In order to improve the mathematical model of Chinese Trachurus japonicus trawls and to optimize network design, the hydrodynamic coefficients of the knotted nylon netting with diamond mesh were measured in the flume tank. The hydrodynamic characteristics represented by the drag coefficient (C_d), lift coefficients (C_L) and their ratio K under varied parameters, i.e. twine diameter, current speed and attack angle, hanging ratio etc. in 5 kinds of netting were studied. The results show that:(1) when Reynolds number(Re) is less than 1500 and the attack angle is less than 45°, the drag coefficient showed a decreasing trend after increasing;And when the attack angle is greater than 45°, drag coefficient showed a decreasing trend. When Reynolds number (Re) is greater than 2800, the drag coefficient reached basically stable states. (2)The maximum values of the ratio of lift coefficient to drag coefficient (K) occurred at about 20 degrees; K values decreased over 30 degrees;(3) The hydrodynamic coefficients firstly increased as d/a increased and then decreased. (4)The hydrodynamic coefficients decreased as the solidity ratio increased.(5)Based on the empirical formula of drag and lift coefficients by multivariate nonlinear regression,the fitness is good.The empirical formula can be used to calculate the resistance of the trawl.

Abstract:Effects of agitator speed, aeration rate, inoculation amount and inoculum age on chitosanase production were studied by single factor experiments designs under the conditions of 0.6 filling coefficient and 0.08 Mpa tank pressure. The results showed that fermentation parameters in 10 L tank were defined as following250 r/min agitator speed, 3% inoculation amount, 2.0vvm aeration rate and seed solution of OD₆₀₀=0.8-1.0. Under these conditions, the highest chitosanase activity in fermentation liquid was detected at 52 h during 56 h fermentation period, which reached (35.2±0.5) U/mL. The maximum chitosanase activity was detected at 60 h during a 64 h fermentation period of feed batch fermentation, which reached (46.4±0.5) U/mL. The enzyme production of feed batch process increased 32% by maintaining the mycelial morphology and extending the time of enzyme production stage. This article has made some contribution to industrial production of chitosanase.

Abstract:Residues of prometryn in edible tissues of codfish, grass carp, channel calfish, catfish, laver were determined by gas chromatography-tandem mass spectrometry (GC-MS/MS) using internal standard method. Such factors as extraction solvent, solvent dosage and choice of solid-phase extraction (SPE) columns were compared in this paper. The target compound was extracted two times with acetonitrile,purified by solid-phase extraction (SPE) with Envi-Carb column and LC-NH₂ column. and analyzed with GC-MS/MS. TR-5MS capillary chromatographic column was used for separation, and the selected reaction monitoring(SRM) with electron impact ionization source was adopted in MS. This method chooses d14-prometryn as internal standard substance. The working curve were linear (r²=0.999) in the range of 5-100μg/L. When spiked with 5.0, 10.0, 25.0μg/kg of prometryn and 10.0μg/kg d14-prometryn, the average recoveries were 82.0%-111.2% and the RSD were 1.2%-6.0%. The detection limit was 0.5μg/kg. The method could meet the requirements of the residul detection. It is suitable for qualitative and quantitative determination of samples.

Abstract:This study aimed to tackle the problems about the subacute toxicity and influence on cytochromeP450(CYP) of Chinese medicine pair(CMP) of Sargassum&Laminaria thallus.Through the test design,18 SD rats,half male and half female,were randomly divided into three groups:low dose,high dose and control.All groups were treated with crude polysaccharides(extracted from Sargassum&Laminaria thallus)or saline by gavage for 2 weeks. During the dosing period,the physiological characteristics of all group members were observed regularly.Until last administration, the animals were sacrificed by anesthesia and were autopsied with the use of HE staining. Three specific probe drugs were utilized for co-incubating in rat liver microsomes to verify the activity of cytochromeP450 in liver.As the results showed,severe chronic pulmonary inflammatories were found in high dose group[86.4 g/(kg·d)]and some adaptive changes occurred in the rat liver as well(e.g.cellular swelling&dilation of hepatic sinusoid)from HE staining. On the other hand,there were no significant changes on liver microsome CYP450 under low dose[10.8 g/(kg·d)] while the high dose one had a significant inducing effect on CYP3A4.As for clinic application, the drug-drug interactions as well as hepatic and pulmonary toxicity might occur when the Chinese medicine pair of Sargassum&Laminaria thallus was taken in high dose orally.

Abstract:Fast accurately coastline extraction using remote sensing method, is one of the important content for marine science research, topographic map surveying, hydrographic and coast & island investigation. LiDAR is becoming one of the most effective remote sensing approach, which could provide 3D surface data of coast and island with high accuracy and speed.First the LAS format of LiDAR data and the data processing flow are analyzed. Based on the average high tide level and the reflection intensity, the LiDAR points cloud data are filtered. Then, the Alpha Shapes algorithm is used in further filtering of the points data and the automatical extracting of the island coastline. The comparison with the high resolution image(0.5m)proves the Alpha Shapes algorithm is precision, effective and suitable for automatically coastline extracting based on LiDAR data.