The Biodiversity Of Benthic Shellfishes In Liusha Bay And Carrying Capacity Of Pinctada Fucata Martensii

Three contents of this thesis were under researched, which contained the biodiversity and tolerance value of benthic shellfishes in Liusha Bay firstly, the Filtration rate, Feeding rate and energy budget of Pinctada fucata martensii secondly, and the carrying capacity of Pinctada fucata martensii in Liusha Bay. The result showed that:1 The biodiversity of benthic shellfishes in Liusha Bay(1) The species, biomass and abundance of benthic shellfishesThe annual survey of benthic shellfishes was helded during the time form March 2008 to January 2009. About 104 species of benthic shellfishes lived in Liusha Bay, within that 24 species belong to Veneridae, and Ostreidae and Mytilidae contained 6 species respectively, the other genera just had less than 5 species. As to the benthic shellfishes'biomass , the average of that was 101.05 g·m^-2 in Liusha Bay, and the highest one was Dajing investigated in September which contained 469.07g·m^-2. Basing on the different survey stations, Yingliang had the biggest biomass(146.46g·m^-2), and Dajing ranked second (the biomass=136.18 g·m^-2), the lowest biomass lied in Haiwei(42.82 g·m^-2). About the different month, from the month contained the highest biomass to the one had the lowest biomass, the sequence was September(159.96 g·m^-2), July (133.10 g·m^-2), November (109.76 g·m^-2), January(73.99 g·m^-2), March(66.10 g·m^-2) and May(63.42 g·m^-2). As to the benthic shellfishes'abundance, the average of that was 129.4 inds·m^-2, Wangzhong was the station having the highest abundance(556.0 inds·m^-2). Basing on the different station, Yingliang had the biggest abundance, about 182.8 inds·m^-2, then Dahu, Titong and Haiwei, the abundance were 181.8 inds·m^-2, 175.6 inds·m^-2 and 59.1 inds·m^-2 respectively. About the different month, from the month contained the highest abundance to the one had the lowest abundance, the sequence was November (183.2inds·m^-2), July(174.6 inds·m^-2), September(134.0 inds·m^-2), March(118.2 inds·m^-2), January(108.9 inds·m^-2) and May(57.4 inds·m^-2).(2) The biodiversity of benthic shellfishes in Liusha BayAccording to the Shannon-Wiener Index(H′for short) of benthic shellfishes, it was found that, only two stations'(Yugang & Daling) H′lied in 1², with the number were 1.22 and 1.08 respectively, which meaned the two station were under moderately polluted. And the other stations such as Titong, Haiwei, Yingliang, Dahu and Wangzhong were all between 0¹, with the numbers were 0.85, 0.64, 0.83, 0.95 and 0.48 respectively, showed that all the stations were heavily polluted domains. As to the Margalef′s species richness index: the higher index, the higher species richness. And the result as fllow: Dahu and Yugang had the same idex(0.94), then the indexes of Yingling, Titong, Haiwei, Dajing and Wangzhong were 0.83, 0.81, 0.61, 0.57 and 0.24 respectively.And the charts of Bray-Curtis & MDS showed that, about theâ… cluster level(50%), the 7 stations were dived into 6 cluster group, only Dahu & Yingliang become a cluster team(Team A). Under the cluster level of 40%, the Team A was joint Haiwei and Yugang firstly, becomed into a new cluster team, meaned the similarity of species composition of the two stations were high. Then Dajing & Titong becomed another cluster team under the cluster level of 42%, only Wangzhong joint the two cluster teams finally, with the reason was the similarity of species composition of Wangzhong was totally different from other stations. As to the ABC Curve of the 7 stations, the curve of Dajing was not overlapped and turned, and the W value of Dajing's curve was positive, but another 6 stations'were all negative, meaned the ocean environment of Dajing without any interference, in a steady state. And the curves of Haiwei, Titong and Yugang were at the intersection of state, meaned the three stations were under mild or moderate interference.As to the K-Dominance Curve, the starting point of Dajing's was lower(30%), showed that the shellfish community of Dajing had not been significantly affected. And the starting point curves of Yugang, Haiwei, Titong, Yingliang and Dahu were higher gradually station by station. It also meaned the influence of the 5 stations would be gradually increased.According to the results above, the sea areas of Liusha Bay were under environmental polluted, and the pollution levels are medium to high.2 The tolerance value of benthic shellfishes in Liusha BayAbout 16 families of benthic shellfishes were under researched, the result showed that, Murucudae, Nassariidae and Potamididae had the highest tolerance value, the figure was 10.0. And the tolerance value of the three families Trochidae, Mitridae and Veneravea lied in 9.0⁹.9. As to the Arcidae, Mytilidae, Ostreidae, Tellinidae, Solenidae, Glauconomidae, Columbellidae, Fissurellidae, their tolerance value were all between 8.0 to 9.0. The tolerance value of another two families of Cerithiidae and Littorinidae were lied in 6.0⁷.0. The tolerance value of all the families were more than 6.5, which manifested the stain resistance capability of the benthic shellfishes in Liusha Bay were strong, they would be better able to adapt to the more harsh environment. 3 Feeding on algae, the Pinctada fucata martensii's filtration rate and feeding rateFeeding physiological experiment on filtration rate and feeding rate of Pinctada fucata martensii showed that: (1) The filtration rate and feeding rate of individual would be raised as the increased of Pinctada fucata martensii's dry weight. And the filtration rate and feeding rate of the per unit dry weight of Pinctada fucata martensii were reduce as the decrease of pet unit dry weight, the two part had a power function relationship. (2) The feeding rate and the filtration rate of Pinctada fucata martensii would had a significant change as the increase of food concentration. On the aspect of feeding rate, Pinctada fucata martensii had a strong ability of Self-regulation, when the food concentration reached a certain level, Pinctada fucata martensii would regulate its feeding rate, assuring the rate maintain a moderate trend of decline. (3) Under the same number of cells of zhanjianggensis and Platymonas subcordiformis, when three different sizes of Pinctada fucata martensii feeding on them, all the feeding rate and filtration rate showed the same trend. The filtration rate and feeding rate to zhanjianggensis were significantly higher than that to Platymonas subcordiformis.4 The energy budget of Pinctada fucata martensiiThe feeding energy, respiration energy, growth performance, energy of nitrogen excretion and energy of defecation would be reduced as the dry weight of Pinctada fucata martensii increased. And energy budget of three different size(big, middle and small) of Pinctada fucata martensii would be: (Big) 100C=43.73P+15.27R+11.03U+29.97F (Middle) 100C=31.75P+24.28R+5.06U+38.91F (Small) 100C=21.52P+22.39R+4.20U+52.33F Note: C stands for feeding energy, P stands for growth performance, R stands for respiration energy, U stands for energy of nitrogen excretion, F stands for energy of defecation. (The Same as the whole equation)Under the experiments of food concentration(7.76±0.4 mg·L-1,15.05±0.7 mg·L-1,23.32±0.7 mg·L-1,38.09±0.4 mg·L-1,49.86±0.7mg·L-1), the feeding energy, respiration energy, growth performance, energy of nitrogen excretion and energy of defecation of Pinctada fucata martensii were showed the trend of a parabola. Furthermore, the feeding energy, respiration energy, growth performance, energy of nitrogen excretion would the highest in the concentration of 38.09±0.4 mg·L-1 The energy budget of the experiments under the 5 different concentration of food would showed that: (7.76±0.4 mg·L-1) 100C=14.39P+43.37R+4.59U+37.65F (15.05±0.7 mg·L-1) 100C=20.34P+35.42R+2.85U+41.40F (23.32±0.7 mg·L-1) 100C=22.20P+30.01R+2.87U+44.92F (38.09±0.4 mg·L-1) 100C=32.17P+23.64R+1.37U+42.82F (49.86±0.7 mg·L-1) 100C=-3.40P+63.40R+3.38U+36.62FUnder the experiments of 5 different levels of salinity (15‰,20‰,25‰,30‰,35‰), the feeding energy, respiration energy, growth performance, energy of nitrogen excretion and energy of defecation of Pinctada fucata martensii were showed the trend of a parabola. It was also found that when the salinity was between 25‰to 30‰, the growth efficiency relatively high than other levels. The energy budget of the experiments under the 5 different levels of salinity would showed that: (15‰) 100C=21.47P+27.50R+7.39U+37.63F (20‰) 100C=23.41P+27.05R+6.57U+40.56F (25‰) 100C=25.95P+22.17R+6.23U+42.47F (30‰) 100C=36.50P+15.14R+1.37U+43.73F (35‰) 100C=30.01P+25.49R+6.65U+36.76FUnder the experiments of 5 different levels of temperature (10℃,15℃,20℃,25℃,30℃), the feeding energy, respiration energy, growth performance, energy of nitrogen excretion and energy of defecation of Pinctada fucata martensii were showed the trend of a parabola, and under the experiment of 25℃, all the parameters of energy budget were highest compared to the other four temperature levels. And it was also found that, the high temperature would do better to the growth of Pinctada fucata martensii. The energy budget of the experiments under the 5 different levels of temperature would showed that: (10℃) 100C=0.07P+36.15R+1.90U+54.15F (15℃) 100C=15.77P+30.55R+1.38U+52.31F (20℃) 100C=18.71P+31.49R+1.08U+48.72F (25℃) 100C=25.78P+29.47R+1.02U+43.73F (30℃) 100C=16.60P+31.59R+2.05U+49.76F5 The carrying capacity of Pinctada fucata martensii in Liusha BayThe nutrition dynamic model ( P = k?BEn) was used to estimate the carrying capacity of Pinctada fucata martensii in Liusha Bay. Within the model, the fresh weigh of phytoplankton in Liusha Bay(B) was 108.74 mg·(m2·d)-1, Eco-efficiency(E) was 15.18%, the Ratio(K) of the weight Shellfish(with shell) to Fresh tissue was 3.88, the nutrition level was 1.05. The result showed that the carrying capacity of Pinctada fucata martensii in Liusha Bay was 25792.9t, with the aquaculture area 69 km2. Obviously, the aquaculture of Pinctada fucata martensii oversaturated, it would be raise the reasonable measure of how to plan and manage the aquaculture area and aquaculture structure of Pinctada fucata martensii in Liusha Bay, basing on the carrying capacity of Pinctada fucata martensii.