[Effects of artificial reef construction to marine ecosystem services value: a case of Yang-Meikeng artificial reef region in Shenzhen].

Based on the researches and statistic data of Yangmeikeng artificial reef region in Shenzhen in 2008 and by the method of ecosystem services value, this paper analyzed the effects of artificial reef construction in the region on the marine ecosystem services. After the artificial reef construction, the tourism service value in the region decreased from 87% to 42%, food supply service value increased from 7% to 27%, and the services value of raw material supply, climatic regulation, air quality regulation, water quality regulation, harmful organism and disease regulation, and knowledge expansion had a slight increase, as compared to the surrounding coastal areas. The total services value per unit area of Yangmeikeng artificial reef region in 2008 was 1714.7 x 10(4) yuan x km(-2), far higher than the mean services value of coastal marine ecosystem in the surrounding areas of Shenzhen and in the world. Artificial reef construction affected and altered the structure of regional marine ecosystem services value, and improved the regional ecosystem services value, being of significance for the rational exploitation and utilization of marine resources and the successful recovery of damaged marine eco-environment and fish resources. Utilizing the method of ecosystem services value to evaluate artificial reef construction region could better elucidate the benefits of artificial reef construction, effectively promote the development of our artificial reef construction, and improve the management of marine ecosystem.

[Effects of di-n-butyl phthalate on the antioxidant enzyme activities and lipid peroxidation level of Perna viridis].

A laboratory experiment was conducted to examine the superoxide dismutase (SOD) and catalase (CAT) activities and the lipid peroxidation (LPO) level presented by malondialdehyde (MDA) in visceral mass and mantle of green mussel (Perna viridis) after exposure to 0.5- 62.5 mg x L(-1) of di-n-butyl phthalate (DBP) for 15 days, and to study the change characteristics of these biochemical indicators after the green mussel released into DBP-free seawater for 10 days. During exposure period, the SOD activity in visceral mass was inhibited first and then reached the level of the control at 0.5 and 2.5 mg x L(-1) of DBP, but inhibited significantly (P< 0.01) at 12.5 and 62.5 mg L(-1) of DBP. The CAT activity in visceral mass was inhibited at all test concentrations of DBP, while the LPO level was obviously induced. During the chronic DBP exposure, the SOD and CAT activities in the mantle were induced significantly but had no regular pattern, and the LPO level was also obviously induced. After the exposed green mussel was released into clean seawater, the SOD and CAT activities in the visceral mass in 12.5 and 62.5 mg DBP x L(-1) groups recovered much slowly, but the LPO level gradually recovered to control level. During the recovery period, the SOD activity in the mantle showed an increasing trend with time, but the CAT activity and LPO level reached gradually to the level of the control.

Antioxidant responses and bioaccumulation in green-lipped mussels (Perna viridis) under acute tributyltin chloride exposure.

Green-lipped mussels (Perna viridis) were exposed to waterborne tributyltin chloride (TBTCl) at different concentrations (0.2, 0.4 and 0.8 µg L(-1)) for up to 72 h. Accumulated TBTCl in Perna viridis correlated linearly with the exposure concentrations of 0.2 µg L(-1)(R(2) = 0.772), 0.4 µg L(-1)(R(2) = 0.952), and 0.8 µg L(-1)(R(2) = 0.909). The results of superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) all decreased in gill tissues after 24 h of exposure, but the hepatic SOD and the hepatic GPx showed either little or no effect on exposure of TBTCl solutions. Analysis using the Spearman rank correlation coefficient showed the hepatic GPx activity appeared to have a significant negative correlativity (R(s) = -0.42) with the exposed TBTCl concentrations, and the hepatic MDA was significantly negatively correlated (R(s) = -0.33) with the tissue TBTCl concentrations. Conversely, a significant positive correlation (R(s) = 0.60) was shown between the gill MDA contents and exposure time. This study illustrates oxyradical scavenger GPx best correlated with stress level of pollutants among the various antioxidant parameters.

Enormous PCBs increase in oysters from the coast of Guangdong, China.

PCBs equivalent to Aroclor 1242 and 1254 in soft tissues of oysters Crassostrea rivularis from the Guangdong coast, China, were measured using a GC-ECD. PCB concentrations (ng g(-1)d.w.) ranged from 30 to 2040 with an average of 315 in 2003-2007, and 0.35-1.43 with an average of 0.56 in 1989-1991. Annual averages were 0.61, 0.65, 313, 290 and 342ng g(-1), respectively in 1989, 1991, 2003, 2006 and 2007. In east Guangdong, the Pearl River Estuary, and west Guangdong, regional means were 444, 273, 194ng g(-1), respectively in 2003-2007, and 0.43, 0.78, 0.38ng g(-1), respectively in 1989-1991, indicating PCB levels in oysters have risen greatly by ratios of 350-1032 compared with earlier data. PCB sources may derive from older transformers, printing materials and pressworks. Fortunately, current residual PCBs in the oysters were 0.004-0.253mg kg(-1) (w.w.), still below hygienic criteria of China and developed countries.

[Variations of fish species diversity, faunal assemblage, and abundances in Daya Bay in 1980-2007].

Based on the 2004-2005 otter trawl survey data and the 1980-2007 relevant historical records, this paper analyzed the variations of fish species composition, faunal assemblage, diversity indices, dominant species, and abundance in Daya Bay. In the 2004-2005 trawl survey, a total of 107 fish species were recorded, belonging to 50 families and 13 orders, among which, meso-demersal fish were predominant, with 48 species recorded, and followed by pelagic and demersal fishes, with 37 and 21 species, respectively. The fishes in the Bay belonged to tropical and subtropical fauna, with the dominance of warm water fishes (97 species) and warm-temperate water fishes (10 species). The diversity index was the highest in summer (3.82), followed by in winter (3.37) and autumn (3.00), and the lowest in spring (2.40). The seasonal variation of Pielou evenness index mimicked that of diversity index. In 1980-2007, the characteristics of fish community in the Bay changed obviously. The species number reduced from 157 species in the 1980s to 110 species in the 1990s and to 107 species in 2004-2005, and the dominant species shifted from the high-value fishes such as hairtail and pomfret in the 1980s to low-value fishes such as sardine fish, anchovy, and juvenile porgy. A non-linear regression model composed of inter-annual trend and seasonal cycle was used to simulate the changes of fish stock density in 1980-1999 and 1990-2007, and the results indicated that in the two periods, the fish stock density in the Bay all showed a decreasing trend, but the decrement was larger in 1990-2007 than in 1980-1999. The seasonal variation of the stock density in 1980-1999 was relatively small, with an amplitude being 0.099, while that in 1990-2007 was relatively larger, with the amplitude being 0.420, illustrating that the fish abundance in the Bay had a larger seasonal fluctuation in 1990-2007.

[Effects of fishing on the marine ecosystem of Beibu Gulf].

By using Ecopath with Ecosim 5.1 software, the Ecosim model of Beibu Gulf marine ecosystem in 1959-1960 was constructed, which included about 20 functional groups such as fishery, marine mammals, sea-birds, sharks, pelagic fishes, demersal fishes, and benthic crustaceans, etc. Through the comparison with the investigation data in 1997-1999, the effects of fishing on the structure and function of Beibu Gulf marine ecosystem were analyzed. The results indicated that with the increasing fishing pressure in past forty years, the ecosystem structure and function shifted drastically, with the biomass of long-lived, high trophic level and piscivorous fishes declined while short-lived and small fishes and benthic invertebrates dominated gradually. The biomass of piscivorous species in 1999 was only 6% of that in 1960, while cephalopods increased 2.7 times or more. The trophic level of the catch declined from 3.2 in 1960 to 2.98 in 1999, which fitted the rule of "fishing down the food web" and suggested that the present exploitation patterns were unsustainable. Based on the data of the 1990s, the changes of the ecosystem under decreasing fishing pressure were predicted. This study validated the feasibility of Ecosim model in predicting the effects of fishing pressure on marine ecosystem.

[Variation characteristics of macrobenthos productivity in Daya Bay of South China Sea].

Based on the 7 cruises survey data collected from 63 research stations in the Daya Bay of South China Sea in January and July 1988 and in March, May, September and December 2004, the variation characteristics of the abundance, biomass, productivity, and P/B value of macrobenthos in the two years were analyzed by using Brey's empirical formula. The results showed that in 2004, the mean productivity and P/B value of macrobenthos in study area were 10.22 g AFDM x m(-2) x a(-1) and 0.85 x a(-1), respectively, being at the medium-high level among the sea areas in China and higher than those in 1988 (7.25 g AFDM x m(-2) x a(-1) and 0.76 x a(-1), respectively), which corroborated the conclusion that the high output system of Daya Bay relied on the fast turnover to maintain its high productivity. The variation characteristics of the productivity and P/B value varied among the four main groups of macrobenthos, and the horizontal distribution of macrobenthos productivity also had a greater variation. The regional differences of the productivity and P/B value were closed related to human activities, and the areas in which the productivity varied significantly were intensively affected by human activities.

[Accumulation and release characteristics of heavy metals in Crassostrea rivalaris under mixed exposure].

With a mixed solution of lead (Pb), zinc (Zn), copper (Cu), nickel (Ni), cadmium (Cd), chromium (Cr), mercury (Hg) and arsenic (As), this paper studied the accumulation and release characteristics of test heavy metals in Crassostrea rivalaris. The results showed that C. rivalaris had a strong ability to accumulate Pb, Cu, Ni, Cd, Cr and Hg, being able to indicate the concentration levels of these heavy metals in solution, but a weak ability to accumulate Zn and As. In the following 35 days release stage, no significant change was observed in the contents of test heavy metals in C. rivalaris, suggesting that C. rivalaris had weak ability to release heavy metals. Two-compartment kinetic model could well fit the accumulation of heavy metals in C. rivalaris, but failed in simulating their release characteristics.

[Theory and application of marker-assisted introgression].

Marker-assisted introgression (MAI) is one of the major applications of molecular information in animal breeding aiming at introgression of one or more favorable genes from a line (donor) to another (recipient), while keeping the genetic background of the recipient as much as possible. It consists of three phases. Firstly, cross donor and recipient lines to produce F1; secondly, repeated backcross the F1 individuals and the subsequent progenies with the recipient to recover its genetic background; and thirdly, intercross the backcrossed progenies to fix the introgressed genes in the population. Many factors affect the efficiency of MAI, among which the methods of foreground and background selection are very critical.

Comparison of different foreground and background selection methods in marker-assisted introgression.

Three different methods for foreground selection and four different methods for background selection were compared in terms of the efficiency of marker-assisted introgression of a QTL allele from a donor line into a recipient line and also in terms of the recovery of the recipient genetic background. The results showed that for the introgression of a donor QTL allele, a direct selection on the QTL itself (when the QTL genotype can be directly identified) would ensure that the allele is successfully introgressed and rapidly fixed. However, when a direct selection on the QTL is not feasible, an indirect selection using two closely linked flanking markers can be used, which also shows similar results. For the recovery of the recipient genetic background, if the goal is to recover the whole genetic background of the recipient, genomic similarity selection or marker index selection would be the best choice: Only three generations of backcrosses were required to recover over 98% of the recipient genome. Whereas if the goal is to recover certain background traits of the recipient, MBLUP selection would give the best results, which achieved not only over 99% recovery of the recipient QTL alleles for the background traits after three generations of backcrosses, but also showed the best genetic improvement of these traits.

[Influence of maternal genetic effect on genetic parameter estimates of production traits of cashmere goat].

The derivative-free restricted maximum likelihood (DFREML) method was used to compare the differences of genetic parameter estimates of Inner Mongolian Cashmere Goats under two models, which differ in whether maternal genetic effect is taken into account. The differences between the two models were, tested by likelihood ratio test. The results show that maternal genetic effect highly affects live body weight and cashmere thickness while has no significant effect on raw cashmere weight, staple length, fibre diameter and fibre length.