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In relation to the stock enhancement program for Chinese white shrimp Fenneropenaeus chinensis, hatchery-released juveniles and wild samples in the Yellow Sea and Bohai Sea were genotyped using amplified fragment length polymorphism (AFLP) markers to investigate the levels of genetic variation among these populations. Five AFLP primer combinations generated a total of 757 bands across the 268 individuals in nine hatchery-released populations and three wild populations. All 757 bands were polymorphic. High polymorphism at AFLP markers was found within both hatchery-released and wild populations. The percentage of polymorphic loci for populations ranged from 87.22 to 98.60%, while the Nei's genetic diversity ranged from 0.1822 to 0.2728. Compared with wild populations, the nine hatchery-released populations showed significant genetic changes based on F values. All populations were divided into two distinct groups by principal coordinate analysis (PcoA) analysis. Three wild populations (Dalian, Kengli, Middle Yellow Sea) with hatchery-released populations from Rongcheng, Panjin, and Dandong clustered as one group; the rest of hatchery populations formed another group. Interestingly, no obvious geographic cluster was found in the unweighted pair group method with arithmetic mean tree and PcoA. We recommend monitoring the genetic variability of selected hatchery populations to enhance the conservation of natural Chinese white shrimp F. chinensis resources. [ABSTRACT FROM AUTHOR]

The effects of artificial shell reef (ASR) on the benthic macroinvertebrates were studied in Shuangdao Bay, Yellow Sea, China. Results showed that the biomass of macroinvertebrates in the ASR increased with the age of the ASR. Based on self-organizing map (SOM), the macroinvertebrate community of short-term artificial reef (SAR), medium-term artificial reef (MAR) and long-term artificial reef (LAR) emerged as a cluster, which may indicate that the benthic community in the ASR formed after three years. The age of the ASR was the main factor affecting the benthic community. The macroinvertebrates belonged to six phyla, Platyhelminthes, Nemertea, Annelida, Mollusca, Arthropoda and Echinodermata, among which the latter four were the ones that contributed the most for abundance. The biomass of Mollusca increased dramatically with age. The dissimilarity of the species composition of Mollusca was mainly caused by Meretrix meretrix and Protothaca jedoensis . The two species accounted for 15.61%, 28.05% and 75.11% of the macroinvertebrate biomass found in SAR, MAR and LAR, respectively. The ASR might be served as a bivalve stock enhancement tool. We conclude that ASR could assemble macrobenthos effectively and increase the environmental quality of the adjacent area, being a valid option for marine habitat restoration purposes. [ABSTRACT FROM AUTHOR]

This study evaluates the ecosystem structure and function of the nearshore reefs in the Lidao coastal ecosystem of northern China, a region of intensive kelp aquaculture, and fisheries enhancements, including the deployment of artificial reefs and release of cultured marine species. An Ecopath model, with 20 functional groups representing 81 species, was developed for a representative area in the region and Ecosim was used to explore two scenarios for alternative fishing practices and surrounding aquaculture activities. The mean trophic levels (TLs) of the functional groups ranged from 1.0 for the primary producers (phytoplankton, benthic algae and seagrass) and detritus to 4.14 for Type III fishes (fishes found in the water column above the artificial reefs, e.g., Scomberomorus niphonius ). The mean transfer efficiency through the whole system was 11.7%, and the ecosystem had a relative low maturity, stability and disturbance resistance, indicating that it was at a developing stage. Nearly half of the total system biomass (48.9% of 620.20 t km −2 year −1 ), excluding detritus, was comprised of benthic finfish and invertebrates. The total yield from all fisheries (86.82 t/km 2 /year) was dominated by low trophic level herbivorous and detritivorous species, such as the sea cucumber Apostichopus japonicus (TL = 2.1, 46.07%), other echinoderms (sea urchins Asterias amurensis and Strongylocentrotus nudus , TL = 2.1, 34.6%) and abalone Haliotis discus hannai (TL = 2.0, 18.4%), and as a consequence, the mean TL of the catch was low (2.1). The results from the Ecosim simulation of closing all fisheries for 20 years predicted an increase of about 100% in the relative biomass of the main exploited species, A. japonicus and H. discus hannai . The simulated removal of all kelp farms over 10 years resulted in a two fold increase in the relative biomass of Type III fishes and a 120% increase in their main prey (i.e. Small pelagic fish), while the relative biomass of A. japonicus and Heterotrophic bacteria decreased by 31.4% and 12.7%, respectively. These predictions indicate that nearshore kelp cultivation favours benthic, rather than water column production, and is likely to be providing energy subsidies for the stock enhancement of benthic species in this region. [ABSTRACT FROM AUTHOR]

The primary genetic linkage maps of Fenneropenaeus chinensis (Osbeck) were constructed by using the “two-way pseudo-testcross” strategy with RAPD and SSR markers. Parents and F1 progeny were used as segregating populations. Sixty-one RAPD primers and 20 pairs of SSR primers were screened from 460 RAPD primers and 44 pairs of SSR primers. These primers were used to analyze the parents and 82 progeny of the mapping family. About 146 primers (128 RAPDs, 18 microsatellites) in the female and 127 primers (109 RAPDs, 18 microsatellites) in the male were segregating markers. The female linkage map included eight linkage groups, nine triplets and 14 doublets, spanning 1,173 cM with the average marker density of 11.28 cM, and the observed coverage was 59.36%. The male linkage map included 10 linkage groups, 12 triplets and seven doublets, spanning 1,144.6 cM with the average marker density of 12.05 cM, and the observed coverage was 62.01%. The construction of the F. chinensis genetic linkage maps here opened a new prospect for marker-assisted selection program, comparative genomics and quantitative trait loci (QTL) gene location and cloning. [ABSTRACT FROM AUTHOR]

The artificial propagation and release of Fenneropenaeus chinensis have been conducted over the past three decades in China. To examine the current population genetic diversity and variability of F. chinensis , six broodstock populations and two wild populations from Chinese coastal waters were collected, and nine microsatellite loci were analyzed. High genetic diversity was found for the eight F. chinensis populations. Inbreeding coefficient ( F is ) estimates were all positive (0.215–0.317), suggesting that inbreeding occurs in this species. A total of 36 (50%) tests deviated from Hardy-Weinberg equilibrium, and all these loci showed evidence of a null allele. Low genetic differentiation among some F. chinensis populations was detected, which is consistent with the microsatellite DNA results of previous studies. A changing geographic pattern was detected for the F. chinensis population, and stock enhancement activity should be focused on F. chinensis because positive inbreeding coefficients were found. [ABSTRACT FROM AUTHOR]