近百年来浙江三门湾海岸线时空演变特征

本文收集了1913年以来的历史地形图、海图和遥感影像,利用地理信息技术和空间分析技术,获取10期三门湾海岸线数据,进而对三门湾近百年来海岸线时空演变特征进行分析.结果表明:(1)海岸线变化主要发生在内海湾,以港汊围堵、连岛并陆为主的围填海活动导致海岸线向海推进的围填海面积总计231.42 km2.(2)海岸线总长度持续...     

Acute toxicity of five sediment-associated metals, individually and in a mixture, to the estuarine meiobenthic harpacticoid copepod Amphiascus tenuiremis

The acute effects of many individual, seawater-solubilized metals on meiobenthic copepods and nematodes are well known. In sediments, however, metals most often occur as mixtures, and it is not known whether such mixtures exhibit simple additive toxicity to meiobenthos. The estuarine meiobenthic copepod Amphiascus tenuiremis was tested in four acute (96-h) sediment bioassays to determine sediment and pore-water LC50s for single-metal exposures to copper (Cu), lead (Pb), nickel (Ni) and zinc (Zn). Laboratory-cultured copepods were exposed to clean 98% silt:clay sediments spiked with metal chloride solutions to yield five exposure concentrations plus a control. Trimmed Spearman-Karber analysis gave sediment 96-h LC50 values of 4.4 mumole Cu/g, 5.7 mumole Ni/g, 11.9 mumole Pb/g, 10.3 mumole Zn/g, and pore-water 96-h LC50 values of 2 mumole/l, 11.7 mumole/l, and 5.7 mumole/l for Cu, Ni, and Zn, respectively. Male survival after exposure to Cu, Pb, and Ni was significantly less than female survival (alpha = 0.05). Toxicity of a combined USEPA priority metal mixture to A. tenuiremis was assessed using sediment spiked equitoxically with Cd, Cu, Ni, Pb, and Zn. The sum toxic unit that produced a median lethal dose was 0.72. The mixture had a significantly greater than additive effect on A. tenuiremis survival, with the mixture being 1.4x more toxic than that expected by simple additivity.     

The description of a new kind and three new types of medusae nematocysts in the Xiamen Harbour, China

A new kind of nematocyst, heteromorphore, and three new types of nematocysts, microbasic spino-mastigophore, microbasic undulata-mastigophore, microbasic laevis-mastigophore, are described from medusae of the Xiamen Harbour and discussed by comparison with the results of other research workers.     

Molecular phylogeny of the families Pleuronectidae and Poecilopsettidae (PISCES,Pleuronectiformes) from Korea,with a Proposal for a new classification

A new classification of the Korean pleuronectids was proposed based on a molecular phylogeny using specimens collected from Korea (including some Japanese specimens) between 2008 and 2013. A molecular phylogeny based on partial sequences of the two mitochondrial DNA regions (COI and 16S rRNA) supported the reciprocal monophyly of the three genera, Cleisthenes, Pleuronectes and Pseudopleuronectes. We also found that the genus Poecilopsetta is clearly distinct from Pleuronectidae at the family level. Therefore, the previous classification of the Korean pleuronectids should be changed as follows; two families (Pleuronectidae and Poecilopsettidae), 18 genera, and 26 species. Further research is required to resolve the taxonomic uncertainty of the five species in the genus Limanda, which clustered into two clades in our analysis.     

The distribution of Mn,Fe, Zn,Cd and Cu in Baltic seawater; a study on the basis of one anchor station

A total of 150 samples were collected at a 10-days' anchor station in the Bornholm basin (55° 31.1′N, 15° 32.1′E) and analyzed for dissolved (< 0.4 μm) and particulate trace metals. For dissolved Mn, large gradients have been found in the vertical distribution with minimum concentrations (< 0.2 μgl^?1) in the halocline zone and considerably higher values in the deep waters (up to 50 μgl^?1). Ultrafiltration studies indicate that dissolved Mn is probably present as Mn²⁺ in the oxygenated bottom layer. The primary production process was not evident in the particulate Mn profile; the suspended particulate material (SPM), however, shows a considerable enrichment with depth, apparently due to Mn-oxide precipitation.The distribution of dissolved Fe was rather homogeneous, with average concentrations throughout the water column between 0.86 and 1.1 μgl^?1, indicating that the oxidation of Fe²⁺ ions released from the sediments must already be complete in the very near oxidation boundary layer. Relatively high concentrations of particulate Fe were actually measured in the bottom layer, with the maximum mean of 11.2 μgl^?1 at 72 m. Similarly to Mn, the profile of particulate Fe does not reflect the SPM curve of the eutrophic layer. On average, about 70% of the total Fe in surface waters was found to be particulate.The average concentrations of dissolved Zn, Cd and Cu were found to be rather homogeneous in the water column but showed a relatively high variability with time. A simplified model on trace-metal uptake by phytoplankton indicates no significant change in dissolved metal concentrations during the period of investigation. On average, only 1.7% Zn, 3.3% Cd and 9.8% Cu of the total metal concentrations were found in particulate form. SPM analyses showed significant correlations of Zn, Cd and Cu with Fe, indicating that particulate iron is an important carrier for particulate trace metals in Baltic waters.     

Determination of chlorophyll in marine waters: intercomparison of a rapid HPLC method with full HPLC,spectrophotometric and fluorometric methods

A statistical comparison was made between chlorophyll measurements made on a suite of marine samples by four methods. The methods were one complete and one rapid high-performance liquid chromatographic (HPLC) method, a fluorometric method and the traditional spectrophotometric method. Generally good agreement was found, provided that consideration was given to the presence of chlorophyllide a and allomers of chlorophyll a as determined by the HPLC methods. The rapid HPLC method (10 min per sample) is recommended as a convenient and accurate alternative to traditional methods for chlorophylls.     

Distribution characteristics of size-fractionated chlorophyll a, primary production and new production in the Laizhou Bay, July 1997

The distributions of chlorophyll a concentration, primary production and new productionwere observed in the Laizhou Bay of the Bohai Sea in both spring and neap tides during July 1997. The results showed that there were marked features of spatial zonation in the surveyed area, due to the differences between the geographic environment and the hydrological conditions. Chlorophyll a, primary production and new production were all higher in spring tides than that in neap tides in the Laizhou Bay. The highest values of these parameters were encountered in the central regions of the bay. At most stations, chlorophyll a concentrations at the bottom were higher than that at the surface. The results of size-fractionated chlorophyll a and primary production showed that contributions of nano-combining pi-coplankton ( > 20 μm) to total chlorophyll a and primary production were dominant in phytoplankton community biomass and production of the Laizhou Bay. The environmental factors, primary production and new product     

Rhinochimaera africana,a new longnose chimaera from southern Africa,with comments on the systematics and distribution of the genus Rhinochimaera Garman, 1901 (Chondrichthyes,Chimaeriformes, Rhinochimaeridae)

Rhinochimaera africana, a new species (Chondrichthyes, Chimaeriformes, Rhinochimaeridae), is described from five specimens from the Western Cape and KwaZulu coasts of southern Africa and from the Moçambique Channel between South-Western Madagascar and Europa Island. Two more specimens are known from off the Agulhas Bank, South Africa. It differs from the partially sympatric R. atlantica Holt and Byrne, 1909, and the Pacific R. pacifica (Mitsukuri, 1895) in its darker coloration, longer, broader, paddle-shaped snout, tooth plates of different shape, a more elongate-oval clasper glans, a shorter caudal fin with very short filament, and possibly a smaller dorsal fin and longer interdorsal space. R. africana males are mature at 568 mm body length (BDL), females adolescent at 476 mm BDL. A large, probably adult female of 650 mm BDL is larger than any recorded R. atlantica or R. africana. Wounds on two specimens indicate possible "cookie-cutter" bites by squaloid sharks, and one has a possible bite by another Rhinochimaera. Data on R. pacifica and R. atlantica, including 45 specimens from off Namibia and South Africa, are presented for comparison with R. africana. Caudal tubercle counts of R. africana (40–46) are intermediate between those of R. atlantica (most with 19–33, rarely up to 43) and of R. pacifica (41–68, rarely as low as 25–34). Southern African R. atlantica agree with North Atlantic R. atlantica in having few caudal tubercles, but there is slight overlap with R. pacifica in the case of higher counts recorded for R. africana. The systematics and distribution of the genus Rhinochimaera are reviewed, a terminology and abbreviation system for morphometries presented, and a key to species provided. The separation of R. atlantica and R. pacifica on caudal tubercle counts is provisionally accepted but considered problematical until adequate samples of both species can be critically compared. Proportional measurements and counts of caudal tubercles were highly variable in Rhinochimaera, with much allometry in proportions with growth and much individual variation. Selected morphometrics are plotted to show allometric trends in proportions that separate R. africana from other species.     

Sponges boring into precious corals: an overview with description of a new species of Alectona (Demospongiae, Alectonidae) and a worldwide identification key for the genus

Precious corals represent peculiar substrata for several species of boring sponges that exploit their carbonatic scleraxis, strongly decreasing their commercial value. Here we describe a new species of the genus Alectona from Japan recorded in a colony of Paracorallium japonicum (Kishinouye, 1903). The spicular complement of the new species consists of diactinal spicules covered by mushroom-like tubercles, often modified into styloid forms, and fusiform amphiasters with two or sometimes four verticils, each generally made up of six short tubercled rays. A complete survey of the literature on boring sponges recorded in precious corals in the Mediterranean Sea and Pacific Ocean indicates that the species of the family Alectonidae are the most strictly associated to this kind of substratum. Their world distribution, in fact, partially or totally overlap that of their coral hosts.