A pleistocene mummified ostracod from the Wairarapa district     

Stephen H. Eagar 《新西兰海洋与淡水研究杂志》2013,47(4):607-609

A mummified specimen of Scottia insularis Chapman is recorded from beds of Upper Nukumaruan age (Pleistocene) at Gladstone in the Wairarapa Valley. This is the first record of a mummified species from New Zealand.  相似文献   

Recovery of benthic macroinvertebrate and epilithic communities following a large flood,in an unstable,braided, New Zealand river     

Garry J. Scrimgeour  Robert J. Davidson  Jacqueline M. Davidson 《新西兰海洋与淡水研究杂志》2013,47(3):337-344

Benthic macroinvertebrates and small stones were collected from a riffle in the Ashley River, North Canterbury, New Zealand, on 12 occasions within a 132‐day period following a particularly large flood in 1986. Despite the occurrence of smaller floods during this period, benthic macroinvertebrate communities and stone surface organic layers recovered rapidly. Mean concentration of stone surface organic carbon increased from 0.23 g/m² to 1.01 g/m² stone surface in the first 23 days after the flood and chlorophyll a concentration increased from 0.13 mg/m² (day 3) to 9.2 mg/m² by day 132. Minor floods during the recovery period had little effect on organic layer biomass. Mean faunal density increased from 230/m² to 7920/m² during this time and taxon richness from 7 to 21 per 5 benthic samples. Immediately after the flood and throughout the study period the fauna was dominated by larvae of Deleatidium (Ephemeroptera: Leptophlebiidae), Hydora (Coleoptera: Elmidae), and Chironomidae. Re‐establishment of Deleatidium populations in previously denuded brands was effected by oviposition, egg‐hatching, and larval immigration. Minor braids are likely to represent important epicentres from which recolonisation proceeds.  相似文献   

Earthquakes,catastrophic sediment additions and the response of urban stream communities     

JS Harding  PG Jellyman 《新西兰海洋与淡水研究杂志》2013,47(3):346-355

Disturbance events can regularly impact stream ecosystems; however, large-scale catastrophic disturbances are rare. From September 2010 to September 2011 Christchurch City experienced over 8500 earthquakes including a magnitude 7.1. One consequence was catastrophic additions of silt and sand into waterways throughout the city. Of 161 km of permanent waterways, 102 km (63%) were affected by earthquake siltation. Benthic invertebrates and fish communities were compared across 16 streams with differing siltation. Invertebrate taxonomic richness decreased significantly (mean 17 taxa reduced to 10 taxa) and EPT taxa (Ephemeroptera, Plecoptera and Trichoptera) were removed entirely from streams receiving heavy siltation. Fish richness and density decreased significantly, with fish absent from some heavily silted streams. Many of these urban streams are sourced from springs and their stable flows and low gradient limit their ability to flush sediment. We predict that without human intervention there will be a long-term sediment legacy and it may take many years for these streams to recover from this catastrophic disturbance.  相似文献   

渤海湾潮下带底栖线虫群落的垂直分布     

张青田  王新华  胡桂坤 《海洋科学进展》2012,30(3):416-422

2007年春季在渤海湾天津潮下带采集小型底栖生物样品,分析沉积物中自由生活线虫的垂直分布情况。多元统计分析结果表明,底栖线虫的垂直分布和沉积物深度有关。在较深的5～10cm层,线虫群落与其上层次的差异较大:0～2cm层和5～10cm层差异极显著(P=0.001),2～5cm层和5～10cm层间差异显著(P=0.016)。不同站点间底层的线虫群落差异明显。而沉积物0～2cm层和2～5cm间的线虫群落差异不明显(P=0.541)。列出了SIMPER分析中16种明显影响表层-底层群落的线虫,13种明显影响中层-底层间群落比较的线虫。在研究和比较线虫群落时,应该考虑取样深度的影响。  相似文献   

Community structure changes of macrobenthos in the South Yellow Sea   总被引：3，自引：0，他引：3  

�ž���  ���ɽ  ������ 《中国海洋湖沼学报》2012,30(2):248-255

The ecological environment in the Yellow Sea has changed greatly from the 1950s to 1990s and this has had significant impact on marine organisms. In this study, data on soft-sediment macrobenthos occurring in depths from 25 m to 81 m in the South Yellow Sea were used to compare changes in community structure. The agglomerative classification (CLUSTER) and multidimensional scaling (MDS) methods were applied. Five communities were recognized by cluster analysis: 1. The Yellow Sea Cold Water Mass community dominated by cold water species, which changed slightly in species composition since the 1950s; 2. The mixed community with the coexistence of cold water species and warm water species, as had been reported previously; 3. The polychaete-dominated eurythermal community in which the composition changed considerably as some dominant species disappeared or decreased; 4. The Changjiang (Yangtze) River Estuarine community, with some typical estuarine species; 5. The community affected by the Yellow Sea Warm Current. The greatest change occurred in the coastal area, which indicated that the change may be caused by human activities. Macrobenthos in the central region remained almost unchanged, particularly the cold water species shielded by the Yellow Sea Cold Water Mass. The depth, temperature and median grain size of sediments were important factors affecting the distributions of macrobenthos in the South Yellow Sea.  相似文献   

Cumulative impacts on seabed habitats: An indicator for assessments of good environmental status     

Samuli Korpinen  Manuel MeidingerMaria Laamanen 《Marine pollution bulletin》2013

The European seas are under anthropogenic pressures impacting the state of water quality, benthic habitats and species. The EU Marine Strategy Framework Directive (MSFD) requires the Member States to assess the impacts of pressures and make a programme of measures leading to good environmental status (GES) by 2020. This study presents a method for assessing the quantity and distribution of anthropogenic impacts on benthic habitats in the Baltic Sea by using spatial data of human pressures and benthic habitats. The southern sub-basins were more extensively impacted than the northern sub-basins. Over the entire sea area, deep sea habitats were more impacted than shallower infralittoral and circalittoral habitats. Sand and coarse sediments were the seabed types relatively most impacted in the Baltic Sea scale. A comparison against tentative thresholds for GES showed that in the sub-basin scale only one third of the habitat types was in GES.  相似文献   

Mapping benthic macroalgal communities in the coastal zone using CHRIS-PROBA mode 2 images   总被引：2，自引：0，他引：2  

G. Casal  T. KutserJ.A. Domínguez-Gómez  N. Sánchez-CarneroJ. Freire 《Estuarine, Coastal and Shelf Science》2011,94(3):281-290

The ecological importance of benthic macroalgal communities in coastal ecosystems has been recognised worldwide and the application of remote sensing to study these communities presents certain advantages respect to in situ methods. The present study used three CHRIS-PROBA images to analyse macroalgal communities distribution in the Seno de Corcubión (NW Spain). The use of this sensor represent a challenge given that its design, build and deployment programme is intended to follow the principles of the “faster, better, cheaper”. To assess the application of this sensor to macroalgal mapping, two types of classifications were carried out: Maximum Likelihood and Spectral Angle Mapper (SAM). Maximum Likelihood classifier showed positive results, reaching overall accuracy percentages higher than 90% and kappa coefficients higher than 0.80 for the bottom classes shallow submerged sand, deep submerged sand, macroalgae less than 5 m and macroalgae between 5 and 10 m depth. The differentiation among macroalgal groups using SAM classifications showed positive results for green seaweeds although the differentiation between brown and red algae was not clear in the study area.  相似文献   

Ecological periodic tables for benthic macrofaunal usage of estuarine habitats in the US Pacific Northwest     

Steven P. Ferraro  Faith A. Cole 《Estuarine, Coastal and Shelf Science》2011,94(1):36-47

This study shows that spatially and temporally recurring benthic macrofauna-habitat patterns validate the ecological relevance of habitat types to benthic macrofauna and suggest they can serve as elements in ecological periodic tables of benthic macrofaunal usage. We discovered patterns across nine habitat types (intertidal eelgrass [Zostera marina], dwarf eelgrass [Zostera japonica], oyster [Crassostrea gigas] ground culture, burrowing mud shrimp [Upogebia pugettensis], burrowing ghost shrimp [Neotrypaea californiensis], shell, sand, mud, and subtidal) on a variety of benthic macrofaunal community state variables in Grays Harbor, Washington, USA and compared them to those in Willapa Bay, Washington, USA. There were nominal differences in benthic macrofaunal Bray-Curtis similarity between all the habitats investigated except eelgrass and oyster in both estuaries. Across-habitat patterns on mean benthic macrofaunal species richness, abundance, biomass, abundance of deposit, suspension and facultative feeders, a dominance and a diversity index for the five habitats common to both studies were the same on a rank measurement scale: eelgrass ≈ oyster > mud shrimp > ghost shrimp ≈ subtidal. The patterns for most of the habitats and benthic macrofaunal measures were the same on a ratio measurement scale.  相似文献   

Effect of nitrogen to phosphorus ratios on cell proliferation in marine micro algae     

张青田  胡桂坤 《中国海洋湖沼学报》2011,(4)

The ratio of nitrogen/phosphorus (N/P) is known to affect cell proliferation of some marine micro algae. We evaluated the effect of N/P ratios on the proliferation and succession of phytoplankton using five marine micro algae species. We used two sources of nitrogen, NH4Cl (N1) and urea (N2), and a single source of phosphorous, NaH2PO4(P). The optimal N/P ratio that differed among the five species was affected by the source of nitrogen, being as follows (N1/P, N2/P in order): Thalassiosira sp. (30/1, 20/1),...  相似文献   

珠江口外表层沉积物底栖有孔虫组合及其与环境的关系     

李涛  向荣  李团结 《热带海洋学报》2011,(4)

对珠江口外CJ14区块250个站位的表层沉积物进行底栖有孔虫分析,共发现底栖有孔虫118种,其中玻璃壳质80种,瓷质壳质21种,胶结壳质17种。有孔虫丰度基本随水深变深而增大。为研究底栖有孔虫分布与沉积环境之间的关系,对底栖有孔虫含量进行Q型因子分析,并选取前4个主因子,分别对应4个有孔虫组合。它们总共解释了总方差的86.2%,基本上反映了沉积物中有孔虫的群落结构。研究表明,水深和盐度是影响珠江口表层沉积物中有孔虫组合分布的控制因素,其他影响因素主要包括沉积物类型、水动力条件和沉积速率。水动力条件主要影响有孔虫的含量;沉积速率主要影响有孔虫的丰度。  相似文献