Total Meiofauna Abundance Research Articles

Comparison of the Meiofauna and Marine Nematode Communities before and after Removal of Spartina alterniflora in the Mangrove Wetland of Quanzhou Bay, Fujian Province

The invasion of Spartina alterniflora is one of the main threats faced by mangrove wetlands in Quanzhou Bay, Fujian. To effectively manage S. alterniflora, mangrove plants (Kandelia obovata, Aegiceras corniculatum, Bruguiera gymnorhiza, Rhizophora stylosa, and Avicennia marina) were used to replace it in 2022 to restore the wetland ecosystem. Samples of meiofauna and marine nematodes were collected four times, including in September 2022 (before the removal of S. alterniflora), October 2022 (after removal), and December 2022 and March 2023 (after planting mangrove plants). This paper investigates changes in the composition, abundance, and biomass of meiofauna in different time periods, with a specific focus on comparing the community structure and biodiversity indices of marine nematodes in S. alterniflora and mangrove habitats. The results indicate that among the five meiofauna groups identified, marine nematodes account for 92.91%, 91.91%, 92.03%, and 85.92% of the total meiofauna abundance in the respective study periods. In the S. alterniflora habitat in September, marine nematodes were identified belonging to 12 families and 20 genera, of which 6 genera were dominant (percentage ≥ 5%). They were Ptycholaimellus, Parodontophora, Terschellingia, Halichoanolaimus, Metachromadora, and Parasphaerolaimus. In the mangrove habitat in December, marine nematodes were identified belonging to 15 families and 23 genera, with 6 genera being dominant, namely Daptonema, Admirandus, Parodontophora, Ptycholaimellus, Terschellingia, and Anoplostoma. Comparing the marine nematode communities in the two habitats, the mangrove habitat exhibits higher diversity than the S. alterniflora habitat. There was a change in the dominant genera, and their dominance has decreased. The dominant genera of marine nematodes found in both habitats are common and widely distributed groups. The changes in the abundance of meiofauna and the community structure of marine nematodes following the restoration of the S. alterniflora habitat by planting mangroves provide valuable insights for ecological monitoring after restoration measures in estuarine wetland conservation areas.

Meiofauna in the southeastern Bering Sea: community composition and structuring environmental factors

The Bering Sea is the second largest marginal sea in the North Pacific and is one of the areas with highest biological productivity in high-latitude waters. The continental shelf of the Bering Sea hosts large populations of marine mammals and fishery resources. However, the smaller organisms in benthic ecosystems, including meiofauna, have been largely overlooked in this area, despite their potential importance in ecosystem functioning and the resultant biogeochemical cycles. This study analyzed spatial differences in the total abundance and community structure of the metazoan meiofauna at five stations around the Bering Canyon, located at the southeastern margin of the Bering Sea. Their association with environmental factors in sediments was also studied. The results confirmed that the investigated stations had meiofaunal standing stocks that were comparable to those of other Arctic seas. Among the investigated sediment biological and geochemical parameters (total organic carbon, median grain size, prokaryotic cell numbers, etc.), multivariate analyses showed that the C/N of organic matter in sediments was the main factor associated with meiofaunal community structure.

Infaunal community structure, diversity, and function in Pacific-Arctic shelf sediments: a comparison of meiofaunal- and macrofaunal-sized nematodes

Meiofauna, and nematodes in particular, perform essential roles in benthic ecosystems and serve as bioindicators of disturbance and environmental change. In the Pacific Arctic, a region experiencing rapid environmental change, this component of the fauna has received little attention, and the role of meiofauna in ecosystem processes is poorly understood. We collected multi-core samples at 10 stations in the northern Bering and southern Chukchi Seas in June 2018 and characterized the sedimentary environment. We also assessed meiofauna community structure and abundance at higher taxonomic levels and evaluated genus-level nematode composition in meiofaunal (63-500 µm) and macrofaunal (>500 µm) size fractions. Nematodes were classified by feeding type and life-history strategies. Total meiofauna abundance and biomass varied greatly, with 1449-12875 ind. 10 cm-2 and 373-2325 µg dry weight 10 cm-2 for the upper 5 cm of sediment. Estimated production of meiofaunal-sized nematodes was 5-28 g C m-2 yr-1. Four distinct communities of meiofaunal-sized nematodes were identified in different sub-regions reflecting food availability and substrate type. The meiofaunal- and macrofaunal-sized nematodes represented 2 distinct communities. The unique taxonomic composition and large standing stock of the macrofaunal-sized nematodes (22 ± 15% of total nematode biomass) suggest they are critical components of the infauna and merit further research to assess their role in critical ecosystem functions. This study provides the first genus-level characterization of nematodes and some of the first measurements of meiofauna standing stock in the region, contributing important data for assessing ecosystem function in a rapidly changing Arctic.

Sympagic Fauna in and Under Arctic Pack Ice in the Annual Sea-Ice System of the New Arctic

A strong decline and thinning of the Arctic sea-ice cover over the past five decades has been documented. The former multiyear sea-ice system has largely changed to an annual system and with it the dynamics of sea-ice transport across the Arctic Ocean. Less sea ice is reaching the Fram Strait and more ice and ice-transported material is released in the northern Laptev Sea and the central Arctic Ocean. This trend is expected to have a decisive impact on ice associated (“sympagic”) communities. As sympagic fauna plays an important role in transmitting carbon from the ice-water interface to the pelagic and benthic food webs, it is important to monitor its community composition under the changing environmental conditions. We investigated the taxonomic composition, abundance and distribution of sea-ice meiofauna (here heterotrophs >10 μm; eight stations) and under-ice fauna (here metazoans >300 μm; fourteen stations) in Arctic 1.5 year-old pack ice north of Svalbard. Sampling was conducted during spring 2015 by sea-ice coring and trawling with a Surface and Under-Ice Trawl. We identified 42 taxa associated with the sea ice. The total abundance of sea-ice meiofauna ranged between 580 and 17,156 ind.m–2 and was dominated by Ciliophora (46%), Copepoda nauplii (29%), and Harpacticoida (20%). In contrast to earlier studies in this region, we found no Nematoda and few flatworms in our sea-ice samples. Under-ice fauna abundance ranged between 15 and 6,785 ind.m–2 and was dominated by Appendicularia (58%), caused by exceptionally high abundance at one station. Copepoda nauplii (23%), Calanus finmarchicus (9%), and Calanus glacialis (6%) were also very abundant while sympagic Amphipoda were comparatively rare (0.35%). Both sympagic communities showed regional differences in community composition and abundance between shelf and offshore stations, but only for the under-ice fauna those differences were statistically significant. Selected environmental variables moderately explained variations in abundances of both faunas. The results of this study are consistent with predictions of diversity shifts in the new Arctic.

Meiofaunal communities and nematode diversity characterizing the Secca delle Fumose shallow vent area (Gulf of Naples, Italy).

Hydrothermal venting is rather prevalent in many marine areas around the world, and marine shallow vents are relatively abundant in the Mediterranean Sea, especially around Italy. However, investigations focusing on the characterization of meiofaunal organisms inhabiting shallow vent sediments are still scant compared to that on macrofauna. In the present study, we investigated the meiobenthic assemblages and nematode diversity inhabiting the Secca delle Fumose (SdF), a shallow water vent area located in the Gulf of Naples (Italy). In this area, characterized by a rapid change in the environmental conditions on a relative small spatial scale (i.e., 100 m), we selected four sampling sites: one diffusive emission site (H); one geyser site (G) and two inactive sites (CN, CS). Total meiofauna abundance did not vary significantly between active and inactive sites and between surface and deeper sediment layers due to a high inter-replicate variability, suggesting a pronounced spatial-scale patchiness in distribution of meiofauna. Nematofauna at site H presented the typical features of deep-sea vents with low structural and functional diversity, high biomass and dominance of few genera (i.e., Oncholaimus; Daptonema) while from site G we reported diversity values comparable to that of the inactive sites. We hypothesized that site G presented a condition of “intermediate disturbance” that could maintain a high nematode diversity. Environmental features such as sediment temperature, pH, total organic carbon and interstitial waters ions were found to be key factors influencing patterns of meiofauna and nematofauna assemblages at SdF. Even though the general theory is that nematodes inhabiting shallow vent areas include a subset of species that live in background sediments, this was not the case for SdF vent area. Due to a marked change in nematode composition between all sites and to the presence of many exclusive species, every single investigated site was characterized by a distinct nematofauna reflecting the high spatial heterogeneity of SdF.

Periphyton Meyofauna natural stony substrate (Odessa Bay, Black Sea)

For the first time, features of the formation of the total number and biomass of permanent members and temporary members) of meiobenthos in periphyton of natural stony substrates are described for the shelf of the northwestern part of the Black Sea. The material for the scientific analysis was quantitative samples collected during 2012, 2014, and 2015. On two polygons of the North-Western shelf of the Black Sea in the coastal zone of Odessa Bay in the area of the Hydrobiological Station ONU I.I. Mechnikov. Representatives of the following large meiobenthos taxa were found on a stony substrate at a depth of 3–10.7 m: Foraminifera, Nematoda, Ostracoda, Harpacticoida, Halacaridae, Turbellaria, Oligochaeta, young Polychaeta, Bivalvia, Balanus, Amphipod, Cumidae, Crayfish. Kinohryncha and Gastrotricha were absent. The species composition of the main meobenthic groups (Nematoda, Harpacticoida and the young Polychaeta) and their numbers are given. Indicators of the total abundance of meiofauna in the periphyton of the stony substrate varied from 59000 to 341500 ind.·m-2 (average density 156107 ind.·m-2), which was dominated by eumeiobenthos, making up 64% of the total number of organisms. At 57% of the stations studied, representatives of the meiobenthos of the harpacticoids dominated in the density of the settlements, which accounted for 53.2–80% of the total number of organisms. Polychaetes belonging to meiobenthos were unevenly distributed in fouling of a stony substrate. Their average number was 18786 ind.·m-2, an average of 12.7% of the total number of organisms. The share of nematodes in the total number of stones was 20%. Their average density is 23,864 ind.·m-2. Studies have shown that the biodiversity of the meiobenthic community of organisms in the periphyton of natural stony substrates is much poorer than on the loose soils of the adjacent water areas.

Analisis Ekologis Meiofauna Sebagai Bioindikator Di Pesisir Pantai Losari, Makassar

Abstract. The research aims to analyze ecological value of meiofauna as bioindicator in Losari Coast, Makassar. The total meiofauna abundance was 66791 indv/m2, consisted of 12 phylum and 91 species/genus. The stations located at the mouth of the Jeneberang River, Tanjung Merdeka, and the Tallo River are research sites with high levels of abundance, due to the presence of organic contaminants produced by surrounding anthropogenic activity that trigger high growth of meiofauna. ostracoda, oligochaeta, tunicata and ciliophora are the phylum with high levels of abundance compared to other meiofauna, as it that phylum has a high adaptability to the entry of pollutant material in the water. Diversity index and evenness indicates the meioufauna in the Losari Coast categorized by a high level of diversity and evenly distributed. While dominance index indicated that no dominant meifauna species, except at research stations located around the Losari Beach reclamation project. Keywords: Abundance, meiofauna, anthropogenic, Coastal Losari Beach, Makassar

Seasonal constancy (summer vs. winter) of benthic size spectra in an Arctic fjord

Size spectra are important descriptors of community structure and can indicate changes in community functioning in response to shifts in environmental conditions. There are relatively few assessments of benthic size spectra, and most are based on summer samples alone. Processes influencing size spectra, such as recruitment and predation pressure, vary seasonally, and understanding this variation is necessary to interpret patterns in time or space. Here we compare summer and winter biomass size spectra in the central basin of Kongsfjorden (west Spitsbergen). We recorded seasonal changes in the quality of organic matter available to the benthos, indicated by higher chloroplastic pigments concentrations in surface sediments in summer, as well as in differences in total abundance and biomass of both macrofauna and meiofauna. No significant seasonal differences were documented by multiple regression models for the normalized biomass and size classes. The slope of a linear relationship between normalized biomass and size classes was − 0.54 ± 0.02 indicating a productive system, compared to ecosystems like estuaries. Summer–winter invariability of size spectra suggests that benthic community functioning in this Arctic fjordic system is relatively independent from the seasonality in the supply of organic matter produced in water column.

Abundance of Meiofauna and Physical-Chemical Parameters as Water Quality Indicator

The zone of Losari Coast is an icon of Makassar city, however increase activity of surrounding communities causes a decrease in the water quality. Meiofauna is an effective benthic organism used as an indicator of water quality. This study assessed the meiofauna abundance and physical-chemical parameters as water quality indicator in the Losari Coast, Makassar. The sampling method in this study was purposive sampling. The resuts showed that total meiofauna abundance identified was 66791 indv.m-2, composed of 12 phylum and 91 species or genera. Stations at the estuary of the Jeneberang and Tallo River are two sites with high level of abundance, this condition allows presence of organic contaminants triggers the high growth of meiofauna in these locations. Dissolved Oxygen is below its supposed level in waters. Acidity, phosphate and nitrate content at some of research stations exceed the threshold of their allowed presence in waters set by Indonesia government. Ostracoda, oligochaeta, polychaeta, tunicata and ciliophora are phylums with a high level of abundance, because the phylum has high adaptability to pollutant. Good water quality is indicated by a variety of biota living in the waters, the range of diversity and uniformity indices shows that meiofauna species are categorized highly diverse and evenly distributed. The dominance index shows that there is no species was dominant, except stations around Losari reclamation project. Temperature, current velocity, depth, brightness, salinity, pH, DO, nitrate-seawater, and phosphate-seawater correlate with meiofauna abundance. The results as a consideration for the management or monitoring of coastal environments.

WATER QUALITY STUDY BASED ON MEIOFAUNA ABUNDANCE AND POLLUTION INDEX IN THE COASTAL ZONE OF LOSARI BEACH, MAKASSAR

The coastal zone of Losari Beach is located in a strategic position and rich in potential coastal resources, but the high density of human activities has decreased the quality of the surrounding waters.This study aimed to examine water quality based on meiofauna abundance and pollution index in the coastal zone of Losari Beach, Makassar. It employed a quantitative descriptive approach with purposive sampling method. The identified total meiofauna abundance was117,176 individuals/m2consisting of 138 species from 13 phyla. Ostracoda, olygochaeta, sarcomastigophora, ciliophora, and polychaetawere phyla with the highest abundance because of their high adaptability to polluted aquatic conditions. Meanwhile, tardigrada and aelosomatidaewere found in very low abundance because both phyla only thrive in pollution-free environments and have a pattern of high migration flow from one habitat to another. As for aelosomatidae, the habitat of its speciesis limitedto brackish or saline waters. A good-quality aquatic environment is a habitat for all benthic organisms and enables their even distribution. It explains the discovery of true and temporary meiofauna with uniform or even compositions in the bottom of the waters. The waters in the coastal zone of Losari Beach are heavily polluted. The stationslocated around the traditional Paotere harbor, hotels, restaurants, Losari Beach Platforms, the waste disposal outlets of Stella Maris Hospital, Fort Rotterdam canals, and Jeneberang River mouthhad very high pollution index. Some of these stations had low meiofauna abundance levels, and the poor water quality in their surroundings was caused by anthropogenic activity. Even though the area around TanjungMerdeka Beach had relatively low pollution index, it was categorized as severely contaminated because the index score was >10.

The Ecological Analysis of Meiofauna as a Water Quality Bioindicator in the Coast of Losari Beach, Makassar

This research aimed to analyze the ecological assessment of meiofauna on the coast of Losari Beach, Makassar. Increased community activity is a trigger of the decline in the water quality surrounding the coast of Losari Beach. Meiofauna is a benthic organism can be used as an indicator of water quality. The purposive sampling is a method in this study. The stations located close to hotels and restaurants showed a high level of abundance because the anthropogenic activities occurring in them generated organic material contaminants that triggered the vast growth of meiofauna in the location. Compared to other phyla included in meiofauna, ostracoda, oligochaeta, and sarcomastigophora existed in higher abundance due to their high adaptability to any contaminating materials entering the waters. The meiofauna species in the coast of Losari Beach were highly diverse with no species prevailing in each observation station. The total meiofauna abundance identified in this study was 40,734 individuals/m2, composed of 10 phyla and 116 species. The range of the evenness index also indicated that the meiofauna species was quite even and affirmed that no species was dominant. This research found the physical and chemical parameters significantly influenced the abundance of meiofauna in the aquatic substrates.

Spatial variation of meiofaunal tardigrades in a small tropical estuary (~6°S; Brazil)

Spatial variations and organism–sediment relationship are paramount subjects of soft-bottom ecology. However, these issues have been unexplored for most minor meiofaunal taxa such as tardigrades. In the present study, we explore this subject on a small tropical (~6°S) estuary. Total meiofaunal abundance ranged from 4 to 1036 individuals per 10cm2, averaging (mean±s.d.) 324.8±245.9 individuals per 10cm2. Nematodes dominated in both seasons, representing >70% of total abundance. Tardigrades were the second-most abundant taxon, representing 15% of the total and up to 71%. Tardigrades were represented by two species, Batillipes dandarae and B. pennaki, the latter dominating in the rainy season, and both with similar abundances in the dry season. Abundance of total meiofauna and both tardigrade species differed significantly (ANOVA; P<0.05) among stations and in the interaction between stations and seasons, but only B. dandarae varied seasonally, with higher values occurring in the dry season. The spatial variations observed were mostly related to differences in the sediment granulometry. Environmental explanatory variables explained 72.6% of the variance of dominant meiofaunal taxa in the Redundancy Analysis. Nematodes and ostracods were mostly associated with fine and very fine sands, both tardigrades with medium sand and oligochaetes with larger size-fractions of the sediment and organic matter. The data gathered here suggest that granulometry was the most important environmental factor in the meiofaunal spatial structure in tropical estuaries and both tardigrade species were closely associated with medium sand.

夏、秋季渤海小型底栖动物类群组成及分布特征

PDF HTML阅读 XML下载 导出引用 引用提醒 夏、秋季渤海小型底栖动物类群组成及分布特征 DOI: 10.5846/stxb201801290236 作者: 作者单位: 中国海洋大学,中国海洋大学,中国海洋大学,中国海洋大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41576135） Meiofauna assemblage composition and distribution in the Bohai Sea during summer and autumn Author: Affiliation: Ocean University of China,Ocean University of China,Ocean University of China,Ocean University of China Fund Project: National Natural Science Foundation of China (No. 41576135). 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:分别于2011年6月和11月，搭载"东方红2号"科学调查船在渤海海域（37.0°-40.0°N，118.0°-122.0°E）进行了小型底栖动物的取样，对小型底栖动物类群组成、丰度、生物量、空间分布及其与环境因子的关系进行了研究。结果表明：研究海域小型底栖动物分布不均匀，表现为黄河口附近及近岸海域小型底栖动物丰度显著低于其他海域。小型底栖动物6月平均丰度高于11月，分别为（1012.7±519.1）个/10 cm2和（829.5±385.8）个/10 cm2，6月平均生物量低于11月，分别为（570.8±307.6）μg干重/10 cm2和（661.3±310.9）μg干重/10 cm2。两个航次共鉴定出18个小型底栖动物类群，其中自由生活海洋线虫为最优势类群，分别占小型底栖动物总丰度的95.0%和90.3%，占小型底栖动物总生物量的67.4%和45.3%。其他数量上较重要的类群还有底栖桡足类、多毛类、动吻类和双壳类等。其中，多毛类丰度具有显著的季节差异，其11月丰度高于6月。两个航次分别有93.6%（6月）和91.1%（9月）的小型底栖动物分布在0-5 cm的表层沉积物内，没有表现季节性垂直迁移。对小型底栖动物生物数据与环境因子的相关分析结果显示，小型底栖动物的丰度与沉积物中值粒径、含水率呈显著负相关，与有机质含量呈极显著负相关，表明这三个因子是决定研究海域小型底栖动物分布的重要因素。小型底栖动物群落组成与环境因子的BIOENV相关分析表明，水深、有机质含量的组合能够最好地解释小型底栖动物群落结构的差异。与渤海海域30年来的小型底栖动物研究比较发现，在过去30年里，渤海小型底栖动物（包括海洋线虫）丰度逐渐增加，而其中的底栖桡足类丰度却在逐渐减少。沉积环境的变化以及人类干扰是引起渤海海域小型底栖动物丰度变化的重要因素。 Abstract:To study the composition, abundance, biomass, and spatial distribution of meiofauna and their relationship with environmental variables, meiofauna samples were collected from the Bohai Sea (37.0°-40.0°N,118.0°-122.0°E) in June 2011 and November 2011 by R/V ‘Dongfanghong Ⅱ’. The results showed that meiofauna and nematode abundance was lower in the Yellow River estuary adjacent water and near shore water. Results also showed that meiofauna abundance differed between the two cruises, with higher abundance in June (1012.7±519.1) ind/10 cm2 compared to November (829.5±385.8) ind/10 cm2. In contrast, meiofauna biomass was higher in November (661.3±310.9) μg dwt/10 cm2 than in June (570.8±307.6) μg dwt/10 cm2. A total of 18 meiofaunal groups were identified during the two cruises. The dominant taxonomic group was free-living marine nematodes, constituting 95.0% and 90.3% of total meiofauna abundance in June and November, respectively. Other important groups were benthic copepods, polychaetes, kinorhynchs, and ostracods. Of these, polychaetes exhibited higher abundance in November compared to June, suggesting significant seasonal variation. Analysis of meiofaunal vertical distribution indicated that 93.5% and 91.1% of the meiofauna was distributed in the top 5 cm of the sediment in June 2011 and November 2011, respectively. No seasonal vertical distribution differences were detected. Correlation analysis between meiofauna abundance and different environmental variables showed that abundance was negatively correlated with sediment medium grain size, water content, and sediment organic matter content, suggesting that these parameters were the most important factors affecting meiofauna abundance and distribution in the study area. The results of BIOENV analysis indicated that the combination of water depth and organic matter content correlated best with the meiofaunal assemblage. After comparing the present data with meiofaunal historical data from the past 30 years in the Bohai Sea, we observed that total meiofauna abundance and biomass increased gradually over that period. However, while meiofauna and free-living nematode standing stock increased, copepod standing stocks decreased in the past 30 years. 参考文献 相似文献 引证文献

Meiobenthic assemblage of the grey mangrove (Avicennia marina) along the Saudi Arabian coast of the Red Sea with emphasis on free-living nematodes

AbstractSpatial variability in the population density of meiofauna and the assemblage of free-living marine nematodes was studied at 20 mangrove sites located along the Saudi Arabian coast of the Red Sea. The total abundance of meiofauna varied between the locations and ranged from 119 to 1380 ind. 10 cm−2. A total of seven main taxa were recorded. Nematodes dominated (64.3%) in all sediment samples. They were followed by harpacticoid copepods (13.2%) and polychaetes (12.9%) with significant differences in their density between the locations surveyed (p< 0.001). The Pearson correlation analysis showed significant positive correlations between the sand fraction and nematodes, harpacticoid copepods and turbellarians. Twenty-five genera of free-living nematodes belonging to 15 families were recorded in the study area. Microlaimidae were the most abundant family, while Xyalidae, Desomodridae and Chromidoridae were the most diverse families.Microlaimus,HalalaimusandTerschellingiawere the most frequent genera. ANOSIM values obtained for the distribution of different nematode genera in various habitats showed no significant differences. Feeding types of different nematode genera were also documented and the epistrate feeders along with the deposit feeders were found to be the common feeding types in the present study.

Meiofauna abundance and community patterns along a transatlantic transect in the Vema Fracture Zone and in the hadal zone of the Puerto Rico trench

Despite the increasing sampling effort that occurred in the deep-sea environment during the last decades, knowledge about meiofauna ecology in trenches and Fracture Zones is still scarce. Based on the lack of this information, a longitudinal transect across the Vema Fracture Zone in the North Atlantic was sampled to test whether meiofauna abundances differ between Northeast and Northwest Atlantic basins, separated by the Mid-Atlantic Ridge. Also, for examination of meiofauna depth pattern, the Puerto Rico trench floor, its upper trench slope and the Western North Atlantic abyssal were investigated.In this study, meiofauna communities were dominated by Nematoda (93%) and Copepoda (4%). The highest total abundance of meiofauna was found in the Puerto Rico trench and the lowest in the Western basin. We found significant differences between the Eastern and Western Atlantic basins, which were potentially caused by differences in current regimes. Stronger currents observed in the Western basin possibly led to the coarser sediment grain size observed in this region, and consequently to the lower abundances of the major groups found there. Besides grain size, the total abundance of meiofauna was significantly correlated with total nitrogen, total organic carbon, and water depth. Moreover, our study reveals a trend of increasing abundance of total meiofauna with increasing water depth in the Puerto Rico trench. Also, significant differences between the Western abyssal and the Puerto Rico trench were discovered. Generally, the meiofauna abundance in the investigated area decreased from East to West but increased with increasing water depth in the Puerto Rico trench. Due to funnelling of organic sediments increased food availability towards deeper regions in trenches could occur and promote higher abundance.

Impact of deposit-feeding chironomid larvae (Chironomus riparius) on meiofauna and protozoans

AbstractChironomid larvae are common members of benthic systems in freshwaters. Their diet consists mainly of detritus, which often leads to the passive ingestion of attached organisms. We hypothesized that larvae would have a strong trophic effect on protozoans and meiofauna. We investigated experimentally the direct effect of 2 densities (1 and 4 larvae/16 cm2) of Chironomus riparius, a nonselective macrofaunal deposit feeder, on a natural zoobenthic community. Larvae significantly reduced the abundance of total meiofauna (nematodes, rotifers, oligochaetes, and copepods) to 56 (1 larva) and 52% (4 larvae) of their initial abundance after 1 d. Protozoans were slightly reduced by 1 larva but their densities increased when 4 larvae were present. A strong decrease in copepod abundance led to a decrease in total meiofaunal biomass to 40 (1 larva) and 43% (4 larvae) of their initial biomass after 8 d. Organisms with body lengths between 0.125 and 1 mm were ingested preferentially. These results indicate that ...

Meiofaunal Distribution across the Oxygen Minimum Zone of Continental Margin, North East Arabian Sea

A quantitative study of metazoan meiofauna across the oxygen minimum zone (OMZ) of continental margin in the N-E Arabian Sea in the depth range 500-1965 m was carried out in September-November 2008. Bottom water oxygen and sediment organic carbon showed large variation between stations. The bottom water temperature and salinity was very similar in the area. The fauna was dominated by nematoda followed by harpacticoid copepoda and polychaeta. Maximum meiofaunal density of 164/10 cm 2 was recorded at St. 1 (500 m) and the lowest density of 25/10 cm² was observed at St. 2 (650 m) which coincided with lowest oxygen concentration. Total abundance of meiofauna was significantly lower than those reported from other areas. The average density was high (65/10 cm 2 ) in OMZ than in non OMZ (52/10 cm 2 ) area. Nematodes were the dominant taxon at every station. The dominance was particularly significant at those stations having very low oxygen. The meiofaunal density was positively correlated with sediment organic carbon while oxygen exhibited a negative correlation. Epibenthic Crustacean groups were more in areas of non OMZ having high oxygen. Vertical distribution revealed consistent reduction in total density and major taxa with increasing depth in sediment. Maximum density was recorded in top 0-2 cm layer. Among environmental parameters the availability of food in the form of sediment carbon appeared to be key factor in controlling meiofauna in study areas.

Meiofauna distribution in a mangrove forest exposed to shrimp farm effluents (New Caledonia)

Meiofauna abundance, biomass and individual size were studied in mangrove sediments subjected to shrimp farm effluents in New Caledonia. Two strategies were developed: i) meiofauna examination during the active (AP) and the non-active (NAP) periods of the farm in five mangrove stands characteristics of the mangrove zonation along this coastline, ii) meiofauna examination every two months during one year in the stand the closest to the pond (i.e. Avicennia marina). Thirteen taxonomic groups of meiofauna were identified, with nematodes and copepods being the most abundant ones. Meiofauna abundance and biomass increased from the land side to the sea side of the mangrove probably as a result of the increased length of tidal immersion. Abundance of total meiofauna was not significantly different before and after the rearing period. However, the effluent-receiving mangrove presented twice the meiofauna abundance and biomass than the control one. Among rare taxa, mites appeared extremely sensitive to this perturbation.

夏季南黄海冷水团及其周边海域小型底栖动物类群组成与分布

PDF HTML阅读 XML下载 导出引用 引用提醒 夏季南黄海冷水团及其周边海域小型底栖动物类群组成与分布 DOI: 10.5846/stxb201405221061 作者: 作者单位: 中国海洋大学海洋生命学院,中国海洋大学,中国海洋大学海洋生命学院,中国海洋大学海洋生命学院,中国海洋大学海洋生命学院,中国海洋大学海洋生命学院 作者简介: 通讯作者: 中图分类号: 基金项目: 中国海洋大学中央高校基本科研业务费专项项目(201462008);国家自然科学基金项目(41006081);山东省优秀中青年科学家科研奖励基金项目(BS2013HZ008) Meiofaunal assemblage and distribution in the southern Yellow Sea Cold Water Mass and its adjacent waters in summer Author: Affiliation: College of Marine Life Sciences,Ocean University of China,College of Marine Life Sciences,Ocean University of China,College of Marine Life Sciences,Ocean University of China,College of Marine Life Sciences,Ocean University of China,College of Marine Life Sciences,Ocean University of China,College of Marine Life Sciences,Ocean University of China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:对2011年6月南黄海冷水团及其周边海域23个站位的小型底栖动物类群组成、丰度、生物量和空间分布及其与环境因子的关系进行了研究。结果表明,调查海域共鉴定出小型底栖动物20个类群,平均丰度为(1194 ±873)个/10 cm2,平均生物量为(881±669)μg干重/10 cm2,其中自由生活海洋线虫是绝对优势类群,占小型底栖动物总丰度的89.7%,其次为底栖桡足类(5.5%)、甲壳类幼体(1.8%)、多毛类(1.2%);对生物量的贡献上依次为海洋线虫(49.0%)、多毛类(22.9%)、桡足类(13.9%)、介形类(7.8%)、涡虫(2.0%)。在垂直分布上,79.1%的小型底栖动物分布在沉积物0-2 cm的表层,16.4%分布在2-5 cm的次表层, 4.5%的小型底栖动物分布在5-8 cm的下层。与环境因子的相关性分析表明,小型底栖动物的总丰度和总生物量与沉积物叶绿素a含量显著正相关;小型底栖动物的生物量和沉积物中部分重金属(Pb、Cu、Fe、Ni、Co)含量呈显著负相关,但与Cd含量呈极显著正相关。BIOENV分析结果表明,沉积物含水量、有机质含量和分选系数组合最能解释小型底栖动物类群组成分布差异。根据小型底栖动物的类群组成可将研究海域划分为3个区域,包括:冷水团中央区域,冷水团边缘区和近岸区,其中冷水团边缘区丰度和生物量最高,冷水团区域次之,近岸区最低;整个冷水团海域小型底栖动物丰度和生物量分别是非冷水团海域的2.3倍和2.1倍。 Abstract:Meiofauna are referred to metazoans, including some protozoans, that can pass through sieves between mesh size of 1 mm (or 0.5 mm) and 0.042 mm (or 0.031 mm). Meiofauna are one of the most important components of the benthic ecosystem and serve as a key link in the benthic food web. They are ubiquitous in nature, with short generation time, small body size and high metabolic rates. Thus their metabolic activity has a direct effect on the rate of matter and nutrient recycling within the benthic ecosystem. Although there are many studies on meiofauna in Chinese seas, such as the Bohai Sea, Yellow Sea and East China Sea, there are only a few reports about meiofauna related to the southern Yellow Sea Cold Water Mass. In this paper, metazoan meiofaunal assemblage, abundance, biomass and spatial distribution in relation to benthic environmental variables at 23 stations in the southern Yellow Sea Cold Water Mass and its adjacent waters in summer 2011 were investigated. The results showed that a total of 20 taxa of meiofauna were identified. The average abundance and biomass of meiofauna were (1194±873) ind./10 cm2 and (881±669) μg dwt./10 cm2, respectively. Free-living marine nematodes were the most dominant meiofaunal group, comprising 89.7% of total abundance and 49.0% of total biomass, followed by benthic copepods (5.5%), crustacean nauplii (1.8%) and polychaetes (1.2%) in terms of abundance, and polychaetes (22.9%), benthic copepods (13.9%), ostracods (7.8%) and tubellarians (2.0%) in terms of biomass. For vertical distribution, 79.1% meiofauna were found in the surface 0-2 cm depth of the sediment, 16.4% in 2-5 cm depth and 4.5% in 5-8 cm depth. The abundance and biomass of total meiofauna showed significant positive correlation with chlorophyll a concentration, while the biomass of the total meiofauna showed significant negative correlation with the concentrations of heavy metals Pb, Cu, Fe, Ni and Co in the sediment and a significant positive correlation with Cd. BIOENV analysis showed that the combination of moisture content, organic matter content and grain size of sediment can best explain the difference of meiofaunal assemblages among the stations. Based on the abundance and biomass of meiofauna, the study area can be divided into three regions, including the centre of cold water mass, area at the perimeter of the cold water mass and the coastal waters. Among the three regions, the abundance and biomass at the perimeter of the cold water mass were the highest, followed by that in the central area of the cold water mass and the coastal water area. The average abundance and biomass of meiofauna in the cold water mass area was 2.3 and 2.1 times of the coastal waters, respectively. 参考文献 相似文献 引证文献

Biostimulation as an attractive technique to reduce phenanthrene toxicity for meiofauna and bacteria in lagoon sediment

A microcosm experiment was setup to examine (1) the effect of phenanthrene contamination on meiofauna and bacteria communities and (2) the effects of different bioremediation strategies on phenanthrene degradation and on the community structure of free-living marine nematodes. Sediments from Bizerte lagoon were contaminated with (100 mg kg(-1)) phenanthrene and effects were examined after 20 days. Biostimulation (addition of nitrogen and phosphorus fertilizer or mineral salt medium) and bioaugmentation (inoculation of a hydrocarbonoclastic bacterium) were used as bioremediation treatments. Bacterial biomass was estimated using flow cytometry. Meiofauna was counted and identified at the higher taxon level using a stereomicroscope. Nematodes, comprising approximately two thirds of total meiofauna abundance, were identified to genus or species. Phenanthrene contamination had a severe impact on bacteria and meiofauna abundances with a strong decrease of nematodes with a complete disappearance of polychaetes and copepods. Bioremediation counter balanced the toxic effects of phenanthrene since meiofauna and bacteria abundances were significantly higher (p < 0.01) than those observed in phenanthrene contamination. Up to 98 % of phenanthrene removal was observed. In response to phenanthrene contamination, the nematode species had different behavior: Daptonema fallax was eliminated in contaminated microcosms, suggesting that it is an intolerant species to phenanthrene; Neochromadora peocilosoma, Spirinia parasitifera, and Odontophora n. sp., which significantly (p < 0.05) increased in contaminated microcosms, could be considered as "opportunistic" species to phenanthrene whereas Anticoma acuminata and Calomicrolaimus honestus increased in the treatment combining biostimulation and bioaugmentation. Phenanthrene had a significant effect on meiofaunal and bacterial abundances (p < 0.05), with a strong reduction of density and change in the nematode communities. Biostimulation using mineral salt medium strongly enhanced phenanthrene removal, leading to a decrease of its toxicity. This finding opens exciting axes for the future use of biostimulation to reduce toxic effects of PAHs for meiofauna and bacteria in lagoon sediment.