基于稳定同位素方法的东海中南部海域主要饵料生物营养生态位季节变动的研究          下载免费PDF全文

张琥顺  宋普庆  郑新庆  刘世刚  李渊  王雪华  林龙山 《应用海洋学学报》2022,41(3):375-385

饵料生物在海洋生态系统中处于承上启下的关键地位,为准确评估东海中南部海域饵料生物的营养关系,基于2018年11月和2019年4月两个航次调查中收集的饵料生物的碳氮稳定同位素数据,对其营养生态位的季节变动特征及种间竞争关系进行了研究。结果表明：该海域饵料生物的碳氮稳定同位素比值跨度较大,海域整体食源多样性水平较高,营养结构较稳定;饵料生物δ13C和δ15N值存在明显的季节差异,春季饵料生物的营养级显著低于秋季;浮游动物的营养生态位在两个季节间未发生明显的偏移,但其他饵料生物的生态位的位置和重叠度发生了一定变化,这或许与饵料生物摄食选择的季节差异有关;鱼类、虾类和头足类的营养生态位在不同采样时期分别表现出不同的重叠和分化特征,证明了不同饵料生物对食物选择的差异性。相关研究结果可为类似海域生物营养生态位的研究提供参考,也可为东海海域渔业资源的可持续开发利用和生态环境的保护提供科学资料。  相似文献   

2020年冬季大亚湾西南海域主要渔业生物碳氮稳定同位素研究     

张婉茹  刘庆霞  黄洪辉  覃晓青  李佳俊  陈建华 《热带海洋学报》2022,41(3):147-155

为了解大亚湾西南海域食物网的营养结构特征, 本研究于2020年1月份使用底拖网采集了该海域的渔业生物, 并分析了35种主要渔业生物的碳氮稳定同位素值。根据δ¹³C和δ¹⁵N值, 计算出该海域食物网6种营养结构的生态指标和主要渔业生物的营养级, 并绘制了连续营养谱。本次调查渔业生物主要为鱼类和虾蟹类, 鱼类的δ¹³C和δ¹⁵N值范围分别为-17.63‰ ~ -14.85‰和12.92‰~15.46‰, 平均值分别为-16.47‰和13.80‰; 虾蟹类的δ¹³C和δ¹⁵N值范围分别为-17.67‰ ~ -15.51‰和11.05‰~12.62‰, 平均值分别为-16.30‰和11.85‰。根据δ¹⁵N值, 用相加模型(trophic position by the additive model, TPA)和缩比模型(trophic position by the scaled model, TPS)分别计算了主要渔业生物的营养级, 结果显示两个模型计算的结果无显著性差异(P>0.1), 呈现鱼类平均营养级>虾蟹类的趋势。本研究发现大亚湾西南海域食物网初始食物来源较为单一, 存在食物链营养层级较少和长度不足, 食物网营养级多样性较低和营养结构冗余程度高的现象。与30多年前相比, 大亚湾近年高营养级生物量减少, 食物网结构由复杂趋向简单化, 生态系统稳定性较差。本研究结果不仅为了解大亚湾食物网结构组成提供了基础资料, 也为保护大亚湾渔业资源, 维持生态系统结构的稳定性提供参考依据。  相似文献   

Xinghaiornis lini (Aves: Ornithothoraces) from the Early Cretaceous of Liaoning: An Example of Evolutionary Mosaic in Early Birds     

WANG Xuri  Chiappe M. LUIS  TENG Fangfang  JI Qiang 《《地质学报》英文版》2013,87(3):686-689

We describe a new species of Early Cretaceous bird from the Yixian Formation of Liaoning Province. Xinghaiornis lini gen. et sp. nov. is relatively large and characterized by a long, toothless rostrum and an elevated pedal digit I. The design of the skull and feet suggests that this bird was likely a mud-prober. This discovery provides strong support indicating that this avian trophic specialization originated at least 125 million years ago.  相似文献   

Nitrogen fixation in polluted intertidal sediments of Waimea Inlet,Nelson     

B. Ben Bohlool 《新西兰海洋与淡水研究杂志》2013,47(3):271-275

Abstract

Nitrogen fixing potential was measured in summer 1975 by acetylene reduction in situ at 5 stations on the intertidal flats of the Waimea Inlet, Nelson, New Zealand, which receive nutrients from several sources. Highest values (644 μmol?m^?2.d^?1) were obtained on sediments near an apple cannery effluent discharge and were linear through at least two tidal cycles. The cannery waste had the highest carbon to nitrogen ratio (10.3 : 1.0) of all the effluents examined and exhibited the highest rate of acetylene reduction (14.0 μmol?_‐l^?1.d^?1). Sizeable populations of the nitrogen fixing bacteria Klebsiella pneumoniae were isolated from the cannery effluent (2 × 10⁴ per millilitre) and also from the mud adjacent to the discharge pipe (5 × 10⁵ per millilitrc). The stimulatory effect of the cannery effluent on nitrogen fixation in the sediment was shown to be restricted to close to the discharge point. Sediments in areas affected by slaughterhouse and sewage effluents exhibited the second and third highest rates of acetylene reduction, (130 &; 28 μmol?m^?2.d^?1 respectively). In both places, the activities were not restricted to the immediate vicinity of the effluent channels. Nitrogen fixation was lowest in sediments fronting a catchment of grazed pasture. Fixation was low also in sediments affected by effluents from the hydraulic debarker of a woodchip mill.  相似文献   

Diet and dietary variation of New Zealand hoki Macruronus novaezelandiae     

AM Connell  J Forman 《新西兰海洋与淡水研究杂志》2013,47(4):289-308

The diet of hoki was determined from examination of stomach contents of 1992 fish of 26–112 cm total length (TL) sampled at depths of 209–904m on Chatham Rise, New Zealand, from summer research trawl surveys and seasonal commercial fishing trawls, during 2004–2008. Prey was predominantly euphausiids, mesopelagic fishes and natant decapods. Multivariate analyses using distance-based linear models, non-parametric multi-dimensional scaling and similarity percentages indicated that the best predictors of diet variability were the position of the fish in relation to the subtropical front (STF), fish size and longitude. Pasiphaeids were more important to the north of the STF, and sternoptychid fishes and euphausiids more important in the STF convergence area. Euphausiids and sternoptychid fishes were important for smaller hoki (26–55 cm TL), myctophid fishes and natant decapods for larger hoki, and macrourids for the largest hoki (>84 cm TL). The longitudinal effect was characterised by pasiphaeids, euphausiids and sternoptychids to the west, and myctophids in the centre of Chatham Rise. Feeding activity was analysed using generalised additive models, and was found to vary with time of day, sample source (research or commercial), longitude, hoki size and depth. The variability in diet suggested hoki forage opportunistically within their preferred habitat and biological limits.  相似文献   

Life history of Galaxias divergens (Salmonoidea: Galaxiidae)     

C. L. Hopkins 《新西兰海洋与淡水研究杂志》2013,47(1):41-57

Galaxias divergent Stokell is a small, bottom‐dwelling fish inhabiting streams in the North Island and the northern part of the South Island. Its ecology is similar in many respects to that of G. vulgaris. The fry develop in the same environment as the adults, unlike the sea‐going young of several other Galaxias spec'es. Spawning occurs in spring and summer, and at least some of the fish mature at the beginning of their second year. The maximum age attained seems to be about 3 years, and the fish can reach a length of about 80 mm in this time. The food consists mostly of small benthic invertebrates taken from both the stream bed and the drift fauna.  相似文献   

Ecology of rocky reef fish of northeastern New Zealand: 50 years on     

GP Jones 《新西兰海洋与淡水研究杂志》2013,47(3):334-359

Abstract

This review examines the history and current understanding of the ecology of rocky reef fishes in northeastern New Zealand, marking the fiftieth anniversary of the Leigh Marine Laboratory. The cumulative number of publications increased steadily to c. 180 by 2012. Most attention has been on the snapper (Pagrus auratus, f. Sparidae), the largest in size and economically most important species, and on triplefins (Tripterygiidae), the smallest in size and most diverse family. A strong quantitative school emerged in the 1980s, a period when there was little research on temperate reef fishes elsewhere. A ‘bottom-up’ view of the effects of habitat structure on fish emerged, identifying the key roles of depth, topography and macroalgae. By 2000, attention shifted to using marine reserves as laboratories for ecological research. A ‘top-down’ view of fish as predators emerged, documenting cascading effects on prey communities and habitats. The two different viewpoints have not yet been integrated. Research gaps, including population connectivity and climate change, represent major challenges for the next 50 years.  相似文献   

Use of particle-size data to predict potential pelagic-fish yields of some southern African areas     

《African Journal of Marine Science》2013,35(1):119-128

A particle-size spectrum model is used to estimate standing stocks of some pelagic fish from measurements of phytoplankton chlorophyll in two exploited regions in southern Africa (southern Benguela and off South West Africa/Namibia) and in two unexploited regions (the Agulhas Bank and off the eastern Cape Province). The model is based on the assumption that equal biomasses occur in logarithmically equal size classes in the pelagic marine environment. Phytoplankton, with an equivalent spherical diameter ranging from 1 to 128 μm, occupy 21 size classes on the logarithmic scale. Two different size ranges are assumed for some commercial, pelagic fish species, equivalent to exploitation with two different purse-seine mesh sizes. A mesh of 12,7 mm would catch 8 size classes of pilchard, horse mackerel and anchovy whereas a mesh of 32 mm would catch only 3,3 size classes of pilchard and horse mackerel. From the model, the potential biomass of these commercial pelagic fish is estimated, after allowing for the presence of other commercial and non-commercial fish and other taxa in the exploited size range. Total pelagic fish production is estimated by assuming constant turnover rates of 1·y^?1 and 1,5·y^?1 when exploited with 32 and 12,7 mm mesh nets respectively. Consideration of the maximum and mean reported catches in the exploited areas indicates that only some 25 per cent of pelagic fish production is exploitable by man. On this basis, the unexploited Agulhas Bank region may yield some 400 000 metric tons (wet) of pelagic fish of the species considered, and the East Coast region some 90 000 tons. Exploitation in these regions cannot be recommended, because the Agulhas Bank is an important spawning ground for many pelagic species, and the fish in both regions probably act as a reserve buffer for the heavily exploited pelagic resource of the Western Cape.  相似文献   

The geographic distribution of Echiura from southern Africa     

《African Journal of Marine Science》2013,35(1):11-21

The echiuran fauna of southern Africa currently comprises two families, four genera and 16 species of which one has recently been described as new to science and four are new records for the region. The taxonomic characters distinguishing the genera are given. The zoogeographic distribution of the southern African species is outlined and discussed. Knowledge of the echiuran fauna is too scanty to throw any light on the division of the coastline into faunistic provinces.  相似文献   

Reef fish and benthic community structures of the Santa Luzia Marine Reserve in the Cabo Verde islands,eastern central Atlantic Ocean     

《African Journal of Marine Science》2013,35(2):177-190

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