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1.
东海浮游糠虾类生态类型划分及其对水团的指示作用 总被引:3,自引:0,他引:3
根据1997-2000年东海23°30′-33°N、118°30′-128°E海域4个季节海洋调查资料,对浮游糠虾类丰度和同步的表层温、盐度数据进行曲线拟合,构造数学模型,计算糠虾类分布的最适温度和盐度,分析其地理分布和季节分布特征,确定物种的生态类型.结果表明:宽尾刺糠虾(Acanthomysis latiscauda)、漂浮囊糠虾(Gastrosaccus pelagicus)、中华节糠虾(Siriel-la sinensis)和美丽拟节糠虾(Hemisiriella pulchra)是亚热带近海种,同时具有暖温种的特征;极小假近糠虾(Pseudanchialina pusilla)、东方原糠虾(Promysis orientalis)、小红糠虾(Erythropsminuta)和双眼准异糠虾(Anisomysis bipartoculata)虽是亚热带外海种,但具有热带大洋种特征.东海浮游糠虾类大多数物种的最适温、盐度偏低,冬春季在东海近海有更多的分布,因而具有暖温近海类型的生物学特征,这是该类浮游动物区别于其它浮游动物类群的重要特征.宽尾刺糠虾、中华节糠虾和美丽拟节糠虾的较高丰度区,也正是长江冲淡水与暖流水团交汇、沿岸水团与外海高盐水团交汇的位置.小红糠虾和双眼准异糠虾可作为暖流指示种.四刺端糠虾(Doxomysis quadrispinosa)和东方原糠虾是台湾暖流指示种.其它种均不是良好的水团指示种. 相似文献
2.
3.
C. Yau M. J. A. George R. A. Coggan † J. A. Criado-Delgado 《Journal of fish biology》1996,49(SA):330-336
Two species of the family Bothidae (lefteye flounders), Mancopsetta maculata metadata and M. milfordi occur in the south-west Atlantic but are caught rarely by commercial bottom trawlers. Little is therefore known about their general biology from this area. A total of 251 M. maculata and 276 M. milfordi were sampled during deep-water exploratory fishing conducted in November 1994 within the Falkland Islands Interim and Outer Conservation Zones, at depths of 400-1000 m, using standard commercial bottom trawling gear. The two species were found to have similar geographical distributions between 48.30'-53.30'S and 55°-62° W and were often obtained at the same stations in depths of 400-900 m on the continental slope. Mancopsetta maculata maculata showed a uni-modal cohort structure with a modal length at the 29-cm total length size-class. Males of M. m. maculata outnumbered females in a ratio of 3.5 : 1. Mancopsetta milfordi showed a tri-modal length distribution, the main mode at the 37-cm total length size-class, with females outnumbering males in a ratio of 1.1 : 1. Length-weight relationships and length-at-age information are presented for the two species. Diet was determined from the analysis of stomach contents and, although the major prey type for both species consisted of crustaceans, the morid fish Austrophycis marginata also formed an important part of the diet of M. milfordi. Key words: Mancopsetta maculata maculata; Mancopsetta milfordi; distribution; south-west Atlantic; size; diet. 相似文献
4.
Catch and discards from experimental trawl and longline fishing in the deep water of the Rockall Trough 总被引:1,自引:0,他引:1
Comparative bottom trawl and longline surveys were carried out on two chartered commercial fishing vessels in the deep waters (350-1300 m) of the Rockall Trough, an area subjected to heavy commercial exploitation. The species composition, catch rates and length distributions from each survey were very different and reflected the fundamental difference in the two types of fishing operations. Bottom-trawled catches produced greater species diversity and higher discard rates. Longline catches produced larger specimens of teleost fish and were dominated by squalid shark. Trawl discards, expressed as kgs of discards per tonne of roundnose grenadier Coryphaenoides rupestris landed, were calculated for a broad range of the most abundant species taken in the catch. First estimates of total international discarding from deep-water trawling operations in the Rockall Trough area (7530 tonnes; 26.5 million individuals) were made by raising the discard rates using international grenadier landings for 1995. The outlook for the continued exploitation of the deep-water fish resource in the Rockall Trough and possible management options are discussed. 相似文献
5.
恢复方式和地形对晋西黄土区退耕林分物种多样性的影响 总被引:1,自引:0,他引:1
运用样带样方调查法,对比不同恢复方式和地形条件下退耕林分的物种多样性,以期为晋西黄土区植被恢复效果评价和经营管理提供参考.结果表明: 恢复方式对退耕林分物种多样性具有显著影响.自然恢复林物种数为刺槐人工林的 1.6倍,Shannon 指数大于刺槐人工林,Pielou 指数小于刺槐人工林.物种多样性受坡位影响显著,各指数均表现为沟底>沟坡>梁峁坡>梁峁顶;坡向对退耕林分物种多样性影响不显著,各指数均表现为阴坡>阳坡.物种多样性受地形和恢复方式综合作用影响显著,在自然恢复林阴坡沟底处最高,物种均匀度在刺槐人工林阴坡沟底处最高.从提高物种多样性角度,黄土区植被恢复在遵循适地适树原则的同时,应参照自然恢复林分,在不同地形部位采用不同的造林设计. 相似文献
6.
During the ARK XI-2 expedition with RV Polarstern in September/October 1995, a transect of epibenthic sledge (EBS) samples was taken in the area of the Northeast Water Polynya
off the Greenland coast, from the shelf down into the deep sea. A total of 85,304 specimens of Peracarida were collected at
seven stations. These individuals comprised 45 families, 103 genera and 180 species. With regard to abundance, Cumacea occurred
with highest numbers, 31,269, followed by Isopoda, Amphipoda, Mysidacea and Tanaidacea. Species richness was highest in Amphipoda
with 94 species, followed by Isopoda with 43 species, Cumacea with 20 species, Tanaidacea with 15 and Mysidacea with 8 species.
Species richness was highest at the shallowest station 37-016 and lowest at the deepest station 37-021, whereas the opposite
pattern was found for abundance. Diversity and eveness were highest at the southernmost station and lowest at the deepest
station. Amphipoda occurred more frequently at the shallower stations, while Cumacea were very frequent at the deepest station.
Numbers of species were lowest for Cumacea at the deepest station, while Amphipoda and Isopoda generally occurred with high
species richness at all stations. On the basis of the species composition stations were compared. 相似文献
7.
Data on the distribution of 72 species of Leptostraca, Decapoda: Reptantia: Anomura, Mysidacea, and Isopoda in the northern Bering Sea, the Chukchi and East Siberian seas, and the adjacent areas of the continental slope in the Arctic basin at depths less than 500 m were used for biogeographic analysis. According to distribution, these species can be united into 15 biogeographic groups. The hydrological regime, primarily, the distribution of waters of different origin in the investigated regions, governs the distribution of different biogeographic groups of crustaceans. Pacific boreal and subtropic-boreal species mostly inhabit the southern part of the Chukchi Sea, coastal waters off Alaska to Point Barrow, and the central region of this sea to the Herald Bank. For these taxa, the boundary between the Pacific and Arctic faunas is in the Chukchi Sea crossing from Cape Serdtse Kamen and Point Barrow to the area west of the Herald Bank. Possible pathways and the major stages of formation of the fauna of the investigated crustaceans for the last 18000 years are discussed. 相似文献
8.
Guéguen F 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》2001,324(8):689-700
In order to describe some aspects of the biology of the deep-water shrimp Aristeus antillensis (Crustacea, Decapoda, Aristeidae) in French Guiana (Western Central Atlantic), a total of 84 bottom trawls were carried out at bottom depths ranging from 200 to 900 m on the Guianan slope during four scientific surveys conducted from August 1990 through July 1991. A. antillensis is distributed in muddy grounds from 456 to 818 m with a peak abundance in the 500-600-m-depth stratum where mean catch rates are about 400 g.h-1. In terms of biomass, catches obtained in day time and at night are similar. All samples observed show great predominance of females. The size frequency distribution indicates the existence of three age-classes for females, probably attributed to three annual cohorts. The results of a detailed study of morphometric relationships (length-weight relationships) are also presented. 相似文献
9.
On the Kolbeinsey Ridge, north of Iceland, 92 species of peracarid crustaceans were sampled using the epibenthic sledge. For an analysis of the multispecies distribution pattern across the ridge, a total of 46 species have been considered, which occurred at least at two stations and with at least 5% relative abundance at any one station. The analysis revealed four assemblages: a deep species assemblage, an eastern slope assemblage, an ubiquitous species assemblage and a western slope assemblage. The western slope assemblage consists mainly of Amphipoda, which were most abundant and diverse on the western slope. The ubiquitous and eastern slope assemblages, however, are dominated by Isopoda, which also comprised most species and individuals on the eastern slope. Cumaceans were the most representative species of the deep species assemblage. These differences in species composition and abundance can probably be attributed to food supply and sediment composition, rather than to salinity or bottom water temperature. 相似文献
10.
砒砂岩区沙棘根系的生境适应性 总被引:1,自引:0,他引:1
以人工种植在内蒙古砒砂岩区3年生中国沙棘根系为研究对象,运用分形理论和统计分析方法,对不同生境条件下沙棘根系分形参数、根长、根数、根系质量、根冠比等进行研究.结果表明: 土壤水分对砒砂岩区沙棘根系构型影响最显著,其次是坡度,坡位对沙棘根系构型影响最小.砒砂岩区沙棘适宜种植在土壤含水率为8%左右的坡腰或坡底,坡腰坡度以30°~35°为宜.随土壤含水率的增加沙棘根冠比逐渐减小,随坡度的增加根冠比先增大后减小,随坡位的上升根冠比也表现出先增后减的趋势.沙棘在干旱贫瘠的坡腰具有根系发达、根冠比高的特征,符合固土护坡树种的基本特征与要求. 相似文献
11.
V. V. Panchenko O. I. Pushchina M. I. Boiko P. V. Kalchugin 《Journal of Ichthyology》2017,57(4):560-568
The spatial and depth-related distribution, the size spectra, and the feeding peculiarities have been studied for the bottom skate Bathyraja bergi in the Russian waters of the Sea of Japan for the trawl catches performed in 1986?2015. The species is found at the depths of 38?577 m at the water temperature of 0.3?3.8°C; during the warm season, the fish keep mainly at the shelf, while they keep at the continental slope in the cold period of the year. This species is found nearly everywhere at the preferred depth range, except a part of the Strait of Tartary. The highest population density has been registered in the southwestern Peter the Great Gulf, along the border with the Korean waters. The schools of the bottom skate of the continental slope and the island shallows do not interact with each other. The specimens reach a body length of 129 cm and a body weight of 13.84 kg. The feeding habits indicate that this species is a predator; decapods (59.9%), cephalopods (23.0%), and fish (15.3%) dominate in the food. In spring, average daily ration constitutes 0.9% of the body weight. In the Russian waters of the Sea of Japan, the bottom skate is a common species, however, it is not abundant; the biomass of the population in this area is approximately 1500 tons. 相似文献
12.
The bottom trawl fishery developed on the slope off Balearic Islands (western Mediterranean) has been analysed from different
sources of information: (i) data obtained during experimental bottom trawl surveys developed annually since 2001; (ii) daily
sale bills from the bottom trawl fleet, available since 2000. Considering both hydrographical and geomorphologic conditions,
the study area was divided in four geographical sectors. Multivariate techniques were applied to identify assemblages and
their main species, and to investigate the influence of environmental variables in the slope communities. Fishery-independent
and fishery-dependent indicators were calculated, both at specific and community level, for the assemblages identified. In
all cases, they were summarised using the Traffic Light approach. Three assemblages have been identified in the slope trawl
fishing grounds off the Balearic Islands: (1) the almost unexploited shelf break, where teleosts predominate; (2) the upper
slope, where teleosts still predominate but crustaceans are also very important (with Nephrops norvegicus as target species); (3) and the middle slope, where crustaceans predominate (with Aristeus antennatus as target species). Depth was the main factor affecting the species composition of the assemblages, although other factors
such as area, year and effort level also affect. Indicators estimated from both sets of data suggested an improvement in the
state of N. norvegicus, although the results suggest the influence of other factors than fishing impact in the state of this resource. For A. antennatus, marked differences have been found depending on the data source. In the upper slope, indicators suggested an improvement
in the state of this assemblage, which can be related to a decreasing trend found in the fishing effort exerted in this depth
range. Indicators from the middle slope showed differences for both sets of data. The characteristics of both data sources
and of the species analysed are discussed as responsible of these differences. 相似文献
13.
Fresia Villalobos-Rojas Juan Carlos Azofeifa-Solano Yolanda E. Camacho-García Ingo S. Wehrtmann 《Molluscan research.》2017,37(3):175-186
Deep-water habitats are among the least studied but most vulnerable environments. By-catch data from deep-water fisheries in Latin America are limited, and detailed reports on associated molluscs are scarce. This study provides information on deep-water shelled molluscs collected between 2010 and 2011 by commercial shrimp trawling fisheries along the Pacific coast of Costa Rica at depths from 112 to 271?m. Twenty-six species were identified, 23 gastropods and three bivalves. Our data extend the depth range of 14 species, and Homalopoma cf. grippii is reported for the first time for Costa Rica. The most common species were the gastropods Fusinus spectrum, Polystira nobilis and Solenosteira gatesi. Only one species (Sinum debile) was captured below 250?m. The catch of molluscs per unit effort was influenced by depth, but not by seasonality or geographic area. It is speculated that these long-lasting bottom-trawling activities have caused negative effects on species diversity and mollusc biomass. Nevertheless, a monitoring program is recommended to assess possible impacts of this type of fishery on mollusc diversity and biomass. 相似文献
14.
Acoustic mapping using a multibeam echosounder reveals cold-water coral reefs and surrounding habitats 总被引:2,自引:0,他引:2
Multibeam surveys were carried out in four areas to the west of Scotland where the coral Lophelia pertusa had previously been recorded. Distinctive seabed mounds were found in one area; video images from the mounds showed coral
reef formation, and grab samples recovered L. pertusa reef framework and rubble. Skeleton samples were dated to 3,800 years BP. Grab samples contained 123 species of fauna. The
reef structures, termed the Mingulay Reef Complex, were identified as topographic mound-like structures from the bathymetric
data and were also visible on the backscatter images. The location of the reefs coincides with Atlantic bottom waters, close
to a primary productivity centre and mixing zone, in an area where currents are likely to be accelerated by rocky seafloor
ridges. This study shows that multibeam echosounders are powerful tools to locate and map deep-water coral reefs irrespective
of water depth.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
15.
D. S. Pavlov A. D. Mochek E. S. Borisenko E. A. Degtev A. I. Degtev 《Journal of Ichthyology》2010,50(11):997-1001
An original method for estimation of the effect of bottom irregularities on density of fish aggregations is elaborated. Calculation
of the investigated relationship is based on material of surveys collected by an AsCor hydroacoustic complex and is made by
means of special software. With reference to a deep-water stretch of the Irtysh channel, the quantitative parameters of the
relationship between densities of fish aggregations and the index of bottom irregularity are revealed. The diagram of the
relationship between bottom irregularities and density of fish aggregations, the three-dimensional model of bottom relief
of the investigated water area, and echograms of fish aggregations on various stretches of the river are presented. 相似文献
16.
北京东灵山不同坡位辽东栎(Quercus liaotungensis)叶属性的比较 总被引:2,自引:0,他引:2
植物在山地环境中生存不仅受到海拔等大尺度地形因子的影响,坡位等小尺度地形因子也会对植物产生影响.不同坡位上光照、温度、土壤养分和水分等均会影响到植物的资源利用策略.为比较不同坡位对辽东栎资源利用策略的影响,在北京东灵山海拔1000~1800 m的辽东栎分布范围内针对比叶面积、叶氮含量和叶干物质含量3个重要的叶属性进行了研究.ANOVA统计分析发现,地形和土壤养分及水分等环境因子在不同坡位上出现变化,但只有土壤有机质含量有显著差异.在叶属性中,干物质含量在上坡位最高,下坡位最低,在坡位间差异极显著.比叶面积与叶干物质含量在不同坡位间均成反比关系,在上坡位比叶面积变化一定的情况下,叶干物质含量的变化幅度最小;而比叶面积与叶氮含量仅在上坡位成反比关系.这些结果说明坡位对辽东栎的叶属性有一定的影响,尤其是上坡位的影响最大. 相似文献
17.
In the Early Carboniferous-Bashkirian the most diverse ammonoid assemblages were associated with deep-water settings of the
outer shelf and the carbonate platform slope. At the end of the Early Bashkirian, ammonoid assemblages of basins of the eastern
slope of the South Urals were associated with shallow-water settings and bioherm buildups, which probably contributed to their
endemism. New species of the genera Neogoniatites, Schartymites, and Stenoglaphyrites are described from localities of the eastern slope of the South Urals. 相似文献
18.
Records of demersal deep-sea fish assemblages in waters around the Falkland Islands (Patagonian shelf area) are rare. Twenty deep-water stations to the east and south of the Falkland Islands were sampled by commercial bottom trawl deployed in upper, middle and lower benthopelagic zones (depth range of approximately 500-1000 m). Forty-one species (22 families) of teleost fish were recorded, 10 species (two families) of elasmobranch and one species of agnathan. Different assemblages of fish were found to characterize each depth zone (e.g. Moridae in deeper waters, Bothidae and Rajidae in shallower waters), with diversity being greatest in the mid-zone and biomass greatest in the upper and lower zones. Some species occurred in all zones but showed depth-related abundance. Four species, namely the grenadiers Macrourus carinutus and Coelorhynchus fasciatus , the southern blue whiting Micromesistius australis , and the Patagonian toothfish Dissostichus eleginoides , accounted for 85% by weight of all fish caught. Quantitative sampling of selected species revealed depth-related variations in their population structure. Length-frequency analyses are presented for M. carinatus and D. eleginoides and show a tendency for larger individuals to inhabit deeper water. Discard rates from the commercial catch were sometimes high, particularly for the smaller species, raising concerns about the impact of a fishery on by-catch species. The potential for deep-sea fisheries in Falkland waters is discussed and further studies are suggested in the light of developing oil, gas and fishing industries. The presence of some invertebrate taxa is recorded. 相似文献
19.
Both living (stained) and dead (unstained) foraminiferal assemblages from surface sediments (0–2 cm) in the northwestern part of the Skagerrak have been studied in order to (1) define and characterize the distribution of various modern benthic environments and (2) by comparing these findings with surface samples collected 40–60 years ago, to document possible faunal changes that might have occurred. The investigated area is physiographically divided into the Norwegian slope, the Skagerrak Basin, and the Danish slope. The latter is under the influence of the Jutland Current, while the basin and the investigated parts of the Norwegian slope are bathed in Atlantic water. All areas have bottom waters with a high oxygen concentration. Three living (stained) and three dead (unstained) assemblages occupy the three physiographic areas. Only one assemblage (on the Norwegian slope) is common to both the living and dead assemblages but the boundaries between them lie at comparable depths. The higher standing crops are found on the fertile Danish slope while the lower ones are in the deep basin where the diversity is at a maximum. In the dead assemblages, the relative abundance of agglutinated tests increases with depth. Comparison with data collected 40 to 60 years ago shows increases in absolute numbers of tests, especially in the deep basin. There are changes in assemblage compositions in all areas. The dominant species found in 1937 are different from those of 1992/1993. There is a major change in the basin where one agglutinated species has changed its depth distribution downslope and two present day abundant species are new arrivals. These faunal events are probably linked to environmental changes. 相似文献
20.
Everard Mark Kuria Anthony Macharia Michael Vale Jacqueline A. Harper David M. 《Hydrobiologia》2002,471(1-3):43-55
Deep-water Oculina coral reefs, which are similar in structure and development to deep-water Lophelia reefs, stretch over 167 km (90 nmi) at depths of 70–100 m along the eastern Florida shelf of the United States. These consist of numerous pinnacles and ridges, 3–35 m in height. Coral growth rates average 16.1 mm yr–1 and biodiversity is very rich. Extensive areas of Oculina rubble may be due to human impacts (e.g. fish trawling and dredging, anchoring, bottom longlines) and natural processes such as bioerosion and episodic die-off. Early in the 1970s, the reefs were teeming with fish. By the early 1990s, both commercial and recreational fisheries, including scallop, shrimp, grouper, snapper and amberjack, had taken a toll on the reefs and especially on populations of grouper and snapper. A 315 km2 (92 nmi2) area was designated the Oculina Habitat of Particular Concern (HAPC) in 1984, prohibiting trawling, dredging, bottom longlines and anchoring, and legislation was enacted in 2000 for expansion of the Oculina HAPC to 1029 km2 (300 nmi2). The United States Coast Guard has been charged with surveillance and enforcement of the ban on bottom fishing and trawling. The primary difficulties in protecting these reefs and other deep-water Marine Protected Areas are their remoteness and time required to engage an enforcement vessel. Education regarding the nature and importance of these rich resources is important for better self regulation and surveillance by the fishing community. Only by bringing deep-water reefs to the public, the fishing community, and enforcement agencies, through video, photos, and education will there be better understanding and acceptance for the need of protection for these unseen resources. This paper reviews the current knowledge on the deep-water Oculina reefs, including the biology, geology, human impacts, and history of conservation and management. 相似文献