共查询到20条相似文献，搜索用时 15 毫秒
1.
2.
Spatial and temporal variability of the Aleutian climate 总被引：2，自引：0，他引：2
3.
Marine environment of the eastern and central Aleutian Islands 总被引：2，自引：0，他引：2
CAROL LADD GEORGE L. HUNT Jr CALVIN W. MORDY SIGRID A. SALO PHYLLIS J. STABENO 《Fisheries Oceanography》2005,14(S1):22-38
4.
Hydrographic features and seabird foraging in Aleutian Passes 总被引：1，自引：0，他引：1
CAROL LADD JAIME JAHNCKE GEORGE L. HUNT Jr KENNETH O. COYLE PHYLLIS J. STABENO 《Fisheries Oceanography》2005,14(S1):178-195
5.
6.
7.
8.
Between May 2001 and September 2003, a series of moorings were deployed in four of the Aleutian Passes – Tanaga Pass (12 months of data), Akutan Pass and Seguam Pass (18 months), and Amukta Pass (36 months). Instruments on each mooring measured temperature, salinity and current velocity. Tidal currents dominated the flow in each pass, including a strong fortnightly component in the three deeper passes (Tanaga, Seguam, and Amukta). Net transport in each of the passes was northward, varying from 0.1 × 106 m3 s?1 in Akutan Pass and 0.4 × 106 m3 s?1 in Seguam to >4.0 × 106 m3 s?1 in Amukta Pass. The transport in Amukta Pass, calculated from current meters, was approximately five times as large as previously estimated from hydrographic surveys. At monthly and longer periods, the variability in transport in Amukta Pass was related to the position and strength of the Alaskan Stream southeast of the pass. Vertical mixing was examined in Akutan and Seguam Passes. Strong tidal currents mix the water column top‐to‐bottom over the shallow sills in the passes, a depth of 80 m in Akutan and 140 m in Seguam Pass, providing a critical source of nutrients to the Bering Sea ecosystem. 相似文献
9.
10.
Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis 总被引：1，自引：0，他引：1
ANDREW W. TRITES ARTHUR J. MILLER HERBERT D. G. MASCHNER MICHAEL A. ALEXANDER STEVEN J. BOGRAD JOHN A. CALDER ANTONIETTA CAPOTONDI KENNETH O. COYLE EMANUELE DI LORENZO BRUCE P. FINNEY EDWARD J. GREGR CHESTER E. GROSCH STEVEN R. HARE GEORGE L. HUNT JAIME JAHNCKE NANCY B. KACHEL HEY‐JIN KIM CAROL LADD NATHAN J. MANTUA CAREN MARZBAN WIESLAW MASLOWSKI ROY MENDELSSOHN DOUGLAS J. NEILSON STEPHEN R. OKKONEN JAMES E. OVERLAND KATHERINE L. REEDY‐MASCHNER THOMAS C. ROYER FRANKLIN B. SCHWING JULIAN X. L. WANG ARLISS J. WINSHIP 《Fisheries Oceanography》2007,16(1):46-67
Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976–77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affected the rates of birth and death of sea lions. Recent studies of the spatial and temporal variations in the ocean climate system of the North Pacific support this hypothesis. Ocean climate changes appear to have created adaptive opportunities for various species that are preyed upon by Steller sea lions at mid‐trophic levels. The east–west asymmetry of the oceanic response to climate forcing after 1976–77 is consistent with both the temporal aspect (populations decreased after the late 1970s) and the spatial aspect of the decline (western, but not eastern, sea lion populations decreased). These broad‐scale climate variations appear to be modulated by regionally sensitive biogeographic structures along the Aleutian Islands and Gulf of Alaska, which include a transition point from coastal to open‐ocean conditions at Samalga Pass westward along the Aleutian Islands. These transition points delineate distinct clusterings of different combinations of prey species, which are in turn correlated with differential population sizes and trajectories of Steller sea lions. Archaeological records spanning 4000 yr further indicate that sea lion populations have experienced major shifts in abundance in the past. Shifts in ocean climate are the most parsimonious underlying explanation for the broad suite of ecosystem changes that have been observed in the North Pacific Ocean in recent decades. 相似文献
11.
12.
１９９３年６～８月，“北斗”号渔业资源调查船在白令海阿留申海盆区进行了狭鳕资源声学调查及渔场环境调查。应用本航次调查资料，本文阐述了调查海区温度、盐度及溶解氧分布特征，并分析了狭鳕分布和移动与理化环境的关系。结果表明：（１）阿留申海盆区为大面积低温水所覆盖，水温在１０℃以下。温盐水平分布特征为公海区低温高盐，调查区的其余水域则为高温低盐。溶解氧水平分布比较均匀，表层溶氧含量在１０ｍｇ／Ｌ左右；（２）温跃层位于２５米和５０米之间，一强冷水团控制着１００米到２００米左右的水层，其水温在３℃以下。盐度随深度增加而增加，溶解氧随深度的增加而降低；（３）狭鳕当年生幼鱼主要分布在海盆水系和东大陆架水系的混合区内，１００米层幼鱼密集区水温在３～５℃，盐度在３２．９～３３．１，溶解氧在８～９ｍｇ／Ｌ；（４）夏季狭鳕成鱼主要在冷水团范围以内垂直移动，２００米层成鱼密集区水温为３～４℃，盐度为３３．２～３３．６，溶解氧为６～８ｍｇ／Ｌ。 相似文献
13.
白令海阿留申海盆区狭鳕当年生幼鱼数量分布的调查研究 总被引：1，自引：0，他引：1
１９９３年夏季白令海狭鳕资源调查期间，作者等应用声学／拖网评估调查方法，首次发现阿留申海盆区有大量当年生狭鳕幼鱼分布。研究结果表明：（１）当年生幼鱼主要分布在海盆区东北部，密集区位于东白令海陆架斜坡与公海区之间，呈西北东南走向；（２）鱼群主要栖息于中上层８０—１２０米处，有明显的昼夜垂直移动现象；（３）７月份海盆区东北部幼鱼鱼体长度为２９—４７毫米，而南部波哥斯洛夫岛附近的鱼体长度仅为１１—１７毫米，系两个不同产卵期鱼群的子代；（４）幼鱼主要栖息层的水温为３—５℃，盐度为３２．９—３３．１，其分布与陆架斜坡地理环境和饵料生物关系较密切。 相似文献
14.
15.
Year-to-year variations in Bering Sea ice cover and some consequences for fish distributions 总被引：7，自引：0，他引：7
The southernmost extension of winter ice cover varies interannually and on longer time scales, reflecting large-scale changes in driving forces, especially in the position and intensity of the winter Aleutian Low Pressure System. A conspicuous pattern is alternating warm and cool periods of several years' duration. These variations in sea ice cover are reflected in the character of a subsurface cold pool, formed as stratification isolates the deeper cold waters from surface exchanges. The cold pool is better developed and more extensive in summers that follow deep southward penetration of winter sea ice. Interannual and decadal-scale variations in the distributions of some fish stocks reflect those of ice and thermal conditions. In particular, the distribution of walleye pollock, Theragra chalcogramma, varies significantly with multiannual cool and warm years while Arctic cod, Boreogadus saida, is only present within the cold pool. The relation among climate variations, sea ice cover, subsurface thermal conditions, and fish distribution provides information on how climate affects marine ecosystems and may also have practical application in predicting fish distributions. 相似文献
16.
17.
In the coastal zone of the Sea of Okhotsk off Hokkaido, Japan, the giant ezo scallop ( Patinopecten yessoensis ) is widely cultivated on the sea bed, making its fishery a major industry. However, the area experiences intense cyclones, including typhoons, about once a decade and the scallop resources appear to have received severe damage from the storms. Such an event occurred on 29 October 1988. The storm caused 12-m-high wind waves, which appeared to be fully developed sea waves. The water above the sea bed repeatedly moved back and forth at speeds of 1∼2 m s-1 causing damage to the scallops due to collisions and rubbing with gravel and other scallops. From a comparison of wind data with the annual catch of scallops, intense cyclones seem to play an important role on the year-to-year fluctuations in the scallop fishery. 相似文献
18.
19.
20.
To investigate their diel vertical migration (DVM), 599 sablefish (Anoplopoma fimbria) were implanted with electronic archival tags in the Gulf of Alaska, Aleutian Islands, and the eastern Bering Sea. Of these tags, 98 were recovered with usable depth data (7,852,773 recordings representing 81,233 days) that we used to identify DVM and to classify DVM into one of two types: normal DVM (rise from the bottom during nighttime) and reverse DVM (rise from the bottom during daytime). The results of our study highlight three important attributes of DVM for sablefish. First, all tagged sablefish carried out DVM, although the occurrence was intermittent (26% of the days with usable data) and most commonly for short durations (10 days or less). Second, bottom depth for normal DVM was about 78 m shallower than for reverse DVM. Third, normal DVM occurred most often in fall and least often in spring, whereas this high/low pattern was shifted about 3 months later for reverse DVM; reverse DVM occurred most often in winter and least often in summer. Normal DVM likely occurred to increase foraging opportunity (e.g., nightly shift to match depth of prey). Reverse DVM more commonly occurred during winter and may represent an increase in foraging by sablefish during the daytime to compensate for decreased pelagic resources. The default foraging strategy for sablefish may be benthic because of the uncertainty of vertically migrating to a location where the occurrence of prey is not guaranteed; sablefish may invoke DVM when the non‐DVM foraging benefit is reduced. 相似文献