scholarly journals Shallow-emerged coral may warn of deep-sea coral response to thermal stress

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julia W. Johnstone ◽  
Rhian G. Waller ◽  
Robert P. Stone

AbstractIn the Gulf of Alaska, commercially harvested fish species utilize habitats dominated by red tree corals (Primnoa pacifica) for shelter, feeding, and nurseries, but recent studies hint that environmental conditions may be interrupting the reproductive lifecycle of the corals. The North Pacific has experienced persistent and extreme thermal variability in recent years and this pattern is predicted to continue in coming decades. Recent discovery of deep-water emerged coral populations in Southeast Alaska fjords provided opportunity for detailed life-history studies and comparison to corals in managed habitats on the continental shelf. Here we show that sperm from deep colonies develops completely, but in shallow colonies, sperm development is prematurely halted, likely preventing successful production of larvae. We hypothesize that the divergence is due to differing temperature regimes presently experienced by the corals. Compared to deep populations below the thermocline, shallow populations experience much greater seasonal thermal variability and annual pulses of suspected near-lethal temperatures that appear to interrupt the production of viable gametes. The unique opportunity to comprehensively study emerged populations presently affected by thermal stress provides advance warning of the possible fate of deep corals in the Gulf of Alaska that will soon experience similar ocean conditions.

1992 ◽  
Vol 70 (11) ◽  
pp. 2125-2131 ◽  
Author(s):  
Andrew W. Trites

Annual estimates of the condition of pregnant northern fur seals (Callorhinus ursinus) and the size of their fetuses were determined from over 2600 samples collected in the North Pacific from 1958 to 1972. A condition index related the observed mass of pregnant females (adjusted for fetal mass) to their predicted mass (calculated from body length). It showed that females carrying male fetuses were in poorer condition than those carrying female fetuses. It also showed that the mean condition of pregnant females improved from 1958 to 1964, but dropped sharply in 1965. Body condition remained poor until 1972, when it plunged again. Fetal mass declined throughout the 1960s, unlike body length, which changed very little. It is suggested that fetal growth, particularly mass, is a sensitive indicator of feeding conditions during the last trimester of pregnancy while pregnant females are in the Gulf of Alaska and Bering Sea. It is further speculated that the condition index for adults reflects overall feeding conditions experienced throughout the annual migration.


2009 ◽  
Vol 39 (6) ◽  
pp. 1317-1339 ◽  
Author(s):  
Robert S. Pickart ◽  
Alison M. Macdonald ◽  
G. W. K. Moore ◽  
Ian A. Renfrew ◽  
John E. Walsh ◽  
...  

Abstract The seasonal change in the development of Aleutian low pressure systems from early fall to early winter is analyzed using a combination of meteorological reanalysis fields, satellite sea surface temperature (SST) data, and satellite wind data. The time period of the study is September–December 2002, although results are shown to be representative of the long-term climatology. Characteristics of the storms were documented as they progressed across the North Pacific, including their path, central pressure, deepening rate, and speed of translation. Clear patterns emerged. Storms tended to deepen in two distinct geographical locations—the Gulf of Alaska in early fall and the western North Pacific in late fall. In the Gulf of Alaska, a quasi-permanent “notch” in the SST distribution is argued to be of significance. The signature of the notch is imprinted in the atmosphere, resulting in a region of enhanced cyclonic potential vorticity in the lower troposphere that is conducive for storm development. Later in the season, as winter approaches and the Sea of Okhotsk becomes partially ice covered and cold, the air emanating from the Asian continent leads to enhanced baroclinicity in the region south of Kamchatka. This corresponds to enhanced storm cyclogenesis in that region. Consequently, there is a seasonal westward migration of the dominant lobe of the Aleutian low. The impact of the wind stress curl pattern resulting from these two regions of storm development on the oceanic circulation is investigated using historical hydrography. It is argued that the seasonal bimodal input of cyclonic vorticity from the wind may be partly responsible for the two distinct North Pacific subarctic gyres.


1993 ◽  
Vol 50 (12) ◽  
pp. 2608-2625 ◽  
Author(s):  
William G. Pearcy ◽  
Joseph P. Fisher ◽  
Mary M. Yoklavich

Abundances of Pacific pomfret (Brama japonica), an epipelagic fish of the North Pacific Ocean, were estimated from gillnet catches during the summers of 1978–1989. Two size modes were common: small pomfret <1 yr old, and large fish ages 1–6. Large and small fish moved northward as temperatures increased, but large fish migrated farther north, often into the cool, low-salinity waters of the Central Subarctic Pacific. Lengths of small fish were positively correlated with latitude and negatively correlated with summer surface temperature. Interannual variations in the latitude of catches correlated with surface temperatures. Large catches were made in the eastern Gulf of Alaska (51–55°N) but modes of small pomfret were absent here, and large fish were rare at these latitudes farther to the west. Pomfret grow rapidly during their first two years of life. They are pectoral fin swimmers that swim continuously. They prey largely on gonatid squids in the region of the Subarctic Current in the Gulf of Alaska during summer. No evidence was found for aggregations on a scale ≤1 km. Differences in the incidence of tapeworm, spawning seasons, and size distributions suggest the possibility of discrete populations in the North Pacific Ocean.


2018 ◽  
Vol 37 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Kenji M. Matsuzaki ◽  
Noritoshi Suzuki

Abstract. Expedition 341 of the Integrated Ocean Drilling Program (IODP) retrieved sediment cores spanning the time interval between the Pleistocene and Miocene from the southern Gulf of Alaska. Onboard Pleistocene radiolarian biostratigraphy is hereby refined by increasing the sampling resolution. The 178 core samples from the upper 190 m CCSF-B (Composite Core Depth Scale F-B) of Site U1417 contained faunal elements similar to the northwestern Pacific; for example, the three biozones in the northwestern Pacific (i.e., Eucyrtidium matuyamai, Stylatractus universus and Botryostrobus aquilonaris) were also recognized in the Gulf of Alaska, spanning 1.80–1.13 Ma, 1.13–0.45 Ma, and the last 0.45 Myr, respectively. Based on the age model that we used in this study and the shipboard paleomagnetic reversal events, the first occurrences (FOs) of Amphimelissa setosa and Schizodiscus japonicus in the northeastern Pacific were preliminarily determined to be 1.48 and 1.30 Ma, respectively. The last occurrence (LO) of Eucyrtidium matuyamai and the FO of Lychnocanoma sakaii, both well-established bioevents in the northwestern Pacific, were dated at 0.80 and 1.13 Ma, respectively. The LO of E. matuyamai is a synchronous event at 1.05 ± 0.1 Ma in the North Pacific, while the FOs of A. setosa and S. japonicus at 1.48 and 1.30 Ma, respectively, are significantly older than what has been found elsewhere.


2000 ◽  
Vol 105 (C2) ◽  
pp. 3253-3280 ◽  
Author(s):  
Yuzhu You ◽  
Nobuo Suginohara ◽  
Masao Fukasawa ◽  
Ichiro Yasuda ◽  
Ikuo Kaneko ◽  
...  

2010 ◽  
Vol 23 (2) ◽  
pp. 294-311 ◽  
Author(s):  
Micheld S. Mesquita ◽  
David E. Atkinson ◽  
Kevin I. Hodges

Abstract The North Pacific and Bering Sea regions represent loci of cyclogenesis and storm track activity. In this paper climatological properties of extratropical storms in the North Pacific/Bering Sea are presented based upon aggregate statistics of individual storm tracks calculated by means of a feature-tracking algorithm run using NCEP–NCAR reanalysis data from 1948/49 to 2008, provided by the NOAA/Earth System Research Laboratory and the Cooperative Institute for Research in Environmental Sciences, Climate Diagnostics Center. Storm identification is based on the 850-hPa relative vorticity field (ζ) instead of the often-used mean sea level pressure; ζ is a prognostic field, a good indicator of synoptic-scale dynamics, and is directly related to the wind speed. Emphasis extends beyond winter to provide detailed consideration of all seasons. Results show that the interseasonal variability is not as large during the spring and autumn seasons. Most of the storm variables—genesis, intensity, track density—exhibited a maxima pattern that was oriented along a zonal axis. From season to season this axis underwent a north–south shift and, in some cases, a rotation to the northeast. This was determined to be a result of zonal heating variations and midtropospheric moisture patterns. Barotropic processes have an influence in shaping the downstream end of storm tracks and, together with the blocking influence of the coastal orography of northwest North America, result in high lysis concentrations, effectively making the Gulf of Alaska the “graveyard” of Pacific storms. Summer storms tended to be longest in duration. Temporal trends tended to be weak over the study area. SST did not emerge as a major cyclogenesis control in the Gulf of Alaska.


1983 ◽  
Vol 61 (9) ◽  
pp. 2064-2077 ◽  
Author(s):  
Juan R. Guzman ◽  
M. T. Myres

Shearwaters, Puffinus spp., were studied off the west coast of Canada from 1975 to 1978. Sooty shearwaters, P. griseus, were the most abundant shearwaters off British Columbia in both May and September–October. Pink-footed shearwaters, P. creatopus, also occurred in both spring and fall. Flesh-footed shearwaters, P. carneipes, were found only in May. Buller's shearwaters, P. bulleri, were encountered in June and July during cruises across the Gulf of Alaska and in September and October off British Columbia. The recent increase of Buller's shearwater in the North Pacific is documented. A review of records of the short-tailed shearwater, P. tenuirostris, shows that it is usually rare and irregular off the coast of British Columbia. One black-vented shearwater, P. opisthomelas, was seen in the Gulf of Alaska. Sooty shearwaters occur off British Columbia in far lower numbers than off northern California, Oregon or Washington State. The manner in which sooty shearwaters migrate is described. The relationship between shearwater distributions and depths of water over the continental shelf are examined.


2009 ◽  
Vol 6 (3) ◽  
pp. 4587-4602
Author(s):  
S. McKinnell ◽  
J. R. Christian

Abstract. The extent of global change in carbon system parameters can only be evaluated by comparing present with past measurements. In the northern North Pacific, where aragonite saturation horizons are among the shallowest in the world, historical measurements of carbonate parameters vary from rare to nonexistent. However, during the summer of 1956 and winter of 1957, an extensive survey of the oceanography of the Northeast Pacific, under the auspices of the Canadian Committee on Oceanography, was conducted by the Fisheries Research Board of Canada. Approximately 2500 measurements of pH at depths from surface to 2000 m were taken throughout the Gulf of Alaska, in addition to measurements of nutrient and hydrographic properties. After conversion to the contemporary total pH scale, these data revealed significant seasonal and latitudinal differences in pH in the upper 200 m. Estimates of aragonite saturation indicate that undersaturated water was a common feature of the surface mixed layer north of 51° N latitude in the winter of 1957. The North Pacific Survey data were compared with the results of a summer 2007 survey of the west coast of North America where pH levels were ~0.1 pH units lower (at a reference density of 26.2σθ than was found in the summer of 1956.


Abstract.—A conceptual model of juvenile coho salmon <em>Oncorhynchus kisutch </em>migration from Oregon, Washington, the Columbia–Snake River system, British Columbia, and southeast Alaska was derived using coded-wire-tag data from juvenile salmon surveys conducted between 1995 and 2004. Over this 10-year period, 914 coded-wire-tagged (CWT) juvenile coho salmon were recovered. In general, the migratory behavior of juvenile coho salmon observed in this study was consistent with previous studies showing that juvenile salmon generally undertake a northward migration and utilize the continental shelf as a migration highway. However, this study also revealed that both regional and specific river stocks of coho salmon from all parts of the North American coast are composed of fast components that take a rapid and direct migration in the summer to as far west as Kodiak Island, Alaska and slow components that migrate over a relatively short distance from their natal rivers and reside over winter on the shelf. The Columbia–Snake River system, coastal Oregon, and coastal Washington had the highest proportion of fast CWT migrants among regions. Furthermore, specific stocks within the lower Columbia River had the highest proportion of fast CWT migrants both within the Columbia–Snake River watershed and along the entire west coast of North America. Distances migrated along the shelf were positively correlated to size at capture during the summer for almost all regional stocks, indicating that fast-migrating juvenile coho salmon have faster growth rates. The widespread dispersion along the continental shelf as a consequence of a mix of slow and fast migrants and the subsequent offshore migration into different regions of the Gulf of Alaska may have been selected over evolutionary time scales. This strategy would have ensured the long-term survival of individual stocks by spreading the risk of mortality among oceanic regions.


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