New Information on the Longevity of Pacific Ocean Perch (Sebastes alutus)

1979 ◽  
Vol 36 (11) ◽  
pp. 1395-1400 ◽  
Author(s):  
Richard J. Beamish
Keyword(s):  
Pacific Ocean ◽  
Key Words ◽  
West Coast ◽  
Growth Pattern ◽  
Age Determination ◽  
The West ◽  
Thin Sections ◽  
New Information ◽  
Key Words Age

A comparison of ages determined from surfaces of otoliths and from sections of otoliths showed that ages were similar up to a section age of 22–24 yr. The growth pattern observed on thin sections of otoliths and from broken and burned otoliths from the region of the nucleus was interpreted to indicate that Pacific ocean perch probably live much longer than previously thought. Because the criteria used to identify annuli from otoliths sections appeared valid for younger fish, there was no justification to reject the application of these criteria for estimating ages of older fish and thus no reason to reject the possibility that Pacific ocean perch might live to be older than 70 yr. Ages determined from sections of otoliths from other rockfish species found off the west coast of Canada such as Sebastes fiavidus and Sebastes brevispinis have ranged from 30 to 60 yr indicating that many species of rockfish may live longer than previously thought. Key words: age determination, otolith, maximum age, age determination errors, Pacific ocean perch, otolith sections

scholarly journals A Climatology of 500-hPa Closed Lows in the Northeastern Pacific Ocean, 1948–2011

2014 ◽  
Vol 53 (6) ◽  
pp. 1578-1592 ◽  
Author(s):  
Nina S. Oakley ◽  
Kelly T. Redmond
Keyword(s):  
United States ◽  
Pacific Ocean ◽  
Interannual Variability ◽  
West Coast ◽  
The United States ◽  
Western United States ◽  
The West ◽  
Reanalysis Dataset ◽  
The Pacific ◽  
Northeastern Pacific

AbstractThe northeastern Pacific Ocean is a preferential location for the formation of closed low pressure systems. These slow-moving, quasi-barotropic systems influence vertical stability and sustain a moist environment, giving them the potential to produce or affect sustained precipitation episodes along the west coast of the United States. They can remain motionless or change direction and speed more than once and thus often pose difficult forecast challenges. This study creates an objective climatological description of 500-hPa closed lows to assess their impacts on precipitation in the western United States and to explore interannual variability and preferred tracks. Geopotential height at 500 hPa from the NCEP–NCAR global reanalysis dataset was used at 6-h and 2.5° × 2.5° resolution for the period 1948–2011. Closed lows displayed seasonality and preferential durations. Time series for seasonal and annual event counts were found to exhibit strong interannual variability. Composites of the tracks of landfalling closed lows revealed preferential tracks as the features move inland over the western United States. Correlations of seasonal event totals for closed lows with ENSO indices, the Pacific decadal oscillation (PDO), and the Pacific–North American (PNA) pattern suggested an above-average number of events during the warm phase of ENSO and positive PDO and PNA phases. Precipitation at 30 U.S. Cooperative Observer stations was attributed to closed-low events, suggesting 20%–60% of annual precipitation along the West Coast may be associated with closed lows.

Observation of virus-like particles in thin sections of the plumose anemone, Metridium senile

2001 ◽  
Vol 81 (5) ◽  
pp. 879-880 ◽  
Author(s):  
William H. Wilson ◽  
David M. Chapman
Keyword(s):  
West Coast ◽  
Sea Anemone ◽  
Dense Core ◽  
Icosahedral Structure ◽  
The West ◽  
Thin Sections ◽  
Virus Like Particles ◽  
Metridium Senile ◽  
Electron Dense Core

Virus-like particles (VLPs) were observed in thin sections of the plumose anemone, Metridium senile, collected from seawater off the west coast of Sweden in 1969. The VLPs were observed in the nucleus of spiroblasts and amoebocytes; they were either pentagonal or hexagonal in section, indicating an icosahedral structure. Virus-like particles were ∼60 nm in diameter, with an electron-dense core 40 nm in width; they had no apparent tail. This is the first substantial report of viruses observed in sea anemone cells.

Marine tube-dwelling diatoms of the Pacific coast of North America. II. Navicula subg. Navicula and a key to the tube-dwelling diatoms of the region

1990 ◽  
Vol 68 (4) ◽  
pp. 707-712 ◽  
Author(s):  
Christopher S. Lobban
Keyword(s):  
North America ◽  
Key Words ◽  
West Coast ◽  
Pacific Coast ◽  
Single Variable ◽  
Morphometric Data ◽  
The West ◽  
The Pacific ◽  
Rectangular Area ◽  
Variable Population

The tube-dwelling cross-lineate Navicula species on the west coast are dominated by a taxon that belongs in or near the N. ramosissima – N. mollis complex. Morphometric data were used to establish that a single, variable population exists. The species was assigned to N. rusticensis. Cells are 28 ± 7 × 5 ± 1 μm and striae number 14 ± 2 in 10 μm; these cells differ from the ramosissima–mollis complex in having 1–3 short central striae that form a narrow rectangular area. The range of size encompasses published limits for both N. ramosissima and N. mollis. A key to tube-dwelling diatoms of the west coast completes this two-part checklist. Key words: diatoms, Pacific, tube-dwelling, Navicula rusticensis, Navicula ramosissima.

Differences in the Age of Pacific Hake (Merluccius productus) Using Whole Otoliths and Sections of Otoliths

1979 ◽  
Vol 36 (2) ◽  
pp. 141-151 ◽  
Author(s):  
R. J. Beamish
Keyword(s):  
Key Words ◽  
Age Determination ◽  
Otolith Growth ◽  
Strait Of Georgia ◽  
Merluccius Productus ◽  
Key Words Age ◽  
Two Populations

Ages determined for older Pacific hake from sections through the nucleus of otoliths were older than the ages determined from the otolith surface for the two populations studied. Growth of all parts of the otolith was not identical throughout the life of the fish. The change in the pattern of otolith growth occurred about the age at which the growth in length of the fish was reduced. Despite the disproportionate growth in length and height of the otolith, the thickness of the otolith, especially in the ventral interior portion, continued to increase with age. Section ages appear to be more reliable for older fish because of this allometric change in otolith growth with increasing fish age. It is suggested that the examination of sections of otoliths should become a routine approach in any attempt to age fish using otoliths. Key words: age determination, otolith, otolith section, otolith growth, aging errors, Pacific hake, Strait of Georgia

Late Holocene variability in pelagic fish scales and dinoflagellate cysts along the west coast of Vancouver Island, NE Pacific Ocean

2005 ◽  
Vol 55 (3-4) ◽  
pp. 183-204 ◽  
Author(s):  
R. Timothy Patterson ◽  
Andreas Prokoph ◽  
Arun Kumar ◽  
Alice S. Chang ◽  
Helen M. Roe
Keyword(s):  
Pacific Ocean ◽  
West Coast ◽  
Late Holocene ◽  
Vancouver Island ◽  
Pelagic Fish ◽  
Fish Scales ◽  
Dinoflagellate Cysts ◽  
The West ◽  
Ne Pacific

Age Determination of Lingcod (Ophiodon elongatus) Using Dorsal Fin Rays and Scales

1977 ◽  
Vol 34 (9) ◽  
pp. 1305-1313 ◽  
Author(s):  
Richard J. Beamish ◽  
D. Chilton
Keyword(s):  
Key Words ◽  
Cross Sections ◽  
Age Determination ◽  
Fish Length ◽  
Dorsal Fin ◽  
Ophiodon Elongatus ◽  
Fin Ray ◽  
Fin Rays ◽  
Key Words Age

Cross sections of the 4th–8th fin rays from the second dorsal fin provided reliable ages of lingcod (Ophiodon elongatus), although there was some difficulty interpreting the ages of 1- and 2-yr-old fish. Length was an acceptable indicator of age 1- and 2-yr-old fish. After a scale age of 5 or 6 yr, the scale annulus became difficult to identify. After age 7 or about 75–85 cm, fin-ray ages were older than scale ages. Some of the oldest fish averaged 8 yr older by the fin-ray method.Mature females attained much larger mean sizes than males of similar age, and there was considerable variation in size of similar-aged older fish. Key words: Age determination, fin rays, scales, Ophiodon elongatus, ageing errors.

Recognition of Leuroglossus schmidti and L. stilbius (Bathylagidae, Pisces) as distinct species in the North Pacific Ocean

1981 ◽  
Vol 59 (12) ◽  
pp. 2396-2398
Author(s):  
Alex E. Peden
Keyword(s):  
Pacific Ocean ◽  
North America ◽  
West Coast ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Distinct Species ◽  
The West ◽  
The North ◽  
Juan De Fuca ◽  
The North Pacific

Data from vertebral counts suggest two species of Leuroglossus occur off the west coast of North America: Leuroglossus schmidti north of the Strait of Juan de Fuca and L. stilbius off Oregon and southward.

Bowie Seamount. A Recently Active, Flat-topped Seamount in the Northeast Pacific Ocean

1971 ◽  
Vol 8 (6) ◽  
pp. 676-687 ◽  
Author(s):  
R. H. Herzer
Keyword(s):  
Pacific Ocean ◽  
Shallow Water ◽  
Sea Level ◽  
Volcanic Activity ◽  
West Coast ◽  
Basaltic Magma ◽  
The West ◽  
Northeast Pacific ◽  
Wave Erosion ◽  
Northeast Pacific Ocean

Bowie Seamount, situated off the west coast of Canada at 53° 18′ N, 135° 39′ W, is a long northeast-trending, volcanic mountain comprising a series of intersecting ridges. These ridges may have grown from extrusions along intersecting fractures in the oceanic crust. Two terraces form the flattened summit of the volcano at approximate depths of 80 and 235 m. These are thought to be remnants of platforms produced by combined shallow-water vulcanism and wave erosion during Pleistocene and Recent times when sea level was lower than it is today. The last episode of volcanic activity on the summit occurred after the formation of the upper terrace which is probably no more than 18 000 years old. Samples dredged from the upper half of the volcano include: pillow fragments, fragments of non-pillowed flows, pillow breccias, bombs, tuffs, ash, and unsorted tephra. The rocks are mainly alkali olivine basalts, accompanied by a few intermediate rocks which are believed to have been derived by differentiation of the basaltic magma.

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