Availability, Size Composition, Age Composition, and Growth Characteristics of Pacific Ocean Perch (Sebastes alutus) off the Northern Washington Coast During 1967–72

1974 ◽  
Vol 31 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Donald R. Gunderson
Keyword(s):  
Pacific Ocean ◽  
Inverse Relationship ◽  
Size Composition ◽  
Growth Characteristics ◽  
Large Fish ◽  
Age Composition ◽  
Bathymetric Range ◽  
Bottom Trawling ◽  
Abundance Estimates ◽  
Slow Growing

Cruises were conducted off the northern Washington coast each year during 1967–72 to study trends in the availability and biological characteristics of Pacific Ocean perch (Sebastes alutus).There were marked differences in catch rate between cruises, and corresponding differences in age composition and age–length structure indicated that they resulted from differential availability of an old, slow-growing segment of the population to on-bottom trawling. Females from this segment of the population were particularly available when the cruise coincided with the period of peak spawning, and both sexes were available during the 1972 summer cruise.Within cruises, adults from different portions of the bathymetric range showed similar age composition, but there was an inverse relationship between depth and size attained by age 15. Size compositions consequently contained a smaller proportion of large fish as depth increased.Juveniles were confined to the shallow portions of the bathymetric range. There were obvious between-year changes in the length and age composition of juveniles, caused by the temporal progression of a dominant 1961 year-class.Fluctuations in availability make it difficult to monitor changes in mortality and since age composition also varies with availability, the problem is compounded further. Unless all segments of the population are located and sampled in proportion to their abundance, estimates of mortality can be made only between those cruises where the old, slow-growing component of the population is equally available.

Size Changes, Mortality, and Equilibrium Yields in an Exploited Stock of American Plaice (Hippoglossoides platessoides)

1969 ◽  
Vol 26 (5) ◽  
pp. 1205-1235 ◽  
Author(s):  
P. M. Powles
Keyword(s):  
Mesh Size ◽  
Food Competition ◽  
Mortality Factor ◽  
Otter Trawl ◽  
Small Fish ◽  
Large Fish ◽  
Age Composition ◽  
Instantaneous Rate ◽  
Factors Affecting ◽  
Ecological Dominance

Records from research surveys and commercial landings for American plaice from the Magdalen Shallows, or the southwestern Gulf of St. Lawrence, showed decreases in percentage of old, large fish and in catch per unit of effort from 1955 to 1962. The changes in age composition were clearly relatable to the fishery, which was mainly by otter trawl. Ricker models indicated that wastage of deck-exposed subcommercial plaice is currently a greater mortality factor than predation by cod. Increased landings in particular years were associated with successful year-classes. Other factors affecting landings were annual differences in fleet dispersal, which were related to movements of cod, a cohabiting species. No clear decrease or increase in absolute recruitment of plaice was demonstratable because quantitative comparisons of research surveys by different vessels using different gears and with different skippers, would be misleading.Mortality estimates of adult plaice by three methods showed agreement, indicating that instantaneous rate of natural mortality was between 0.09 and 0.13. The instantaneous rate of fishing for 1957–62 was 0.46. Increasing mesh-size would reduce cod catches and have little effect in conserving plaice, but marketing small fish would increase plaice landings. Voluntary release of small plaice promptly on capture would help maintain the stock, as would reduction in numbers of large cod, the main predator of small plaice. Increased numbers of small cod since 1959, as reported by other workers, could result in greater food competition with small plaice, effectively reinforcing the ecological dominance of cod over plaice.

Variation of Taxane Content in Needles of Taxus x media Cultivars with Different Growth Characteristics

2006 ◽  
Vol 61 (9-10) ◽  
pp. 619-624 ◽  
Author(s):  
Xinkun Wang ◽  
Yinghua Huang ◽  
Andrew J. Mort ◽  
Yuhong Zeng ◽  
Charles G. Tauer ◽  
...  
Keyword(s):  
High Performance ◽  
Biomass Accumulation ◽  
Dry Weight ◽  
Growth Characteristics ◽  
Alternative Methods ◽  
Baccatin Iii ◽  
Fast Growing ◽  
Taxus X Media ◽  
Slow Growing ◽  
Group 1

AbstractNeedles from 17 different Taxus x media cultivars, belonging to 4 groups showing different growth characteristics, were analyzed using high performance liquid chromatography for their content of 10-deacetylbaccatin III, baccatin III, cephalomannine and paclitaxel (Taxol®). The 4 Taxus x media cultivar groups were: 1.) medium to fast growing and upright form; 2.) slow growing and upright form; 3.) fast growing and spreading form; and 4.) slow growing and spreading form. The purpose of this study was to identify yew cultivars of fast growth rate, upright growth and high taxane content in their needles. The highest content of paclitaxel was found in ‘Coleana’ of group 1 (378 μg/g of the extracted dry weight). Three cultivars in group 1, ‘Coleana’, ‘Stovekenii’ and ‘Hicksii’, make good candidates for taxane extraction because of their high paclitaxel and 10-deacetylbaccatin III content, fast biomass accumulation and upright growing form. They are also good starting materials to develop alternative methods for the production of paclitaxel and its analogous compounds through modern biotechnology approaches.

Biology of the Pacific Pomfret (Brama japonica) in the North Pacific Ocean

1993 ◽  
Vol 50 (12) ◽  
pp. 2608-2625 ◽  
Author(s):  
William G. Pearcy ◽  
Joseph P. Fisher ◽  
Mary M. Yoklavich
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Gulf Of Alaska ◽  
Small Fish ◽  
Large Fish ◽  
The North ◽  
The Pacific ◽  
Subarctic Current ◽  
The North Pacific

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.

Population dynamics and status of striped marlin (Kajikia audax) in the western and central northern Pacific Ocean

2013 ◽  
Vol 64 (2) ◽  
pp. 108 ◽  
Author(s):  
Kevin R. Piner ◽  
Hui-Hua Lee ◽  
Ai Kimoto ◽  
Ian G. Taylor ◽  
Minoru Kanaiwa ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Pacific Ocean ◽  
Spatial Data ◽  
Large Scale ◽  
Size Composition ◽  
Maximum Sustainable Yield ◽  
Catch Per Unit Effort ◽  
Fully Integrated ◽  
Northern Pacific ◽  
Spawning Biomass

A new understanding of the structure of striped marlin stocks in the Pacific Ocean was the basis for estimating the population dynamics in the western and central northern Pacific (1975–2010). Dynamics were estimated using large-scale spatial data and a fully integrated length-based and age-structured model. The model used fishery-dependent catch, size composition and catch per unit effort (CPUE) as likelihood components. Time-varying selectivity patterns were used in the modelling to account for changes in fishing practices. Estimates of fishing intensity showed a pattern of exploitation generally exceeding the levels associated with maximum sustainable yield (MSY). Estimates of spawning biomass and recruitment described a population that was relatively stable near biomass levels associated with MSY until the 1990s, when recruitment declined and biomass levels fell below those associated with MSY. The reduction in recruitment could be explained by a loss of spawning biomass and potentially changes in environment. The future prospects of rebuilding the stock will depend on the relative importance of the roles maternal biomass and environment play in determining recruitment strength.

scholarly journals New species of Eurythenes from hadal depths of the Mariana Trench, Pacific Ocean (Crustacea: Amphipoda)

Zootaxa ◽  
2020 ◽  
Vol 4748 (1) ◽  
pp. 163-181 ◽  
Author(s):  
JOHANNA N. J. WESTON ◽  
PRISCILLA CARRILLO-BARRAGAN ◽  
THOMAS D. LINLEY ◽  
WILLIAM D. K. REID ◽  
ALAN J. JAMIESON
Keyword(s):  
Pacific Ocean ◽  
Morphological Characteristics ◽  
Anthropogenic Pollution ◽  
Ocean Basin ◽  
Northwest Pacific ◽  
Central Pacific ◽  
Bathymetric Range ◽  
Northwest Pacific Ocean ◽  
Mariana Trench ◽  
Central Pacific Ocean

Eurythenes S. I. Smith in Scudder, 1882 are one of the largest scavenging deep-sea amphipods (max. 154 mm) and are found in every ocean across an extensive bathymetric range from the shallow polar waters to hadal depths. Recent systematic studies of the genus have illuminated a cryptic species complex and highlighted the benefits of using a combination of morphological and molecular identification approaches. In this study, we present the ninth species, Eurythenes plasticus sp. nov., which was recovered using baited traps between the depths 6010 and 6949 m in the Mariana Trench (Northwest Pacific Ocean) in 2014. This new Eurythenes species was found to have distinct morphological characteristics and be a well-supported clade based on sequence variation at two mitochondrial regions (16S rDNA and COI). While this species is new to science and lives in the remote hadal zone, it is not exempt from the impacts of anthropogenic pollution. Indeed, one individual was found to have a microplastic fibre, 83.74% similar to polyethylene terephthalate (PET), in its hindgut. As this species has a bathymetric range spanning from abyssal to hadal depths in the Central Pacific Ocean basin, it offers further insights into the biogeography of Eurythenes. 

Giant multiloculated ameloblastoma of the mandible: a case report and review of literature

2016 ◽  
Vol 2 (2) ◽  
pp. 91
Author(s):  
Nitish Virmani ◽  
Jyoti Dabholkar
Keyword(s):  
Case Report ◽  
Buccal Mucosa ◽  
Growth Characteristics ◽  
Surrounding Tissue ◽  
Cortical Plate ◽  
Imaging Features ◽  
Review Of Literature ◽  
Ameloblastic Carcinoma ◽  
Full Extension ◽  
Slow Growing

<p class="abstract">Ameloblastomas, in general, are considered benign but locally invasive neoplasms. They present as slow growing, painless swellings and can grow to enormous sizes over the years. While planning the treatment of ameloblastoma, it is important to understand the growth characteristics and removing the full extension of tumor, including the surrounding tissue. Recurrence of ameloblastoma in many cases reflects the inadequacy or failure of the primary surgical procedure. We report a case of giant multiloculated ameloblastoma of the mandible with destruction of the cortical plate and extensive and rapid infiltration of the buccal mucosa. Along with the clinical and imaging features, the importance and method of ruling out malignant ameloblastoma and ameloblastic carcinoma in such a case is discussed.</p>

Monitoring environmental effects of a deep-sea mining test in shallow water

2020 ◽  
Author(s):  
Henko de Stigter ◽  
Sabine Haalboom ◽  
Christian Mohn ◽  
Thomas Vandorpe ◽  
Marck Smit ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Shallow Water ◽  
Surface Sediment ◽  
Environmental Sustainability ◽  
Deep Sea ◽  
Field Tests ◽  
High Tech ◽  
Sediment Layer ◽  
Equatorial Pacific Ocean ◽  
Bottom Trawling

&lt;p&gt;Concerns about future access to strategic raw materials for the high-tech industry have led to a renewed interest in mining of mineral resources from the deep-sea as a potential alternative for land-based mining. Polymetallic nodules, especially abundant in the eastern equatorial Pacific Ocean in water depths of 4000-6000 m, are a likely target of future deep-sea mining. However, many questions exist about the environmental sustainability of deep-sea mining, as it would involve the removal of hard substrate, disturbance of the surface sediment layer and dispersion of mobilised sediment over large areas of seabed adjacent to the mining sites. Anticipating on full-scale industrial mining tests, which are likely to start in the near future in the deep Pacific Ocean, we tried approaches for environmental monitoring of mining activities during two industry field tests in relatively shallow water offshore southern Spain, carried out in the framework of the European Blue Nodules project. The aim of these field tests was to assess technical and environmental performance of a scaled polymetallic nodule mining vehicle developed by the Dutch shipbuilder and maritime technology provider Royal IHC. Although the tests were performed in only 300 m water depth, much less than the depth where future deep-sea mining will take place, the weakly stratified bottom water, tide-dominated near-bed currents with mean magnitude around 5-10 cm s&lt;sup&gt;-1&lt;/sup&gt;, and gently sloping seabed covered with fine muddy sediment are fairly comparable to operational conditions in the deep-sea. The plume of suspended sediment mobilised by the mining vehicle, considered to represent a major environmental pressure which may extend far beyond the actual mining area, was monitored with turbidity sensors deployed with ship-operated ROV and CTD, as well as in a static array of moored sensors. It was found that the generated sediment plume extended not more than 2 m above the seabed close to the disturbance (&lt; 100 m), but increased in height with distance away from the disturbance site. Turbidity decreased rapidly with increasing distance from the source, but a distinct signal could still be distinguished above background turbidity at 350 m away from the source. In this near-coast setting, plume monitoring suffered significant interference by bottom trawling activities in neighbouring areas. The monitoring setup proved to be well designed and the findings on the plume size and dispersion can be significantly extrapolated to account for a more realistic mining situation. Seabed surveys with ROV-based video and scanning sonar showed that the tracks of the test vehicle, exerting an average pressure of 3 kPa on the seabed, left impressions of 4&amp;#177;0.8 cm deep in the surface sediment. In sediment cores collected from the path of the vehicle, geotechnical testing showed an increase in undrained shear strength and bearing capacity, as compared to undisturbed sites, indicating compaction of the surface sediment. Surveys revealed ubiquitous signs of bottom trawling, including furrows of approximately 10 cm deep produced by trawl doors.&amp;#160;&lt;/p&gt;

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