Megalopal Spatial Distribution and Stock Separation in Dungeness Crab (Cancer magister)

1993 ◽  
Vol 50 (2) ◽  
pp. 416-429 ◽  
Author(s):  
G. S. Jamieson ◽  
A. Phillips
Keyword(s):  
Dungeness Crab ◽  
Cancer Magister ◽  
Strait Of Georgia ◽  
Daily Movement ◽  
The Pacific ◽  
Juan De Fuca ◽  
The Pacific Ocean ◽  
Estuarine Flow ◽  
Juan De Fuca Strait ◽  
Outer Coast

During the day, Dungeness crab (Cancer magister) megalopae from off the outer coasts of Vancouver Island and Washington are aggregated at about 25 m whereas those from the Strait of Georgia are at about 160 m. At night, both populations of megalopae seem to be mostly in the top metre of water. Juan de Fuca Strait, which connects the Strait of Georgia to the Pacific Ocean, typically has an estuarine circulation, with outflow in the top 50–100 m and deeper inflow. Because the daylight to dark ratio when megalopae are present is about 3:1, the Strait of Georgia and outer-coast megalopae are mostly retained within their own systems by currents at their daytime depths. Occasional intrusions of outer-coast megalopae into Juan de Fuca Strait may occur when estuarine flow in the Strait temporarily breaks down following sustained, strong, southwesterly winds; such intrusions are typically restricted to the south and head of Juan de Fuca Strait, and even extensive ones do not carry megalopae far into the Strait of Georgia. The daily movement of larval crab to cold (<10 °C), deep water in the Strait of Georgia may explain, at least partially, the delay in seasonal timing of settlement and their smaller physical size at settlement compared with outer-coast megalopae.

Surface Tidal Currents in Juan de Fuca Strait

1954 ◽  
Vol 11 (1) ◽  
pp. 14-31 ◽  
Author(s):  
R. H. Herlinveaux
Keyword(s):  
Pacific Ocean ◽  
Sea Level ◽  
Surface Current ◽  
Linear Functions ◽  
Strait Of Georgia ◽  
The Pacific ◽  
Juan De Fuca ◽  
The Pacific Ocean ◽  
The Difference ◽  
Juan De Fuca Strait

Surface-current measurements were made at half-hour intervals throughout thirty-hour periods at three positions in Juan de Fuca Strait. These were repeated during spring and neap ranges of the tide in spring, summer and late autumn during 1952. The currents are linear functions of the difference of sea level between the Pacific Ocean and the Strait of Georgia. A rule is given for predicting the currents from data in the Tide Tables.

scholarly journals Tidal Resonance in Juan de Fuca Strait and the Strait of Georgia

2005 ◽  
Vol 35 (7) ◽  
pp. 1279-1286 ◽  
Author(s):  
Graig Sutherland ◽  
Chris Garrett ◽  
Mike Foreman
Keyword(s):  
Numerical Models ◽  
Puget Sound ◽  
Dissipative System ◽  
Tidal Elevation ◽  
Strait Of Georgia ◽  
The Pacific ◽  
Juan De Fuca ◽  
Resonant Period ◽  
Quality Factor Q ◽  
Juan De Fuca Strait

Abstract The resonant period and quality factor Q are determined for the semienclosed sea comprising Juan de Fuca Strait, Puget Sound, and the Strait of Georgia. The observed tidal elevation gain and phase change, from the Pacific Ocean to this inland sea, are fitted to the predictions of simple analytic models, which give a resonant period of 17–21 h and a Q of about 2. The low Q value, indicative of a highly dissipative system, is consistent with the need for numerical models for the area to employ large bottom friction coefficients. These include the effects of form drag.

scholarly journals Isolation of Tellurite- and Selenite-Resistant Bacteria from Hydrothermal Vents of the Juan de Fuca Ridge in the Pacific Ocean

2002 ◽  
Vol 68 (9) ◽  
pp. 4613-4622 ◽  
Author(s):  
Christopher Rathgeber ◽  
Natalia Yurkova ◽  
Erko Stackebrandt ◽  
J. Thomas Beatty ◽  
Vladimir Yurkov
Keyword(s):  
Hydrothermal Vents ◽  
Deep Ocean ◽  
Juan De Fuca Ridge ◽  
Resistant Bacteria ◽  
Ocean Water ◽  
Bacterial Films ◽  
The Pacific ◽  
Juan De Fuca ◽  
The Pacific Ocean ◽  
Reducing Bacteria

ABSTRACT Deep-ocean hydrothermal-vent environments are rich in heavy metals and metalloids and present excellent sites for the isolation of metal-resistant microorganisms. Both metalloid-oxide-resistant and metalloid-oxide-reducing bacteria were found. Tellurite- and selenite-reducing strains were isolated in high numbers from ocean water near hydrothermal vents, bacterial films, and sulfide-rich rocks. Growth of these isolates in media containing K2TeO3 or Na2SeO3 resulted in the accumulation of metallic tellurium or selenium. The MIC of K2TeO3 ranged from 1,500 to greater than 2,500 μg/ml, and the MIC of Na2SeO3 ranged from 6,000 to greater than 7,000 μg/ml for 10 strains. Phylogenetic analysis of 4 of these 10 strains revealed that they form a branch closely related to members of the genus Pseudoalteromonas, within the γ-3 subclass of the Proteobacteria. All 10 strains were found to be salt tolerant, pH tolerant, and thermotolerant. The metalloid resistance and morphological, physiological, and phylogenetic characteristics of newly isolated strains are described.

Offshore Characteristics in the Deep Waters of the Strait of Georgia as Indicated by Bathypelagic Fish

1954 ◽  
Vol 11 (5) ◽  
pp. 501-506
Author(s):  
W. E. Barraclough ◽  
M. Waldichuk
Keyword(s):  
Deep Water ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Deep Waters ◽  
Juan De Fuca ◽  
Bottom Waters ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Juan De Fuca Strait ◽  
Inflowing Water

An attempt is made from oceanographical observations to explain the occurrence of certain bathypelagic species of fish which have been captured in the bottom waters of the southern Strait of Georgia. It is noted that there is a considerable seaward surface Sow of water from the Fraser River. The water from intermediate depths over the continental shelf forms the inflowing deep water of Juan de Fuca Strait mixing with the Fraser River water in the turbulent channels of the San Juan Archipelago. This mixture forms the deep inflowing water of southern Strait of Georgia and the outflowing surface water of the Juan de Fuca Strait as shown by salinity distribution and current measurements. The net inward movement of deep water is suggested as an agent of transport or a directive factor for the occurrence of these fish in this region. Physical and chemical conditions of the deep water in the Strait of Georgia are shown to be only slightly different from those found in the intermediate offshore water. It is probable that a combination of factors provides conditions suitable for survival of these species in the deep water of the southern Strait of Georgia.

Late Pleistocene history and geomorphology, southwestern Vancouver Island, British Columbia

1979 ◽  
Vol 16 (9) ◽  
pp. 1645-1657 ◽  
Author(s):  
Neville F. Alley ◽  
Steven C. Chatwin
Keyword(s):  
British Columbia ◽  
Continental Shelf ◽  
Late Pleistocene ◽  
Vancouver Island ◽  
Glacial Lakes ◽  
Small Lakes ◽  
Strait Of Georgia ◽  
Coast Mountains ◽  
Juan De Fuca ◽  
Juan De Fuca Strait

The major Pleistocene deposits and landforms on southwestern Vancouver Island are the result of the Late Wisconsin (Fraser) Glaciation. Cordilleran glaciers formed in the Vancouver Island Mountains and in the Coast Mountains had advanced down Strait of Georgia to southeastern Vancouver Island after 19 000 years BP. The ice split into the Puget and Juan de Fuca lobes, the latter damming small lakes along the southwestern coastal slope of the island. During the maximum of the glaciation (Vashon Stade), southern Vancouver Island lay completely under the cover of an ice-sheet which flowed in a south-southwesterly direction across Juan de Fuca Strait, eventually terminating on the edge of the continental shelf. Deglaciation was by downwasting during which ice thinned into major valleys and the strait. Most upland areas were free of ice down to an elevation of 400 m by before 13 000 years BP. A possible glacier standstill and (or) resurgence occurred along Juan de Fuca Strait and in some interior upland valleys before deglaciation was complete. Glacial lakes occupied major valleys during later stages of deglaciation.

Clustering coupled biochemical-physical model results formalizes regional provinces in a coastal region

2021 ◽  
Author(s):  
Susan Allen ◽  
Tereza Jarnikova ◽  
Elise Olson ◽  
Debby Ianson
Keyword(s):  
Physical Model ◽  
Three Dimensional ◽  
Coastal Region ◽  
Sparse Sampling ◽  
Strait Of Georgia ◽  
Northeast Pacific ◽  
Juan De Fuca ◽  
Main Basin ◽  
Physical Variables ◽  
Juan De Fuca Strait

&lt;p&gt;Coastal regions by their very nature are dynamically diverse.&amp;#160; Within one geographical region there are often multiple areas dominated by substantially different dynamics that shape not only the physical characteristics but also the ecosystem.&amp;#160; The Salish Sea, in the northeast Pacific, is an excellent example with strongly tidally mixed regions, freshwater-dominated regions, and regions directly influenced by the open ocean.&amp;#160; These regions are generally well known and multiple disciplines refer to them with various boundaries and under various names.&amp;#160; Here we use unsupervised clustering on numerical model results to formalize these regional provinces.&amp;#160; The model is SalishSeaCast,&amp;#160; a three-dimensional real-time coupled bio-chem-physical model based on the NEMO framework.&amp;#160; We find that the regions clustered on ecosystem variables (phytoplankton biomass) spatially coincide with those clustered on physical variables, particularly the stratification as diagnosed by the halocline depth.&amp;#160; The clusters are robust across years with interannual variability manifesting mostly in changes in the size of the clusters.&amp;#160; As the clusters are dynamically distinct, they provide a natural framework on which to evaluate the model against observations.&amp;#160; We find that the model accurately simulates each of the major clusters.&amp;#160; The spatial and temporal resolution of the model can then characterize these different clusters more systematically than the observations, revealing biases associated with sparse sampling in the observations. Two examples will be given, one addressing a long-standing issue of the productivity gradient in the stratified main basin, the Strait of Georgia, and another concerning the seasonal cycle of productivity in the ocean-influenced Juan de Fuca Strait.&lt;/p&gt;

Sign in / Sign up

Export Citation Format

Share Document