Distribution patterns of Pacific halibut (Hippoglossus stenolepis) in relation to environmental variables along the continental shelf waters of the US West Coast and southern British Columbia

2014 ◽  
Vol 23 (3) ◽  
pp. 225-241 ◽  
Author(s):  
Lauri L. Sadorus ◽  
Nathan J. Mantua ◽  
Timothy Essington ◽  
Barbara Hickey ◽  
Steven Hare
Keyword(s):  
British Columbia ◽  
Continental Shelf ◽  
West Coast ◽  
Environmental Variables ◽  
Distribution Patterns ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis ◽  
The Us ◽  
Us West

scholarly journals Evidence for rapid avoidance of rockfish habitat under reduced quota and comprehensive at-sea monitoring in the British Columbia Pacific halibut fishery

2020 ◽  
Vol 77 (8) ◽  
pp. 1409-1420
Author(s):  
Robyn E. Forrest ◽  
Ian J. Stewart ◽  
Cole C. Monnahan ◽  
Katherine H. Bannar-Martin ◽  
Lisa C. Lacko
Keyword(s):  
British Columbia ◽  
Spatial Clustering ◽  
Clustering Methods ◽  
Quota System ◽  
Encounter Rates ◽  
System A ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis ◽  
Footprint Area ◽  
Management Changes

The British Columbia longline fishery for Pacific halibut (Hippoglossus stenolepis) has experienced important recent management changes, including the introduction of comprehensive electronic catch monitoring on all vessels; an integrated transferable quota system; a reduction in Pacific halibut quotas; and, beginning in 2016, sharp decreases in quota for yelloweye rockfish (Sebastes ruberrimus, an incidentally caught species). We describe this fishery before integration, after integration, and after the yelloweye rockfish quota reduction using spatial clustering methods to define discrete fishing opportunities. We calculate the relative utilization of these fishing opportunities and their overlap with areas with high encounter rates of yelloweye rockfish during each of the three periods. The spatial footprint (area fished) increased before integration, then decreased after integration. Each period showed shifts in utilization among four large fishing areas. Immediately after the reductions in yelloweye rockfish quota, fishing opportunities with high encounter rates of yelloweye rockfish had significantly lower utilization than areas with low encounter rates, implying rapid avoidance behaviour.

scholarly journals Analysis of the effectiveness of face-coverings on the death ratio of COVID-19 using machine learning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ali Lafzi ◽  
Miad Boodaghi ◽  
Siavash Zamani ◽  
Niyousha Mohammadshafie ◽  
Veeraraghava Raju Hasti
Keyword(s):  
Machine Learning ◽  
West Coast ◽  
Economic Condition ◽  
Preventive Measure ◽  
Accuracy Score ◽  
Machine Learning Classification ◽  
Monthly Average ◽  
The Us ◽  
Recent Outbreak ◽  
Us West

AbstractThe recent outbreak of the COVID-19 led to death of millions of people worldwide. To stave off the spread of the virus, the authorities in the US employed different strategies, including the mask mandate order issued by the states’ governors. In the current work, we defined a parameter called average death ratio as the monthly average of the number of daily deaths to the monthly average number of daily cases. We utilized survey data to quantify people’s abidance by the mask mandate order. Additionally, we implicitly addressed the extent to which people abide by the mask mandate order, which may depend on some parameters such as population, income, and education level. Using different machine learning classification algorithms, we investigated how the decrease or increase in death ratio for the counties in the US West Coast correlates with the input parameters. The results showed that for the majority of counties, the mask mandate order decreased the death ratio, reflecting the effectiveness of such a preventive measure on the West Coast. Additionally, the changes in the death ratio demonstrated a noticeable correlation with the socio-economic condition of each county. Moreover, the results showed a promising classification accuracy score as high as 90%.

scholarly journals The impact of alternative rebuilding strategies to rebuild overfished stocks

2016 ◽  
Vol 73 (9) ◽  
pp. 2190-2207 ◽  
Author(s):  
Chantel R. Wetzel ◽  
André E. Punt ◽  
Keyword(s):  
West Coast ◽  
Life Histories ◽  
Estimation Error ◽  
The United States ◽  
Fish Stocks ◽  
Strategy Evaluation ◽  
The Us ◽  
History Of ◽  
The Impact ◽  
Us West

Abstract Ending overfishing and rebuilding fish stocks to levels that provide for optimum sustainable yield is a concern for fisheries management worldwide. In the United States, fisheries managers are legally mandated to end overfishing and to implement rebuilding plans for fish stocks that fall below minimum stock size thresholds. Rebuilding plans should lead to recovery to target stock sizes within 10 years, except in situations where the life history of the stock or environmental conditions dictate otherwise. Federally managed groundfish species along the US West Coast have diverse life histories where some are able to rebuild quickly from overfished status, while others, specifically rockfish (Sebastes spp.), may require decades for rebuilding. A management strategy evaluation which assumed limited estimation error was conducted to evaluate the performance of alternative strategies for rebuilding overfished stocks for these alternative US West Coast life histories. Generally, the results highlight the trade-off between the reduction of catches during rebuilding vs. the length of rebuilding. The most precautionary rebuilding plans requiring the greatest harvest reduction resulted in higher average catches over the entire projection period compared with strategies that required a longer rebuilding period with less of a reduction in rebuilding catch. Attempting to maintain a 50% probability of rebuilding was the poorest performing rebuilding strategy for all life histories, resulting in a large number of changes to the rebuilding plan, increased frequency of failing to meet rebuilding targets, and higher variation in catch. The rebuilding plans that implemented a higher initial rebuilding probability (≥60%) for determining rebuilding fishing mortality and targets generally resulted in fewer changes to the rebuilding plans and rebuilt by the target rebuilding year, particularly for stocks with the longer rebuilding plans (e.g. rockfishes).

scholarly journals Climate Extreme Seeds a New Domoic Acid Hotspot on the US West Coast

2020 ◽  
Vol 2 ◽  
Author(s):  
Vera L. Trainer ◽  
Raphael M. Kudela ◽  
Matthew V. Hunter ◽  
Nicolaus G. Adams ◽  
Ryan M. McCabe
Keyword(s):  
Early Warning ◽  
West Coast ◽  
Domoic Acid ◽  
Large Scale ◽  
Early Warning Systems ◽  
Warning Systems ◽  
Dungeness Crab ◽  
The Pacific ◽  
The Us ◽  
Us West

A heatwave that blanketed the northeast Pacific Ocean in 2013–2015 had severe impacts on the marine ecosystem through altered species composition and survival. A direct result of this marine heatwave was a sustained, record-setting harmful algal bloom (HAB), caused by the toxigenic diatom, Pseudo-nitzschia, that led to an unprecedented delay in harvest opportunity for commercial Dungeness crab (Metacarcinus magister) and closure of other recreational, commercial and tribal shellfish harvest, including razor clams. Samples collected during a cruise in summer 2015, showed the appearance of a highly toxic “hotspot” between Cape Mendocino, CA and Cape Blanco, OR that was observed again during cruises in the summers of 2016–2018. The transport of toxic cells from this retentive site northward during wind relaxations or reversals associated with storms resulted in economically debilitating delay or closure of Dungeness crab harvest in both northern California and Oregon in 2015–2019. Analyses of historic large-scale Pseudo-nitzschia HABs have shown that these events occur during warm periods such as El Niño, positive phases of the Pacific Decadal Oscillation, or the record-setting marine heatwave. In order to reduce the impacts of large-scale HABs along the west coast of North America, early warning systems have been developed to forewarn coastal managers. These early warning systems include the Pacific Northwest and California HAB Bulletins, both of which have documented elevated domoic acid and increased risk associated with the northern California hotspot. These early warnings enable mitigative actions such as selective opening of safe harvest zones, increased harvest limits during low risk periods, and early harvest in anticipation of impending HAB events. The aims of this study are to show trends in nearshore domoic acid along the US west coast in recent years, including the recent establishment of a new seed bed of highly-toxic Pseudo-nitzschia, and to explore how early warning systems are a useful tool to mitigate the human and environmental health and economic impacts associated with harmful algal blooms.

scholarly journals High-Tide Floods and Storm Surges During Atmospheric Rivers on the US West Coast

2021 ◽  
Author(s):  
Christopher G Piecuch ◽  
Sloan Coats ◽  
Sönke Dangendorf ◽  
Felix W Landerer ◽  
J T Reager ◽  
...  
Keyword(s):  
West Coast ◽  
High Tide ◽  
Storm Surges ◽  
Atmospheric Rivers ◽  
The Us ◽  
Us West
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