Environmental Effects on the Distributions of Groundfish in Hecate Strait, British Columbia

1994 ◽  
Vol 51 (6) ◽  
pp. 1401-1409 ◽  
Author(s):  
R. Ian Perry ◽  
Max Stocker ◽  
Jeff Fargo
Keyword(s):  
British Columbia ◽  
Early Summer ◽  
Sediment Type ◽  
Depth Range ◽  
Pacific Halibut ◽  
Gadus Macrocephalus ◽  
Hippoglossus Stenolepis ◽  
By Catch ◽  
Groundfish Fishery ◽  
Variable Condition

Hecate Strait, British Columbia, is an area of variable topography with a variety of bottom habitats, which supports an important mixed-species groundfish fishery. A previous analysis identified three characteristic assemblages of groundfish species. In the present study, we identify relationships between the dominant species of these assemblages and environmental conditions in early summer 1989 and 1991: bottom type and depth (invariant conditions) and temperature (a variable condition). Three categories of species were identified: (i) those consistently associated with particular depths and temperatures between years, (ii) those with variable depth and temperature associations, and (iii) those with no apparent relationships to depth, temperature, or sediment type. Category (i) was dominated by flatfishes and could be further separated into groups associated with deep and cool, shallow and warm, and intermediate depth and temperature conditions. Category (ii) included roundfishes plus Pacific halibut (Hippoglossus stenolepis) and were widely distributed. At least one species (Pacific cod (Gadus macrocephalus)) tended to maintain a particular temperature range while changing its depth range between years. Identification of significant associations between fish species and habitat conditions is the first step towards incorporating environmental information into survey abundance indices and reducing by-catch problems.

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.

Optimal F0.1 Criteria and Their Relationship to Maximum Sustainable Yield

1987 ◽  
Vol 44 (S2) ◽  
pp. s339-s348 ◽  
Author(s):  
R. B. Deriso
Keyword(s):  
Quantitative Relationship ◽  
Maximum Sustainable Yield ◽  
Sustainable Yield ◽  
Fish Stocks ◽  
Pacific Halibut ◽  
Western Lake ◽  
Gadus Macrocephalus ◽  
Hippoglossus Stenolepis ◽  
Stock Recruitment ◽  
Yield Per Recruit

There is a unique size of entry into the fishable population that maximizes yield per recruit when an F0.1 fishing criterion is applied to the simple theory of fishing developed by Beverton and Holt in 1957. I define such a pair of parameters (size of entry, F0.1 value) to be the optimal F0.1 criteria and show that they are characterized by the single quantity M/K. A quantitative relationship is established between maximum sustainable yield and the optimal F0.1 criteria for a model population where recruitment is governed by a Ricker stock–recruitment function. This new theory is applied to three fish stocks: Pacific halibut (Hippoglossus stenolepis), western Lake Erie walleye (Stizostedion vitreum vitreum), and Bering Sea Pacific cod (Gadus macrocephalus).

Two new species of stalked crinoids from the northeastern Pacific in the genera Gephyrocrinus and Ptilocrinus (Echinodermata, Crinoidea, Hyocrinidae). Effects of ontogeny and variability on hyocrinid taxonomy

Zootaxa ◽  
2011 ◽  
Vol 2825 (1) ◽  
pp. 1 ◽  
Author(s):  
MICHEL ROUX ◽  
PHILIP LAMBERT
Keyword(s):  
British Columbia ◽  
New Species ◽  
Single Species ◽  
Depth Range ◽  
Evolutionary Trend ◽  
Exceptional Collection ◽  
The Family ◽  
Two New Species ◽  
Northeastern Pacific ◽  
Stalked Crinoids

Two new species of deep-sea stalked crinoids belonging to the family Hyocrinidae were collected in the northeastern Pacific. The descriptions contain detailed information on character variations and ontogeny. The five specimens of Gephyrocrinus messingi n. sp. lived at depths ranging from 1,777 m to 2,110 m off British Columbia and California. This new species is the first record of the genus Gephyrocrinus in the Pacific Ocean, which was previously known from only a single species, G. grimaldii, from the northeastern Atlantic at the same depth range. The two species illustrate opposing phenotypes within the same genus. Fifty-eight specimens of the second new species, Ptilocrinus clarki n. sp., were dredged off British Columbia close to the type-locality of P. pinnatus, the type species of the genus Ptilocrinus, but at shallower depths ranging from 1,178 to 1,986 m. This exceptional collection provides significant data on intraspecific variation in the main morphological characters, especially arm pattern. The ontogeny of stalk articulations and the main traits of adoral plate differentiation are described in detail. A complementary investigation on P. pinnatus was conducted using specimens collected by the “Albatross” expedition at a depth of 2,906 m. Despite similarities in external morphology, tegmen and cover plates, the two ptilocrinid species display significant differences in pinnule architecture, aboral cup and stalk articulations. From comparison with Gephyrocrinus messingi n. sp. and Ptilocrinus clarki n. sp., G. grimaldii and P. pinnatus are interpreted as the result of heterochronic development by paedomorphy after ecological or geographic isolation. Pinnule architecture in the two new species suggests first steps in an evolutionary trend toward a rigid box which protects gonad inflation in the proximal part of the pinnule. These new data on Ptilocrinus and Gephyrocrinus create problems in the current taxonomy of the family Hyocrinidae. The main derived characters, especially in pinnule and arm pattern, are used to propose new hypotheses for hyocrinid phylogeny.

scholarly journals Using Incentives to Reduce Bycatch and Discarding: Results Under the West Coast Catch Share Program

2019 ◽  
Author(s):  
Lisa Pfeiffer
Keyword(s):  
West Coast ◽  
Bottom Trawl ◽  
The West ◽  
Annual Variability ◽  
Environmental Objectives ◽  
By Catch ◽  
Groundfish Fishery ◽  
Dover Sole ◽  
Ecosystem Benefits ◽  
Over Time

Catch share management was implemented in the bottom trawl sector of the West Coast Groundfish fishery in 2011 to address a range of issues including high bycatch and discard rates. The catch share programwas designed to remove the incentives to discard through full catch accounting, tradeable quotas, increased flexibility in fishing, and penalties for catch overages. We assess the effectiveness of the program in meeting its environmental objectives by comparing discard weights, proportions, and variability from 2004–2010 with 2011–2016. We analyzed these metrics for species managed using quota, including historically overfished stocks, as well as for non-quota species caught in the fishery. Discard amounts decreased over time for all species and declined to historic lows after the implementation of the program, remaining low through 2016 with much less inter-annual variability. Mean annual discards of two highly-targeted quota species, sablefishand Dover sole, showed the greatest decreases, falling by 97 and 86%, respectively. The discard proportion of overfished quota species fell by 50% on average. The unanticipated decline in discards of non-quotaspecies as well as the decreased variability in discard amounts for all species indicate that the incentives produced by catch share management provided additional ecosystem benefits.

Diversity and abundance of arthropod by-catch in semiochemical-baited traps targeting apple clearwing moth (Lepidoptera: Sesiidae) in organic and conventional apple orchards in British Columbia, Canada

2014 ◽  
Vol 147 (2) ◽  
pp. 227-243 ◽  
Author(s):  
V. Marius Aurelian ◽  
Maya L. Evenden ◽  
Gary J.R. Judd
Keyword(s):  
British Columbia ◽  
Grape Juice ◽  
Tree Density ◽  
Mass Trapping ◽  
Apple Orchards ◽  
Apple Industry ◽  
Baited Traps ◽  
Clearwing Moth ◽  
The Difference ◽  
By Catch

AbstractApple clearwing moth (ACM),Synanthedon myopaeformis(Borkhausen) (Lepidoptera: Sesiidae), is an invasive species and destructive pest of commercial apple trees in British Columbia (BC), Canada. Mass trapping with Concord grape juice and sex pheromone is being developed as an organic pest management tactic. We quantified the diversity and abundance of arthropod by-catch in these traps during the 2009 flight (13 June–31 July) of ACM. Paired traps were deployed in organic and conventionally managed apple orchards planted using different tree densities representing the extremes of the current BC apple industry. Using seasonal by-catch and community-level statistical analyses we determined that family communities of arthropods caught in juice-baited and pheromone-baited traps differed significantly. Yellow juice-baited traps caught a greater variety of arthropod families in greater abundance than pheromone-baited yellow Unitraps®. We show that for each trap type, family communities caught in organic versus conventional orchards were significantly different. Organic orchard management affected abundance of some beneficial taxa, but the sign of the difference depended on the taxon examined (e.g., ladybeetles increased versus lacewings declined). Tree density had no effect on by-catch. Managing ACM by mass trapping may be detrimental to ecosystem services because many nontarget beneficial species are caught. A balanced risk-to-benefit approach should be taken before this technology is widely implemented against ACM.

scholarly journals Humpback Whale (Megaptera novaeangliae) observations in Laskeek Bay, western Hecate Strait, in spring and early summer, 1990–2018

2020 ◽  
Vol 133 (3) ◽  
pp. 263-269
Author(s):  
Anthony J. Gaston ◽  
Neil G. Pilgrim ◽  
Vivian Pattison
Keyword(s):  
British Columbia ◽  
Humpback Whale ◽  
Early Summer ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
The West ◽  
Peak Period ◽  
West Side

We describe observations of Humpback Whales (Megaptera novaeangliae) made along the west side of central Hecate Strait, British Columbia, during the spring and summer of 1990–2018. From none in March, the frequency of sightings increased from early April to a peak in May, then fell in June with few in July. The frequency of sightings during the peak period (1 May–20 June) increased over the course of the study at a mean rate of 6% a year, similar to increases recorded elsewhere in British Columbian waters. The frequency of sightings was highest in years when the Oceanic Niño Index for January–March was low and peaked earlier in years when the Oceanic Niño Index was high. Both of these relationships suggest a connection between Humpback Whale sightings in western Hecate Strait and the larger oceanographic context, with sightings more frequent in years of lower water temperatures.

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