scholarly journals The effect of white and green LED-lights on the catch efficiency of the Barents Sea snow crab (Chionoecetes opilio) pot fishery

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258272
Author(s):  
Kristine Cerbule ◽  
Bent Herrmann ◽  
Eduardo Grimaldo ◽  
Leif Grimsmo ◽  
Jørgen Vollstad
Keyword(s):  
Field Experiments ◽  
Barents Sea ◽  
Carapace Width ◽  
Snow Crab ◽  
Chionoecetes Opilio ◽  
Light Emitting ◽  
Green Led ◽  
Minimum Landing Size ◽  
White Light Emitting Diodes ◽  
Led Lights

In commercial snow crab (Chionoecetes opilio) fishery, the catch efficiency of the conical pots is important for increasing the profitability of the industry. This study evaluated the effect of adding green and white light emitting diodes (LED) on the catch efficiency of commercially used conical pots. The results from the field experiments showed that inserting artificial lights significantly increases the catch efficiency for snow crab over the minimum landing size of 95 mm carapace width of up to 76% when using green LED, and by 52–53% on average when using white LED. This study shows that it is possible to improve the catch efficiency of the snow crab fishery by applying artificial LED lights to the conical snow crab pots, potentially resulting in an important economic benefit to the snow crab fishery.

Functional Maturity in Small Male Snow Crabs (Chionoecetes opilio)

1988 ◽  
Vol 45 (12) ◽  
pp. 2106-2109 ◽  
Author(s):  
G. P. Ennis ◽  
R. G. Hooper ◽  
D. M. Taylor
Keyword(s):  
Rapid Development ◽  
Carapace Width ◽  
Reproductive Potential ◽  
Snow Crab ◽  
Small Male ◽  
Chionoecetes Opilio ◽  
In Captivity ◽  
Breeding Migration ◽  
High Level ◽  
Snow Crabs

The mean size of male snow crabs (Chionoecetes opilio) in sexual pairs during the annual spring breeding migration to shallow water in Bonne Bay, Newfoundland, decreased from 118.6 mm carapace width (CW) in 1983 to 100.3 mm in 1987. This decrease is due to an increase in males <95 mm CW participating from 1.5% in 1983 to 32.3% in 1987. This change appears to have resulted from a reduced abundance of commercial size [Formula: see text] males due to a rapid development of an illegal fishery on this previously unfished population and, as a consequence, less competition between males for possession of females. The percentages of spermathecae containing new spermatophores for females paired with males <95 mm CW (67%) and those with males [Formula: see text] (79%) were not significantly different. We assumed that each female with new spermatophores had recently mated with the male with which it was paired. Observations on selected pairs in captivity showed that males <95 mm CW are capable of mating with both primiparous and muitiparous females. Our results indicate that small mature males can replace large males in breeding activity in a snow crab population. We conclude that in the male-only snow crab fishery in Atlantic Canada with a minimum legal size of 95 mm CW, population reproductive potential is maintained at a high level despite high exploitation rates on males [Formula: see text].

scholarly journals Effect of light-emitting diodes (LEDs) on snow crab catch rates in the Barents Sea pot fishery

2019 ◽  
Vol 76 (6) ◽  
pp. 1893-1901 ◽  
Author(s):  
Khanh Q Nguyen ◽  
Odd-Børre Humborstad ◽  
Svein Løkkeborg ◽  
Paul D Winger ◽  
Shannon M Bayse
Keyword(s):  
Capital Investment ◽  
Barents Sea ◽  
Economic Benefits ◽  
Financial Strain ◽  
Snow Crab ◽  
Catch Per Unit Effort ◽  
Important Species ◽  
Light Emitting ◽  
The Barents Sea ◽  
Catch Rates

Abstract Snow crab (Chionoecetes opilio) has become an important species for the Norwegian seafood industry since its first commercial harvest in 2012. However, periodically catch rates can be low, causing a financial strain on the fishery. Thus, improving the catch rate of existing pot designs has the potential to significantly improve the profitability of fishing enterprises. In this study, we investigated whether the addition of low-powered purple and white light-emitting diode (LED) fishing lights inside the pots could improve catch rates of snow crab in the Barents Sea. Results showed that pots with purple lights harvested a 12.8% higher catch per unit effort (CPUE; number of crab per pot) of legal-sized crab, which was significantly more than the control pots (p = 0.035); pots with white lights did not catch significantly more crab (p &gt; 0.05). Pots equipped with only light (no bait) caught very few crabs and were not considered a viable alternative. Although purple LEDs increased snow crab capture, the economic benefits of using underwater lights in pots remains unclear given the high capital investment required.

scholarly journals Temperature selection and the final thermal preferendum of snow crab (Chionoecetes opilio, Decapoda) from the Barents Sea

Polar Biology ◽  
2019 ◽  
Vol 42 (10) ◽  
pp. 1911-1914 ◽  
Author(s):  
Sten Ivar Siikavuopio ◽  
Snorre Bakke ◽  
Bjørn Steinar Sæther ◽  
Tina Thesslund ◽  
Jørgen S. Christiansen
Keyword(s):  
Barents Sea ◽  
Snow Crab ◽  
Temperature Selection ◽  
Chionoecetes Opilio ◽  
The Barents Sea

Morphometry and Gonad Maturity of Male Snow Crab, Chionoecetes opilio

1992 ◽  
Vol 49 (12) ◽  
pp. 2460-2468 ◽  
Author(s):  
Michel Comeau ◽  
Gérard Y. Conan
Keyword(s):  
Carapace Width ◽  
Immature Stage ◽  
Juvenile Stage ◽  
Snow Crab ◽  
Sexual Character ◽  
Gonad Maturity ◽  
Chionoecetes Opilio ◽  
Juvenile Males ◽  
The Relationship ◽  
Determinant Factor

The relationship between chela height (CH) and carapace width (CW) of male snow crab, Chionoecetes opilio, goes through three allometric stages. The "immature stage" (mostly < 34 mm CW) evolves into a "juvenile stage" (34–120 mm CW) through a "juvenile molt" defining a change in allometry marked by an angular point around 34 mm CW. Fifty percent of males reach gonad maturity, defined by the presence of spermatophores inside the vasa deferentia, at an estimated size of 34 mm CW) The third allometric stage, "morphometrically mature," is separated from the juvenile stage by a "molt to morphometric maturity" at sizes ranging from 50 to 120 mm CW. Juvenile males have smaller claws than morphometrically mature males of the same size. This secondary sexual character is justified by a specific behavior of the males holding the pereipods of the female in one chela during precopulatory embrace. Male snow crab efficiently mate in nature with intermolt multiparous females only after reaching morphometric maturity. Therefore, the presence of spermatophores is not the sole determinant factor necessary for male copulation. Juvenile males larger than the minimum legal size of 95 mm CW are harvestable before, they may efficiently mate.

Hemolymph Ecdysone Concentration as a Function of Sexual Maturity in the Male Snow Crab (Chionoecetes opilio)

1992 ◽  
Vol 49 (8) ◽  
pp. 1619-1623 ◽  
Author(s):  
Roland J. Cormier ◽  
Alan R. Fraser ◽  
Richard F. J. Bailey ◽  
Nicole Raymond
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Dry Weight ◽  
Mature Male ◽  
Snow Crab ◽  
Allometric Relationship ◽  
Biochemical Basis ◽  
Chionoecetes Opilio ◽  
Relationship Of ◽  
Juvenile Crab

Ecdysone concentrations in the hemolymph of juvenile and morphometrically mature male snow crab (Chionoecetes opilio) were determined by radioimmunoassay. A logarithmic transformation of the allometric relationship of the dry weight of the chelae versus the carapace width was used to identify morphometric maturity. Results indicate that concentrations of ecdysone found in the hemolymph of juvenile crab are higher than those found in morphometrically mature crab, thus providing a biochemical basis for the observation that the onset of sexual maturity seems to coincide with a terminal molt.

scholarly journals Phototactic Response of the Oriental Armyworm, Mythimna separata (Lepidoptera: Noctuidae), to Light-Emitting Diode Lights of Different Wavelengths

2019 ◽  
Author(s):  
Kil-Nam Kim ◽  
Hye-Sung Song ◽  
Ryong-Jin Choe ◽  
Zhi-Juan Huang ◽  
Qiu-Ying Huang ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Insect Pest ◽  
Light Trap ◽  
Mythimna Separata ◽  
Light Emitting ◽  
Led Light ◽  
Phototactic Response ◽  
Green Led ◽  
Oriental Armyworm ◽  
Led Lights

Recently, light traps using light-emitting diode (LED) lights have been applied to monitor or control insect pests. The oriental armyworm, Mythimna separata Walker, is an important insect pest that has caused damage to several cereal crops, including corn, wheat and rice. The present study aims to seek out a sensitive wavelength causing high phototactic response in M. separata. The study evaluated the phototactic responses of M. separata moths to several LED lights of different wavelengths and luminance intensities under laboratory condition. Results showed that green (520 nm) LED light resulted in significant phototactic response of M. separata moths compared to LED lights of other wavelengths. Additionally, the highest attraction rate of the moths to green LED light appeared in luminance intensity group of 200 lux compared to the other intensities groups. Experiments under optimum conditions based on the above experiments revealed that the green LED light exhibited the strongest attraction rate (64.44%) among all experimental groups. An experiment performed in a net cage also showed that green LED light resulted in the highest phototactic response of M. separata moths, 1.7 times more than a commercial black light used as control. These findings clearly demonstrate that M. separata moths have a high sensitivity to the green LED light. Therefore, a light trap equipped with green LED light could be useful for monitoring and controlling M. separata moths.

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