White LED Helps Greatly Increase The Capture Rate Of Canadian Snow Crabs

- Jul 22, 2019-

In 2013, the snow crab fishery in Newfoundland and Labrador in eastern Canada will be the 200th MSC-certified sustainable fishery.


Just like for all fisheries, the capture rate of Canadian snow crabs is critical for fishermen, although it is often difficult to achieve them.


At the 4th International Marine Protected Areas Conference, Khanh Nguyen, a Ph.D. candidate at the University of Newfoundland's School of Oceans and Fisheries, suggested a way to increase the capture rate of Canadian snow crabs – and no additional cost to retrofit the appliance.


Nguyen's research focuses on the biological behavior of Canadian snow crabs - especially those that detect light and respond to light. There are currently several known marine creatures that are attracted to light, such as squid jigging, which uses light to attract prey. Although there are some fishing methods that use relatively strong light to attract prey, Nguyen focuses on low-power, light-colored LED lights.


The main stage of the first phase of the study was the laboratory. The main research object is the response of the male Canadian snow crabs suitable for fishing (all captured female crabs must be released in situ), Nguyen shows five different color LED lights of snow crabs for blue, green, red, purple and white. Reaction. And measure the reaction behavior of snow crabs. Snow crabs do not have any significant response to red and green LEDs, with 75% of snow crabs moving toward white and blue light; and up to 85% of snow crabs avoid purple LED light.


In the second phase, Nguyen studied the area where LEDs were brought to the sea to catch snow crabs. Newfoundland and Labrador snow crabs are mainly harvested from smaller vessels, using a conical grid with bait, usually enough to put in water for about 24-48 hours.


In order to compare the "unit effort catch (CUPE)" of low-power LED lights, the researchers attached LED lights of different color lights to parts of the network, and also released fishing nets without any LED lights as a control group. In the laboratory, Canadian snow crabs react differently to the colorless.


Finally, for fishermen who want to create high-unit efforts to capture the amount, the results are obvious, white LED lights can significantly increase the capture rate. Compared to a control group without any LED lights, a low-power white LED lamp can achieve a 77% unit effort capture.


The use of LED lights to obtain the increase in the catch rate of Canadian snow crabs is obvious for the entire snow crab fishery. The snow crab fishery wants to increase the capture rate, while the white LED light bulb can absorb 1.7 times more than the original catch.


Nguyen said: "In the past, fishermen had to run 8-9 趟 to capture the target number of target crabs, but now only 5 趟 can catch the target catch on that day."


The reduction in operating costs, such as fuel costs, can directly contribute to the financial cooperation of the snow crab fishery.


The snow crab fishery brings jobs to many locations along the coast of Newfoundland and Labrador. The promotion of financial capital also means direct assistance to fishermen. Using Nguyen's research, it seems that it really helps the capture rate of Canadian snow crabs. As far as we know, he has received many inquiries from snow crab fishermen, hoping to LED in the next fishing season. light.