Key Takeaways

  • Bycatch is one of the most significant threats to marine ecosystems, biodiversity, and conservation efforts. 
  • In the U.S., bycatch could be upwards of 2 billion pounds annually, which is the equivalent of 17 Titanic’s worth of sea life killed and discarded. 
  • Researchers at Arizona State University are using green LED lights on fishnets to reduce bycatch.
  • This could significantly help to reduce bycatch if adopted globally by coastal gillnet fisheries by at least 63%. 

Shedding Light on Bycatch

Have you ever been fishing and accidentally reeled in something you weren’t looking to have for dinner? In the commercial fishing industry, this happens every day on a massive scale. 

Bycatch is recognized as the inadvertent trapping of undesirable sea life as a result of commercial fishing. Including animals like sea turtles, sea birds, fish like sharks, squids, and dolphins, bycatch can reduce populations of prey and predator species, which can throw off the balance of the food chain. Fishers aren’t crazy about bycatch either. Not only is it difficult to remove undesired sea life from nets, but laws in many regions prevent endangered sea life from being sold. This often leads to decreased profits for hauls with significant bycatch. 

Mitigating net bycatch is challenging because nets are nonselective, meaning they don’t choose what ends up in them. Designing more selective nets may be the answer to our bycatch conundrum. Jesse Senko, a senior sustainability scientist at Arizona State University, has been researching the use of green LED lights on nets in coastal fisheries. Recent results show that the use of these lights can serve as a visual cue for non-target species, reducing bycatch as much as 63% in a recent study. 


Fishing for a Solution

Due to its thriving fishing industry and high marine biodiversity, Baja California Sur in Mexico served as the perfect location for Senko to test out the effects of net-lights. It is estimated that in these fisheries, six to eight turtles are caught per boat per day using traditional nets. In partnership with local fisheries, Senko’s team attached LED lights along nets in 33-foot intervals. Traditionally, the LED bulbs were battery-powered and lasted up to four weeks, but new solar-powered lights have been developed. The newly developed solar lights can double as a buoy and can stay light for up to a week with only 30 minutes of sunlight. 

Senko’s operation found that using green LEDs on nets had a profound impact on the reduction of bycatch biomass, including a 48% decrease in unwanted fish, a 50% decrease in loggerhead turtles, 81% decrease in Humboldt squids, and 95% decrease in sharks and rays. An added benefit is that net lights decrease the time needed to retrieve and untangle nets, easing this burden for fishers. In a recent interview with NPR, Senko identifies green LED net lights as a solution to bycatch for three basic reasons:

  1. Sea turtles, sharks, sea birds, and other marine mammals can see green very easily, which helps them avoid nets and subsequent capture.
  2. Green transmits well in water, meaning it can be seen from a great distance by creatures. 
  3. Green light is more energy-efficient than other colors. 

While it is still unclear if lights warn organisms of impending danger, or serve simply as an annoyance that repels the creatures, it is clear that this is a promising solution that benefits both marine life, coastal fisheries, and even the everyday consumer. The average consumer eats about 10 pounds of seafood per year, which contributes to 2 pounds of bycatch per consumer! Senko’s net lights have the potential to cut this down by half. 


The Bottom Line

Senko’s LED lights have the potential to decrease bycatch rates without closing down fisheries, serving as a reminder that win-win sustainable solutions are possible. Conservationists, fishing managers, and stakeholders should keep this in mind, and work with industry to increase the manufacturing of net lights, develop new technologies, and seek out ways to integrate these new advancements within fisheries at a global scale. 

Keep in mind, LED net lights have a ways to go before they are fully incorporated into fishery protocol at a global scale. Until then, here are some things you can do as a consumer to avoid supporting bycatch:

  1. Purchase MSC-certified sustainable seafood.
  2. Use the Monterey Bay Aquarium’s seafood watch to avoid fish with high rates of bycatch.
  3. Reduce your overall fish intake and opt for vegetarian or vegan options. Find out what would happen if the entire world went vegan here