The Catch with Netting

The ocean is a beautiful place filled with crystal blue waters, colorful coral, and magnificent creatures; however, as the developing human world collides with the ocean, the natural beauty and wonder within has begun to vanish. The sparkling waters are becoming soiled with trash both large and microscopic, the colorful coral is bleaching, and the magnificent creatures are being killed for one reason or another. It is clear that the meshing of these two worlds isn’t as seamless as one would hope, and while its effects seem to only be a hazard to the life within the ocean, the degradation of such a delicate ecosystem begins to affect the world as a whole. Whether it’s from the bioaccumulation of microplastics as fish are consumed or unjust murder for “humanity’s benefit”, the ocean is suffering. Many solutions for these problems have been discussed and are being experimented with, but the one to be discussed here, which offers a piece of the solution to both of these issues, is the development of a new technology called “Electric Shark Punching.” Before discussing this innovative technology, let’s get a little background on the effects of plastic netting and how that plays into the intentional/unintentional killing of ocean life.

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Though not commonly considered a huge contributor to plastic pollution, abandoned netting, initially used for fishing or beach goer protection, can lead to both the entanglement and death of assorted wildlife and/or the formation of microplastics. Wandering nets kill without reason taking any life that gets entangled in it, whether it’s a dolphin, turtle, or shark. One report, issued jointly by the Food and Agriculture Organization and the UN Environment Program (UNEP), estimated that 640,000 tons of ghost nets are spread across our oceans, making up 10% of ocean litter. While fishermen may try to ignore many environmental statistics, they are sure to listen and help with the cause when they hear figures such as: one abandoned net can kill $20,000 worth of Dungeness crabs in a year while removing a net costs only $1,358. In addition to strangulation, mismanaged plastic netting will break apart into small pieces called microplastic. While you may not be able to see them, a recent study published in the Environmental Research Letters predicts approximately 93-236 thousand tons of microplastics are floating around in our oceans that are affecting smaller organisms and leading to negative effects on larger fish. These are the same large fish that are ending up on our dinner plate and in our stomachs, microplastics and all. With evidence of microplastics halving oyster reproduction and damaging implications of DDT and BPA being able to adhere to microplastics, there is no telling what kind of harm the build-up of these in our oceans and consequently a human body could cause.

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Fisherman need to fish and asking them to change their fishing habits is a huge hurdle, but all hope for decreasing plastic netting is not lost. Another use for netting in the oceans is for beach protection from dangerous animals like sharks, and that’s where “Electric Shark Punching” comes into the scene. This innovative technological experiment is being performed by the KwaZulu-Natal Sharks Board in a shark hot spot off the coast of Southern Africa. Instead of putting up a physical barricade, the KwaZulu-Natal Sharks Board decided to go after a physiological barrier specific to sharks. Sharks have a pouch of gel that sits right on the tip of its nose used in its hunt for pray. This same pouch is extremely sensitive to any electric field, so what researchers are aiming to do is lay a cable along the ocean floor that will form an electric field causing sharks to turn back. The project leader Paul Von Blerk compares the effects of the electric field on a shark to a human’s response to heat, “From a distance, we can sense the warmth [fire] emits, but the closer we get the more discomfort we experience. Once the discomfort gets too much we can move away from the flame.” The electric field effects no other fish allowing them to pass freely across the barrier, as well as humans though they may feel a slight tingling.

Do you think this is a technology worth investing in? Are there possible repercussions you can imagine that may not have been thought of here? Are there any other circumstances you feel this technology would apply or other technologies you know of that are similar to it?

Sources:

  1. Dr. Jambeck and her research team
  2. http://www.earthisland.org/journal/index.php/elist/eListRead/ghost_fishing_nets_invisible_killers_in_the_oceans/
  3. http://www.seadocsociety.org/california-lost-fishing-gear-removal-project/
  4. Environmental Research Letters (iopscience.iop.org…/124006;jsessionid=123F0E078E457FC6106D3ACEE956F209.c3.iopscience.cld.iop.org)
  5. https://voices.nationalgeographic.org/2016/04/04/pesky-plastic-the-true-harm-of-microplastics-in-the-oceans/
  6. https://www.smithsonianmag.com/innovation/electric-fence-wards-sharks-180953380/

 

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20 thoughts on “The Catch with Netting

  1. Something about putting electricity and water together where people are in the water just doesn’t seem like a good idea to me. I would also be curious to know how much netting from shark protection there is. Ive never been to a beach that advertised they had one or have ever seen one myself, so I’m skeptical. Im not sure if we actually need the technology. I would also be concerned with the “tingling” effect that humans feel. Is it safe to be in the water for more than 30 minutes? There would have to be a lot of science and data to back up the research before I would get into water with the electric fence.

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  2. Kenzie, this is a great piece! You brought up a lot of insightful points. It’s unfortunate how we’e affecting the ocean ecosystem just by our negligence. Hopefully the fact that micro-plastics have a potential health implication on humans through consumption of fish that are in these littered ocean can bring awareness to the change that needs to be made. As for the electric fence for Sharks, I am not sure if that is such a great investment as the probability of shark attacks are so low and also this might discourage people from going in the ocean.

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  3. I disagree with the idea of using an electric field to deter shark populations near the beach. If it is a shark infested area then people need to avoid swimming there. This electric field may have the desired affect on sharks, but there is no way to truly know what other effects it may have on other creatures and plants in the area. It would disrupt the natural balance in the area with unknown consequences.

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  4. I have heard that ghost nets are a huge problem right now. I think this is mainly due to the overfishing done to our oceans. Too many boats, too many nets. I’d be curious to know if there are any repercussions to a boat that loses a net other than the obvious capital investment and loss of future earnings.

    Like someone else mentioned I have never heard of shark netting. I am not doubting its existence, just merely wondering how prevalent it is. Again someone else mentioned being hesitant about running electricity through water. I don’t imagine the current to be strong enough to hurt someone, but what are the logistics of such a project? The cost of upkeep and running it?

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  5. As others have said, the thought of mixing water and electricity worries me a little bit. The fact that humans can feel the electric barrier is also concerning, as that could be potentially harmful. Is there any concern on how this would affect the ecosystem of the shark? I do think it is great that they are trying to move away from plastic netting, but I do feel like the concerns outweighs the pros on this one.

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  6. The electric shark punching is an interesting thought, but like others have mentioned, the unknown effects that electricity and water may be a no-go. Without knowing how feasible this technology actually is, it could end up being more harmful than helpful. I agree that it will disrupt the natural nature of the ocean. I think the biggest solution here is to take preventative action by not trashing the ocean with objects than can harm wildlife. However, I know it is not as simple as it seems because there’s always going to be people who don’t care about the environment.

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  7. First off I liked the title. My opinion on the crab is that while 20,000 worth of crabs will be lost the fisherman won’t feel the repercussion of longer fishing charters as a cause of the lost netting. Spending $1300 to retrieve an abandoned net will be soaked up by the fisherman who comes up on it, and the net may have already wrecked havoc on the local crabs. The only way I see a solution would be to issue nets at the beginning of each crabbing season, and if they are not checked in at the end of the season, fisherman should be held accountable for the 20,000 dollars of crab that they caused damage to effecting the rest of the fleet.

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  8. I think the idea of issuing a certain number of nets is very interesting, if perhaps not entirely practical. I’m not an authority on fishing but with the amount of netting lost in the ocean I assume that nets break, tear, or are worn out really often, which means that the high turnover rate might be an issue in trying to send all the nets through one central route. That being said, if it were possible to route all the nets through one place, they could also be tagged with something like an RFID chip that could aid in their later retrieval. Maybe someone needs to work on biodegradable netting? It might be difficult to formulate plastic that doesn’t fall apart in water for long enough to actually catch fish with the product, but if there’s a way to avoid the ghost nets and microplastics it might be worth investigating.

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  9. Great read! Your post really intrigued me, so I did some research of my own. With a family member that surfs the west coast, I was already familiar with the shark repellent wet suit; but doing some digging I found that there are many options such as electrical, magnetic, acoustic, and sprays. With that, I too am curious how prevalent the shark netting is, and I feel that if it is not so prevalent then beachgoers could take matters into their own hands with some of the other products on the market that may not be as intrusive as planting an electric cable on the ocean floor. Harm from the electricity should be of no concern, considering that researchers have been using backpack shockers to catch fish for ages. I do agree that ghost netting is definitely a force to be reckoned with and that many people would jump on a bandwagon to do something about it.

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  10. I think this idea is a really cool! Since humans use so much netting for many different purposes it is very likely that some will get lost in the ocean. As a result it is not a surprise to be seeing all the marine life deaths that we have. Our pollution of the oceans is having detrimental effects and we need to fix it. Any technology that is feasible and is aimed at doing so is a good idea. This electric field would eliminate potential for harming any marine life and provide the protection needed!

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  11. I think this could be a useful technology. If it was me getting in the water though I’d want to be certain that this method will stop sharks every time. I think it needs to be thoroughly shown that a shark will not push through this discomfort under certain circumstances before it should be implemented on a large scale.

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  12. Thanks for sharing about the major issue of ghost nets! It’s such a sad issue. It’s so ironic that using these high-quality synthetic nets and then dumping them ultimately kills the commodity that fishing companies are trying to harvest! I’d like to think that that fact alone would improve behaviors and increase the desire for sustainable innovations in the commercial fishing industry. Regarding the “electric shark punching” idea, I am torn about the combination of electricity and water in recreational swimming areas, like many of the other commenters! I’d be interested in learning more about it and its safety features. Also, I know little about shark eating and mating preferences, but it seems that these electric fences could potentially harm their natural behaviors by preventing them from going to certain areas in their habitat.

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  13. I see the technology being effective, but also causing a lot of debate, so I don’t know if it will ever be used throughout the world. I agree with an above post that if a body of water is known for being infested with sharks, people should just avoid it in the first place. It is their habitat, not the swimmers. I also wonder if these electrical signals have negative impacts on other aquatic organisms as well? Putting something of this nature into a delicate aquatic ecosystem just so that people can swim seems a little off to me.

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  14. You bring up some really great points. I never even thought how the wild-caught fish I am eating could be eating the microplastics, therefore, tainting their body with toxic chemicals. Who knows how this is going to affect humans. On another note, it’s really sad to hear how these ghost nets are killing so many large marine animals, because the large ones tend to be the species that die off first during mass extinctions. Are there are cleanup missions currently being pursued?

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  15. I think this is a great technology worth looking into. This will greatly reduce marine life loss in the nets that exist off certain beaches now. The only factors I can see that might contribute to it not being implemented is the price of the technology, and the potential adverse affects of the electromagnetic fields on other fish species. Ill have to look into the costs and how it affects other fish.

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  16. The shark deterrent technology has been being used for quite a while now by divers and fishermen. There are technologies that work on a small scale that use electric fields to keep sharks away from a single diver or the area around a boat so it is not surprising to see proposals to use this technology on a larger scale. On the subject of netting, killing fish and marine animals is not the only problem. Another huge problem with netting is the destruction of sea grass beds.

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  17. I think this is an innovative idea, but it can have harsh effects on the ocean’s social environment. Fish will eventually learn that shark do not go within a certain distance of the shore. Eventually, they will begin to use this to their survival advantage against sharks and creatures similar. This would probably increase the population of other fish on the beach. Just creating another creature that humans do not like.

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  18. As for controlling the nets that are left behind by fisherman, I think a great way to deter this would be to make the cost associated with this more common knowledge. I would bet that a lot of fisherman probably believe that the nets that they leave just sink to the ocean floor and are left there alone. But if they knew the monetary costs that could affect them, like those that were included in this article, I bet they would think twice before leaving a net behind. Also, I have to agree that I don’t think the electric shark fence is the best idea. If sharks are a big enough problem in the area for there to be a need for this fence, then people probably just shouldn’t be swimming in the water. How would the fence affect humans? What happens if the fence loses electricity and we can’t see that it’s not functioning? I would have to see a lot more evidence and statistics to get behind that technology.

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  19. I think this is an interesting idea and the concept behind it seems great. On the other hand, I personally do not think we should be pushing sharks out of the area. Shark attacks are not very common and I feel as though typically every organism has a role in its habitat. Sharks may be playing a significant role in that environment so displacing them could lead to a number of consequences. I think this technology should only be put in place if sharks were more of an immediate threat to the human population and if there was an extensive amount of research on the potential consequences/benefits.

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  20. I enjoyed reading this article! As engineers, introducing technology in the environment can be so tricky. More often than not, the solution can be solved, but will have trade-off. Our jobs sometimes involves deciding which trade-off is worth keeping and which we can allow to harm. To your question, (Is there repercussion we are not seeing): I am sure there is; since environmental is changing constantly, we don’t know 100% how the environment will behave in the future.

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