Ghost fishing is a modern issue of today. The reason I decided to talk about it in my blog is that I wanted to learn more about it, as on the DY120 research cruise in October, we had one oceanographic mooring that had a massive tuna longline attached to it.
Ghost fishing
is when derelict fishing gear 'continues to fish.
Climate change is aggravated by impacts from overfishing, pollution, and habitat degradation...all of which ghost fishing plays a part.
As the oceanographic mooring was rolled in over the back of the Discovery a massive longline was found to be attached to it. Read here for what a deep-sea mooring is!
It is not able to go through the block to winch it onboard, so each section needed to be cut off with a knife. This added at least 1.5 hours to the operation, we had a tight schedule this year with timing and weather so delays were pretty stressful.
So what is ghost fishing?
https://www.ghostfishing.co.uk/ explain ghost fishing as, "The problem of ghost fishing gear has reached public prominence over the past five years. It is a normal but unfortunate part of fishing that nets, pots, and lines become lost. This is rarely a deliberate act on behalf of the fishing community, but simply a reality of a very harsh environment.
The main issue of this derelict fishing gear sometimes referred to as "ghost gear," is that any discarded, lost, or abandoned, fishing gear in the marine environment. This gear continues to fish and trap animals, entangle and potentially kill marine life, smother habitat, and act as a hazard to navigation. Derelict fishing gear, such as nets or traps and pots, is one of the main types of debris impacting the marine environment today."
We did not find any marine life tangled up within the deep-sea mooring, just our sensors!
Incredibly, it was just this one microcat sensor that had held the longline in place, which over time with the currents had then got attached around the buoys and tangled themselves. The microcat was not even damaged.
Estelle and Lewis took the time to detach the metal hooks so that they could be recycled. The net did not look that old. We think what happened was that the hook must have got caught to the microcat when deploying their net and when it got caught the only option was for them to cut the line...!
It then got tangled around all of the buoyancy buoys.
So from a scientist's perspective, the next question would be did this mess (cause an anomaly) up the data? The plot below was plotted by tech Lewis Drysdale from SAMS on Matlab. I personally thought that the weight of the net would have dragged the whole mooring system downward or sideways. Like this: 
What actually happened is that it looks like there was enough buoyancy to prevent the deep-sea mooring from moving off course from vertical. The data below correlates to data we have seen over the years of collecting this data. Over the two years of this dataset, it shows the usual interannual variation in currents.
One of the other big issues about these nets is the plastic and debris left behind!! There is a great podcast from Costing the Earth about ghost netting and there is a diver from ghost fishing helping remove a net they found. "Plastic nets and equipment left in the ocean by fishing boats are estimated to make up over 10% of marine rubbish and in the 'Great Pacific Garbage Patch' over 40% of the accumulated plastic is lost fishing gear. Even worse these plastic 'ghost nets' can go on catching fish and attracting other wildlife which then becomes entangled too. Often these nets are very old and once they finally do start to degrade they add to the problem of 'microplastics' which are ingested by sea creatures. It's a big global problem but as Lucy Siegle discovers in Cornwall and Italy there are lots of solutions on offer and teams of enthusiastic volunteer divers who want to get these old nets out of the sea and into a recycling scheme.
With the help of 'Ghost Fishing UK,' Lucy takes a look at what can be done to prevent more 'ghost gear' being lost and to help get existing nets out of our oceans and she mentions how tax causes issues of recycling the nets, however, there are now new projects that recycle the nets to make kayaks, jewelry, and many other things. The crux of the matter is that the nets are super expensive and fishermen do not mean to dump their nets unless there is no other option, they want and need the nets for their livelihood. When the net disappears so does their own money and they put 5% is usually set aside in their budget for lost gear. As usual...and it is a pet hate of mine because people just do not seem capable to do it properly...communication. Communication between the fishermen especially, their lost gear and catch, and also between a reporting system to get a team of divers, for example, to work together to prevent the net from becoming ghost gear. Lucy concluded, "Changes in legislation could set the president for global action. A small change could have big results!"
One reason for writing this blog was for me to learn too, did you know that you can report what you find!" All scuba divers can contribute to the clean up of our oceans by reporting any ghost gear they see on their dives to Ghost Fishing UK through our online reporting system on this website."
For the future? Well as Sir David Attenborough in his latest documentary called, 'A life on our planet' he alludes to overfishing and how we should live in more of a sustainable way, especially with overfishing... which I think I will talk about in a different blog because it is a large topic!
