Ghost nets: The fishing gear that haunts the sea
It's in our name, so it would make sense to explain what they are so we're all on the same page from here on out.
What ghost nets are: Any lost, abandoned or discarded fishing gear (ALDFG)
What ghost nets aren't: Floating ghosts that catch things in the sea.
These lost, abandoned or discarded nets can come in all shapes and sizes depending on what the fishing gear was previously used for. So, what are the different types of nets? Most fishing gear is fairly self-explanatory and does exactly what it says on the tin. For example, trawling nets are nets that are trawled through the ocean either mid-water column or along the seafloor; longlines are long lines with numerous hooks hanging below the main line; gill nets are thin netting left in a location to catch species by their gills; lobster pots are pots that sit on the seafloor waiting to catch lobster! One net that springs to mind for being a little off-brand are purse seine nets, these nets are used to circle a school of fish and then catch the whole school.
Despite their differences, they all have one objective: to catch fish. Unfortunately, whether or not anyone is hauling these nets in at the end of the day, they are still catching fish, along with almost anything else in their path. These are ghost nets, and the reality is devastating. Unlike other forms of plastic, once animals get caught in ghost nets, they seldom make it out alive, without help at least.
It's not just the capture of animals that ghost gear is responsible for. ALDFG has also been shown to have adverse consequences such as transporting and transferring toxins and microplastics into marine food webs; transporting invasive alien species; distributing microalgae that may cause harmful algal blooms; altering and damaging habitat; obstructing in-use fishing gear and navigation; creating safety risks at sea, and reducing the socioeconomic value of coastal and nearshore habitats. Baring in mind there are 4.6 million fishing vessels actively fishing in our waters, that's a lot of potential ALDFG causing all of the above.
Which begs the question, if we know how much damage this is causing, how and why on earth is this still happening? Let's circle back to the definition, the answer is mostly, in there. For the most part, ghost nets are a result of accidental loss. Sometimes they may get caught on the seafloor when trawling, it might get stolen or they may even just get lost overboard in rough seas. At the end of the day, fishers aren't likely to want to lose this gear, because it's their way of making money.
Having said that, there are a few reasons why it might be purposefully discarded. Firstly, if the fishing is being carried out illegally, unreported or unregulated (IUU), they may want to dispose of the obvious evidence, such as the nets. Another potential reason is a lack of storage space on the boat. If they have had a particularly successful trip, they may be limited available space on the boat, and so they cut their losses (literally) and the fishing gear is thrown overboard. Equally, if the trip has been successful, a heavy added load to the fishing vessel when the gear is pulled in, may cost more in fuel to get a heavier ship home than it would be to remove the nets and buy more back at shore. As with many industries, almost all potential avenues are driven by money.
Our growing population and greed come with a higher demand for seafood, in turn, fuelling the fishing industry to catch more and more. Aside from the numerous problems that causes in its own right - this ultimately means more fishing gear will enter the ocean as ALDFG. It is estimated that 1.14 million tonnes of fishing gear is entering our oceans annually which is highlighted when looking at the composition of plastics in the great pacific garbage patch, where ghost nets comprise 46% of the waste. Now while these are all estimates (because science is good, but not regulating 4.6 million vessels good), it's important to remember these numbers will always be on the rise until we take action.
However more often than not, regardless of whether the ghost nets are a result of purposeful or accidental loss, the reason stems from a lack of resources. Normally you hear the phrase "cut out the middle man", but in this case, I think a middle person is very much required. Because even if fishers were aiming to do the best thing (which many are) they may not have the financial, time or resource freedom to locate, remove or prevent ghost nets from entering in the first place.
There's a lot going on in here and it's a very complex issue (as most are!) so it's important we take the right messages away, in order to understand the problem, tackle it and restore a little bit of hope to ourselves. So in conclusion: There are MANY drivers behind ALDFG (ghost nets) and to tackle this problem effectively we need to consider all aspects. Luckily there are solutions to all of these that can move us towards a more circular economy, for fear of always sounding doom and gloom - future write-ups will aim to be solution orientated!