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Monday 27 October 2014

Ghost fishing - let's have accurate information and data please!

Below is an extract from an article that appeared in the Western Morning News this week. While the content is entirely well-intentioned and the motives for beach cleaning by students interested in the environment entirely commendable the information and way in which the story is presented is not quite so commendable. 


"A team of 25 volunteers from the Green Team at Cornwall College Newquay, spent two hours tackling 400 metres of coastline as part of the Surfers Against Sewage autumn beach clean.
The event was organised by student Beth Buckell-May, who said: “I am so happy with the amount of litter we collected; 10 full bags of rubbish and over 300 pieces of ghost fishing gear removed in just two hours. This is so important, as millions of sea animals become ensnared in discarded fishing gear every year. We have saved countless lives.”
According to figures from Surfers Against Sewage, in the tangle net fishery off the southern tip of Cornwall, it was recently found that 18 vessels lost a total of 263 nets per year; a total length of 24km.
Only around one third of these nets were recovered."

Firstly, it would be good to see a reference for the source of seemingly very accurate data over the amount of fishing gear lost by those 18 fishing vessels.

Secondly, using superlatives such as 'millions of sea animals' and 'countless lives' seeks only to sensationalise the story. It would be equally accurate to surmise that in the waters off Cornwall millions of fish are eaten by other fish and predators like seals each year - it's what happens in a food chain naturally.


Thirdly, 300 pieces of ghost fishing gear removed in just two hours sounds highly improbable - 300 pieces of beach litter maybe.

Let's put this in perspective: 
There are ten net boats based in Newlyn to which the figures refer to in the article.
Let's say a box (30Kg) of fish sold for auction on the market in Newlyn contains on average 30 fish.
An average trip consists of 200 boxes - that's 200 X 10 = 2000 fish.
A boat might do on average 20 trips in a year owing to weather etc that's 20 X 2000 = 40000 fish.
Using the same figures, let's calculate what that would mean for the 30 large boats fishing from Newlyn, that's 30 X 40000 = 1,200,000 fish.
In other words, the entire fleet of net boats plus another 20 tralwers from the largest port in Cornwall (3rd in England) lands, one million two hundred thousand fish in a year in total. Let's say those figures are inaccurate - let's double them to 2.4 million fish.
Can 'countless' fish be lost to ghost fishing?

Ask any net fisherman to tell you what happens to a net when it is lost and he will tell you - within a few days the net becomes rolled up due to the action of the tide in the water - as any fisherman will testify when they have retrieved lost nets - it takes hours to untangle and un-roll the net! As soon as a net is rolled up it no longer 'fishes'. Monofilament nylon nets are used because they are almost invisible to fish - however, once they have been in the water for a few days they become covered in algae and sediment from the seabed - this makes them visible to fish who, in turn, then avoid being caught.




Fishermen go to great lengths to see that they don't lose gear - it's expensive. Nealry 200 boats fishing from Newlyn and other ports take part in the 'Fishing for Litter' campaign. 


They re-cycle their old nets as part of the project.

Read the full story above in the WMN here: