Dredging for the truth

Editorial Comment

Cormac Burke, IFSA

Those of you in the fishing industry who follow the never ending well-funded attacks on this industry by almost every green group in the world are likely to well remember that in 2021 a widely published report claimed that fishing trawlers, particularly those using bottom trawls (caused by the trawl ‘doors’ occasionally bouncing or intermittently dragging along the seabed), release significant amounts of carbon dioxide emissions into the atmosphere by disturbing seabed sediments, which contain vast stores of organic carbon.

This, the green report claimed, was a practice estimated to release annual emissions and air pollution “comparable to total global aviation industry” and that it was costing societies billions of euros due to its climate and ecological impact and went on to state that “the disturbance of these carbon-rich sediments by trawling nets remains a significant concern for climate goals”.

After some in-depth research by leading international scientists this claim was very publically debunked, particularly in a 2023 study published in NATURE which found the actual figures to be significantly lower, by a factor of 100 to 1,000.

The initial study, by Sala et al. (2021) in the same journal, overestimated emissions by confounding fast-releasing surface carbon with more stable deep-sediment carbon and misattributing the natural decay of top-layer carbon to trawling. While bottom trawling still has some environmental impacts, the claim of it being a major carbon source rivaling air travel is now considered false, according to renowned experts.

But despite the initial report shown to be out by 90% in its claims of amount of carbon emissions, many green groups known for rarely letting the truth get in the way of a good story, continue to cite the original report and neglect to tell the public that these ‘facts’ were completely debunked by genuine researchers (researchers who were obviously not on the payroll of certain environmentalist groups).

The ‘blind eye’

You might wonder where I’m going with all of this when it appears as ‘old news’… but my interest is in the marine dredging industry….. and what seems to be a complete blind eye turned to this sector by the same groups who had to make up stories to try and blacken the international fishing industry.

Let’s look at a few facts, firstly that some 22% of all sand and gravel for the construction industry in the UK is dredged from seabeds (*Source UK GBC)

Also, according to agg-net.com, in London alone, half of all sand and gravel comes from marine sources, while in the wider south east a third of the aggregate is dredged while, in South Wales, aggregates from the seabed make up 90% of the sand used in construction.

Marine sand and gravel is no different to its land-based equivalent, having been laid down by the same processes but at a time when sea levels were much lower than today.

Based on a five-year average of mineral extraction data from the UK’s Office for National Statistics, marine aggregates provide around 17% of the sand and gravel used in England and Wales. This vital contribution to the UK’s total primary aggregate needs equates to some 50 medium-sized land-based quarries.

And so, given that such mineral dredging (gravel / sand) is undertaken by dragging along the seabed at several metres deep, compared to the contact of fishing gears (trawls, doors or beams) then surely whatever the actual percentage of estimated carbon emissions from fishing activities, it must be vastly more in the marine aggregate dredging industry.

Therefore, when i did some online research under the key search words of ‘environmental impacts of marine aggregate dredging’ then nothing, or at least practically nothing, came up compared to the thousands of links that come up if you use keywords ‘fishing and environmental impacts’….

Out of the lowly results of my search of ‘environmental impacts of marine aggregate dredging’ (approximately six results) these included a UN report from 2022; a UK ‘Marine Bulletin’ report on ‘impacts of dredging’ 2018; an Irish Marine Institute recommendations report for this industry from 2008; and a UK CEFAS report from 2005.

Which all goes to show that the group who spent so much time and resources in trying to highlight their concern regarding the release of carbon emissions from the seabed by human interaction…. so much so that they had to falsify their data to fit the narrative they wanted…. These same ‘researchers’ at no point thought it was worth checking another industry that may be releasing 10 times, maybe 100 times, more carbon emissions than commercial fishing does.

It is certainly no conspiracy theory to believe that there is a global witch hunt against the fishing industry… but the groups involved seem to only target certain sectors of the industry and only those operating in certain areas.

And it is clear to everyone that the research of such ‘green’ groups always seems to come up to support the narrative of those who are funding that same group.

Photo: Martide