Aquaculture for all

Galician Hake Has Smaller Carbon Footprint Than Others


A study carried out by the University of Santiago de Compostela (USC) has analysed the greenhouse gas emissions of Galicia's fishing industry by species and fishing method.

It estimates the carbon footprint of this activity to be some 888,620 (metric) tons annually. By species, it detected high variability according to the distance from the fishing ground and the technique employed.

"Initially, the study was conceived to analyse the CO2 footprint of various fishery products such as sardines or hake -species typical of the sector in Galicia-. But, given the large number of boats that we could inventory and analyse, in the end we carried out a more ambitious project, examining all of Galicia's fishing fleets, and we estimated the total emissions for one year", says Ian Vázquez-Rowe, co-author of the study and researcher at the USC, in comments to SINC.

The researchers followed the movements of Galicia's long-distance, deep-sea and inshore fishing boats as well as those used in fish farming. The work was carried out in two stages. In the first, the researchers contacted fishermen's organisations directly so that they could be sent the necessary information and, in the second stage, they did fieldwork to increase the amount of data.

"We selected representative samples from the different fishing fleets, such as longline fishing and trawling. Likewise, for some data we contacted shipyards and providers of certain materials such as refrigerants", adds the expert.

They received a high percentage of responses and analysed close to a third of the boats by type of fishing fleet, to reach a total carbon footprint for each fleet. According to their results, the deep-sea and long-distance fishing fleets have significantly greater carbon footprints than those calculated for the inshore fleet and, especially, those for fish farming.

On the other hand, they also observed significant differences depending on the fishing method. "The long-distance boats that go to the Indian or Pacific Oceans, being seiners, consume less diesel and other substances that affect climate change. However, most of the deep-sea boats that were analysed in the Great Sole Bank fishing ground (in the North Atlantic), which were trawlers, have a much greater energy intensity because of the characteristics of this type of fishing", Mr Vázquez-Rowe comments.

For the researchers, the main causes of environmental impact in fishing are distance and technique, followed in last place by operational factors. But on analysing the fleets, they also found differences according to the species of fish.

"The case of hake is a very interesting one, because it is caught in any number of fishing grounds. It is the species par excellence consumed in Spain and, according to our research, the young hake caught on the Galician coast has a substantially lower impact on climate change than that captured in the Great Sole Bank or off Mauritania. Nevertheless, the fishing method - trawling - is the same."

The economic value of the different species means, also, that on the coast of Galicia species like the sardine, horse mackerel and mackerel are caught, whereas in other fishing grounds outside the EU they are not. Mr Vázquez-Rowe indicates that "they are just not considered", as in the case of the Mauritanian fishing ground, where they have evidence that boats get "significant" catches of horse mackerel which are simply thrown back into the sea.

"Efforts must be increased to get solid data on greenhouse effect emissions from the fishing fleets. Besides, the phased change towards new types of refrigeration that pollute less should be complete by 1 January 2015, when the use of the refrigerant gas R-22 will be totally prohibited. This may lead to important changes in the contribution of these refrigerants to the global emissions of European fishing fleets", concludes the study.

June 2011
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