Krill Bill: new-age fad contributing to overfishing, food web destruction and climate change
I should be studying hard for an exam on marine biodiversity on Tuesday and finishing a report on copepod (zooplankton) populations in the Hopkins River. But after seeing a tweet from the Blue Planet Society (@seasaver) about a newly accepted paper on Antarctic krill fishing, I had to get in on the debate.
As basic background, krill is a shrimp-like marine crustacean near the bottom of the food chain, feeding on phytoplankton and operating as a suitable food source for much larger sea creatures. Concerns about the impact of krill harvesting for human consumption have been around for some time but academic debate has been somewhat limited, for various reasons including the usual issue of research funding.
Parker and PH Tyedmers wrote on the issues surrounding claims of krill overfishing in Environmental Science and Technology journal, in a paper titled Life Cycle Environmental Impacts of Three Products Derived from Wild-Caught Antarctic Krill (Euphausia superba).
In their own words, their aim was to “apply life cycle assessment to measure the contributions of krill meal, oil, and omega-3 capsules to global warming, ozone depletion, acidification, eutrophication, energy use, and biotic resource use”.
Krill meal and krill oil tablets, along with the more common omega-3 supplements, have become a trendy way to increase omega-3 in the diets of gym junkies and hipsters but are worryingly catching on further. Anecdotally at least, this trend would have increase the amount of krill being sourced from the most reproductive areas of the Southern Ocean and seas around Japan and contribute to climate change through fossil fuel use.
Parker and Tyedmers found, in studying Norwegian company Aker BioMarine’s krill fishery, that about “190 litres of fuel was burned per tonne of raw krill landed, markedly higher than fuel inputs to reduction fisheries targeting other species. In contrast, the biotic resource use associated with extracting krill is relatively low compared to that of other reduction fisheries.”
When you consider krill is a major food source for whales, dolphins, penguins, and some types of squid and fish, growth in the human demand for krill should be of serious concern. On a personal level, I had a heated discussion last September with my sister – a very keen follower of new vitamin supplement trends – about the impact of increasing krill demand on the larger animals that feed on them.
It didn’t help that my argument at the time was short on published fact about the problem, so I had to concede I didn’t really the long-term effects of krill fishing on large mammals or whether reproductive rates could keep up with human demand.
But obviously, as a marine biologist in training, getting the facts on the problem is more important just proving a point: it’s a chance to have a say and further publicise the potential issues overfishing has on a food web as complex as that based on krill.