Fisheries Invasive Species

Eating invasive species and the future of sustainable fisheries

Kourantidou, M. and B.A. Kaiser. 2019. Sustainable seafood certifications are inadequate to challenges of ecosystem change. ICES Journal of Marine Science, 76(4): 794-802. doi:10.1093/icesjms/fsy198

Invasive species, aquatic and terrestrial, are a human phenomenon, but not a new one. Feral pigs have been wreaking havoc on the Hawaiian ecosystem since they were introduced (as early as 800 years ago and again by James Cook in the late 1770s) but efforts to eradicate them generally meet with community resistance, as locals don’t want to give up a dish that has long since become a ceremonial mainstay. The dandelion, pigeon, and bullfrog have been here nearly as long—long enough for many of us to believe that they’re native. Some conservation biologists and chefs think that we can also provide the solution: eat the invaders! But are we ready for this? Can it really make an impact, and if so, would it really fix the problem?

Is this smart?

First and foremost, this is not a new idea. Kudzu cookbooks cropped up shortly after the vine’s introduction to the Americas (1870s), and yet kudzu keeps spreading by more than 100,000 acres per year. In 1998, the State of Louisiana enticed chefs in New Orleans to create recipes for Nutria, an introduced rodent (1930s) that was being cooked as early as the 1960s, but which is still destroying wetlands throughout Southern and mid-Atlantic states. As with so many things, what was old is new again, and there is once again plenty of talk about eating invasives, including in our own pages (Oceanbites, 19 July 2018).

There are scientific and social reasons that hyping the consumption of an invasive species would not be productive, or even counter-productive. First, to decrease a population via harvest, the total taking needs to exceed the birth rate, on reproductive individuals (i.e. not just on older individuals or those that would have died via other means) on a consistent basis year over year.  This is particularly difficult for invasive species, which tend to have high reproductive capacities. Indeed, this is one typical feature of invasive species that allow them to be so successful in the first place. As an example, keeping the US wild hog population (another invasive) controlled requires culling of as much as 75%, or more, per year!

Secondly, as was noted in an opinion piece in Ensia, the creation of a market often provides the incentive to maintain a lucrative population, not to decimate it. Sometimes, introductions are even purposefully done in order to create a market from scratch. This was the case in the 1960s when the Soviet Union Academy of Sciences successfully (on the second attempt) introduced the Red King Crab  (Paralithodes camtschaticus),native to the Bering Sea and northern Pacific, to the Barents Sea, a high latitude waterbody that borders both Russia and Norway (thought without the Norwegians’ cooperation, or indeed knowledge). In the 1990s when bycatch began damaging Norway’s other fisheries (and its fleet’s fishing gear), Norway, in consultation with Russia, set commercial quotas, resulting in an artificially created, internationally-managed commercial fishery, ostensibly to compensate those fishers who had suffered bycatch-related losses in their targeted fisheries. The Red King Crab fishery, therefore, provides an ideal test case at the intersection of invasive species ecology and marketplace policy!  Luckily for us, a paper published in ICES last year asks how this fishery and others like it should be dealt with in terms of “sustainability” certifications. In essence, should we be encouraging consumers to choose these fisheries?

Paralithodes camtschaticus accessed 2/16/2020

What do we mean by “Sustainable Seafood?”

The authors of the paper critique the successful sustainability certification of the Red King Crab fishery by the Marine Stewardship Council.  Many of us are familiar with sustainability certifications of seafood or fisheries. The Marine Stewardship Council (MSC), Friend of the Sea, Monterey Bay Aquarium Seafood Watch, Ocean Wise and the Marine Conservation Society all have rating platforms, apps and/or tools useful for use at supermarkets or restaurants to aid consumers in the quest to make responsible choices. Most, if not all of these, use primarily population levels and other factors related to individual fish stocks, and information on the welfare and methodologies of the fishers. While all of these are undoubtably important, they do not all consider each relevant factor potentially influencing the ‘sustainability’ of a fishery. An additional hurdle lies in agencies and governments reaching a consensus on what constitutes ‘overfishing,’ ‘exploited,’ etc. Of course, further disruption from climate change and other human impacts will continue to threaten ecosystems globally, raising the question if these programs will even be able to accurately reflect and predict fishery conditions.

In the case of the Red King Crab, the species in question is a known invasion risk. Two countries, Russia and Norway, are managing the same fishery in a politically divided but hydrodynamically joined waterbody. Russia is managing it as it would any other fishery, with long-term fishery management quotas in place. Norway, on the other hand, has quotas from the 26⁰E line of longitude east to the Russian border, but west of that line it currently manages an open-access fishery. Open-access continues north of 71⁰ 31’N as well.  Around the world, open-access generally leads to over-exploitation of stocks, and generally eliminates a fishery from ‘sustainable’ designation.

The Barents Sea borders both Norway and Russia. Norway is operating an open-access fishery west of 26⁰ E and north of 71⁰ 31’N to prevent range expansion and further invasion. Russia is managing the Red King Crab very differently. GoogleEarth, accessed 2/12/2020

However, in this case decimation of the fishery is the goal! Norway’s attempt to stop westward spreading of the species is in direct opposition to the qualifications for ‘sustainability’ according to these programs, and yet is fully in line with the stated objectives – a “spirit of the law” rather than the “letter of the law” situation – and is therefore a better option than more traditional quota management. This is one example of the flexibility that such ‘Sustainability Designation’ organizations are going to need in the future. The authors call for broader definitions that take ecosystem issues into account and consider a less narrow definition of sustainability.

MSC certification is based on three major principles: sustainable stocks, minimum environmental impact and effective management. Applying this certification to the RKC fishery, the authors conclude, challenges the second principle, based on studies that have shown increased risk of parasitic infestation in other coastal species, predation by the crabs on native commercial species and their eggs, including the Icelandic scallop, and decreases in soft-bottom community biodiversity.  As it is defined, certification assumes that by altering fishing techniques and using quotas, the habitat for a species will be protected and therefore the ecosystem impacts will be minimized. When the species in question is itself an invasive, this breaks down quickly. The authors highlight that climate change will continue to disrupt this connection even in non-invasive fishery scenarios.  As they point out, had the introduction occurred today it would have been in violation of the Convention for Biological Diversity, which itself would have eliminated any possibility of a ‘sustainable’ label. Should it do so now?

These issues will continue to crop up as climate change alters habitats and species’ ranges, and as invasive species make their way around the globe. While consuming invasives is likely net neutral or beneficial as a consumer, the market around invasive species as a commodity deserves further scrutiny. We as consumers depend on these certifying organizations to create tools that we can take to our seafood counters and restaurants to make the healthiest decisions for our bodies as well as for our planet.

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