Where Does Our Fish Come From?
The world of open data is a strangely complex one, as any data scientist will likely testify. It’s a world that I, a recent BSc graduate, am a relative novice to. But this week, working under the stewardship of Anne McCrossan (a data business specialist, founder of Visceral Business and lead for the Open Data Institute in Cornwall) I have looked to explore this world to answer a question I have long pondered but never quite comprehensively understood — where does the fish we consume in the UK actually come from?
It seems a simple question, anyone can pick up a tin of tuna in the supermarket and check, but what I was particularly interested in was the overall scope of the fishing industry; more specifically Britain’s “Big 5”: cod; haddock; salmon; tuna; and shrimps and prawns. As a nation we are wedded to these 5 groups of fish. They dominate the UK fish market, so much so that supermarkets have begun campaigns to raise awareness that other fish exist and should at least be considered. I myself have an interest in the question due to my recent completion of a Conservation Biology and Ecology degree where I skewed my studies to focus on marine issues. What I’ve come to learn is that, like the world of open data, the fishing industry is difficult to fathom; imports and exports seem to travel at random across the globe. Depleted fish stocks and the rise of aquaculture have contributed to the complexity, but I decided to focus primarily on where the Big 5 are coming from, and perhaps offer some pointers about which fish one should target (or avoid!) if they wanted to reduce their environmental footprint.
So how can open data be used to answer this question, and present it in a format which is easily communicable to a wider audience? That was my task, and to understand it one must understand what open data itself is. The Open Data Institute defines open data as “data that’s available to everyone to access, use and share”. Seems simple enough, but these are early days for the industry and the world of open data is just developing. Various verified government databases exist (data.gov.uk, eurostat etc) but the issue with open data in its current form is that very few people know where to look, let alone how to interpret what they find.
I experienced this first-hand during my training week for the internship, set up by the University of Exeter’s employability programme, as my group and I trawled through numerous databases looking for any evidence of corporations’ plastic use. From what I gathered, at this stage anyway, corporate open databases are virtually nonexistent and government databases are hard to navigate, containing a plethora of highly-specific quotas, spreadsheets, surveys and records for anything and everything, sometimes going back centuries.
The training week offered me a glimpse into the data industry, but also got me thinking about how exactly I could utilise it, and within which sector. Anne helped answer the second question by saying we’d be focusing on food data, but even within this there was so much to work with I spent a while trawling before it dawned on me that the fishing industry is one area where the open data supply is plentiful. Import data, export data, landing quotas, catch quotas, ecosystem viability, you name it, there’s a government spreadsheet for it. With a clear question in mind then, I set about my data trawling, looking for patterns and trends for our Big 5.
It took a while to find a viable dataset — there’s a lot out there and only a small amount of it is downloadable, let alone interpretable. However, towards the end of my first day I came across the “UK Sea Fisheries Annual Statistics” — an absolute goldmine stretching back multiple years, even with an accompanying archive section holding years prior to 2012.
I figured it was worth starting at the most basic level — the consumer themselves. How much fish does the average person consume per week and how much do they spend on fish compared to other food products? The data for this was mostly consistent — in some instances years had been split as evidenced by the graph below, but it did yield results. Answers were somewhat unsurprising — fish consumption in the UK has followed a trend similar to meat and cheese over the years (Fig. 1a, b, c), remaining relatively stable but increasing in price along with inflation. The most surprising result was actually brought about by our egg consumption (Fig. 1d) — I was not aware the average Brit’s egg consumption essentially halved towards the end of the 20th century.
Following this I moved onto the fish themselves. Starting with overall data, I moved onto the Big 5 (cod; haddock; salmon; tuna; and shrimps and prawns) and the import/export ratio of each group. As you can see, the initial graph details perfectly the exploitation of demersal (bottom-dwelling) fish stocks throughout the 20th century, with pelagic (open-water) and shellfish faring somewhat better (Fig. 2a). This trend has however stabilised during the 21st century (Fig. 2b), and recent data is thus what I will focus on.
Moving onto recent Big 5 data though (Fig. 3), some startling results began to reveal themselves, perhaps offering an explanation for the leveling-off seen in Figure 2a. It’s worth bearing in mind that this data is just for 2016, however, upon revision of previous years I found 2016 to not be particularly anomalous therefore elected to keep the focus on just this year. What I found was not only an alarming lack of UK ships landing goods at home, but also that the ratios of imports to exports of certain fish were intriguing to say the least. Take salmon, for instance. Salmon happens to be both the UK’s most imported AND most exported fish over the last five years, yet I could find no record of UK salmon actually being landed in the UK. Quite why this is so is likely related to economic factors slightly outside my area of expertise, however the discovery was an interesting one. A more pleasant surprise was the amount of UK-caught haddock being used in the UK. Statistics for the rest of the 5, such as a complete lack of UK-caught tuna, shrimps and prawns, and the low levels of UK-caught cod (our stock is notoriously depleted — again see Figure 2a) were consistent with what I had read previously.
So, having discerned that (haddock aside) our fish isn’t really coming from UK-registered fishing vessels, I set about answering my overall question — where is it coming from then? The following graphics go a way to illustrating it.
As illustrated, cod and haddock (Fig. 4a,b) show similar trends, both primarily imported from the UK and Europe (haddock showing a more UK-dominated trade). However, what at first glance looks surprising is that China is our second and third most utilised source of the fish-and-chip favourites, respectively. This is likely due to their complete dominance of the global aquaculture (fish farming) market — FAO data from 2011 shows China to contribute more to worldwide aquaculture than rest of the top 20 nations combined. Salmon (Fig. 4c), already shown to be the most imported and exported fish, also comes in primarily from northern Europe, with Thailand and Canada also contributing. As shown earlier (Fig. 3), I could find no record of the UK contributing to its own Salmon supply.
The other two members of the Big 5, however, show completely different trends. Tuna (Fig. 4d), a controversial fish at the best of times, comes in from all over the globe, with Ghana somewhat surprisingly turning out to be our biggest suppliers. In fact, the vast majority of British tuna comes in from outside Europe, with other African nations Seychelles and Mauritius, south-east Asian countries and Ecuador all also contributing more than the biggest supplying European nation — Spain. Finally, shrimp and prawns (Fig. 4e) showed the greatest variation in their supply. Again, south-east Asia is a key player (aquaculture again likely to be the reason as data shows the nations highlighted are all significant investors in shrimp farming), however the Latin American nations of Honduras and Ecuador both contributed as well as certain European countries. Take from these graphics what you will, I personally have gained a lot of understanding about how far different members of our Big 5 tend to travel before reaching us and will think twice before purchasing tuna, shrimps and prawns in particular.
Overall, I have greatly enjoyed my exploration into the world of open data and my time working with Anne as a whole. In using open data to answer a question I’ve caught a glimpse into its potential, but I’ve also come to realise how young this sector really is. How many other questions’ answers are out there, waiting to be unearthed from the labyrinth which government databases represent? How many more could be answered if governments and corporations provide more open data sources and make what’s already out there more easily accessible? I’ve just started with open data, but I’ve quickly come to understand why people like Anne have dedicated themselves to developing this emerging, exciting sector.
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