Driven by Curious Data

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Is eating fish safe anymore? As children we all heard the old wives tales: ‘carrots help you see in the dark’, ‘crusts make your hair curly’, ‘eat your fish if you want to be smart’. It turns out they were right –maybe not about the crusts but fish is a prime source of Omega 3 fatty acid an essential nutrient for neurological development. It is especially important for the developing fetus during the second trimester of pregnancy. The problem however is that fish, well, some fish is also the source of one of the most dangerous neurotoxins.

Bermuda - Research in the early 2000s found elevated blood concentrations of mercury in Bermudian pregnant women, (seven times that of average North American levels). And the source of the majority of this mercury was locally harvested fish.

Several hundred fish were sampled to measure mercury concentrations, as well as the beneficial nutrients of omega-3 fatty acids and selenium and with this data fish consumption guidelines were created for the island’s healthcare providers serving pregnant women. These guidelines highlighted a multitude of local fish species that were low in mercury and high in omega-3 fatty acids and therefore good to eat.

In the years following the blood mercury concentrations in Bermudian pregnant women dropped five-fold. But while this drop was a public health success, there were concerns that overall fish intake was falling, depriving pregnant women in Bermuda of essential nutrients found in fish, nutrients important to optimal child development.


Mercury – This never used to be an issue. Mercury consumption did not impact our grandmothers and the techniques, traditions or old wives tales to avoid its toxifying effects never developed over the centuries. They were not needed.

Humans have known of the dangers of mercury for thousands of years but the first evidence of mercury intoxication in food was recorded in 1956. Years of releasing industrial mercury into Minamata Bay, Japan led to devastating neurological symptoms in the local population after the consumption of contaminated fish and mollusks.

Mercury is a neurotoxin effecting the cerebellum, the part of the brain that controls coordination and movement. It is particularly harmful to babies in the womb, causing brain damage and effecting hearing and vision.

In the Environment - Global contamination of mercury registers at significant levels from the 1970s, its prevalence attributed to a variety of industrial processes. The main source was fossil fuel emissions until the global recession in 2008 triggered huge demand for gold. Today it is artisanal gold mining that is the single greatest contributor of environmental mercury pollution.

10-15 million unregulated mines use mercury illegally. It is poured into sluice pools and binds to gold particles suspended in the silt to form an amalgam.  Most of the mercury washes into the river systems and makes its way into the oceans.

Mercury is a persistent pollutant – it does not break down in the environment. It binds with organic molecules in aquatic systems becoming methyl mercury. Methyl mercury can be absorbed by plants in highly polluted areas but more far reaching is the proliferation of the toxin into the global food chain through ocean fish.

Bioaccumulation of mercury in the marine food chain

Bioaccumulation of mercury in the marine food chain

Fish – the molecular structure of methyl mercury mimics an essential amino acid, transported freely throughout the body including across the blood–brain barrier where it can elicit neurotoxic effects and across the placenta where it is absorbed by the fetus causing a variety of developmental defects.

It is easily absorbed but not easily eliminated and accumulates, as you move up the aquatic food chains, to dangerous concentrations in a process of biomagnification. But as is our way, we have managed to make things worse for ourselves.

The fish traditionally caught in Bermuda, the reef fish, grouper, hinds, hogfish have relatively low concentrations of methylmercury but the near shore fishery has been severely over exploited so that now fishermen venture further offshore to procure fish. And it is in these pelagic species, the large tuna, the amberjack, the swordfish, the fish that we have developed a taste for, these are the fish that are a potential health threat.

Health Advice - The Fish Consumption Guideline was designed to provide the nuanced information necessary to identify what was safe to eat and what to avoid or limit during pregnancy. Released in 2008 our research on levels of Beneficial nutrients Omega 3 fatty acids an selenium along with levels of the contaminant mercury led to specific recommendations about local fish for resident pregnant women. This pointed public health message arguably led to an extremely significant decrease in mercury in Bermuda newborns - a 5 fold decrease by 2012. Despite this success our research team questioned wether the important beneficial local fish options available to the pregnant consumer were being sidelined when this data was communicated to pregnant women in Bermuda. As is often the case broad ranging information is distilled down into blanket statements. These sound-bites permeate through internet and media propagation and become rules that are accepted and repeated without question.

Research by our team in 2013, showed that healthcare providers and the internet were the primary sources of information about fish consumption during pregnancy in Bermuda. Guidelines online provided by major international health organizations recommend that pregnant women consume no more than 2 portions of fish per week irrespective of what kind of fish they are eating. However, specific research around the world shows that this advice is relevant only to species of fish with the greatest concentrations of mercury. By applying such restrictions to ‘safe’ fish species pregnant women are in fact denying themselves and their child vital nutrients.

The custom made Fish Consumption Guideline for Bermuda outlined these benefits and identified the fish with the highest benefit to risk ratios. However our research in 2013 indicated that much of the messaging concerning fish consumption during pregnancy in Bermuda  continued to focus on the risks and resulted in the positive aspects of the report, the healthy eating options and recommendations for increased consumption of beneficial local fish, being sidelined.  Bermuda’s pregnant women were going without. 

The App - Reports suffer from a shelf life. They do not remain front and centre, they are not omnipresent! Among the ever-updating information we are immersed in it is too easy for reports to be read, filed and forgotten. And as our research suggests, when information is required, the internet is usually the first port of call.

So to cut through the confusion and inaccuracies relating to consuming fish we needed to find a new way to communicate our data, to present the information clearly and simply straight to the people who needed it. We created BeneFISHiary, a mobile app that allows the consumer to search local species and obtain the most recent information about average mercury concentrations, as well as the healthy nutrients.

The app is attractive and simple to use to provide the consumer with the important facts to allow them to make an informed choice. Moreover, the app contains species-specific sustainability details, given concerns about overfishing in the Atlantic and even contains tasting notes for users curious to try new fish in their cooking.

By shortening the information chain we can put the facts that matter into the palm of your hand – so that you can have your cake and eat it, or is that fish?

Visit the website here - BeneFISHiary