"Small fish, however, not only provide higher levels of beneficial nutrients, but are significantly lower in contaminants..."

This was originally published in December 2008 here.

Eating with Intelligence ...
Philippe Rouja, Department of Conservation Services, Government of Bermuda, Bermuda
Eric Dewailly, Faculty of Medicine, Laval University, Québec, Canada

Fisheries of different species around the world have already collapsed or are in imminent danger of collapse. The demand for fish continues to increase yearly even though consumers remain confused about the risk-benefit balance of fish consumption.1 Is it possible to maintain the benefits of fish consumption while minimizing the risks to both human health and global fisheries?
We are familiar with the image of a series of fish, each progressively larger than the other, eating the fish in front and being eaten by the larger fish behind. These kinds of cultural representations have been created by our incredible brain capacity, which arguably evolved due to the availability of marine fats.2 Western culture has transcribed our assessment of what one could call the brain chain (with the human species posited at the top) to the food chain so that we logically believe that we are, and should eat, at the top. But this mistaken belief may be leading us to the nutritional equivalent of the Peter Principle,3 whereby our harvesting from higher trophic levels in the marine food chain eventually leads us to make nutritionally and ecologically incompetent choices. Ironically, while seafood may have pushed us to the top of the brain chain, the way we consume seafood today may not keep us there. We are eating the wrong kinds of fish and too many of them. Fish consumers and the planet alike might be much better off were they to follow the example of many indigenous fishermen by fishing and eating with more intelligence.

The Bardi people of North Western Australia follow fishing strategies in which fish are selected for both their nutritional quality and their relative seasonal fatness, rather than their size, ease of capture and relative quantity of calories they might provide. The Bardi teach us that in temperate and tropical fisheries such a seasonal fishing strategy based on procuring seasonally fat fish enhances human health and leads to the avoidance and protection of spawning fish, many of which are not fat when reproducing.4
In traditional Polynesian society, pregnant women specifically avoid pelagic fish consumption, fish that we now assess as being relatively low in nutrients and high in contaminants such as mercury.5,6 The Polynesians and many other Pacific islanders also cook fish whole with the guts, head and skin intact in order to consume the fats found therein. These parts of the fish are discarded and rarely eaten by most western consumers but are considered a delicacy in many other cultures around the globe. For many indigenous fishing cultures these parts of the fish are the prime motivating factor in choosing which fish to catch.

Our recent research in Bermuda, which measured omega-3 fatty acids, selenium and mercury in a wide range of local fish species, indicated that some of the smaller fish species have more to offer to human health with less risk than larger fish closer to the top of the food chain.7 There are several reasons for this. Fish at the top can become significant repositories for a range of contaminants—both natural and anthropogenic—and may also have unhealthy concentrations of certain nutrients that have negative impacts on human health. The flesh of most large predator fish from warm water fisheries (big tuna, swordfish, marlin and shark) is usually lean with low omega-3s and high in mercury/selenium ratios.7

Small fish, however, not only provide higher levels of beneficial nutrients, but are also significantly lower in contaminants ubiquitous to the marine food chain. Small fish, such as sardines, tend to be eaten whole, whereas large fish like tuna or swordfish are treated, sold, prepared and eaten in much the same way as cattle. What we are left with is a slab of meat, that is for larger fish species, referred to (without irony) as a steak and for smaller fish, a fillet. The fillet and the steak are both divorced from the most nutritious parts of the fish: the skin, bone, brain and eye. The parts of the fish that we discard are, in fact, preferred by the brown and black bear which, during specific seasons, only consume the head and stomach of salmon, leaving the racks along the river’s edge for less nutritionally discerning scavengers.8 As people have less time to prepare fish, the fish fillet and steak have taken over from the whole fish that may have once been available from the fishmonger. Smaller fish, however, continue to be eaten whole, giving consumers access to the full warehouse of nutrients that fish can deliver.

Get off the Top of the Food Chain

Small fish have not been subject to the same over-fishing pressure that has befallen almost all of the larger fish species. Sardines, for example, have been the top pick for many fish watch organizations as they are healthy to eat and sustainably harvested.

We are selling ourselves short every time we use smaller more beneficial fish to catch or grow larger, more contaminated fish. We need to investigate how we can catch fish exclusively for the particular nutritional benefits they impart, not just for the ubiquitous meat and protein all fish can provide. Like the Bardi, we should learn that every fish has its season where both its taste and its nutritional value will be maximized. In seeking the best from their resources, they also nurture their sustainability. It has worked for them for at least 27,000 years9--–perhaps it is not too late for us. Think big. Eat small.

Link to References
This paper is based on research project partially funded by a funded by a grant from the Lepercq Foundation.

Fats of Life

Do You Hear That? There's a Rumbling on the Horizon. A Storm is Brewing Off the Coast of Everywhere. Eat Small Fish. Rush down to your Local and Demand Responsible Fishing, Fresh Sardines, and Better Tins. Use the Power of your (insert local currency here). Slow Down, Pop a Tin and Drink Local.