2016 Edited to Add: When I first began writing here I generated a searchable database for references and I have since done away with that option. This entire series remains to be edited to include the full references within each piece. As time allows, this series will be edited to include complete references at the end of each part in the series.
Essential Fat: Oceans, Lakes and Rivers
While it is clear that humans populated almost all areas of the planet, it is rare to find even land-locked cultures where fish was not consumed.
“Fatty acids (FA) are inextricably linked with key physiological and biochemical processes and are thus integral to proper ecosystem functioning. FA not biosynthesized effectively by animals are termed essential fatty acids (EFA). These EFA are important “drivers” of ecosystem health/ stability and are therefore highly conserved in aquatic food chains...
Finally, there is growing evidence that EFA have been an important force in our past evolution, leading us and others to speculate that an unbroken link exists between EFA, our present health, and, in all likelihood, our continuing evolution (emphasis mine).” [M. Arts et al., 2001].
There is a good chance we have the fabulous brains that we do because we hung out by rivers and oceans and ate pretty much anything that moved around in those waters. So whether our ancestors were aquatic apes, river apes, or shore-dwelling apes, we found a ready supply of what our brains needed in the water.
Had human populations on the planet remained at 950 million or so, then our brains’ love of seafood, lakefood and riverfood would not likely have outstripped supply. But then we found another kind of oil.
Cheap Energy, Over-Fishing and the World’s Toxic Toilet
We are now at 7 billion humans on the planet. We can power our societies for now, but we may struggle to keep powering all those hearts and minds in future.
The concentrated energy found in petroleum has no equivalent. That humans discovered how to extract and use petroleum, enabled a population explosion from 900 million to 7 billion in a mere 160 years.
And although we even eat petroleum by-products (both purposefully, as in chewing gum, and not so purposefully, as in pollutants in our foods), it doesn’t power us as living creatures.
Even if petroleum were a renewable resource, the ways in which we manage its extraction and refinement; the ways in which we use our waterways as dumping grounds; and the ways in which our huge populations require the same nutrients they did when our brains first started on their journey to becoming human, are all challenging the planet’s ability to keep such an enormous human infestation going.
I live in the poster-child country for over-fishing (Canada). The Atlantic cod population collapse, occurring in 1978 and finally recognized by the federal government in 1993, was a catastrophe. Five hundred years ago off the coasts of Nova Scotia and Newfoundland, Atlantic cod was easily caught by hanging wicker baskets off the boat. It was not until the introduction of sea trawlers in the 1950s that the cod stocks off our coast took a complete nosedive. The peak catch was in 1968 at 810,000 tons of cod. The trawlers were able to haul up in 15 years what it had taken 100 years to haul up from 1650-1750 approximately [J. Hutchings, R. Myers, 1995].
“Despite the imposition of strict management measures in force since the early 1990s, the Scotian Shelf ecosystem has not reverted back to its former structure.” [K. Frank et al., 2011]
When you fish the top predators, then you create something called a trophic cascade, where forage fish populations then explode and consequently decimate zooplankton numbers, resulting in forage fish collapse, etc. etc. Trophic cascades can happen in all ecosystems, not just the aquatic ones.
“…the unanticipated impacts of trophic cascades [include] processes as diverse as the dynamics of disease, wildfire, carbon sequestration, invasive species, and biogeochemical cycles.” [J. Estes et al., 2011]
Our aquatic sources of fatty acids are inherently all sustainable. However now, we may inadvertently be at the top of the ultimate trophic cascade. With 7 billion of us, is there any possible way to have anything consumed at sustainable rates?
The North Pacific Gyre
The North Pacific subtropical gyre is one of five ocean gyres on the planet. This particular gyre has the unfortunate honorific of also being the world’s biggest landfill. In fact the gyre itself has two garbage patches: the western and eastern patches. The eastern patch sits between Hawaii and California (about the size of Texas), and the western sits between Hawaii and Japan [How Stuff Works].
The synthetic polymers (plastics) swirling around in the gyre are long-term threats to the marine environment in the following ways:
- marine life ingest plastics fragments and plastic absorbs hydrophobic pollutants
- the bioavailability of toxins within plastic subsequently appear in marine life eggs and fat deposits.
- the plastic is colonized by invasive species and becomes a vector for transport of these species to other fragile ecosystems.
- the plastic inhibits the normal gas exchange, subsequently smothering marine life.
- As over 50% of all thermoplastics sink, it is also unknown how much damage these plastics are doing to the marine life at, or near, the seafloor.
[C.J. Moore, 2008]
Toxic Toilet: Mercury, Methylmercury, Dioxins, PCBs and Other Heavy Metals
I can go into way too much detail on the flow of mercury around the world because I once wrote a very long paper on it. To spare you, I’ll try to give you the executive summary:
- we are primarily exposed to elemental or organic mercury through dental amalgams, and, for those in certain occupational settings, through inhalation [J. Risher et al., 2002].
- organic mercury is readily methylated in many living organisms, particularly bacteria and also through abiotic methylation in aquatic environments [F. Morel al., 1998; V. Celo et al., 2005]
- methylmercury bioaccumulates in all living creatures, particularly the fish we like to eat [C.J. Watras et al., 1992; R.P. Mason et al., 1995]
- fossil fuel combustion (primarily coal fired power plants) produces 45.6% of the world’s atmospheric mercury emissions [United Nations Environment Program, Chemical Branch, 2008].
- artisanal and small scale gold production (dirty gold) accounts for 18.2% of global atmospheric mercury emissions; metal production (excluding gold): 10.4%; cement production: 9.8%; waste incineration, waste other: 6.5%; large scale gold production: 5.8%; chlor-alkali plants: 2.4%; dental amalgam creation: 1.6% [ibid.]
PCBs (polychlorinated biphenyls) have been manufactured since the 1930s for various electrical installations. Largely no longer manufactured, they are incredibly persistent in the environment. They have estrogenic effect linked to retardation of development and lower IQ in children [E. Bonefeld-Jørgensen et al., 2001; J. Jacobson et al., 1996].
Dioxins (PCDD: polychlorinated dibenzo-p-dioxins) are produced and released into the atmosphere, again bio-accumulating in all living things, through the manufacture of herbicides, bleached papers and the burning of polyvinyl chloride (PVC) materials. Dioxins are endocrine disruptors and known to cause cancer in humans [X. Gao et al., 1999; K. Steenland et al., 2004].
Cadmium, one of the heavy metals, is a byproduct of various smelting processes of non-ferrous metals. Lead, another heavy metal, is one of the more common contaminants found in jewelry, lipstick, children’s toys and so on. Arsenic is a key heavy metal for the semi-conductor business. All these heavy metals end up in the environment and all bio-accumulate in living things.
Sadly, it doesn’t really look too good for humans when it comes to their traditional source of essential fatty acids, but there are still choices we can make on an individual level, and on a population level to improve our lot.