Posts Tagged ‘algae and omega-3’

Omega 3 Fatty Acids

Wednesday, December 30th, 2009

Last summer in a cove on the coast of Maine, a fishing boat trapped a school of Menhaden by extending a net across the cove and then encircling the school with a purse seine. The captured school of fish was a very small one, yet it was the only one trapped there in many years. A few decades ago, menhaden schools were sometimes 40 miles long, supporting a large and thriving fishery, and providing food in turn for the mackeral and tuna that followed their migration north along the coast each summer. Now of course these are just memories. The largest remaining schools are still hunted aggressively in Chesapeake Bay.

Part of a small Menhaden school. The fish accumulate Omega-3 fatty acids from the red-brown algae they eat as part of their diet.

Part of a small Menhaden school. The fish accumulate Omega-3 fatty acids from the red-brown algae they eat as part of their diet.

You probably haven’t eaten menhaden knowingly. It’s a very oily fish, of the clupeid or herring family, and its value is in its oils, rich in Omega-3 fatty acids. Wherever it is still hunted, it is hunted for for Omega-3, to feed to humans in capsules of oil, or to feed to farmed salmon. Even to add to lipsticks and paints.

All ‘oily’ fish are rich in Omega-3 fatty acids – for example salmon, tuna, mackeral, and the smaller herring and menhaden. None of them actually make the Omega-3 themselves, but they store it in their tissues. Omega-3 fatty acids are instead produced in red-brown single-celled marine algae, which are browsed by forage fish such as herring and menhaden, which in turn are eaten by the larger predatory fish.

We know now that Omega-3 fatty acids are essential to our own health. We need them as part of our diet to help us avoid atherosclerosis and heart disease. We can get them from eating salmon and tuna, but then they come with contaminants such as mercury. To avoid the contaminants, one company is marketing Omega-3 extracted from Hoki, a member of the hake family caught from deep cold water near new Zealand. This is a slow growing species that currently supports what appears to be a sustainable fishery, but it will not support a fishery that is focussed on harvesting them for fish oil.

If not salmon, mackeral, tuna or hoki, then where do you get your Omega-3? Probably from menhaden. Yet to supply Omega-3 to humans and farmed salmon, schools of menhaden have shrunk to oblivion in many places, and the remaining populations are small remnants of what they were.

This all sounds quite bleak, once again, but there are solutions. The oils can be extracted from fish discards. More promising, red-brown algae can be cultivated directly, and in fact can be cultivated to be particularly rich in fatty acids. The oil is easily removed, and it uncontaminated by heavy metals and pesticides, and millions of fish are not killed. Check out the company Udo for the details.

You don't need to eat a fish to get your Omega-3. (udoerasmus.com)

You don't need to eat a fish to get your Omega-3. (udoerasmus.com)

My own conclusions are that 1) I probably need more Omega-3 in my diet; 2) it should not come from fish, but from cultivated marine algae; 3) all harvesting of menhaden should cease in hopes of letting the species at least partially recover; 4) if we can’t find an acceptable substitute source of fish oils to feed to farmed salmon, we should again consider abandoning the farming of salmon: and 5) at all costs, we should avoid products from Omega Protein of Houston: it still harvests half a billion menhaden each year.