Since a large scale experiment showed that iron was deficient, and the chemistry of phytoplankton is not mysterious, it seems likely that it's causation, not just correlation.
Since iron is a major part of meteorites, it's not surprising that iron supplies vary.
< Estimates for the total mass of material that falls on Earth each year range from 37,000-78,000 tons. Most of this mass would come from dust-sized particles. (This study was led by P. A. Bland and was published in Monthly Notices of the Royal Astronomical Society.) >
One kilogram of fish needs something like 5 milligrams of iron. So 50,000 tons a year of iron from meteorites would provide 50,000,000,000,000 milligrams of iron or enough for 10,000,000,000,000 kilograms of fish. That's a lot of fish. For 5,000,000,000 people that would be 2000 kilograms of fish each. Burp!! That's more than we can eat.
Of course people wouldn't get all that fish, but 10 trillion kilograms of fish is a lot of fish. That's production every year.
The variation of incoming iron from space must be large as there are clouds of material in space such as the Leonid meteorite shower. There are some decades with lots of incomings and some centuries with not so much.
Since people tend to be farmers, wanting more regular production of food, it is a good idea to mine iron and spray it over the oceans to grow fish. It would make economic sense for New Zealand for example to spray iron over our exclusive economic zone to enhance fish growth. It might make sense for Japan and others to form a consortium to pay ship owners to spray return trip ballast iron over wide areas of ocean.
It might make sense to distribute floats to act as habitats for marine life to nucleate food supplies all over the ocean. Maybe just wood chips would be good enough. Barnacles would soon grow and a lot more besides.
Mqurice
PS: Iron in fish: <Shellfish
Some types of shellfish are very good sources of dietary iron. For example, six medium oysters provide about 5 milligrams of iron, while 3/4 cup of fried clams contains 3 milligrams. Shrimp are relatively high in iron, with 1.3 milligrams in eight large shrimp. Lobster and crab also contain some iron, with 0.5 milligrams in 1 cup of cooked lobster and 0.7 milligrams in a 6-ounce serving of steamed crabmeat.
FishMost types of fish contain iron, providing up to about 10 percent of the RDA in an average serving. For example, a 6-ounce serving of canned salmon or tuna contains about 1.5 milligrams of iron. Other varieties of fish also provide iron, including cod, with 0.8 milligrams in 6 ounces; flounder, with 0.6 milligrams in 6 ounces; and haddock, with 0.4 milligrams in a similar-sized serving. Both wild-caught and farmed fish supply iron. For example, a 6-ounce serving of cooked, farmed trout provides about 0.6 milligrams of iron.
Seaweed
Seaweed, another food obtained from the sea, is also a good source of iron. Raw kelp, sometimes used in salads or other dishes, contains about 0.5 milligrams of iron in a 1/4-cup serving. Spirulina, another type of seaweed usually used in a dried form, has 0.3 milligrams of iron in 1 tablespoon. Finally, the Japanese seaweed called laver or nori, which is roasted and used in sheets in many Asian dishes, is also a source of iron, with about 0.5 milligrams of iron in 10 sheets.> |
