According to my latest guru, sea minerals are the best biostimulant for your garden. That is, sea water. Makes sense, since all our runoff (including nutrients) ends in the sea. 1 cup of sea water per square foot of soil is the annual suggestion. Many of you already know the benefits of using clean sea salt on your food. You can buy sea solids, or a concentrated liquid such as Sea Crop. This product is diluted significantly, so you only use teaspoons at a time.
There are over 80 trace minerals in the ocean. Compared to rock dust, sea water has significantly more minerals.
As for pollution in the ocean, yes, that is a valid concern. Pristine, deep ocean water and living microbes make the packaged product possibly higher quality than you can gather on your own from your local coast. But, I would support trying ocean water first if you can get some away from an impaired river mouth. Those chickens we have grazing will benefit, too.
Original research done by Maynard Murray: Sea Energy Agriculture. Additional research published by Dr Charles Water: Fertility from the Ocean Deep.