Menhaden were the most important fisheries throughout American history. When the first settlers learn to farm corn, it was with menhaden that they fertilized the seeds. When the whaling industry reached its height, it was outweighed by menhaden oil. Menhaden ruled the ocean from the middle of the food chain, they were the dominant prey of most large predatory fish. They swarmed the sea in schools several miles long and millions of fish deep. Their huge biomass supported by plankton, they regulated algal blooms, mediated the transfer of primary production up the food chain, filtered the ocean.