Nitrogen fixation by chemosynthetic symbionts was overlooked for a long time," says Petersen. "Since their discovery in the deep sea in the late 1970s, we have spent almost four decades researching the symbionts' role in providing a source of carbon such as sugars for their hosts." However, even marine clams cannot live from sugar alone. This new research raises the possibility that these symbionts may provide the unexpected benefit of a natural source of nitrogen to augment their host's diet. They could even be fertilizing the surrounding habitat by releasing available nitrogen to the surrounding water. "Our future research aims to answer this question: Do these marine symbiotic bacteria help to 'fertilize' the oceans, too?