They are coming from rivers that connect with the ocean and the water almost always stay the same
hope this helps!!!
Many cases seem to occur without an apparent cause, while some may occur due to a genetic ( inherited ) defect, environmental exposure during pregnancy, or a combination or both factors. Syndactyly may also occur as a part of an underlying genetic syndrome and can be found in over 300 different genetic syndromes
Many such as Mt St Helens, Washington, and Lava city Navada, and Shieldville Oklahoma, and last Makahoona Hawaii.