It is estimated that up to 50,000 African elephants are lost to poaching each year with fewer than 470,000 remaining. That’s one-tenth of the population per year. They are mostly shipped out from large ports (Mombasa is one) but to control the actual poaching, the place of origin of the ivory was needed.
In 2013 delegates of the Convention on International Trade in Endangered Species (CITES) unanimously passed a decision, urging all seizing countries to turn over samples from their large seizures for origin analysis within 90 days of the seizure.
Since then, the Center for Conservation Biology in Washington has received samples of 28 large tusk seizures that occurred between 1996 and 2014, and analysed them to see where the poaching centres are, so that efforts can be concentrated there.
How they first mapped the genetic spread distribution of elephants by finding dung samples, and then matched the ivory samples to areas, is at theconversation.com/where-is-all-the-ivory-from-using-forensic-science-and-elephant-dna-to-stop-poachers-43443. The map showing the main poaching areas is at www.pnas.org/content/101/41/14847.abstract.