Hundreds Of Horseshoe Crabs Washed Up Dead On Japan Beach, Is Global Warming The Reason?

When horseshoe crabs arrive on the shores of southern and western Japan to lay eggs every year, it is expected that some of them die in the process. However, this year's numbers are already as high as a few hundreds, leaving scientists mystified.

Mass horseshoe crab die-off in Japan! Yet another human created devoid! https://t.co/xeIvH5q1X1

— brazen introvert! (@Jassisglasses) September 18, 2016

According to The Independent UK, around 50 to 60 dead horseshoe crabs can be found on the tidal flats of Sonehigata, but so far, around 490 have already been found this year. Kyushu University Museum researcher Hiroko Koike said that the rises in the sea level, as well as the shortage of places to lay these eggs due to global warming resulted to these crabs' deaths. The dead crabs began appearing as early as January, a time when they were usually dormant, but the numbers started increasing in late June, and continued on rising since.

Shungo Takahashi, head of a local branch of an organization that strives to protect these crabs said that there are around 2,400 horseshoe crabs estimated to be at the tidal flats this year-meaning that the 490 dead already accounted for 20 percent of the population, and eight times higher than normal number of deaths. Another factor is the temperature: the Fukuoka Fisheries and Marine Technology Research Centre said that the seawater temperature at Fukuoka Prefecture has been one degree higher than usual this summer.

BBC reported that these species are classified as endangered in Japan, and their habitat is being destroyed. Despite being called crabs, these prized species, which are considered as one of the oldest creatures in the world and are prized for their blue blood, are not actually crabs - they are more related to spiders and scorpions.

Their blue blood have been harvested by scientists since the 1970s to test sterility of medical equipment and intravenous drugs, as their blood coagulates around the smallest amounts of bacteria and immobilizing pathogens. One litre of it can sell up to $15,000.