Sea Stars are Melting!

 Multiple types of bacteria living just millimeters away from sea stars are depleting oxygen from the water around them and the sea stars. These microbes thrive in warm waters with high levels of organic matter As a result of insufficient oxygen, sea stars begin to "melt" into a puddle of slime. This phenomenon was previously named the Sea Star Wasting Disease, identified as lethal symptoms of decaying and loss of limbs in sea stars. It was first noticed in 2013 when sea stars off the U.S. Pacific coast were dying off in large numbers. Though it was originally thought to be caused by a virus or bacterium, no link was ever found between the suspected virus (the subject of another 2014 study in a virus making various animals ill) and dissolving sea stars. The truth was discovered by a team of marine biologists at Cornell University that examined the types of bacteria living around healthy seas stars as compared to those living around ones with wasting disease. Seas stars were found to begin wasting away when researchers added phytoplankton or common bacterial-growth ingredients to warm water tanks containing the seas stars, copiotrophs (bacteria that thrive in environments with a lot of nutrients), and a bacterial species known to thrive in low oxygen environments. Depleting oxygen in the water had nearly the same effect. Since seas stars breathe by diffusing oxygen over small external skin gills, the lack of oxygen and flourishing copiotrophs essentially suffocate the seas stars- causing them to degrade in a way that could be due to massive cell deaths. The disease is not contagious, however it is somewhat transmissible considering that dying sea stars generate more organic matter that encourages bacteria to grow on nearby healthy animals. Climate change may worsen the issue as water temperatures continue to rise. Luckily, scientists have found a way to combat the disease by increasing oxygen levels within the water tanks at research facilities, and getting rid of excess organic matter through ultraviolet light or water exchange.

This threat to one of the more well known and beloved seas creatures is a rather tragic consequence of the times. With global warming increasing yearly, waters will only get warmer and many more of our five legged friends may find themselves dissolving as a result. The mass death of seas stars not only threatens marine biodiversity but also eludes to a potential decrease in environmental health as more bacteria and microbes thrive under condition many other species cannot. Economically speaking, it may be in the best interest of researchers to get a good idea of how to control these low oxygen-consuming bacteria before they begin affecting other species, such as fish, and the fishing industry gets affected. Seas stars and other sea floor dwelling creatures already face enough threat from the bottom trawling of mass fishing- therefore id is vital researchers understand this bacterial disease better to help save the sea star species.

https://www.sciencenews.org/article/bacteria-suffocating-sea-stars-wasting-disease-goo