Lion's mane jellyfish are appearing near the surface thanks to a perfect combination of water conditions. Image by Cheryl Costello.

VIDEO: Why are Jellyfish Appearing En Masse on the Bay?

If you’ve been at the water’s edge on certain Chesapeake Bay tributaries this week, you may have noticed something unexpected: a whole mess of jellyfish. What are they doing here in late March, and why do they look different than the ones that sting us during swims in the summer?

Cheryl Costello finds out from the experts. Watch below: