RSPB Mersehead Blog 16th - 22nd November 2024
Earlier this week, hundreds of strange-looking jellyfish washed up along the coastline at Mersehead. We had no idea what species of jellyfish they were, so we sought out help from the Solway Firth Partnership. Thankfully they were able to shed some light on this matter, informing us that these translucent, gelatinous blobs along the beach were in fact Dustbin-lid Jellyfish (Rhizostoma pulmo).
Rhizostoma pulmo at RSPB Mersehead. Photo credit: R. Chambers
Fascinatingly, Rhizostoma pulmo is the biggest jellyfish species found along the shores of the UK, reaching up to 1 metre in width and weighing as much as 35kg (this is equivalent in weight to an average-sized Labrador!!). Given this, it’s hardly surprising that Rhizostoma pulmo is often referred to as the Dustbin-lid Jellyfish or Barrel Jellyfish. In late summer, these jellyfish frequently wash up along the shorelines in this area, sometimes in large quantities as seen at Mersehead the other day. A fact I found particularly interesting about this species of jellyfish is that they are commonly consumed by Leatherback Turtles - the largest sea turtles in the world!! Now that these Dustbin-lid Jellyfish have washed up on the beach at Mersehead, they will instead be feasted upon by millions of Sand Hoppers.
Sandhoppers on the beach at Mersehead in September 2024. Photo credit: F. Sanders
Hundreds of Sand Hoppers feeding on organic debris on the beach at Mersehead in September 2024. Photo credit: F. Sanders
After this interesting discovery at Mersehead, I started to do further research into jellyfish and I thought I would share a few quick facts with you! Fascinatingly, jellyfish pre-date the dinosaurs, existing for around 500-700 million years. Amazingly, jellyfish survived all five of the main mass extinction events on Earth, and nowadays there are thousands of different species found across the globe. Six of these are commonly sighted around UK coastlines, for example the Moon Jellyfish, Blue Jellyfish and Lion's Mane Jellyfish. Made up of about 95% water, jellyfish are very simplistic organisms with no brain, blood, bones, or heart. Most species have a very short life span ranging from smaller jellyfish that live for a few hours, to larger species such as the Lion's Mane that can survive for a few years. I hope you've learnt something new after reading this and aren't feeling too "jelly" of this cool sighting we had at Mersehead!!
Bruiach Hide Closure and Footpath Closure
Please note that Bruiach Hide and footpath will be CLOSED on Monday 25th November. This is because we will be starting works to upgrade the footpath to the hide. Works will continue over the course of the winter therefore the path will be reopened whenever it is safe to do so. Apologies for any inconvenience caused.
Freya Sanders, Assistant Warden
*Flooding - Please note that Mersehead nature reserve is prone to flooding during periods of high rainfall and/or strong winds and tidal surges. To avoid disappointment at these times, please contact the reserve in advance of your visit by email in the first instance at mersehead@rspb.org.uk or check the RSPB Dumfries and Galloway Facebook Page for daily updates.