A surprisingly salp-y summer!

The coastline around Cornwall is filled with weird and wonderful marine life that never fails to surprise – none more so than the recent invasion of a large number of small gelatinous creatures called Salps.

Salps off Porthcurno, image by Heather Hamilton, Cornwall Underwater

Salps are strange relatives of sea squirts that live in the open oceans filter feeding, often in chains. These chains create fairy-light like structures in the water.

Salps are rare visitors to Cornish waters – with usually only a handful of sightings reported at this time of year in Cornwall. However, when conditions are right, populations can reproduce and grow rapidly, creating huge booms. Thanks to recent conditions, Common salp Salpa fusiformis have become a common sighting in Cornwall’s waters in recent weeks.

Their gelatinous, barrel-shaped, transparent bodies are made of cellulose and circular muscles, which they are able to contract, pumping water rapidly through their tube- shaped bodies. Mostly herbivores, they feed on vast quantities of phytoplankton and are easy prey for pelagic snails, jellyfish, sea turtles, sea birds, and many types of fish.

Salps are said to possibly be the fastest growing multicellular animal, increasing their body length by up to 10% per hour, to reach maturity in just 2 days. The number of records flooding in this year in Cornwall are exceptional, with sightings from across the west and south coasts. In some areas where onshore winds have driven them into bays, they are accumulating in large numbers. This includes a sighting reported in Porthgwarra on August 28th of more than a thousand!

Cornwall Wildlife Trust’s Marine Conservation Officer Matt Slater said:

“It is incredibly rare to spot a Salp around Cornwall, let alone to encounter numbers like this and the spectacle that they create. It’s difficult to say what’s causing this population boom in our local waters. Various factors could be the cause, including wind direction and ocean currents, alongside environmental factors such as temperature or numbers of predators. It’s very exciting to see some of the numbers being reported and images that people are recording of them being sent in from all around the Cornish coast.

“We are keen to record as much information about this unusual spectacle as possible so please, if you do encounter this exciting phenomenon, make sure you report the sighting via our Orks website.”

Local wildlife photographer Heather Hamilton of Cornwall Underwater was snorkelling near Logans Rock, Porthcurno and encountered a large number of salps.

Heather said:

“My dad and I came across the salp bloom near Logans Rock, Porthcurno. We go out snorkelling together as much as possible and are blown away by the incredible marine life found on our doorstep.

“This evening in particular was very special. As we stepped into the water, there was an abundance of salps all around us. They swirled around and pulsated through the water. Some chains were metres long and covered every inch of the sea.

“It felt like we were in space and the salps looked as if they were stars in the sky. This incredible encounter was breath-taking and very special.

“Wildlife photography has been my passion since a very young age. I grew up in Cornwall and over on the Isles of Scilly. I have been lucky enough to be close to the sea and to be able to snorkel most days. I began taking marine photographs and became obsessed. It feels amazing to share wildlife stories with others and to be able to research into the diverse marine life we have in Cornwall.”