Fisherman’s black tie reveals new species record for Guernsey waters

May 10th, 2011 by Richard Lord

Commercial fisherman Clive Brown pots for crab and lobster off Guernsey's south coast (click image to expand - ©RLLord)

In February 2011 Dr Waltraud Klepal, an electron microscopist in the Department of Cell Imaging and Ultrastructure Research at the University of Vienna, working in areas of interest to medical and biomedical researchers, sent an email requesting barnacle specimens.  The email found its way to Guernsey and was forwarded to Guernsey commercial crab and lobster fisherman Clive Brown.

Clive Brown places his pots in water up to 55 metres deep off the spectacular south coast of Guernsey.  During the warmer months crab pots become fouled with sessile organisms such as ascidians, bryozoans, crustaceans, hydroids and sponges.

Clive noticed that some unusual barnacles were growing on a black plastic tie that lashed part of his crab pot together.

Knowing of Dr. Waltraud Klepal’s request, in late April he cut off a 45 mm piece of this black plastic tie and brought it to me for photography.

The 45 mm long black plastic tie with colonies of barnacles on it brought to me by Guernsey commercial crab and lobster fisherman Clive Brown (click image to expand - ©RLLord)

Besides some small animals crawling on the surface of this colony of life attached to the plastic black tie there were clearly two species of barnacle – a stalked barnacle and an acorn barnacle.

The stalked barnacle was Scalpellum scalpellum.  Dr. Charles David of the Guernsey Biological Records Centre in St Peter Port wrote that the stalked barnacle Scalpellum scalpellum was last recorded in Guernsey waters by Ansted in 1862.  This is not to say that this species hadn’t been seen since then but its presence hadn’t been reported.  In searching a computer database I discovered that I had photographed this species on 25 August 2003 when it was attached to a small scallop that I had recovered from a trawl net.

Close-up view of the stalked barnacle, Scalpellum scalpellum, from one of Clive Brown's crab pots off the south coast of Guernsey (click image to expand - ©RLLord)

Dr. Paul Chambers from Jersey identified the acorn barnacles as Solidobalanus fallax.

Dr. Keith Hiscock from the Marine Biological Association in Plymouth confirmed this identification.

In 1995 the Journal of the Marine Biological Association (JMBA) of the UK published a paper by Professor Alan Southward on the “Occurrence in the English Channel of a Warm-Water Cirripede, Solidobalanus Fallax“.

Professor Southward wrote that Solidobalanus fallax was recorded for the first time in the English Channel off Plymouth at a depth of 44 to 56 metres.

Acorn barnacles, Solidobalanus fallax. One is open for feeding (click image to expand - ©RLLord)

This acorn barnacle, he wrote, lived off west Africa from Angola to Morroco and Algeria.  Up until this time it had not been reported from European waters.  Although he wrote that it was likely to have been unreported in Europe waters until its population increased possibly as a result of climate change.

Solidobalanus fallax, is newly recorded for Guernsey waters even though it is now increasingly common on crab and lobster pots off the coast of south-west England.  A JMBA paper, Habitat and distribution of the warm-water barnacle Solidobalanus fallax, published in 2004 stated this species “has the potential to be a serious pest of fish farming structures to the south of Britain.”

The paper also clarified the 1995 paper by Professor Southward stating “with one exception the species was unrecorded in Europe before 1980; it may have increased in abundance during recent years as a result of rising temperatures.”

“This barnacle is not found on rocks or stones, but settles on biological substrata, including algae, cnidarians, bivalves, gastropods and crustaceans. It also settles on plastic bags and nets, plastic-coated objects such as crab and lobster pots and octopus pots made of ceramic or plastic.”  Dr. Keith Hiscock wrote that this barnacle “loves plastic.”

Clive Brown and other Guernsey fishermen who spend their lives fishing have a keen eye for species that look different.  Clive Brown has recorded species new to the British Isles before but there are too few of us in the Channel Islands observing our changing marine environment and noticing the new species arrivals.

As our environment changes it behooves us to notice new species and report them to the Guernsey Biological Records Centre or MarLin in the UK so our changing environment can be monitored.

Dr. Paul Chambers from Jersey wrote “I suspect that we have quite a few of the recent invasive barnacles around here which are awaiting discovery.”

Dr Waltraud Klepal will be receiving Scalpellum scalpellum for her research.


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