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Andy Horton spends a year examining the biology and behaviour of the rock pool fish and other marine life.

 
 
 

     Green Ormer
 

Common Name(s):   Green Ormer    Ormeau Scientific Name:   Haliotis tuberculata  Family:   Haliotidae (Ear-shells or Abalone) Usual Size:  to 120 mm long Photograph  by Sue Daly

Identification: The Ormer is a single-shelled gastropod that crawls (limpet-like) over the rocks feeding on algae. It remains attached by a powerful green foot and shows a mantle of green. A curved line of round holes  is distinctive and white parts of the mantle occasionally protrude from largest of these.    Illustration by Chris Hicks (Northolt) The interior of the shell is a smooth nacre ("Mother of Pearl"). The outside is rough usually a dirty green or brownish colour. Occasional specimens could be red. The frilly margin running around the perimeter of the shell is called the epipodium. Similar Species:  Common Ormer, Haliotis lamellosa (Mediterranean Sea only). Links for Images: Jersey Molluscs (UK Conchology) Ormer  Feeding: Haliotis chump through vast quantities of macro-algae every night.  At the moment Ulva (Sea Lettuce) seems to be their favourite but they also like Calliblepharis, Palmaria and Cryptopleura (all reds).  A certain amount depends on what we can keep for a reasonable length of time in the tanks but most flat red or green algae seem suitable. by Jenny Mallinson (Southampton Oceanography Centre) Palmaria, the red seaweed that looks like a red Sea Lettuce is a favourite. The adult specimen fed extensively on microalgae. by Jenny Glanvill (Devon WWT). Juveniles eat microalgae, diatoms, bacterial film. Adults consume brown algae, including kelps, but will eat almost any seaweed.  Breeding:  In late summer. The sexes are separate and fertilisation is external. The larvae (trochophores) have a short  life of only 5 or 6 days in the plankton, which does not favour a wide dispersal. It takes over 3 years for the mollusc to attain a breeding size of 40 mm. (Is this the wild growth rate?) Their life span does not exceed 6 years. Habitat: This edible mollusc is well known from the Channel Islands. This is the northern limit of their distribution. They are found from the Mediterranean up the Atlantic coast of France and Portugal where they are commercially fished.  Up to 12 cm long, Ormers are found in shallow water underneath weed-covered rocks and boulders. Their muscular foot allows them a remarkable turn of speed when they need to escape from a predator or inquisitive diver.  For centuries ormers have been gathered by hand on the lowest spring tides, known locally as ormering tides, and are considered a great delicacy in the islands. by Sue Daly. Further information on Sue Daly's Channel Islands "Feature Creature on the Ormer". Click on the logo below to go to her site. Further information on the family Haliotidae is also found in the book "Living Marine Molluscs" from page 50. The rounded openings are used for the discharge of water from the mantle cavity after the oxygen has been extracted.  (from the Student's Guide to the Seashore by J.D. & S. Fish). About half the holes near the mantle end are closed and not in use. Report: A mystery animal discovered by Richard Huggett (Eastbourne) was originally identified incorrectly by Andy Horton as Haliotis tuberculata. It has now been found to be a foreign species but still an interesting discovery. Full Report This specimen (above) was found in a shell collection from Lancing, West Sussex, but it was probably brought back from abroad. The species has not been identified at the time of writing (16 January 2003).    August 1999 Ormer Decline "For the last three weeks now divers and snorkellers on the north coast have been finding freshly empty shells. I found about 30 over one weekend. Normally you may find one or two if you looked really hard. On a night dive recently I have seen lobsters eating dead ormers, something I've never seen before. Survey dives at various locations along the north coast have revealed the same results. Our fisheries department did some survey dives at the Minquiers reef which is off the south coast of Jersey half way to St Malo, and only found one live ormer. All very, very depressing. As you have probably realised we are all very fond of ormers down here and proud to have them in our waters. They have been gathered by locals for centuries with ormering and ormer casserole a part of the island's heritage. Jersey's Environmental Services Unit and the Dept. of Agriculture and Fisheries are looking into the problem. The same thing happened this time last year along the French coast with a large proportion of their population dying out. It is also happening there again this year and they fear that those that survived last year will die this year. On a slightly brighter note - I was in Sark yesterday diving with some people from Guernsey and it seems that so far neither of these islands have been affected." by Sue Daly (Jersey) The Ormer die off in Jersey is serious.  An article in the Guernsey Press on 2 September 1999 said "that Jersey may close its ormer fishery this winter".  The mortality is reported at 50 to 60%.  I spoke to Grey Morel at Jersey Sea Fisheries.  He said that this die-off started in Southern Brittany in 1997, reached northern Brittany in 1998, and now it is in Jersey in 1999.Guernsey is clear at the moment.An infectious agent has not been discovered. by Richard Lord (Guernsey) 29 January 2002 Jersey States (Government) discussed if the ban on fishing for ormers - Haliotis tuberculata should be lifted. This ban was put in place in 1999 when a mysterious virus (possibly caused by some sort of toxic algae , results have either not been found, or are yet to be made public) alledgedly killed many of the already overfished stocks in Jersey and France. The virus was found in France three years prior to Jersey and today it was reported that their stocks had recovered in France and the ban lifted there, although when I was in Brittany in November the ban was still in place in France, saying this several French fishermen where seen taking them in Jersey waters during the summer of 2001. Jersey stocks are reported as recovering slightly. Fishing for ormers takes place during the low spring tides that occur at the equinoxes, high pressure can make the tide draw about 2 feet more than predicted, and low pressure has the opposite affect (the tide actually pushes higher), fishermen go down to kelp covered boulders or reefs and mostly scour underneath the rocks with a long blunt hook, or turn over large boulders, there is an unwritten law that the boulders are always turned back to protect the marine life. Historical reports of ten tons being landed to the Jersey market and 30 tons being in the market come from the latter 19 century are reflected with personal catches before the ban being in 1999 being counted individually, a dozen per fisherman being the average or good ! The virus never reached Guernsey, which is said to be because the sea temperature is a degree or two cooler than the waters to the south.   The following are pieces from the "Bulletin of the Jersey Society in London" published in 1959 In 1673 an article was written "News from the Channel" referring to Sark it said ormers were eaten fresh or pickled, and it went on about the delights of this delicacy. In 1859 F.C. Lukis wrote about the use of shells as in furniture. "Although the demand for ormer shells is on the decline, one merchant has at least 15 to 20 tons in store" prices fetched 7/6 per cwt, the quantity bought to this merchant is 4 - 9 tons per season. The average weight of a normal shell is 23.9 gm, which would mean 42,500 shells per ton ( this would take 212,500 ormers to make 5 tons of shells!) in 1859 Jeffrey's writes "The principal use to which the shell now appears to be put to in the Channel Islands is to frighten away small birds from the standing corn, two or three of them being strung together and suspended from a stick so as to make a clatter when moved by the wind" I think the following was about Guernsey In 1923 T.A Stephenson carried out an investigation for the States. He stated that during the preceding 20 years catches had diminished from 10 to 14 dozen to only 3 dozen per head. At his suggestion ormering was suspended from 1924 to 1926. Report by Nick Jouault Eating: The mollusc is eaten in France and the Channel Isles. The rather tough flesh is first battered and tenderised before being fried. The flesh has an appealing sweet smell.  Collecting: Strict restrictions apply to the collection of this mollusc in the Channel Islands. Further Information: Abalone Facts http://www.fishtech.com/abfacts.htm http://hannover.park.org/Guests/Shells/Shell_Catalogue/Shell_Pages/ T/Shell_Haliotis_tuberculata_lamellosa.html Phylogeny of Abalone http://www.lam.mus.ca.us/~dgeiger/phylogeny.html The Epipodium of Abalone http://www.lam.mus.ca.us/~dgeiger/epipodium.html     Article: 25 April 1998 Weekend Telegraph. You 'orrible little shellfish Ormering in Guernsey.  Phylum:  Mollusca  Class:  Gastropoda  Order:  Vetigastropoda  Family:  Haliotidae Information wanted: Please send any records of this invertebrate, with location, date, who discovered it, how it was identified, prevalence, common name and any other details to Shorewatch Project EMail Glaucus@hotmail.com. Molluscs Page     All messages will receive a reply.    Shorewatch Project

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