Major Stranding of Sepia elegans in North Wales

Tom Clifton

On the 4 June 2005, I found one small cuttle bone of Sepia elegans at Porth Daffarch on the south west coast of Anglesey. I have seen them before on rare occasions in this area but usually they have been too fragmented and beach worn to enable accurate identification. This one however was not only nearly perfect, it was also a juvenile. Three weeks later on 2 1/6/05 at the same location and also at Trearddur Bay nearby, they were found to be common. Over the next few days, specimens were found at three other locations on southwest Anglesey.

It was not until mid July whilst on holiday in Barmouth, where I found them also present and common on the upper drift line at Lianaber just north of Barmouth, that the extent of the stranding was realised. On my return home I decided to make a whistle stop tour of all of the easy access drift lines on the Lleyn Peninsula to see if they were present there also. Out of the 20 sites visited (it was a very long day), Sepia elegans was found to be present at 16 locations on the upper drift line and ranging from frequent to rare. After making other searches since in the Anglesey and Liverpool Bay areas where they have been recorded pre 1991, they have been found to be present at 25 locations between Porth Daffarch and Barmouth, and may well, have extended further south.

Sepia elegans is a new record for sea areas S23 Anglesey and S22 Cardigan Bay though on this occasion they were not found at the sites visited around Llandudno in the Liverpool Bay sea area.

In most cases, the specimens consisted of 50% adults and 50% juveniles, the smallest being 11mm x 29mm and the largest fragments 29mm wide. The average juvenile was about 16mm x 54mm. The best specimens were the juveniles as many of the larger ones were broken. The picture shows a cross section of what was found.

The stranding also coincided with unusually large numbers of Sepia officinalis, which is generally common in these areas. These again consisted of 50% adults and 50% juveniles, in fact, the event has produced more juvenile Sepia officinalis than I have seen in 30 years of shell collecting. The map shows the coastal area effected.

The specimens found on 4/6/05 and 21/6/05 were on the most recent drift lines or not much higher than that. After 28/6/05, all the specimens found were on the uppermost drift line with nonlower down the shore. This suggests that the stranding occurred over just a few days in early June 05 and is not an ongoing occurrence throughout the summer. The proportions of adults and juveniles of both species are interesting as it suggests a very large number of animals moving in one group with adults and juveniles together. At some locatjons such as Abersoch, Pwllheli, Criccieth, Shell Island etc. there were so many holiday makers about that the upper drift line had been trampled out of recognition, and therefore no specimens were found there. So far, there have been no further strandings of Sepia elegans, though the occasional Sepia officinalis is still beached from time to time.

Because of the degree to which Anglesey and the Lleyn Peninsula project out into the Irish Sea, they do make good collecting areas from time to time for unusual species carried up from southern regions. One good example is Velella velella, which will be the subject of a later article. Sepia elegans is not very widely distributed throughout the British Isles, and as I have a fair number of spare specimens, anyone who would like some can contact me on Clifton, and I will be pleased to provide them with some.