REFLECTIONS ON A RARE BASKING SHARK ENCOUNTER
August 2020
Dr. Simon Berrow narrates his experience with basking sharks in the fall off West Clare. The species is often seen feeding in this area in the spring - but the seasonal timing of this experience was not the only unusual component...
© Chelsea Gray
SPECIES | History
Ireland has an important historic association with the basking shark through the earliest-published references. The first record was authored by William Henry in 1739. Of greater fame was the subsequent description made by Thomas Pennant during his tour of Scotland and Ireland's Bay of Ballyshannonin in 1772: “they inhabit most parts of the western coasts of the northern seas”. There is also written and archaeological evidence of the establishment of a whale and shark fishery with a rendering plant built by Mr Thomas Nesbitt, the inventor of the first swivel gun, in Donegal Bay in 1759 (McGonigle, 2008).
This seasonal fishery became an iconic symbol of indigenous maritime life on the western seaboard of Ireland (McNally, 1976). Its rich associations with Irish coastal heritage are represented in visual form by the film “Man of Arran” and in oral form by the old Gaelic proverb Chomh Sámh le Liamhán Gréine, meaning "as tranquil as a basking shark" (Daltaí na Gaeilge, 2008). As depicted in these cultural forms, the basking shark as a resource has been subject to limited periods of intense target fishing. In addition to Donegal's aforementioned basking shark fisheries, the best-recorded and largest basking shark fishery in the world was established off the coast of Achill, Co. Mayo. At its peak, the Achill fishery caught a total of 9,000 individuals between 1950 and 1964 (McNally, 1976). Basking sharks were traditionally prized for their liver oil; however, following a steady decline in liver oil prices, the species was later targeted for its large characteristic fins, which became a valuable asset in the Asian shark fin soup and ornamental markets. Prices were reported at US$ 1000- 2400 per shark at first sale in 2004 (Sims et al, 2005).
FIGURE 1.
Basking sharks have been exploited for centuries, leading to extreme declines in their regional populations. Several countries have now established protective policies for this species.
The last records of target fishing of basking sharks in Irish and EU waters occurred in 2006, undertaken by ships from the Norwegian whaling fleet. The Norwegian fisheries, like the Irish, have a similarly long historic relationship with this species, beginning in the early 1700s. Deck mounted harpoons were deployed in the early 1920s and utilised until the fisheries closure in 2006. According to catch records, Norwegian catches peaked between the 1950s and 1980s, with over 4000 sharks landed in a "good year". After 1998, this fishery only amounted to an EU quota of 100 tonnes of basking shark liver (or 250-300 basking sharks; ICES WGEF Report, 2008).
Basking shark fisheries were not unique to Ireland and the UK. A small commercial fishery was instigated off the coast of California in the 1940s and early 1950s with limited success (Squire James L., 1990). To the north in British Colombian waters, a government-sponsored eradication programme was initiated in the 1950s due to persistent shark entanglement in drift nets targeted for more economically-valuable species. Sightings since the programme ended in 1970 have been rare and usually of single sharks (CSAS, 2008).