00:00 Saturday 14 June 2008  Written by Nic Slocum

Conservation or preservation which works?

The word conservation means different things to different people. In 1975 I was involved in a captive breeding programme for one of the world's rarest antelopes, the Addax. Small, timid but immensely beautiful these small ungulates had been driven from their wild ranges through indiscriminate hunting, mining disturbance and prolonged drought reducing their foraging range. Some 200 animals still survive in the more remote areas of Chad and Niger. Captive breeding has resulted in numbers of little more than 1,000 animals resulting from locally organised conservation initiatives.

So does this captive breeding programme constitute a conservation success? Regrettably not! It is simply preservation and has done nothing to remove these animals from their critically endangered status with continually decreasing numbers and inevitable extinction! Conservation is the preservation of species within the framework of intact plant and animal ecosystems on which interconnected species may rely for food or shelter. In other words habitat maintenance and removal of threats is an integral part of any conservation objective. Simply preserving one species in isolation, whilst the intention may be laudable, is pointless unless they can be reintroduced into the wild as part of a habitat reconstruction and biodiversity restoration programme.

Interesting, I hear you say! A small antelope with a name more like a proprietary drain cleaner than that of a critically endangered mammal, but what does it have to do with marine conservation? Absolutely everything! Marine ecosystems differ from terrestrial environments in two fundamental ways. The effects of pollution, indiscriminate hunting and habitat destruction are less visible in marine environments and their impacts on the overall ecosystem less easy to measure. It is also nigh impossible to reintroduce captive bred species into marine ecosystems, except perhaps in the case of seeding programmes for crustacean species. This means that when we know marine environmental damage is occurring, or is likely to occur, we must err on the side of caution and ensure remedial action is taken sooner rather than later. West Cork's marine environment, as indeed much of Ireland's coastline, is under enormous pressure but still maintains reasonable biodiversity within ecosystems. It is therefore of paramount importance that we don't, like the poor Addax, wait until the point of no return but act now to ensure the conservation status of key marine species is maintained.

This came home to me this past May holiday weekend as we all enjoyed balmy sunny weather and calm seas and an influx of those leviathans of the deep, basking sharks. Along the south Cork coast from Cape Clear to The Old Head of Kinsale we had sightings and received further reports of these completely harmless giants, the second largest fish in the world. Notable hotspots included Galley Cove and Sands Cove at the Galley Head to the east and Barlogue Bay, The Kedges and Sherkin Island to the west. These early summer sightings are part of a treasure trove of wildlife spectacles for which West Cork should be justly proud and as part of the greater coastal marine ecosystem must be vigorously conserved. Locals and visitors alike were out in force in their kayaks, speedboats, jet skis and sailboats enjoying the spectacle - as were we. At one point, however, it did occur to me that the fish might not be enjoying the attention, as there was some clear avoidance behaviour and I had the feeling we might all be stressing the animals unduly with the risk of collision a possibility.

The basking shark is an elasmobranch, one of two subclasses of cartilaginous fish comprising rays, sharks and skates, their supporting skeleton being cartilage not bone. Elasmobranches are part of an ancient class that was patrolling the world's oceans when man's arboreal ancestors were swinging from the trees. Although these huge fish do have small teeth, thought to be used by males when gripping the females during mating, they are not used for feeding. This is achieved by passing plankton-laden sea water through the mouth, over the gill arches and out through the gill slits so visible as the animals turns away from you. The mucus-covered gill arches trap plankton and show up white as the animal turns towards. A large animal will pass enough water over their gills in an hour to fill an Olympic swimming pool!

Perhaps the characteristic that endears them to us more than many fish is they give birth to live young. They are ovoviviparous and the developing young are not physically attached to their mother as in placental mammals but are sustained initially by a large yolk sac, later feeding on unfertilised ova. Development may take as long as two years. Originally thought to lose their gill rakers and slow down, even to hibernate, it is now known from recent studies that basking sharks continue to feed through the winter months, seeking out deep water plankton up to 900 metres deep, covering thousands of miles in search of their microscopic prey.

Man's interaction with these magnificent gentle creatures has not always been so benign. In Ireland the Achill Island basking shark fishery took nearly 13,000 animals over 25 years, largely for their liver, a monstrous organ that weighs a quarter of the body weight and runs the length of the abdominal cavity. It is considered to play a role in energy storage and buoyancy regulation. Although no longer seriously at risk in Irish waters, this cosmopolitan species is IUCN listed as vulnerable and at risk of extinction largely due to the trade in shark fins for the soup trade.

It would be a hard man who is not moved when encountering these gentle, harmless creatures as they glide through our coastal waters. Occasionally witnessing the unusual breaching behaviour as we did over the long weekend off Carrigcleamore, east of Sherkin Island when a 6-metre shark launched itself clear of the water in a rare double breach - breathtaking by any measure. It would be a sad day if this beautiful elasmobranch failed to grace Ireland's shores during the early summer months. It has happened before though.

Talking to the wise men of West Cork's coastal communities it would appear that basking sharks were a regular sight in the early seventies after which there was a steady decline in numbers with several years where few sightings were made. Certainly, 2007 and 2008 have seen significant increases in basking shark activity along Cork's southern coastline compared with the previous four years during which we have been keeping records.

The complex environmental conditions that result in an influx of basking sharks may be poorly understood but the greatest threat to these slow-moving animals while they are in Irish coastal waters is noise disturbance and ship strike. This is from the very boats we use to go and view them, so we must be aware that without care our desire to view the unusual may result in their significant disturbance and possible damage. If we appreciate that then we need to ask ourselves the searching question: Do we value basking sharks' presence in West Cork waters? If yes, then implement the conservation principles that will reduce disturbance to a minimum and adopt a "leave no trace" approach by minimising noise, reducing speed and lessening your personal impact.

Past experience shows that credible conservation initiatives rarely come from above; they come from below through concerned individuals who take pride of ownership and view their natural heritage as a privilege to be cherished.

Column may be contacted through www.whale.ie

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