Turtles, eels and toads endangered

THE solstice is a time to take stock and make new resolutions.

The National Parks and Wildlife Service, with the help of organisations north and south, reviews conservation progress regularly.

Red List No. 5, its health assessment of the amphibian reptile and freshwater fish populations, was issued recently.

Ireland is poorly endowed with such creatures, all the more reason to cherish the few we have. So how are our cold-blooded vertebrates doing? It’s a varied picture.

Of the 151 reptile species found in Europe, only two are native to Ireland. There are no size estimates for the common lizard population but, with no evidence of a decline in numbers, it remains in the ‘least concern’ category both here and globally. The leatherback turtle, the world’s heaviest reptile, breeds in the Caribbean and visits our waters in summer. It’s ‘critically endangered’ internationally but numbers around Ireland are increasing. We receive, the authors estimate, ‘2,500 migrants per year, approximately 2%-3% of the North Atlantic population’. A jelly-fish eater, the leatherback swallows plastic bags which block its food canal. Unable to feed, it starves to death. Long-line fisheries are another threat.

Amphibians face problems worldwide. Of the 85 European species, three occur here. Our common frog and smooth newt populations are thought to be stable. Natterjack toad numbers, however, fell during the 20th century, mainly through habitat destruction. The decline seems to be halted now and the toad, hopefully, is holding its own. Placed in the ‘least concern’ category in Europe, it is deemed to be ‘endangered’ here.

When the ice sheets melted 10 millennia ago, fish species able to survive in both fresh and salt water colonised Irish rivers and some became isolated in lakes. There are 15 on the list of which the salmon, trout and eel are the best known. ‘Coarse’ fish, such as pike and perch, were introduced by man. Listed only because their status may be ‘relevant to the conservation of native fish and .. freshwater systems’, they appear in a separate poor-relations section of the report. In all, we have 29 freshwater fish species, compared to 55 in Britain and 236 in Europe.

All of the non-native fish receive ‘least concern’ ratings. Some of them are doing too well; perch and dace compete for food with brown trout. Dace, introduced to Ireland in 1889, eat trout and salmon fry. The native fish, generally, are faring less well. The sea lamprey, the notorious ‘lamper eel’, is not in trouble globally but gets a ‘near threatened’ designation here. Pollution resulting in fish kills, habitat loss through dredging and the disruption of fish movements by weirs may be factors.

The allis shad, a relative of the herring and sardine, enters the “three sisters”, Barrow, Nore and Suir, to spawn. It also visits the Slaney, the Munster Blackwater and the Foyle. It used be classed as ‘endangered’. The twaite shad, the ‘bony horseman’, occurs in estuaries more generally and is deemed ‘vulnerable’. It frequented the Liffey up to the 1960s and was recorded in the Boyne in 2010. The Killarney shad, found only in Lough Leane, is also on the ‘vulnerable’ list. About 20,000 individuals of this Irish sub-species remain.

“It is clear that the pollan is unique to the Irish vertebrate fauna,” declare the authors. Regarded as ‘vulnerable’ here, it’s endangered globally. The decline of salmon stocks since the 1970s has been well documented. The species receives a ‘vulnerable’ designation.

The really sick man of the fish world, in Ireland and globally, is the European eel. The numbers of ‘glass eels’ arriving from the Sargasso Sea have fallen to less than 7% of pre-1980 levels. This species is now ‘critically endangered’. Climate change leading to alterations in sea temperatures and changes in ocean currents may be to blame.

* Ireland Red List No. 5 Amphibians, Reptiles & Freshwater Fish by J. King, F. Marnell, N. Kingston, R. Russell, P. Boylan, J. Caffrey, U. FitzPatrick, P. Gargan, F. Kelly, M. O’Grady, R. Poole, W. Roche & D. Cassidy. NPWS.

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