Time to catch on to fish struggling for survival

CLANNISHNESS runs deep among anglers who feel a local river or lake is peculiarly "theirs" even more so when the fish they catch is of a kind that can't be bought in shops and that most people have never even heard of.

Down on the lower Barrow just now, they have started spinning for shad, a plump and silvery fish with a beautiful blue back. It's like a large, rich herring, but very bony a Jane Grigson recipe suggests cooking for six hours in foil, to make it crunchy like a tinned sardine.

The twaite shad its fill name, is on its spring run from the sea into fresh water, to spawn.

For the first few thousand years, after the glaciers melted, it was all along the east coast as people began cluttering rivers with weirs, dams and locks, it was shut off from most of its spawning beds. Today, the only populations known to spawn in Ireland are those of the Barrow, Suir and Nore, and the Cork Blackwater.

The twaite shad, Allosa fallax, is one of the freshwater fish that we need to be concerned about precisely because, unlike salmon or sea trout, they exist on the margins of our awareness and interest.

There are more, than a dozen native species which are considered "vulnerable" or "threatened". Yet, as two of our fish experts told a European conservation symposium recently, very little is known about their biology, distribution or abundance.

Declan Quigley and Kevin Flannery pointed out that while several of the species are protected under European conservation legislation, specific care in Ireland is urgent and long overdue. The island has few enough native freshwater fish, compared with Britain and the Continent, and needs to care rather more about the biodiversity of our rivers and lakes.

The situation was underlined recently in the report on the environment published by the Environmental Protection Agency. Among endangered species it listed were three of the freshwater fish listed by Quigley and Flannery.

Two of them are further kinds of shad. The allis shad, very similar to the twaite in appearance and habit, is now so rare as to be almost a lost cause. A handful of records since 1960 put it in the Foyle, at two rivers in north Mayo, and in the River Corrib in the late 1980s, but still there's no, evidence that it ever spawned in Ireland.

The Killarney shad or "goureen", is a unique form of the twaite shad, dwarfed and landlocked in the lakes. Like that other veteran of pure but hungry waters, the freshwater pearl mussel, the shad is highly sensitive to organic pollution, so the clean up of Killarney's sewage problems may have come only just in time for the small lake population. Until, the work of a PhD student, N. O Maoileidigh, in the late 1980s, very little was known about them not even where they spawned.

To many Northerners, the idea that the pollan is now "endangered" will seem extraordinary since this small, silvery fish is still caught commercially in Lough Neagh and may, even now, number several million there. But it seems to be on the verge of extinction in Upper Lough Erne and is rarely found now in the lakes of the Shannon catchment, which was probably its route into Ireland after the last Ice Age.

The pollan is virtually the same fish as the Arctic cisco, found in Alaska, northern Canada and Siberia. In Ireland it is breeding at the southern limit of its range cut off from the rest of the world population. If the climate warms up, this could help to hasten it into extinction.

The trout like Arctic charr is another circumpolar fish of the salmon family that became isolated in Irish lakes after the retreat of the ice. Populations in some lakes have become extinct in this century Ennel, Owel and Neagh are examples and the charr in Lough Conn, once the epitome of a cool, clean western lake, have virtually disappeared in the last few years with the impact of pollution.

But new locations for charr are still being discovered and their conservation status remains merely "vulnerable". In two of our lakes Lough Finn in Donegal and Lough Coomasaharn in Kerry the charr have become dwarfed because of their environment, and the genetic integrity of the Irish populations is something ecologists prize. They fear the impact of smolt rearing operations in the charr lakes, and even the introduction of charr farming, with foreign strains of fish.

A surfeit of lamprey" may or may not have killed Henry I (how the phrase hangs on, and it's not even Shakespeare!) but few people in Ireland have seen one of these feel like creatures, which has a sucker for a mouth. As an adult, it latches on to other fish, such as sea trout and salmon, and bores into their flesh with a revolving disc of teeth.

It is listed among our indigenous and "threatened" species or rather, all three lampreys are, since there are separate forms in small streams, rivers and the sea. The sea lamprey may well be widespread, and even common in estuaries it moves into the rivers to spawn and there have been non migratory populations in Loughs Conn and Corrib. The major haunt of the river lamprey is thought to be around Lough Neagh.

Lampreys are examples of fish which figure in European conservation measures, such as the Habitats Directive and the Bern Convention, but which we know almost nothing about least of all, how "threatened" they are.

This is why Isabelle Kurz, at the Environmental Sciences Unit in Trinity College, Dublin, is looking for any information about the distribution and spawning areas of our lam preys, as well as the shad species, in a special study for the National Parks and Wildlife Service. Contact her at 01-6082403 fax 01-6719047.