Lough Hyne in west Cork is in trouble and action is needed

Just a few Saturdays ago, Dr Colin Little and his wife, Penny Sterling, stepped out of the coach house they had been staying in beside Lough Hyne, got into their car and drove down the lane where the northern shore comes into view. It was early morning and the usual hordes of kayakers, wild swimmers and tourists had yet to appear. The lake looked as it did when the couple first visited it in 1979: quiet, calm and serene. They said goodbye to it for the final time and left.

It was a poignant moment. Now in their 80s, Little and Sterling have dedicated four decades to researching the lake; that morning, it was like saying goodbye to a dear old, sick friend. What’s going on underneath the water is, they say, “disastrous”.

It wasn’t always this way. When Little first travelled to Lough Hyne from his home in Bristol in the late 1970s, he was amazed at what he saw. Just a few kilometres southwest of Skibbereen in West Cork, Lough Hyne is a rare, remarkable thing: a kind of deep sea-lake that, historically, has been a hotbed of biodiversity. It used to be a freshwater lake, but about 4,000 years ago, rising sea levels allowed the Atlantic seawater to break through a narrow, thundering channel called “the rapids” at the southern end, turning it salty.

Lough Hyne is like an enormous, sheltered rock pool which stands alone in low-lying hills. Nearly 75 per cent of all marine life is found within the lake, and for marine scientists who are used to battling storms, tides and high winds, it is a Godsend. It’s so extraordinary that in 1981, following lobbying from An Taisce, it was designated Europe’s first marine nature reserve.

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Not surprisingly, its uniqueness has captured the attention of many scientists, going back to the Youghal-born naturalist William Spotswood Green in 1886. After him, a long line of researchers followed.

Funded by their own money, they have packed their car in Bristol with boats, oars, waders, survey equipment, waterproof paper and pencils, pots and pans and travelled to Lough Hyne to conduct this annual census of life

In 1979, Little and Sterling took the baton from a Bristol-based zoologist, Jack Kitching, born in 1908 into a Quaker family in York, who first visited Lough Hyne in 1938. It was a trip that changed his life, and following the end of the war in 1945, Kitching organised annual expeditions to the lake and established a series of monitoring and research stations along its shores. (Kitching’s trips continued for 40 years, and a phenomenal amount of data was amassed.)

Little, a marine biologist, and Sterling, an electron microscopist, remember Lough Hyne back then as being exotic and otherworldly, set in a wild and charming countryside with small, windy roads on which donkeys and carts travelled to take the milk from the farm to the local creamery.

Each September for the past 40 years, Little and Sterling have continued Kitching’s work and used his sites as the basis of their surveys. Funded by their own money, they have packed their car in Bristol with boats, oars, waders, survey equipment, waterproof paper and pencils, pots and pans and travelled to Lough Hyne to conduct this annual census of life, from the limpets, winkles and mussels, to the variety of seaweeds, sea mats and top shells.

Final survey

Last month, they completed their final survey, and the results will be published next year. Using their 40-year data set and historical research as far back as 1886, Little and Sterling see the extent of the decline of life in the lake. Life is draining away. It is, says Little, “very sad”.

Take the pincushion-shaped purple sea urchin. When they started counting them in the late 1990s, Little and Sterling logged 2,000 urchins on one stretch along the northern shore. Today, they say, they’d be lucky to find three around the lake. This urchin tells us something about the water, because it’s intolerant to pollution and low oxygen levels. The pressures on it are unrelenting, including disease, illegal poaching and an excessive amount of nutrients in the water. The population in Lough Hyne will now only recover with improved water quality and a restocking programme.

[ Another Life: Anemones, urchins and, in Lough Hyne, the richest rock pool in Ireland ]

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It’s a similar story deeper down in the lake, where the sea sponges live. Between 1990 and 2019, they have shown a marked decline, driven by too many nutrients in the water and an increase in temperature.

Nitrates are seeping from farmland into the water, causing algae to grow, sucking up the available oxygen and suffocating other life. According to scientists, the source of nutrient runoff in Lough Hyne is the seawater along the entire Irish southwest coast.

The public could be forgiven for not comprehending the scale of loss in Lough Hyne. Although it is the most studied marine site of its size globally, the research – much of it publicly funded – is kept in scientific journals behind expensive paywalls

The pressures from human activity are everywhere. Like nearly every nature reserve in the country, especially post-Covid, Lough Hyne attracts thousands of people. The northern shore, say Little and Sterling, is “pretty much dead” because so many people use it day and night for recreation.

The public could be forgiven for not comprehending the scale of loss in Lough Hyne. Although it is the most studied marine site of its size globally, the research – much of it publicly funded – is kept in scientific journals behind expensive paywalls. The value of such a long data set is lost if only a select few can access it.

Given it’s a marine reserve, the Irish State has clearly failed to uphold its legal responsibility to protect the lake. Little and Sterling believe that the first step is for the authorities to immediately bring together the stakeholders – the farmers and kayakers, sea swimmers and tourist operators, landowners and local residents, nature lovers and scientists – to agree on a management plan.

This may be the only way to help Lough Hyne to recover to full health in the future.