There is an upside to climate change
But a positive side to modern climate change is that it may lead to a revival of our shellfish and the opportunity to develop fisheries for other warm water species, such as tuna, according to a Marine Institute report.
From the discovery of shells on archaeological sites, we know that periwinkles, cockles, oysters and limpets were an important source of food going back thousands of years. Oysters were abundant, with collectors reaping bountiful harvests in one famous fishery - Galway Bay.
Enormous overfishing - sometimes compared to the clearance of the Irish oak forests - almost wiped out stocks.
Richard Nairn, in his recently-published Ireland’s Coastline, wrote: “The rate of exploitation of native oysters in the 19th century was unsustainable and almost all the native oyster beds disappeared.”
Oysters are very sensitive to water quality and there have been problems in Cork Harbour and Bantry Bay due to pollution or algal blooms.
Perriwinkles are still widespread and collected by hand around the coast, mainly for bagging and exporting to France. A survey in the late 1990s found a growth in periwinkles in many areas, including the shores of East Cork and Waterford.
In the past, people mainly picked shellfish for home consumption. In Dublin, crowds flocked to strands and sold the fruits of their labour on the streets. Molly Malone was not alone.
Warmer seas, wetter winters, increased coastal flooding, more intense storms and geographic shifts in the range of key commercial fish species are just some of the challenges facing Ireland’s €3 billion marine industry, says the Marine Institute report.
The report isn’t all negative. It points out, for instance, that our location, on at the eastern end of the Gulf Stream and the southernmost temperature limits of many commercially important species makes us an ideal observatory for studying the implications of climate change on the marine environment.
Changes in the weather are opening up opportunities, Marine Institute chief executive Dr. Peter Heffernan believes.
“The recent deployment of a network of five weather buoys relaying back weather, wave and sea temperature information on a continuous basis also gives us a unique window on what is happening at sea,” he said.
Most scientists agree climate change will affect fish farming. Such change could have serious consequences for salmon production and could lead to an increase in harmful blooms, pests and diseases. On the other hand, increased temperatures could result in a longer growing season for shellfish.
Climate change aside, however, seas have been deteriorating much faster than expected in recent years, with pollution and overfishing being serious problems.
The EU Commission is developing a marine strategy to ensure Europe’s seas and oceans are safe, clean, healthy and productive. The North-East Atlantic, the Mediterranean and the Black Sea are three of the seven regions where fish stocks are in greatest need of recovery.
Threats also come from oil and gas exploration, shipping, coastal development, tourism and dredging for sand and gravel.
The report for the Marine Institute was written by marine environmental advisor Rick Boelens, Dr. Dan Minchin, of Marine Organism Investigations, and Geoffrey O’Sullivan, a senior member of the Marine Institute staff to inform discussions on a national marine strategy for the years 2006-2010.
It looks in detail at the evidence for marine climate change and the implications. It also makes a number of key recommendations aimed at minimising any effects and turning potential change to our advantage.
These include:
* Establishing partnerships with other European and Atlantic boundary countries to provide early warning of climate change effects;
* Developing and implementing a strategy and for assessing the positive/negative impact of new marine species likely to become established as a result of changes in climate;
* Extending the network of automated monitoring stations;
* Establishing a marine climate archive, combining historical and new information;
* Intensifying the measurement of deep ocean currents to the west and north of Ireland as a contribution to scientific understanding of current patterns and their effects on climate change.
* The establishment of an expert group to advise the government of findings from marine climate research.
