The Marine Geography of Cork Harbour

 

 

Taken from Atlas of Cork City - The Challenge of Change

Contemporary Marine Geography of Cork Harbour

Valerie Cummins and Vicki O Donnell (2005)

 

 

As one of the finest natural Harbours in the world, Cork Harbour (Figure 1) has shaped the history and lives of the people of Cork City and surrounding towns and villages such as Blackrock, Cobh, Monkstown, Passage West, Whitegate and Aghada, amongst others.   The topography of the landscape is gently undulating, with a mixed coastline consisting of built infrastructure, shallow cliffs, intertidal mudflats, reedbeds, shingle and rocky foreshores, which are exposed by the tide.  The bathymetry of the Harbour reflects the morphology of the coastline, with gentle slopes dropping to a depth of 28m near the mouth of the harbour (11m in the channel which is maintained at that depth for navigation). 

 

 

 

Figure 1. An aerial view of the Cork Harbour showing the city centre (top left), Haulbowline and Spike Islands (centre) and Roches Point at the east entrance to the Harbour (bottom) (OSi).

 

 

It’s sheltered environment and deep-water channels make Cork Harbour an ideal location for shipping and boating activities. The physical geography of the Harbour on the south coast of Ireland provides a strategic location for the Port of Cork situated in close proximity to the main shipping line to Northern Europe.  The Port of Cork, the second most important port in the Republic of Ireland, provides significant economic contribution to the southern half of Ireland, handling just under 10 million tonnes of traffic in 2002 (Moloney, 2003a).  More recently, Cork Harbour has become a primary destination for cruise liners, which berth in the heritage town of Cobh with its poignant history linked with the Great Famine and the Titanic.  Cruise liner facilities at Cobh can provide berthage for ships up to 280 metres in overall length (Figure 2).  2003 saw a 25% increase in vessel numbers to 33 cruise ships between May and October, with cruise traffic at the Port of Cork providing €14 million per annum to the regional economy (Moloney, 2003b). 

 

 

Figure 2. A visiting cruise liner to Cobh. The scale of the ship highlighted by comparison to Cobh’s Cathedral, normally the most imposing sight in the town (Valerie Cummins).

 

From a contemporary industrial perspective, Cork Harbour offers employment for people from all areas of the city through the chemical and pharmaceutical industries that are concentrated mainly in the Little Island and Ringaskiddy regions.  The Harbour also contains Ireland’s only oil refinery situated at Whitegate.  The presence of the Kinsale gas fields, almost 50km off the Old Head of Kinsale, have resulted in the location of many exploration companies in the Harbour over the last 30 years, including Conocco Philips, Shell and Marathon among others.  More recently the Port of Cork has been servicing the new Seven Heads Gas Field located in the Celtic Sea.  Gas from the Seven Heads, to be brought ashore at Inch Terminal near the entrance to Cork Harbour, has the potential to supply in excess of 10% of Ireland’s current gas demand.

 

While contemporary use of large tracts of the Harbour is marked by concentrations of urban populations and widespread chemical and pharmaceutical industries, much of the coast remains unspoilt and characterised by rural agricultural land use or protected habitats, which remain uninfluenced by human activities. Thus, a tour around Cork Harbour will reveal a whole suite of interesting man made and natural features, influenced by history and the Harbour’s link to the sea.

 

Landmarks include Camden Fort (renamed Fort Meagher, 1938) on the west side of the Harbour entrance, flanked by Carlisle Fort (renamed Fort Davis, 1838) on the east side.  These forts, along with installations on Haulbowline Island, Spike Island, Rocky Island and Fort Templebreedy present an insight into the British military presence that shaped the Harbour until the British Royal Navy finally withdrew from in 1938.  Haulbowline Island is now the home of the Irish Naval Service (Figure 3), while Spike Island contained a detention facility.  Cork Harbour is steeped in local history, much of which has been documented in published format (Barry, 1999a; Barry, 1999b; Barry,1895; Broderick, 1994; Brunicardi, 1982; Brunt, 1980; Dennehy, 1990; O Mahony, 1986 ). There is also a plethora of unpublished anecdotal stories and folklore material, including audio and visual archives relating to the Harbour, which provide a sense of its maritime heritage and culture. Such resources range from material relating to the city dockers to the Cobh liner trade of the earlier 20th century. 

 

 

Figure 3. A Naval Service Guard of Honour on Haulbowline Naval Base. (Mick Mackey).

 

 

For natural history enthusiasts, the entire Cork Harbour is of major international importance for waders (20,000) and wildfowl (5,000), particularly winter migrants, which are supported by its extensive mudflat areas around Lough Mahon, the Douglas Estuary and the North Channel, Lough Beg, Saleen, Rostellan and Whitegate.   Cork Harbour hosts the largest number of wintering birds in any area on the east and south east coasts of Ireland.  It is designated as both a Special Protection Area for birds and a Ramsar site of international importance for this reason (Figure 4).  Other designations within the Harbour protect important habitats of salt marsh, reedbed and intertidal mudflat.  They include proposed Natural Heritage Areas (Douglas Estuary, Great Island Channel, Lough Beg, Rostellan Lough/Aghada Shore/Poulnabibe inlet, Whitegate Bay, Cuskinny Marsh), and candidate Special Areas of Conservation (Great Island Channel).  The River Lee is also designated as a salmonoid river under the EU Freshwater Fish Directive.  This implies there is an obligation to maintain specific water quality standards and to control pollution in this area.   Protected fauna include the otter (Lutra lutra), the grey seal (Halichoerus grypus) and the common seal (Phoca vitulina).  Cetaceans such as common dolphins (Delphinus delphina) and bottlenose dolphins (Tursiops truncatus) are occasionally sighted in the Harbour.  In Summer 2001, the arrival of a pod of three Orca whales (Orcinus orca) in Cork Harbour attracted great attention from local spectators and national media. 

 

 

Figure 4.  EU designated areas in Cork Harbour. The darker areas show population hotspots in relation the areas that are protected (Vicki O’Donnell).

 

 

The main fishing resources within the Harbour include angling for salmon, trout, coarse fish and sea fish, oyster and commercial salmon and eel fisheries.  The Harbour waters supply important spawning and nursery areas for sea fish species.  Draft netting operations occur in the Harbour, and are located in areas traditionally known for their salmon movement.  The main salmon and trout bearing rivers are the Owenacurra, the Glashboy, the Lee and the Owenabue.  The coastal scenery around much of Great Island, including Fota, provides scope for many other recreational activities centred in the Lower Harbour such as sailing, walking and golfing. The general trend towards increased expenditure on leisure activities within Europe can be seen in the significant growth in the number of recreational boats located in Cork Harbour, with increases in the numbers of moorings at popular havens such as Crosshaven (Figure 5), Monkstown and Aghada.  Cork Week, which is held in Crosshaven every second summer, generates significant revenue for the local economy, is one of the most significant sailing regattas in European waters and has a reputation as a world class sailing event (Shields et al, 1997).  

 

 

Figure 5. Crosshaven, Home of the Royal Cork Yacht Club, the oldest sailing club in the world, which was founded in 1720 (Vicki O’Donnell, OSi)

 

 

Table 1.  Some seasonal visitors to Cork Harbour Special Protection Areas (SPAs) and Ramsar sites.  Annex 1 bird species are highlighted in blue.

 

SEASON

BIRD SPECIES

All year

Mute Swan, mallard, Oystercatcher, Curlew, Kingfisher

Winter

Slavonian Grebe, Black-necked Grebe, Little Egret, Bewick’s Swan, Whooper Swan, Canada Goose (feral), Wigeon, Gadwall, Teal, Pintail, Shoveler, Pochard, Tufted Duck, Scaup, Goldeneye, Red-brested Merganser, Golden Plover, Lapwing, Black-tailed Godwit, Bar-tailed Godwit, Mediterranean Gull, possible Glaucous Gull.

Spring

Whimbrel, terns.

Summer

Breeding Ringed Plover, Common Tern.

Autumn

Passage waders including possible Little Stint, Curlew Sandpiper, Ruff, Spotted Redshank, Green Sandpiper, Wood Sandpiper, Common Sandpiper. Migrating Terns.

 

Anthropogenic influences

 

Pressures which influence the condition of Cork Harbour stem largely from human activities including coastal development; waste disposal; coastal agricultural; increasing recreational use of the Harbour, transport and over exploitation of natural resources including fisheries.  Changes in key indicators such as the extent of loss of natural habitat over time can be evaluated to determine the level of degradation of harbour resources from these influences.  Loss of natural habitat to development can be identified utilising satellite imagery, such as the Landsat image of Cork Harbour in Figure 6 which highlights urban versus rural land uses around the Harbour.  Figure 7 shows the results of a shoreline inventory of Cork Harbour carried out in 2003 where over two thirds of the shoreline is dominated by man made structures such as sea walls and rock reinforcements (O Donnell & Cummins, 2004). This shows a significant impact on the nature and shape of the shoreline of Cork Harbour.  Many of these defense infrastructures are in a state of disrepair and are inadequate for current coastal defense needs. 

 

 

Figure 6. A Satellite image of Cork Harbour. Areas in bright green show concentrations of residential building and industry including quarries and Cork Airport, with the runway visible (left centre). Areas in red show vegetation, predominantly farming areas (Vicki O’Donnell, Eurimage).

 

One of the most visible indicators of environmental quality within the Harbour is water quality.  Water quality is threatened by a number of factors, most significantly by nutrient loading  of phosphorous and nitrogen from agricultural runoff, sewage and industrial discharges.  Excessive nutrient loading from the River Lee is an ongoing problem especially in Spring and Summer, leading to algal blooms which can have detrimental effects on the condition of fish stocks within the harbour.  The eutrophication (the process by which a body of water becomes excessively rich in dissolved nutrients resulting in increased primary productivity that can lead to a deficiency in dissolved oxygen) is mainly due to the intensive farming that is practiced in the large catchment of the River Lee (EPA, 2004). 

 

Expected improvements in the water quality of the upper Harbour regions will be derived from the completion of the Cork Main Drainage Scheme,  (initiated in response to the EU Urban Waste Water Treatment Directive), one of the largest engineering and environmental projects undertaken by a local authority in Ireland.  Nevertheless, threats to water quality remain a concern in Cork Harbour, where careful monitoring and regulation is needed to control effluents arising from the Harbour industries. 

 

The potential for conflict between the different plans for Cork Harbour is epitomized by a proposal to build a hazardous waste incinerator in Ringaskiddy.  Many residents feel that the location of such a facility would conflict with plans to embrace the redevelopment and restoration of the Lower harbour as an outstanding natural amenity.  Implementation of this vision has commenced with the location of the new National Maritime College at Ringaskiddy which emphasises the importance of the Lower Harbour as a hub of maritime expertise and activity.  Further planning challenges exist with the recent closure of ISPAT (formerly Irish Steel) in Ringaskiddy and Irish Fertiliser Industry in Marino Point. The remediation and future treatment of these brownfield sites has the potential to influence the future character of  the Lower Harbour.

 

Natural variation

 

The Inter-governmental Panel on Climate Change (IPCC) has presented the most generally accepted scientific argument that climate change is occurring, with predictions of a global temperature increase of between 1.4 and 5.8 degrees by 2100 (IPCC, 2001).  Sea levels will rise as a consequence of the melting Arctic and Antarctic ice caps and thermal expansion associated with warmer water temperatures.  However, studies indicate that increased impacts from storminess are likely to be of greater immediate significance for Ireland (REF).  If sea level rises occur in tandem with greater and more frequent storms, the implication for increased coastal flooding and erosion will be clear. Problems will be exacerbated by estimated increases in winter rainfall of up to 15% (REF), with potentially greater volumes of freshwater discharge into Cork Harbour from the five main freshwater influences, including the River Lee.  

 

Figure 7 shows the natural shoreline of the Harbour as predominantly mixed sediment or rocky shore type.  Although Cork Harbour is sheltered from the full impact of Atlantic swell, wave and storm activity, the soft coastline dominated by unconsolidated sediments, remains vulnerable to the impacts of storm activity which is predicted as a result of future climate change scenarios.  While a number of measures have been set in place at a national level to deal with the issue of climate change, little has been done to take the implications of climate change into consideration at the regional or local planning levels.  There is a need for the development of models to simulate potential coastal change scenarios, and for information gleaned through research to be made available to local planners for incorporation into a long term strategic plan for Cork Harbour and it’s surrounding environment.

 

 

 

Figure 7. A snapshot of the Coastal Inventory. The natural shoreline type is predominantly mixed sediment or rocky. The western areas of the Harbour are more developed than the east and the shoreline here is predominantly made up of seawalls and rock reinforcements (Vicki O’Donnell).

 

 
The Challenge of Change

 

The coastal ecosystem of Cork Harbour is highly productive containing rich biological diversity and fishery resources.  Cork Harbour also supports a diverse array of related industries (e.g. pharmaceuticals, tourism and shipping industries), which provide enormous economic productivity.  However, urbanisation and uniform agricultural and industrial developments have considerably reduced the biological diversity and cultural distinctness of the coastal landscape.  Development pressures have resulted in the loss of natural habitats along the shoreline and the depletion in the quality of the coastal environment.  Along with these problems, recent research has shown that climate change could involve a rise in sea level of several millimetres per year, and an increase in the frequency and intensity of coastal storms (REF). Depending on where they occur, the combined effects of these two phenomena will have serious repercussions, such as causing major flooding events and altering the coastal zone (REF).   As a result, citizens of the 21st centuary are challenged with the implementation of Integrated Coastal Management (ICM) ensuring the sustainable development of coastal environments for future generations.

 

These issues are pertinent from the global level down to the local level and are as relevant to coastal communities, such as the stakeholders living and working in Cork Harbour, as they are to coastal communities living near marine parks of international significance such as the Great Barrier Reef. 

 

It is clear that Cork Harbour supports a diverse range of activities, ranging from urban and industrial to natural and rural in character.  Many of these activities are potentially conflicting.  The dynamic nature of both human and natural influences on the harbour will ensure that the social, economic and physical fabric of the harbour will be subject to change.  Thus, the challenge for decision makers will be:

 

 

In order to make this possible, an integrated approach to coastal management should be adopted for Cork Harbour.  This approach should involve all responsible agencies (Department of Communications, Marine and Natural Resource; Department of Environment; Cork County Council, Cork City Council, The Port of Cork, etc.) and stakeholders within the harbour area to develop a long-term strategic plan for Cork Harbour and to tackle the Challenge of Change.

 

 

Figure 8. The colourful harbour front at Cobh, last port of call to the Titanic and home to tourism, fishing and sailing industries (Vicki O’Donnell).

 

 

 

 

REFERENCES

 

Barry, J. M. (1999).  Queenstown for Orders: Queenstown Harbour and the Port of Cork 1800-1922. Sidney Publishing, Cork. ISBN: 0953315134. pp185.

 

Barry J. M. (1999).  Old Glory at Queenstown: The US Maritime Presence at Queenstown 1840-1920. Sidney Publishing , Cork. ISBN 09531512X.  pp206.

 

Barry W (1895).  Port of Cork Steamships.  Journal of Cork Historical and Archaeological Society.  Vol: 1.  pp433-446.

 

Broderick, M (1994).  History of Cobh (Queenstown) Ireland. pp175.

 

Dennehy, H. E. (1990).  History of Great Island.  The Cove of Cork and Queenstown. Tower Books. Pp 142.

 

Brunicardi, N (1982). Haulbolwine, Spike and Rocky Islands in Cork Harbour. Eigse Books.  ISBN 090756805X. pp58.

 

Brunt, B. M (1980). Industrial and Harbour Development in Cork.  Irish Geography. Vol: 13 pp88-93. 

 

O Mahony, C. (1986).  The Maritime Gateway to Cork.  A History of the Outports of Passage West and Monsktown from 1754-1942.  Tower Books. ISBN 0902568167.

 

Moloney, R (2003b).  Tourist Expenditure - A Study of the Economic Impact of the Port of Cork’s Cruise Traffic.  Commissioned by the Port of Cork Company, 2003. 

 

Moloney, R. (2003a).  Economic Contribution of the Port of Cork to the Irish Economy.  Commissioned by the Port of Cork Company, 2003.

 

Shields, Y., Deane, B. & McDowell N. (1997).  A Case Study: The Economic Significance of Ford Cork Week 1996 Sailing Regatta. Marine Institute.  Marine Resource Series, No. 3 1997.

 

EPA (2004).  Ireland’s Environment.  Environmental Protection Agency, 2004.  ISBN 1-84095-134-6.

 

O Donnell, V. & Cummins, V. (2004).  Poster: GIS Tools for Decision Support: The Coastal Inventory Dataset. ECO-IMAGINE Conference Proceedings, Saville. May 13th-15th 2004. May 13th-15th. 

 

IPCC (2001).  Climate Change 2001: Synthesis Report.  Intergovernmental Panel on Climate Change.  Third Assessment Report.  Geneva, Switzerland.  pp184.