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With the growing pressures on the global fisheries to provide more and more product than is readily available, the aquaculture or mariculture industry has become more and more prominent in recent years. However, there are many constraints placed upon aquaculture that can become issues for the coastal communities involved in aquaculture production. One such constraint is the need for space, which in turn is effected by an  understanding of the life-cycles and processes of the organisms in question and also public perception.

The Real Map of Ireland.jpg

‘The Real Map of Ireland’ outlines the extent of  Ireland’s marine territory (WWW1)

The Need For Space

Marine organisms require the water in which they live to have the proper physical and chemical parameters to yield large, healthy individuals. Such conditions are very difficult to maintain in ponds or tanks due to the requirement for complex water treatment systems and filtering devices to remove potentially toxic materials and natural wastes. Most attempts to raise marine organisms on a large scale involve significant economic investment to maintain water quality. For example, in Co. Cork, the largest finfish species to be farmed is salmon, with 3,467 tonnes produced annually. This demands for a high usage of physical space, be it in cages, tanks or ponds, where regulations and biological information, constrains the number of individual fish per until area, in order to produce commercially viable product (Theodouru, 2002). Further to this, these sites may require zoning in close proximity to freshwater resources for the treatment of diseases such as Amoebic Gill Disease as we discussed in last week’s blog post.


AGD present in gills of Atlantic Salmon (WWW2)

Complexity of Life Cycles

Many marine organisms go through a complex series of larval stages, each requiring different surrounding conditions and food requirements prior to reaching marketable size. To rear each form successfully is often costly, challenging and even not currently possible in captivity. This has led to the importing of young fish into the aquaculture industry, which brings with it, its own potential dangers. This introduction of “foreign” individuals is seen to be one of the primary threats to native biodiversity around the world (Bax et al., 2003). Invasive species can take the form of microbial life, fish pathogens, juvenile invertebrates, molluscs, crustaceans, and fish, each of which is capable of creating immense damage through biofouling cages and other structures. An example of this can be seen in the intentional distribution of the Pacific oyster (Crassostrea gigas) which can dominate native species and destroy local habitats (Molnar et al. 2008; WWW3). With the developing understanding, stemming from scientific research, these risks are being minimised, but are still a long way off from being totally closed cycles with the aquaculture industry.


Map of harmful invasive species by ecoregion (Molnar et al. 2008, 488)

Public Perception

One issue facing the aquaculture industry is that of public perception. Anecdotally, fish cages and mussel/algae lines have been described as “unsightly” and can affect the aesthetic beauty of an area. Complaints have also been made about unpleasant odours and water contamination arising from aquaculture practices, which can all have a detrimental effect on tourism and for the local community. Artisanal and recreational fishermen have also registered complaints with groups like “Save Bantry Bay”, about infringement on traditional fishing grounds (WWW4).


Marine Harvest salmon farm in Northern Ireland (WWW5)

Ireland’s coastline, which has been traditionally interpreted or perceived as a common property resource, plays host to several competing industries and sectors both commercial and recreational. Because of this, Ireland’s waterways are put under increasing pressures which has lead the European Union (EU) and its member states to move towards ‘Ecosystem Based Fisheries Management to balance food production and security with wider ecosystem concerns”(Tidd et al. 2015). Since 2008, the EU has placed the responsibility on member states to establilsh a set of common principles, referred to as ‘Maritime Spatial Planning’ which operate withing the  Marine Strategy Framework Directive, in order to to (ibid.):

  • manage *anthropogenic activities in space and time
  • preclude an minimise conflicts between competing sectors without negatively impacting the ecosystem

It is hoped that these spatial strategies will mitigate many of the issues surrounding the aquaculture industry and zonal allocations.

Seán & Orla-Peach

*Anthropogenic – (chiefly of environmental pollution and pollutants) originating in human activity


Bax, N., Williamson, A., Aguero, M., Gonzalez, E., & Geeves, W. (2003). Marine invasive alien species: A threat to global biodiversity. Marine Policy, 27(4), 313–

Clarke, M., Farrell, E.D., Roche, W., Murray, T.E., Foster, S. and Marnell, F. (2016) Ireland Red List No. 11: Cartilaginous fish [sharks, skates, rays and chimaeras]. National Parks and Wildlife Service, Department of Arts, Heritage, Regional, Rural and Gaeltacht Affairs. Dublin, Ireland.

FAO (2002) The state of world fisheries and aquaculture, FAO, Sofia.

Molnar, J.L., Gamboa, R.L. Revenga, C. & Spalding, M.D. (2008) Assessing the global threat of invasive species to marine biodiversity. Frontiers in Ecology and Environment 6(9): 485–492,

Theodorou, J.A. (2002). Current and future technological trends of European seabass– seabream culture. Reviews in Fisheries Science, 10, 529–543.

Tidd, A.N., Vermard, Y., Marchal, P., Pinnegar, J., Blanchard, J.L.&  Milner-Gulland, E.J. (2015) Fishing for Space: Fine-Scale Multi-Sector Maritime Activities Influence Fisher Location Choice. PLoS ONE 10(1)

WWW1 – INFOMAR – Marine Institute

WWW2 – Amoebic Gill Disease

WWW3  – Pacific Oyster (Crassostrea gigas)

WWW4 – Save Bantry Bay 

WWW5 – Marine Harvest