3 Aquaculture and Coastal Space Management
95
Recreational boating also impacts water quality (McGee and Loehr 2003).
Disposal of untreated sewage has been defined as the most significant problem
associated with recreational boating; significantly higher faecal coliform levels
exist in coastal waters where recreational boating activity is high (Davies and Cahill
2000). Discharge of sewage from boats lowers water quality, which represents a
problem in water bodies that undergo limited flushing or support shellfish beds
located nearby. Special wastewater treatment procedures should be necessary for
coastal tourist areas to limit the entry of effluent to the sea, while adequate planning
for different activities, such as recreational boating, should take into account the
water quality link to aquaculture.
From a regional point of view, the impacts associated with the development of tourism and aquaculture on water quality, and existing impacts such as agriculture, will be
synergistic. The sum of the nutrients introduced from aquaculture, sewage, river discharges and agricultural run-off (e.g., fertilisers) to the marine environment has the
potential to exceed the assimilative capacity of benthic and pelagic systems and cause
eutrophication. Carrying capacities vary regionally, for example, Ervik and Aure (2006)
state that modelling indicates that coastal sites in northern Norway have greater carrying
capacities than sites in the south. Planning for regional economic development of
coastal zones should therefore account for varying carrying capacities and set limits
of “acceptable change” of environmental conditions for aquaculture. Potential changes
of water quality will occur over different temporal and spatial scales. Therefore, it is
necessary to investigate, using remote sensing and other geospatial and long-term data
sources, coastal changes relating to coastal urban development, human demographic
trends in coastal areas, increases in aquaculture facilities and other sources of pollution
such as agriculture. Knowledge of these processes will enable tighter regulation of the
allowable limit of N and P added to water bodies and marine sediments.
Technological advances in real time measurement can help monitoring and
management of coastal water quality, particularly where many users simultaneously require high water quality yet reduce water quality through their activities.
For example, the EU project I-MARQ (5
th EFP, No IST-2001-34039; www.imarq.
inf) developed a system for marine decision support, which aimed to simplify the
common Environmental Decision Support Systems (EDSS) that help users assess
the state of the marine ecosystem depending on different management regimes.
This kind of technological advance can be used to evaluate microbiological and
eutrophication risks related to aquaculture development.
3.5 Interactions of Wild Fish, Aquaculture and Fishing
3.5.1 Siting of Farms in Coastal Waters
Interactions of coastal aquaculture with fishing must be managed both before and
after installations are in place. Before allocation of new aquaculture sites, consideration must be given to whether farms will displace fishers from existing fishing grounds
through physically restricting access to fishing. Information on the importance of a
95
Recreational boating also impacts water quality (McGee and Loehr 2003).
Disposal of untreated sewage has been defined as the most significant problem
associated with recreational boating; significantly higher faecal coliform levels
exist in coastal waters where recreational boating activity is high (Davies and Cahill
2000). Discharge of sewage from boats lowers water quality, which represents a
problem in water bodies that undergo limited flushing or support shellfish beds
located nearby. Special wastewater treatment procedures should be necessary for
coastal tourist areas to limit the entry of effluent to the sea, while adequate planning
for different activities, such as recreational boating, should take into account the
water quality link to aquaculture.
From a regional point of view, the impacts associated with the development of tourism and aquaculture on water quality, and existing impacts such as agriculture, will be
synergistic. The sum of the nutrients introduced from aquaculture, sewage, river discharges and agricultural run-off (e.g., fertilisers) to the marine environment has the
potential to exceed the assimilative capacity of benthic and pelagic systems and cause
eutrophication. Carrying capacities vary regionally, for example, Ervik and Aure (2006)
state that modelling indicates that coastal sites in northern Norway have greater carrying
capacities than sites in the south. Planning for regional economic development of
coastal zones should therefore account for varying carrying capacities and set limits
of “acceptable change” of environmental conditions for aquaculture. Potential changes
of water quality will occur over different temporal and spatial scales. Therefore, it is
necessary to investigate, using remote sensing and other geospatial and long-term data
sources, coastal changes relating to coastal urban development, human demographic
trends in coastal areas, increases in aquaculture facilities and other sources of pollution
such as agriculture. Knowledge of these processes will enable tighter regulation of the
allowable limit of N and P added to water bodies and marine sediments.
Technological advances in real time measurement can help monitoring and
management of coastal water quality, particularly where many users simultaneously require high water quality yet reduce water quality through their activities.
For example, the EU project I-MARQ (5
th EFP, No IST-2001-34039; www.imarq.
inf) developed a system for marine decision support, which aimed to simplify the
common Environmental Decision Support Systems (EDSS) that help users assess
the state of the marine ecosystem depending on different management regimes.
This kind of technological advance can be used to evaluate microbiological and
eutrophication risks related to aquaculture development.
3.5 Interactions of Wild Fish, Aquaculture and Fishing
3.5.1 Siting of Farms in Coastal Waters
Interactions of coastal aquaculture with fishing must be managed both before and
after installations are in place. Before allocation of new aquaculture sites, consideration must be given to whether farms will displace fishers from existing fishing grounds
through physically restricting access to fishing. Information on the importance of a