62
M. Holmer et al.
phytoplankton blooms. Finfish flesh is monitored for bacteria, chemical residues
and phytoplankton toxins once every year, or in some countries, every year before
marketing.
2.1.1 Research Support for Monitoring of Environmental
Impacts
There have been several papers, reports and other documents dealing with the
principles of monitoring and particularly so in the case of the monitoring of fishfarming impacts. The report by GESAMP (1996) addressed this issue by describing possible scenarios of fish farm locations and suitable monitoring programmes.
Although the paper included a list of variables used for monitoring the ecological
effects of coastal aquaculture, the authors realised that the information provided
by some of these variables is of limited use in some situations. A comprehensive
series of studies on monitoring and regulation was also undertaken in the framework of the MARAQUA project (The Monitoring and Regulation of Marine
Aquaculture in Europe). These studies resulted in a series of papers on the scientific principles underlying the environmental monitoring of aquaculture (Fernandes
et al. 2001), on the control of chemicals (Costello et al. 2001), on the genetic
interactions between farmed and wild fish species (Youngson et al. 2001) and on
the use of hydrodynamic and benthic models for the management of aquaculture
impacts (Henderson et al. 2001). However, research on aquaculture-environment
interactions has progressed remarkably during the last 5 years, particularly in the
framework of EU-funded projects, which have provided useful information for
the understanding of various ecosystem processes affected by the presence and
operation of fish farms.
The effects of aquaculture on marine benthos, particularly on macrofauna, have
been known for long (Gowen and Bradbury 1987), and in general, they seem to
follow the pattern described by Pearson and Rosenberg (1978) regarding the succession of macrofaunal organisms along the benthic enrichment gradient. However,
more than 40 articles in the scientific literature (review in Kalantzi and Karakassis
2006) have studied these affects using in total 120 biological and geochemical
variables, most of which were highly intercorrelated. A meta-analysis of the most
commonly used of those variables by Kalantzi and Karakassis (2006) showed that
their values are determined by a combination of distance from the farm with bottom depth and/or latitude. Although the benthic effects are relatively easy to
detect, there are some concerns regarding the cost of the associated faunal analysis, which becomes more and more difficult due to the rarity of experts in the taxonomy of benthic organisms (GESAMP 1996). A series of papers have addressed
this issue by studying the potential use of surrogates and their effect on data quality. Karakassis et al. (2002) have used sediment profiling imagery (SPI) as a means
for monitoring the effects of fish farms on silty bottoms and found that SPI can
provide very reliable information on the state of the benthic environment. The use
M. Holmer et al.
phytoplankton blooms. Finfish flesh is monitored for bacteria, chemical residues
and phytoplankton toxins once every year, or in some countries, every year before
marketing.
2.1.1 Research Support for Monitoring of Environmental
Impacts
There have been several papers, reports and other documents dealing with the
principles of monitoring and particularly so in the case of the monitoring of fishfarming impacts. The report by GESAMP (1996) addressed this issue by describing possible scenarios of fish farm locations and suitable monitoring programmes.
Although the paper included a list of variables used for monitoring the ecological
effects of coastal aquaculture, the authors realised that the information provided
by some of these variables is of limited use in some situations. A comprehensive
series of studies on monitoring and regulation was also undertaken in the framework of the MARAQUA project (The Monitoring and Regulation of Marine
Aquaculture in Europe). These studies resulted in a series of papers on the scientific principles underlying the environmental monitoring of aquaculture (Fernandes
et al. 2001), on the control of chemicals (Costello et al. 2001), on the genetic
interactions between farmed and wild fish species (Youngson et al. 2001) and on
the use of hydrodynamic and benthic models for the management of aquaculture
impacts (Henderson et al. 2001). However, research on aquaculture-environment
interactions has progressed remarkably during the last 5 years, particularly in the
framework of EU-funded projects, which have provided useful information for
the understanding of various ecosystem processes affected by the presence and
operation of fish farms.
The effects of aquaculture on marine benthos, particularly on macrofauna, have
been known for long (Gowen and Bradbury 1987), and in general, they seem to
follow the pattern described by Pearson and Rosenberg (1978) regarding the succession of macrofaunal organisms along the benthic enrichment gradient. However,
more than 40 articles in the scientific literature (review in Kalantzi and Karakassis
2006) have studied these affects using in total 120 biological and geochemical
variables, most of which were highly intercorrelated. A meta-analysis of the most
commonly used of those variables by Kalantzi and Karakassis (2006) showed that
their values are determined by a combination of distance from the farm with bottom depth and/or latitude. Although the benthic effects are relatively easy to
detect, there are some concerns regarding the cost of the associated faunal analysis, which becomes more and more difficult due to the rarity of experts in the taxonomy of benthic organisms (GESAMP 1996). A series of papers have addressed
this issue by studying the potential use of surrogates and their effect on data quality. Karakassis et al. (2002) have used sediment profiling imagery (SPI) as a means
for monitoring the effects of fish farms on silty bottoms and found that SPI can
provide very reliable information on the state of the benthic environment. The use