ECASA - Summary of WP2 indicators (29/07/05)
List
AMBI
– A Marine Biotic Index
Impact of shellfish culture on trophic groups of the benthic macrofauna
Chlorophyll a
Shannon-wiener index for evaluation of meiofaunal harpacticoid copepod diversity
Nitrifier population - heterotrophic bacteria involved in nitrification processes
Sediment test, meiofauna (1)
Sediment test, meiofauna (2)
Sedimentation fluxes
Macrofauna/Meiofauna – multivariate analyses
Accumulation of heavy metals in sediment
Macrofauna – Infaunal Trophic Index (ITI)
Macrofauna - Univariate indicies (some also applicable to meiofauna)
Aquaculture production per km of shoreline
Consumer prices for aquaculture products
Environmental damage costs per unit
Total employment in aquaculture products by species and country
Multiplier indicators of dependency
Total output of aquaculture products by species and country
Producer prices for aquaculture products
Productivity ratios
Profit per unit
Sulfate and ammonia gradients
Sulphide / oxygen in sediments using combined electrode
Sediment oxygen consumption
Genetic markers - microsatellite analysis of DNA
DNA damage - biomarker of exposure to genotoxic substances
Genetic markers - analysis of mtDNA
EROD – E thoxyresorufinO -deethlyase activity (EROD) in fish liver
Validated distance (VD) from sensitive aquatic areas
Water availability
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AMBI (A Marine Biotic Index) – Borja - The AMBI (Borja et al., 2000, 2003a) is a biotic index which provides a ‘pollution classification’ of a particular site representing the benthic community ‘health’. The AMBI is based upon previous ecological models
(Glémarec and Hily, 1981; Hily, 1984). Theoretical basis is the ecological adaptative strategies of the r , k and T (McArthur and Wilson, 1967; Pianka, 1970; and Gray, 1979) and the ecological succession in stressed environments (Bellan, 1967; Pearson and
Rosenberg, 1978; Salen-Picard, 1983).
Impact of shellfish culture on trophic groups of the benthic macrofauna - Change in trophic groups before/after beginning of aquaculture operation. Excess in particulate matter due to aquaculture operations results in increased deposition of fine and organic particles. At the same time, bivalves are active food competitors with other filter feeders and may swallow larvae and reduce the recruitment of other species (Smith & Shackley
2004).
Chlorophyll a - Angel - The "scientific meaning" of Chl a concentration seems fairly simple since there is usually a fairly direct (linear?) relationship between the abundance of phytoplankton and the concentration of chlorophyll a that can be extracted from seston concentrated on glass fiber filters. Environmental "over-loading" of nutrients, as may potentially occur if fish farms are not properly sited and managed, often leads to
"eutrophication" and one of the early signs of eutrophication is an increase in Chl a levels.
Shannon-Wiener index for evaluation of meiofaunal harpacticoid copepod diversity
(mostly second meiofaunal dominant) - Borut Vriser, Mateja Grego, NIB - Most used diversity index for macro- and meio-benthic studies applied in organically poluted environments and compared with an unpolluted environment (i.e. reference samples).
Nitrifier population - heterotrophic bacteria involved in nitrification processes –
Forte – Application of Fluorescent in situ hybridisation (FISH) method and specific probes for detection of dominant group of nitrifiers. When probes are determined their distribution can be followed around the fish farm to see how far away pollution can be detected.
Sediment test, meiofauna (1) - Borut Vriser, Mateja Grego, NIB - We take corer samples from beneath a mariculture operation (A) and other samples from different control locations (B). Comparison between affected and unaffected (natural) environment.
Sediment test, meiofauna (2) - Mateja Grego, Borut Vriser, NIB - We take 2 parallel box-corer samples from the local area, one box situated at the control site-C- and the second box-M- under mariculture. After a certain time, boxes are collected and analysed and samples from M and C compared. This test should be performed 6-9 times.
Sediment fluxes – Forte - The increased sedimentation of organic matter leads to anoxic sediments bellow the farm cages (Hall et al. 1990, Holmer 1991) with negative redox
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characteristics (Hargrave et al. 1993) and a high organic content (Hall et al. 1990, Hall et al., 1992; Holmer 1991; Karkassis et al. 1998). Alterations of sediment chemistry result in changes of biomass abundance and species composition of benthos (Weston 1990,
Karakassis et al. 2002).
Macrofauna/Meiofauna – multivariate analyses - The fraction of the variance of a particular species in the canonical correspondence analysis is calculated, and the cumulative percent variance (cumulative fit per species as a fraction of variance of species) is tabulated. The species can then be ordered, and the top contributors assessed.
Accumulation of heavy metals in sediment - Of the metals present in fish farm sediments, elevated concentrations of copper and zinc have been reported in Scotland and
Canada. The principal sources of these metals are antifoulant paints and fish feed.
Additionally, cadmium, molybdenum and uranium are enriched in fish farm sediments, and up to 150 m away from farms. Metal concentrations have been shown to increase over the farm growing season. Redox-sensitive metals may be subject to sediment horizon migration due to increased organic enrichment from farm activities.
Macrofauna – Infaunal Trophic Index (ITI) – The purpose of the Infaunal Trophic
Index (ITI) is to describe the feeding behaviour of soft bottom benthic communities in terms of a single understandable parameter. These animals fall into four groups; they are either suspension or deposit feeders that feed above, on or below the mud surface. The
ITI was developed in California, USA and was first published in 1979 (Word, 1979).
Since then it has been adapted for use in UK waters (WRc 1992) but the principles remain the same.
Macrofauna - Univariate indicies -
S, A and B, S/A, B/A, H’, Evenness, Simpson.
Certain indicator species and families have been shown to indicate impact by their presence/absence (recent example in the Mediterranean - Karakassis and Lampadariou, unpublished). Disturbance of macrobenthic community results in recognised changes in these indices. Primarily, diversity decreases along an increasing organic gradient, with a corresponding increase in abundance expected. A severely impacted situation may result in abundance tending to zero (azoic). Biomass changes along an organic gradient are typically more complex, with peaks in biomass associated with peaks in opportunistic species and a larger peak in biomass at unimpacted locations.
Aquaculture production per km of shoreline – Whitmarsh - Density of farms along the shoreline. This can be compared with other uses or with other areas. 100*A/B where A = length of shoreline occupied by aquaculture facilities (excluding land-based operations and fresh water aquaculture); B = length of the shoreline within a defined geographic area
(bay, administrative limit or country).
Consumer prices for aquaculture products – Whitmarsh - Prices paid by consumers for farmed fish will vary according to local market conditions, but an indication of the underlying trend can be obtained from wholesale prices. Because these are determined in
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relatively few market centres (in Europe, these would be Rungis and Billinsgate) the task of obtaining representative prices is much simplified.
Environmental damage costs per unit
– Whitmarsh - Very great uncertainty attaches to the economic costs arising from the environmental impact of aquaculture, and this is further complicated by the fact that such costs are highly context-specific (i.e. the harm caused by aquaculture pollution will vary widely according to circumstances – farm location, feeding regime, etc.).
Total employment in aquaculture products by species and country
– Whitmarsh -
Employment is normally classified according to whether it is full-time or part-time, though the latter can be converted to FTEs using appropriate weights. Most statistical sources measure employment in terms of absolute numbers (or FTEs).
Multiplier indicators of dependency
– Whitmarsh - Multiplier effects define the total economic activity supported directly and indirectly by one industry or sector. In this context they can be used to determine the dependency of particular regions on aquaculture. If multiplier effects are large it implies that changes in the output of aquaculture may induce correspondingly large (i.e. ‘multiplied’) changes in the output and employment of other sectors, which is clearly a matter of policy concern in regions of high unemployment.
Total output of aquaculture products by species and country – Whitmarsh - Output can be measured in physical terms (e.g. metric tonnes) and / or value (€, £, $, etc.).
Producer prices for aquaculture products – Whitmarsh - Prices are not usually given explicitly, but can be derived from data on the value and quantity of aquaculture production. FAO FishStat Plus gives values in US $, which have been converted from local currencies using the appropriate yearly exchange rates.
Productivity ratios – Whitmarsh - Productivity is a measure of output per unit of input.
Despite its limitations, trends in labour productivity are an important indicator of technical progress in aquaculture, and productivity differences between farms may give a portent of which farms are most vulnerable to falling prices and profits.
Profit per unit
– Whitmarsh - Profitability is a basic indicator of financial viability, but with the exception of Norway few countries appear to publish cost and earnings surveys of their aquaculture sectors on a routine basis. In the absence of published data, profitability needs to be calculated from its different elements (i.e. input costs, FCRs, prices, etc.) and this information necessarily has to be assembled from a variety of sources.
Sulfate and Ammonia gradients - (proposed by Ray Cranston) – I do not have the reference with me, but a paper by Ray Cranston in Modelling benthic impacts of organic enrichment from marine aquaculture . Can. Tech. Rep. Fish. Aquat. Sci. 1949. xi+125 p.
B. T. Hargrave, Ed. describes the method and provides the necessary background. This is
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a very general indicator that can be used for all sites and thus provides a global measure of the impact of carbon burial.
Sulphide / oxygen in sediments using combined electrode - Established relationship between organic enrichment processes and concentration of sulphide within the sediment pore water (Wildish et al.
2004). Wide range of sulphide concentrations which cause impact. There is some information in the literature regarding the level of sulphide concentration toxic to specific organisms (Bagarinao 1993, Gamenick et al. 1998,
Hentschel et al. 1999, Wang et al. 1999).
Sediment oxygen consumption - Marine sediments may become anoxic as a result of insufficient dissolved oxygen to maintain aerobic respiration of deposited material arising from the aquaculture operation. Availability of oxygen and associated biochemistry are major factors in determining the structure of the benthic faunal community and microbial populations.
Genetic markers - microsatellite analysis of DNA
– Forte - Microsatellites are codominant markers, very abundant, evenly distributed through the genome with small locus size and high polymorphism. They are extensively used in fisheries research including studies of genome mapping, parentage, kinship and stock structure. They have broad use in identifying the degree of divergence within and among brood and native populations, hybrid identification, paternity identification, analysis of genetic diversity, stock identification etc.
DNA damage, biomarker of exposure to genotoxic substances - Measuring DNA damage gave us information about genotoxic risk for marine organisms exposed to mixed environmental pollution as well as the information about the presence of unknown mixtures of genotoxic contaminants in the marine environmental. One of the advantages of this method is that it allows determination of genotoxic effects in living animals (e.g. withdrawn of haemolyph from Mytillus galloprovincialis ).
Genetic markers- mtDNA haplotypes- analysis of mtDNA - Sequences of mitochondrial protein coding genes and/or non-transcribed control region from broodstock and native populations samples. The sequence evolution of mtDNA has been relatively well studied in fishes and mtDNA structure, gene organization and secondary structure are largely conserved in fishes.
EROD - Measurement of ethoxyresorufinO -deethlyase activity (EROD) in fish liver is an indicator more related to the impact of sea water quality on the aquaculture. Measurement of
EROD activity in fish is a well established biomarker of exposure to planar halogenated and polycyclic aromatic hydrocarbons and structurally related compounds.
Validated Distance (VD) from sensitive aquatic areas (e.g. from an MPA or other protected area, habitat of an endangered or protected species, important spawning ground) - For certain types of sensitive aquatic areas it is desirable to exclude human impact (typically this is chemical pollution, organic enrichment, and eutrophication). To avoid costly field campaigns a standard value for a Safe Distance should be defined.
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Water availability - J.M. Kapetsky and U. Barg, Fishery Resources Division,
FAO, Rome, Italy - The need for water for a farm should not exceed a fraction of the available water, in order not to compromise other activities and future developments.
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