5 4/14/2017Posidonia: provides shelter to juvenile fish and many manire invertebratesSpp reproducing in P. oceanica meadowsLithignathus mormyrusSparus auratusOblada melanuraSapra sapraParacentrotus lividusSymphodus roissaliAntedon mediterraneusMurena helenaConger congerLichia amiaSeriola dumeriliMullus surmuletus
6 Under anthropogenic pressure Posidonia meadows easily become degraded 4/14/2017Under anthropogenic pressure Posidonia meadows easily become degraded
7 4/14/2017… so that its past presence can only be detected by rhizomes left on the seabed
8 4/14/2017High turbidity in the water column is known to adversely affect PosidoniaThe reduced availability of light reduces the potential space for colonization by Posidonia to a more and more narrow coastal zone
9 During recent years it has been reported that Posidonia oceanica faces strong copetition by Caulepa taxifolia4/14/2017C. taxifolia is an alien species that recently invaded W. Mediterranean. It has no local grazers or other means to control its population and it excludes P. oceanica from coastal waters when established there
10 Why Posidonia is of vital importance Mediterranean endemic (in need of protection under the Habitat Directive)a nursery ground for several speciesprovides important services for coastal marine ecosystems (3D habitat for several invertebrate species)it stabilises the sandy beaches in the littoral zoneunder increasing pressure due to anthropogenic effects (pollution, trawling, harbour constructions etc)under increasing pressure due to nutrient enrichment of the coastal zones and flourish of fast growing macroalgae, e.g. Cladophora spp., Caulerpa sp.
11 Posidonia meadows as fish farming sites The habitat of P. oceanica (coarse sediment and strong currents) is “ideal” for fish farming since:it allows rapid dispersion of solute wastesminimal accumulation of particulates andexcellent oxygenation of the water
13 However f/f causes adverse effects on Posidonia by: reducing penetration or availability of lightimmediately under the cages (shadow effect)due to increased phytoplankton biomassdue to increased suspended particulatesby favouring the growth of epiphytes on Posidonia leavescompetition with fast growing macroalgaeaccumulation of OM in the sedimentsincreasing NH4 and H2S in the sediments
14 Posidonia: primary production near and far from fish farms 4/14/2017Posidonia: primary production near and far from fish farmsReference stationChanges in pp by an order of magnitudeFarm sitesCancemi et al. (2003) Estuar coastal shelf Sci vol56
19 MedVeg Bioassays * * * * * * * * * * * * * * Control site* signif different from control siteMedVeg Report 2005, unpublished data
20 MedVeg Bioassays - Ulva **********Control site* signif different from control siteMedVeg Report 2005, unpublished data
21 MedVeg: Posidonia mortalities with distance MedVeg Report 2005, unpublished data
22 MedVeg: Posidonia mortalities with sedimentation rate 4/14/2017MedVeg: Posidonia mortalities with sedimentation rateMortality increases rapidly beyond the sedimentation rate of 6g m-2 d-1MedVeg Report 2005, unpublished data
23 MedVeg: Posidonia density & cover 4/14/2017MedVeg: Posidonia density & coverDecrease close to the farmsMedVeg Report 2005, unpublished data
24 MedVeg: Posidonia biomass 4/14/2017MedVeg: Posidonia biomassDecrease close to the farmsMedVeg Report 2005, unpublished data
25 MedVeg recomendations-2 If monitoring studies indicate a decrease in seagrass meadow extension or shoot density, the amount of waste material (as C, N and P loads) must decrease for a equivalent percentage until recovery of the previous conditions. Alternatively, cages should be moved to other sites, according to guidelines reported above.Concessionaires must present a plan for the monitoring of possible pressures and damages to seagrass beds and include this in the Environmental Agenda for certification ISO14000 and EMAS (Eco-Management and Audit Scheme).A suitable monitoring program must use reliable techniques and include quality control procedures, and should be based on the rapid assessment techniques as described below
26 MedVeg descriptors/indicators: at individual plant level Morphometric descriptorsshoot biomass, expressed as the average dry weight of at least ten replicates shootsPhysiological descriptorstotal phosphorus content in different tissues, specifically young leaves and rhizomes, expressed as % of dry weight.total non-structural carbohydrates reserves in rhizomes, expressed as % of dry weightelemental sulphur content (as μmol per g dry weight) in roots.
27 MedVeg descriptors/indicators: At population levelshoot density, based in counting the number of shoots inside patches of Posidonia oceanica and expressed as the number of shoots per square meter .At community levelepiphyte biomass, expressed as the dry weigh of epiphytes in relation of the size of the shoots.sea-urchin density, based on counting the number of individuals inside patches of Posidonia oceanica and expressed as the number of individuals m-2
28 However...Our results do not mean that any fish farming activity should be banned at distance less than 800m from any Posidonia oceanica plant in the Mediterranean.However, adopting this distance could be an appropriate precautionary measure in the vicinity of important and well-developed Posidonia meadows that environmental authorities have set as priority areas for conservation.Whenever a fish farm is located in the vicinity of seagrass meadows, the health of the seagrass meadow should be annually monitored.Working definitions of the term "Posidonia meadow" should be harmonised among Mediterranean countries and common standards are set regarding priorities for conservation of such meadows.Otherwise, it is likely that MedVeg recommendations will be enforced differently in different member states and other Mediterranean countries thereby resulting in both inadequate environmental protection and in violating equal terms of competition within aquaculture industry.
29 Mass balance models4/14/2017Detailed mass balance models have been established for salmonid farmingAccording to these there are some remarcable differences in the amount of soluble and sedimenting proportions between nitrogen and phosphorusSince no such models exist for the Mediterranean we have used the estimates provided through these models in order to obtain a rough estimate for the additional nutrient loads in the Mediterranean.Karakassis et al. (2005) Sci Mar vol 69
30 Land-based tanks Diel high frequency sampling experiments on fluxes of 4/14/2017Diel high frequency sampling experiments on fluxes ofNutrientsPOCPONBacteriatanks containingdifferent fish sizes(1, 31 & 53gr)inputoutputsea bassTsapakis, Pitta, Karakassis (2006) Aquat. Liv. Resour vol 19
31 Nutrient dynamics Fish size: 1gr Significant difference and 4/14/2017Fish size: 1grSignificant difference andDiel pattern in dischargeTsapakis, Pitta, Karakassis (2006) Aquat. Liv. Resour vol 19
32 POC and PON dynamics Significant difference and 4/14/2017Significant difference andDiel pattern in dischargeTsapakis, Pitta, Karakassis (2006) Aquat. Liv. Resour vol 19
33 N & P mass balance: % losses over feed input 4/14/2017141316PO4(%)266Average2775329531211NH4PONFish Size(gr)Fine particulate material settling at very slow rates and over larger distance from the discharge pointsTsapakis, Pitta, Karakassis (2006) Aquat. Liv. Resour vol 19
34 However4/14/2017Several studies have failed to detect significant changes in dissolved nutrients, Chl-a and POC concentrations even at fairly short distance from the cages (Pitta et al 1998, La Rosa et al., 2002, MEDVEG unpublished data, Soto & Norambuena 2004)This paradox might be due to:The dispersive nature of the sites (nutrients are rapidly diluted)Inefficient sampling (concentrations vs fluxes)Intensive grazing and transfer to higher trophic levelsCombination of the above
35 Grazing experiment in Crete using dialysis chambers 4/14/2017Grazing experiment in Crete using dialysis chambersfiltered8Chlorella6unfilteredChl a (mg l-1)423080200>500Distance (m)Karakassis et al. (submitted)
36 Local Fisheries landings :time series analysis AnalysesLocal Fisheries landings :time series analysisEnvironmental: OC, Chla, NutrientsFish: Species, Abundance + Biomass per species, diversity, biodiversity, LF, age, condition factor, fecundity, G Index, stomachs, lipids, proteinsMega: S, A + B per species, diversity, biodiversityMacro: S, A, B total, diversityBacteria: CountsMicro zoo + Phytoplankton: S, A, B (total), diversityFish spatial structure: geostatistics
37 Fish communitiesThe communities differed firstly according the substrate and secondly according to fish-farms presence.The effect of fish-farm presence was mainly quantitativeNo significant differences in diversity or biodiversity indices (taxon. distinctness etc)
38 Fish communitiesThe total abundance and biomass was higher near to fish farms in May – and fairly similar in the recruitment period in September.It seems that during the recruitment period all sites (Near and Far) are stocked with fish close to the carrying capacity
39 Effects on LandingsTotal LandingsFarm Production
40 Effects on Landings: MAFA analysis The correlation between the size of the fishing fleet & the landings trend could be coincidental: due to a clear declining trend because of a vessel withdrawal policyRainfall & Temperature did not show any correlation with the common trend (except Chios)fish-farming production related to an increase of local fisheries landingsAB
41 AQCESS conclusions No change in macrofauna Small changes in megafaunal biomassBig change in fish abundance and biomass documented through:Before-after study: Machias et al 2004, ECSS, v. 60Near-far study: Machias et al 2005, MEPS, v. 288Landings: Machias et al. (2006) Aquaculture v. 261Hydroacoustics: Giannoulaki et al. 2005, JMBA UK v. 85FAD effect? No, the list of species (<30 spp) aggregating near the cages are known (Dempster et al 2002 MEPS for W. Med, Smith et al submitted from the E. Med). Not the ones increasing in the above studies
42 AQCESS conclusionsNot all benthic communities respond in the same way to disturbanceLarge long living animals could be more efficient means for monitoring subtle changesThe most possible explanation is the rapid transfer of nutrients up the food web in a nutrient-starving environment
43 sediment: horizontal changes 4/14/2017sediment: horizontal changescurrentTOC (%)TON (%)Eh (mV)CephaloniaIthakiSounionKarakassis et al. (2000) ICES J mar sci 57
44 Meta-analysis of benthic effects 4/14/2017Meta-analysis of benthic effectsKalantzi & Karakassis (2006) Mar. Pollut. Bull vol 52
45 Meta-analysis of benthic effects 4/14/2017Meta-analysis of benthic effectsKalantzi & Karakassis (2006) Mar. Pollut. Bull vol. 52
46 Meta-analysis of benthic effects 4/14/2017Meta-analysis of benthic effects
47 Sediment profiling imagery (SPI): an «inverted periscope» 4/14/2017Sediment profiling imagery (SPI): an «inverted periscope»cameraglassmirror
48 SPI images beneath fish farms 4/14/2017SPI images beneath fish farmsUFCH4 or H2SFSBgFSBLTBLTBTSource: Karakassis, Tsapakis, Smith, Rumohr. (2002) Mar Ecol Prog Ser, 227
49 Multivariate analysis of SPI data 4/14/2017Multivariate analysis of SPI dataOctoberFebruaryJulyEuclidean distancefaunaSPIComparisons between multivariate patternsSource: Karakassis, Tsapakis, Smith, Rumohr. (2002) Mar Ecol Prog Ser 227
50 Minimizing monitoring requirements All correlation coefficient values were significant (p<0.001)Lampadariou, Karakassis, Pearson (2005) Mar. Pollut Bull vol 50
51 Modelling spatial patterns of settling particles DEPOMOD -> MERAMOD4/14/2017A tool for prediction of benthic degradationHigh correlation between predicted and observed sedimentationHigh correlation between predicted sedimentation and macrofaunal diversityCromey et al. in preparation
52 Sedimentation by fish farms 4/14/2017Sedimentation by fish farmsDetailed mass balance models have been established for salmonid farmingAccording to these there are some remarcable differences in the amount of soluble and sedimenting proportions between nitrogen and phosphorusSince no such models exist for the Mediterranean we have used the estimates provided through these models in order to obtain a rough estimate for the additional nutrient loads in the Mediterranean.* for trout cage farming in Swedenby Holby & Hall (1991) and by Hall et al. (1992) MEPS
53 effects on benthos Pearson & Rosenberg (1978) 4/14/2017effects on benthosThe succession pattern described by Pearson & Rosenberg is one of the most robust models in marine ecologyAll the work done on benthic communities reveals this general pattern, although different organisms might be involved in different parts of the succession in different parts of the worldPearson & Rosenberg (1978)
54 Hierarchical response to stress 4/14/2017Hierarchical response to stressPearson & Rosenberg (1978)Replacement by different order,class, phylumReplacement by different familyReplacement by different genusstressReplacement by different speciesEνα αρκετά γνωστό πρότυπο που σχετίζεται με την απόκριση των βενθικών βιοκοινοτήτων στη διατάραξη είναι ηReplacement by more addapted individuals from a polymorphic stockPhysiological reponse of the individualtime
55 Biotic coefficient (BC) - AMBI 4/14/2017Biotic coefficient (BC) - AMBIThe BC proposed by Borja et al (2000) distributes species into various groups depending on their ability to tolearate disturbence/pllutionGroup I. Sensitive species, present only in complete absence of pollutionGroup II. Indifferent species always present in small densities without significant fluctuation with timeGroup III. Tolerant species. they may be found under natural conditions but their population growth is stimulated under organic enrichmentGroup IV. Second stage opportunists. Mainly small-size subsurface deposit feeders (e.g. Cirratulidae)Group V. First stage opportunists. Deposit feeders thriving in reduced sediments.
56 Biotic coefficient (BC) 4/14/2017Biotic coefficient (BC)The value of BC is then calculated for every sample based on the % of each group on total macrofaunal abundance.(0xGI)+(1.5xGII)+(3xGIII)+(4.5xGIV)+(6xGV)BC=100This index is supported by a software in EXCEL (AMBI) and a data base providing characterization of >3000 benthic species (www.azti.es)Borja A, Franco J, Perez V (2000) A marine biotic index to establish the ecological quality of soft-bottom benthos within European estuarine and coastal environments. Marine Pollution Bulletin 40:1100–1114.Muxika I, Borja A, Bonne W (2005) The suitability of the marine biotic index (AMBI) to new impact sources along European coasts. Ecol. Indic, 5:19–31.
57 Limits for BC classification BC Dominant group 4/14/2017Limits for BCclassificationBCDominant groupBenthic community healthIn terms of pollutionNon polluted0.0<BC<0.2InormalNon polluted0.2<BC<1.2poorSlightly polluted1.2<BC<3.3IIIunbalancedModerately polluted3.3<BC<4.3Transitional to pollutedModerately polluted4.3<BC<5.0IV-VpollutedHeavily polluted5.0<BC<5.5Transitional to havily pollutedIn oder to assess the level of impact we have sampled the water column in 3 farms x 3 seasons x 3 depths with 5 real replicatesand with a control site in each fram. The idea was to investigate the variability induced by “natural sources” and compare it to the variability induced by f-farming.Among the nutrients only ammonium ions showed a significant increase exceeding all other sources of variabilityHowever this increase was not transleted into high CHLa nor increased POC or PON which are the variables most relevant to the increase in phytoplankton biomass.Heavily polluted5.5<BC<6.0VHeavily pollutedextremely pollutedαζωικήαζωικήazoicBorja et al (2000) Mar Pollut Bull –1114.
58 4/14/2017BENTIXBENTIX (Benthic index) is a variation of BC proposed by greek scientists (Simboura &, Zenetos 2002)The difference from BC is that BENTIX recognizes only 3 groups of species and the list of species for which there is some characterization is not available except the first edition in Mediterranean Marine Science.Because BENTIX is calculated giving high scores to intolerant species low values indicate degradation whereas high values «pristinity»Simboura N, Zenetos A. (2002) Benthic indicators to use in ecological quality classification of Mediterranean soft bottom marine ecosystems including a new Biotic index. Mediterranean Marine Science 3:77–111.
59 4/14/2017BC and BENTIXBoth methods are based on subjective judjment on the ecological role of benthic speciesTheir use needs communication with the authors (direct or indirect through their web page) and up to a point confidence in their oppinion.The role of each species and the assignment of one group is inflexible and is given only once.There is no agreed procedure for revising the classification of a species in the groups of each indexThe thershod values assigned are more or less arbitrary.
60 Benthic quality index (BQI) 4/14/2017Benthic quality index (BQI)BQI (proposed by Rosenberg et al 2004) is somehow different than the previous indices.Species are not divided into categories but they receive a score depending on their disdtribution in a set of samplesThe index is based on the assumption that opportunistic species are primarily found in stations/samples with low diversity whereas the «normal» or sensitive species in stations/samples with increased diversity.Therefore if the distribution of a species is determined over a series of samples covering a wide range of diversity then the distribution pattern will vary from species to species depending on their sensitivity or tolerance.Rosenberg R, Blomqvist M, Nilsson HC, Cederwall H, Dimming A (2004) Marine Pollution Bulletin 30 (7), 470 –474
61 Calculation of ES500.05 disturbed undisturbed 4/14/2017Calculation of ES500.05The shaded area includes the 5% of the total abundance of the species which is related to low diversity stationsIn oder to assess the level of impact we have sampled the water column in 3 farms x 3 seasons x 3 depths with 5 real replicatesand with a control site in each fram. The idea was to investigate the variability induced by “natural sources” and compare it to the variability induced by f-farming.Among the nutrients only ammonium ions showed a significant increase exceeding all other sources of variabilityHowever this increase was not transleted into high CHLa nor increased POC or PON which are the variables most relevant to the increase in phytoplankton biomass.disturbed undisturbedRosenberg R, et al. (2004). Mar Pollut. Bull. 30:470 –474
62 Calculation of ES500.05 for various species 4/14/2017Calculation of ES for various speciesIn oder to assess the level of impact we have sampled the water column in 3 farms x 3 seasons x 3 depths with 5 real replicatesand with a control site in each fram. The idea was to investigate the variability induced by “natural sources” and compare it to the variability induced by f-farming.Among the nutrients only ammonium ions showed a significant increase exceeding all other sources of variabilityHowever this increase was not transleted into high CHLa nor increased POC or PON which are the variables most relevant to the increase in phytoplankton biomass.Low values: tolerant species, High values: sensitive speciesΧαμηλές τιμές: ανθεκτικά είδη, Υψηλές τιμές: ευαίσθητα είδηRosenberg R, et al. (2004). Mar Pollut. Bull. 30:470 –474
63 Benthic quality index (BQI) 4/14/2017Benthic quality index (BQI)After calculating ES for each species, BQI is calculated for each sample:BQI= x ES x 10log(S+1)()nΣi=1(Ai)tot A
64 BQI and sediment condition 4/14/2017BQI and sediment conditionSPI imagesCondition in relation to Pearson & Rosenberg 1978In oder to assess the level of impact we have sampled the water column in 3 farms x 3 seasons x 3 depths with 5 real replicatesand with a control site in each fram. The idea was to investigate the variability induced by “natural sources” and compare it to the variability induced by f-farming.Among the nutrients only ammonium ions showed a significant increase exceeding all other sources of variabilityHowever this increase was not transleted into high CHLa nor increased POC or PON which are the variables most relevant to the increase in phytoplankton biomass.Thresholds and sediment qualityRosenberg R, et al. (2004). Mar Pollut. Bull. 30:470 –474
65 4/14/2017Hypotheses to testDo all these indices describe the conditions similarly?Are they intercorrelated?Do they depend on sieve size?Do they depend on season?Do they assign the same environmental quality to the samples examined?
66 Sieve size Highly correlated y=1.0*x Good news ! Values at 1.0 mm 4/14/2017Sieve sizeHighly correlatedy=1.0*xGood news !Values at 1.0 mmValues at 0.5 mm
67 season Highly inter- correlated for most indices 4/14/2017seasonHighly inter- correlated for most indicesRelatively Good news !Spearman rank correlationindex
68 Do they intercorrelate? 4/14/2017Do they intercorrelate?Highly inter- correlated (p<0.01) for most indicesRelatively Good news !So we can chose any of them without worrying?
69 4/14/2017How similar they are?Using the correlation matrix we can run an MDS and obtain similarities among indicesD+L+AMBIBENTIXH’BQIStress:0.01
70 Do they agree in Environmental status? 4/14/2017Do they agree in Environmental status?Well… NoIn fact they reach a «consensus» in 4% of the samples and they had 3-4 different «verdicts» in 39% of the samplesbadpoormoderategoodhigh
71 Are there consistently easy-to-pass and difficult ones? 4/14/2017Are there consistently easy-to-pass and difficult ones?Yes BENTIX and H’ tend to show more High and Good qualityBQI tends to show (reveal?) more Bad and Poor conditions
72 4/14/2017furthermoreThe Pearson & Rosenberg model works well with silty sedimentsFor coarse sediments it is possible to have a “healthy picture” despite the fact that environmental degradation may have severely affected other components of the ecosystem.
73 4/14/2017Χαρακτηριστικά των ιχθυοτροφείων στο δείγμα (fish farms characteristics)% ιλύος αργίλου(% silt-clay)Βάθος (m) depthΠαραγωγή (τόνοι/έτος)Production (tn/year)