Browsing by Subject "Suomenlahti"

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  • Hällfors, Guy (Vesihallitus. National Board of Waters, 1979)
    Vesientutkimuslaitoksen julkaisuja 34, 3-24
    Tiivistelmä: Alustava pohjoisen Itämeren kasviplanktonluettelo.
  • Pettersson, Heidi (Merentutkimuslaitos, 2001)
    Meri 44
  • Huurtomaa, Satu (Helsingin yliopisto, 2019)
    The Baltic Sea is a vulnerable marine environment and susceptible to pollution. The situation is especially severe in the Gulf of Finland due to a large catchment area compared to the size of the Gulf. The north eastern Gulf of Finland has been described as one of the most contaminated areas of the entire Baltic Sea, with extensive pollution load via river Kymi in the past. Still today, the currents bring contaminants from the eastern part of the Gulf – the Neva estuary and the Bay of Viborg. The concentrations of V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Hg, Pb, Bi and La were studied in the surface sediments and three GEMAX cores. The vertical distribution revealed the temporal change in the metal accumulation. The spike in the Cs concentration, indicating the Chernobyl disaster in 1986, enabled the estimation of the accumulation of studied elements over time. The horizontal distribution maps based on the concentrations in the surface sediments enabled the discovery of the sites with most intense metal accumulation. Correlation coefficients showed the effect of carbon and sediment grain size in the distribution of metals. The comparison of the metal concentrations to the natural background levels and the Canadian sediment quality guidelines (SQGs) enabled the estimation of the degree of contamination of the area. The metal concentrations have declined during the last decades in the north eastern Gulf of Finland, indicating lower contamination input towards present day. However, in the oxidized Ravijoki core, the decline was not that obvious, probably due to metal scavenging by Fe and Mn oxides and bioturbation. The regional metal distribution was strongly affected by the grain size and carbon – most metals showed high positive correlations with carbon and finer sediment fraction. Mn was an exception, showing negative correlations with both carbon and clay, probably due to the Mn reduction at sites with high organic matter accumulation. The regional distribution pattern suggested main Cd pollution arriving from the eastern part of the Gulf. The distribution of Hg, Mo, Cu and Zn also suggested a possible source in the east. High concentrations of Hg, Pb and Cu were discovered in the outlets of river Kymi. According to the Canadian SQGs, the sediments in the north-eastern Gulf of Finland were contaminated. The situation is especially severe in the case of Zn – the higher reference value PEL, above which adverse biological effects frequently occur, was exceeded even in the oxidized Ravijoki sediments. The highest concentrations of the elements with defined SQGs (Cd, Cr, Zn, Cu, Hg, Pb and As) exceeded the lower reference values in the surface sediments, indicating that all these metals could, at least locally, pose a severe threat to benthic species.
  • Myrberg, Kai (Finnish Institute of Marine Research, 1998)
    Monographs of the Boreal Environment Research 10
  • Westerlund, Antti; Tuomi, Laura; Alenius, Pekka; Myrberg, Kai; Miettunen, Elina; Vankevich, Roman E.; Hord, Robinson (Taylor & Francis, 2019)
    Tellus A: Dynamic Meteorology and Oceanography, 71:1
    We studied circulation patterns in the Gulf of Finland (GoF), an estuary-like sub-basin of the Baltic Sea. Circulation patterns in the GoF are complex and vary from season to season and year to year. Estuarine circulation in the gulf is heavily modified by many factors, such as wind forcing, topography and geostrophic effects. Based on a 7-year run of the NEMO 3D hydrodynamic model with a 500 m horizontal resolution, we analysed seasonal changes of mean circulation patterns. We found that there were clear seasonal differences in the circulation patterns in the GoF. Features that moved or changed direction from season to season were damped or hidden in the averages. To further study these differences, we also carried out a self-organising map (SOM) analysis of currents for several latitudinal sections. The results of the SOM analysis emphasised the estuary-like nature of the GoF. Circulation changed rapidly from normal estuarine circulation to reverse estuarine circulation. The dominant southwesterly winds supported the reversal of the estuarine circulation. Both normal and reversed estuarine circulation were roughly as common in our data. The SOM analysis also demonstrated how the long-term cyclonic mean circulation field and the average salinity field emerged from the interaction of normal and reversed estuarine circulation.
  • Lehtoranta, Jouni (Finnish Environment Institute, 2003)
    Monographs of the Boreal Environment Research 24
    One of the main threats facing the Baltic Sea is eutrophication due to an excess supply of nutrients. In the Gulf of Finland, primary productivity and biomasses of autotrophic and heterotrophic organisms are among the highest in the Baltic. The high biomasses are attributed mainly to the eutrophying effects of the large land-derived nutrient inflow from St. Petersburg and via the River Neva. The role of sediment phosphorus (P) in eutrophication is, however, poorly understood in the Gulf. The aim of this study was to obtain information on the regional levels of sediment P and to specify the pools of P. Efforts were also made to define the sediment retention ability of P along the estuarine gradient, to establish the factors that affect the benthic fl ux of P and to assess whether sulphur (S) is a significant factor in sediment P cycling. On the basis of the results it was possible to quantify and consider the ecological implications of the benthic flux of P.The sediments of the Gulf are rich in organic matter, nitrogen (N) and P. A large portion of the mobile pool of P in these sediments consists of iron (Fe)-bound P, which is released when Fe(III) oxides are reduced under anoxic conditions. The increase in the sediment organic matter concentration along the estuarine gradient seems to impair the sediments’ ability to retain P. The highest benthic P efflux was measured in summer and the lowest in winter. The decrease in the near-bottom oxygen concentration in summer may favour anaerobic sulphate reduction followed by iron sulphide (FeS) formation close to the sediment- water interface. In the sediment, the key role in preventing P from entering the water is played by the binding ability of P related to diffusing Fe. In the brackish Baltic Sea, in contrast to most lake systems, the diffusion of Fe may be inactivated by FeS formation. Thus, high effluxes of P to oxic water were measured on bottoms where black sediment indicating the presence of FeS extended to the surface of the sediment.The P released from the sediments of the Gulf itself may largely explain the high P concentrations and low N:P ratios in near-bottom waters in summer and, after autumn mixing, in the entire water column. However, the input of P from the main Baltic basin may also lead to an increase in P concentrations in the Gulf. The high release rates of P measured – rather than denitrification – largely explain the N limitation of the primary production. A relationship seems to exist between the increase in near-bottom salinity and the weakening of the sediment oxidation state of the Gulf since 1996. The inflow of saline water to the Gulf strengthens density stratification, thus favouring the release of P to water. Therefore, the variations in hydrological factors may produce a marked between-year variation in the benthic P efflux and counteract the reduction in the external P load. The ability of sediment to retain P could most likely be promoted by decreasing the sedimentation of labile organic matter on the bottom. Organic matter sedimentation could be lowered by cutting the amount of bioavailable N and P from an anthropogenic sources.
  • Salojärvi, Joona (Helsingfors universitet, 2014)
    The objective of this study is to assess the willingness to pay of the Finnish public for improvements in the ecological status of the Gulf of Finland using the choice experiment method (CE). The change in the status of the environment is described with four attributes that contribute to the provision of ecosystem services in the Baltic Sea: (1) the populations of key species (including species of mammals, birds, fish, invertebrates and plants), (2) the visibility of the key species, (3) the intensity and duration of algal blooms, and (4) possibilities for recreational fishing. The study considers moderate and substantial improvement scenarios resulting from a range of management measures proposed under the marine strategy framework directive (MSFD), and estimates the accruing benefits with multinomial logit and random parameters logit models. The results of the study show that significant benefits could occur for the Finns if improvements in the environmental status of the Gulf of Finland are achieved. Reduction in algal blooms was found to be most important to the respondents followed closely by improvements in the populations of key species. The third most important attribute was the recreational fishing possibilities, while significantly smaller willingness to pay values was estimated on the visibility of key species. This thesis is conducted within the European Union funded ODEMM project. The overall aim of the project is to develop management options and operational procedures to help in achieving the objectives of the MSFD and implementing ecosystem based marine management.
  • Pitkänen, Heikki (National Board of Waters and the Environment, 1994)
    Publications of the Water and Environment Research Institute 18
    Suomen rannikkovesien rehevöityminen: jokivesien tuomien ravinteiden alkuperä, käyttäytyminen ja vaikutukset.
  • Kuprijanov, Ivan; Väli, Germo; Sharov, Andrey; Berezina, Nadezhda; Liblik, Taav; Lips, Urmas; Kolesova, Natalja; Mannio, Jaakko; Lips, Inga; Junttila, Ville (Macmillan, 2021)
    Marine Pollution Bulletin, 170 (2021), 112642
    Contamination by hazardous substances is one of the main environmental problems in the eastern Gulf of Finland, Baltic Sea. A trilateral effort to sample and analyse heavy metals (HMs), polycyclic aromatic hydrocarbons (PAHs), and organotins from bottom sediments in 2019–2020 were conducted along with harvesting historical data in Russian, Estonian and Finnish waters. We suggest that the input of organotins still occurs along the ship traffic routes. The tributyltin content exceeded the established quality criteria up to more than 300 times. High contamination by PAHs found near the ports, most likely originate from incomplete fuel incineration processes. The Neva River Estuary and Luga Bay might potentially suffer from severe cadmium contamination. The high ecological risk attributed to the HMs was detected at deep offshore areas. The simulated accumulation pattern qualitatively agrees with field observations of HMs in sediments, demonstrating the potential of numerical tools to tackle the hazardous substances problems.
  • Unknown author (Vesihallitus, 1972)
    Vesihallitus. Tiedotus 28
  • Snellman, Anna (Helsingin yliopisto, 2020)
    Tässä tutkielmassa tarkastellaan särkikaloja väli-isäntinä hyödyntävien imumatolajien esiintyvyyttä, niiden tunnistamista ja merkitystä. Tutkielmassa keskitytään lähinnä imumatolajeihin, joiden pääisäntäeläimiä ovat nisäkkäitä, ja joilla on havaittu olevan kliinistä merkitystä myös ihmisille. Tutkielma sisältää kirjallisuuskatsauksen lisäksi alkuperäistutkimuksen, jossa selvitettiin Itämerestä pyydetyissä särjissä loisivien imumatojen esiintymistä. Tutkimuksen aikana tavoitteena oli myös selvittää, löydetäänkö särjistä Pseudamphistomum truncatum -lajin metacercarioita, sillä kyseisestä lajista oli tehty aiemmin havaintoja Kaakkois-Suomen alueella elävistä ketuista. Imumatojen esiintymisen selvittämisen lisäksi tutkielmassa perehdytään kalojen iänmääritykseen, joka voidaan tehdä esimerkiksi laskemalla hartian lukkoluun (cleithrum) kasvuvyöhykkeiden lukumäärä. Tutkimuksessa hyödynnettiin WHO:n vuonna 1995 julkaisemassa raportissa esiteltyä digestiomenetelmää, jolla imumatojen metacercaria-muotoja vapautettiin särkien lihaskudoksesta. Näytteinä olivat joitakin päiviä aiemmin preparoidut särkifileet, joita tutkittiin yhteensä 85 kappaletta. Fileet käsiteltiin loiskystien vapauttamiseksi mekaanisesti sauvasekoittimella ja kemiallisesti pepsiiniliuoksella. Syntynyt seos laskeutettiin suppilossa, ja selkeytysten jälkeen sedimentti kerättiin mikroskoopin avulla tarkasteltavaksi. Iänmääritykseen satunnaisesti valikoiduilta 20 särjeltä irrotettiin hartian lukkoluu. Keittämällä suoritetun puhdistuksen jälkeen luusta laskettiin mikroskoopin avulla kasvuvyöhykkeet, joiden lukumäärä vastaa kalan ikää vuosissa. Aineistossa havaittiin imumatojen metacercaria-muotoja 98 %:ssa tutkituista näytteistä. Valtaosan löydöksistä muodostivat kolme ulkonäöltään toisistaan erottuvaa metacercaria-tyyppiä. Lisäksi erotettiin silmämääräisesti ainakin kolmenlaisia digestion aikana vapautuneita imumatoja. Metacercarioita ja vapautuneita imumatoja kerättiin joiltakin laskentamaljoilta (noin 10 %:sta) erilleen ja lähetettiin PCR-menetelmällä suoritettavaan lajinmääritykseen. PCR-tulosten perusteella 46 %:ssa tutkituista särjistä tehtiin silmämääräisen morfologisen tunnistuksen perusteella P. truncatum -löydös. Iänmäärityksessä havaittiin kokonaisuutena positiivinen korrelaatio iän ja pituuden välillä. Tutkimuksessa löydettiin särjistä nisäkkäisiin tarttuvia imumatoja. Tämän tuloksen ja aiempien Euroopassa ja Venäjällä tehtyjen selvitysten perusteella voidaan olettaa, että kalaa ravintonaan käyttävillä nisäkkäillä on riski saada imumatoinfektio särjenlihasta. Ihmisiin ja kalaa syöviin lemmikkieläimiin kohdistuvaa riskiä voidaan kuitenkin pienentää etenkin, jos kalanliha kuumennetaan valmistuksen yhteydessä kauttaaltaan. Muita särkikaloja ei sisällytetty tutkimukseen, mutta myös niistä aiheutuva imumatoinfektioriski on todennäköisesti alueella suuri, koska monen lajin ekologinen lokero on jossakin elämänvaiheessa samankaltainen särjen kanssa.
  • Vanninen, Vesa (Kaakkois-Suomen ympäristökeskus, 2006)
    KASra 2/2006
    Tässä tutkimuksessa selvitettiin merkintä-takaisinpyynti -menetelmän avulla kuhaistutusten tuloksellisuutta itäisellä Suomenlahdella. Lisäksi tutkittiin mm. kuhapopulaation rakennetta ja kuhan kasvunopeutta. Vuosina 1999 ja 2000 istutettiin noin 43 000 yksikesäistä polttomerkittyä kuhanpoikasta Haminan ympäristön merialueelle. Niiden takaisinpyynti suoritettiin verkkopyyntinä vuosina 2000–2005. Saaliiksi saaduista kuhista otettiin suomunäyte sekä tarkastettiin mahdollinen polttomerkintä. Suomujen perusteella määritettiin kuhien ikä sekä tehtiin takautuva kasvunmääritys. Vuosiluokassa 1999 istutettujen kuhien osuus näytekaloista oli alle prosentti ja vuosiluokkaan 2000 kuuluvia istukkaita ei havaittu lainkaan. Tämän perusteella voidaan olettaa, että itäisen Suomenlahden kuhasaaliit perustuvat pääasiassa luontaiseen lisääntymiseen. Olettamusta tukee istutusten ja saaliin välillä tehty vertailu, jossa ei havaittu selvää trendiä. Kuhan kasvu on itäisellä Suomenlahdella samankaltaista kuin Porvoon ja Sipoon edustalla. Kalastusalueen säätämän 40 cm:n alamitan kuha saavuttaa tavallisesti kuudennella kasvukaudella. Kuhan kasvussa on sekä suuria vuosiluokkakohtaisia että yksilöllisiä eroja. Itäisen Suomenlahden kuhasaaliista valtaosan saavat vapaa-ajankalastajat. Kuhan kokonaissaaliista verkkopyynnin osuus on noin 90 %. Pyynnissä käytetään pääasiassa solmuväliltään alle 50 mm:n verkkoja. Tämän vuoksi pyynti kohdistuu pääasiassa alle kilon painoisiin ja viiden-seitsemän vuoden ikäisiin kuhiin. Kuhan kilomääräistä saalista on mahdollista kasvattaa ja kuhan luontaista lisääntymistä tehostaa suurentamalla pyynnissä käytettävien verkkojen solmuvälejä, korottamalla kuhan alamittaa sekä rauhoittamalla kuhan kutulahtia pyynniltä touko-kesäkuussa. Kuhaistutusten heikon tuloksellisuuden ja istutusten aiheuttaman kuhakantojen sekoittumisen takia istutukset tulisi lopettaa. Istutusten lopettaminen säästäisi varoja tuottavampaan käyttöön sekä saattaisi välillisesti parantaa kuhan luontaista lisääntymistä ja kuhasaaliita.
  • Wartiovaara, Jyrki (Vesihallitus, 1975)
    Vesientutkimuslaitoksen julkaisuja 13
    Engl. summary: Amounts of substances discharged by rivers off the coast of Finland
  • Friman, Mikko (Helsingfors universitet, 2010)
    The Baltic Sea area, formerly an importer of crude oil, has become an important node for oil export. In 2015, between 160 and 240 million tons of oil (and some 150 million tons of other cargo) will be transported through the Gulf of Finland only, in 2006, 140 million tons of oil was shipped through the Gulf. There are a number of development projects going on in Russia and Estonia concerning both old and new terminals. Also new pipelines from the Russian production sites to the coastal oil terminals are under planning or construction. According to an estimate by the EU Commission, in 2010 about 400 million tons of oil and petrochemicals will be processed in the seaports of the Baltic Sea. The risk of accidents is increasing with busier traffic and larger ships. Oil can contaminate the sea through various routes: spills during loading, unloading and other port operations, accidental oil spills from tankers, oil terminals, refineries, pipelines, exploration sites and regular non-tanker shipping, runoff from land, and as municipal and industrial wastes. Any step toward improved safety in shipping decreases the risks and impacts on the marine environment. Therefore the Baltic Sea countries have to continue to work toward pollution-free marine transportation by providing employees environmental protection education and training, by combating substandard shipping, and by increasing international recognition for the ecological significance of the status of the Baltic as a Particularly Sensitive Sea Area (PSSA). The International Maritime Organization (IMO) designated the Baltic Sea a PSSA in 2004.. Several modern tools have been installed for the Gulf of Finland navigation to reduce the risk of ship collisions. One of them is the Gulf of Finland mandatory Ship Reporting System (GOFREP), which went into operation on 1 July 2004. The system covers the international waters of the Gulf of Finland in a joint effort between Finland, Estonia and Russia. By Traffic Separation Schemes (TSS) ships are referred to use a different route when travelling from east/north to west/south and vice versa. Important steps forward to further decrease the risks of shipping and oil accidents were taken in July 2006, when new traffic routing measures entered into force in the central Baltic Sea, in Bornholmsgat, and north of Rügen. In the Gulf of Finland, which is a hot spot area for increasing oil transports, the Vessel Traffic Management and Information System (VTMIS) was taken into use in 2004, including TSS. The HELCOM Automatic Identification System (AIS) provides, since 2005, a very helpful source of information documenting, which enables the identification of the name, position, course, speed, draught and cargo of every ship of more than 300 gross tons sailing in the Baltic Sea. The valuation of oil spill damages is challenging because it attempts to estimate the harm from possible future oil spills, and because the harm depends largely on the conditions at the time of the spill. In addition, it might be difficult for people to perceive the probabilities and uncertainties related to oil spills and their impacts. Against this background it is of utmost importance to improve both the technical and the human aspects of ship operation.
  • Ryttäri, Terhi (Suomen ympäristökeskus, 2011)
    Suomen ympäristö 20/2011
    Merimetso on Itämeren piirissä ja Suomen rannikolla voimakkaasti levittäytyvä pesimälintu, jonka kannan kehitystä on Suomessa alusta alkaen seurattu tarkasti. Tässä 1998-2010 tehdyssä selvityksessä arvioidaan merimetsoyhdyskuntien vaikutusta pesimäsaartensa kasvistoon. Merimetsojen vaikutus saarten kasvistoon on osittain samanlaista kuin lokkien. Ne lannoittavat oleskelualueitaan hyvin voimakkaasti, paikoin niin, etteivät edes lintuluodoille tyypilliset typensuosijajäkälät kestä lantakuormitusta. Lanta leviää sadevesien mukana samalla laimentuen kallioiden rakoihin ja juotteihin, joissa kukoistavat lintuluodoille luonteenomaiset merisauniot, ruoholaukat ja keltamaksaruohot. Osa putkilokasvilajistosta hyötyy lannoituksesta, osalle se on haitta. Selvimmin ylimääräisestä lannoituksesta kärsivät happamilla mailla viihtyvät varpukasvit ja kataja. Puuvartiset kasvit kärsivät myös merimetsojen aiheuttamista mekaanisista vaurioista, sillä merimetsot katkovat oksat pesänrakennustarpeiksi. Merimetsojen vaikutus saarten kasvistoon poikkeaa lokkien vaikutuksista selvimmin siinä, että ne eivät kalansyöjinä levitä kasvien siemeniä saarelta toiselle. Puuvartisten, typpeä karttavien kasvilajien hävitessä saarilta, ravinteisuutta suosivien lajien osuus kasvaa.
  • Uurasjärvi, Emilia; Pääkkönen, Minna; Setälä, Outi; Koistinen, Arto; Lehtiniemi, Maiju (Elsevier, 2021)
    Environmental Pollution 268, Part A (2021), 115700
    In the Baltic Sea, water is stratified due to differences in density and salinity. The stratification prevents water from mixing, which could affect sinking rates of microplastics in the sea. We studied the accumulation of microplastics to halocline and thermocline. We sampled water with a 100 μm plankton net from vertical transects between halo- and thermocline, and a 30 L water sampler from the end of halocline and the beginning of thermocline. Thereafter, microplastics in the whole sample volumes were analyzed with imaging Fourier transform infrared spectroscopy (FTIR). The plankton net results showed that water column between halo- and thermoclines contained on average 0.92 ± 0.61 MP m−3 (237 ± 277 ng/m−3; mean ± SD), whereas the 30 L samples from the end of halocline and the beginning of thermocline contained 0.44 ± 0.52 MP L−1 (106 ± 209 ng L−1). Hence, microplastics are likely to accumulate to thin layers in the halocline and thermocline. The vast majority of the found microplastics were polyethylene, polypropylene and polyethylene terephthalate, which are common plastic types. We did not observe any trend between the density of microplastics and the sampling depth, probably because biofilm formation affected the sinking rates of the particles. Our results indicate the need to sample deeper water layers in addition to surface waters at least in the stratified water bodies to obtain a comprehensive overview of the abundance of microplastics in the aquatic environment.
  • Nisula, Kirsi (University of Helsinki, 2000)
  • Kauppila, Pirkko (Finnish Environment Institute, 2007)
    Monographs of the Boreal Environment Research 31
    The tackling of coastal eutrophication requires water protection measures based on status assessments of water quality. The main purpose of this thesis was to evaluate whether it is possible both scientifically and within the terms of the European Union Water Framework Directive (WFD) to assess the status of coastal marine waters reliably by using phytoplankton biomass (ww) and chlorophyll a (Chl) as indicators of eutrophication in Finnish coastal waters. Empirical approaches were used to study whether the criteria, established for determining an indicator, are fulfilled.The first criterion (i) was that an indicator should respond to anthropogenic stresses in a predictable manner and has low variability in its response. Summertime Chl could be predicted accurately by nutrient concentrations, but not from the external annual loads alone, because of the rapid affect of primary production and sedimentation close to the loading sources in summer. The most accurate predictions were achieved in the Archipelago Sea, where total phosphorus (TP) and total nitrogen (TN) alone accounted for 87% and 78% of the variation in Chl, respectively. In river estuaries, the TP mass-balance regression model predicted Chl most accurate when nutrients originated from point-sources, whereas land-use regression models were most accurately in cases when nutrients originated mainly from diffuse sources. The inclusion of morphometry (e.g. mean depth) into nutrient models improved accuracy of the predictions.The second criterion (ii) was associated with the WFD. It requires that an indicator should have type-specific reference conditions, which are defined as “conditions where the values of the biological quality elements are at high ecological status”. In establishing reference conditions, the empirical approach could only be used in the outer coastal waters types, where historical observations of Secchi depth of the early 1900s are available. Most accurate prediction was achieved in the Quark. However, the average reference values in the outer coastal types are underestimated in sites near the zone of the inner coastal waters. In the inner coastal water types, reference Chl, estimated from present monitoring data, are imprecise - not only because of the less accurate estimation method - but also because the intrinsic characteristics, described for instance by morphometry, vary considerably inside these extensive inner coastal types. As for phytoplankton biomass, the reference values were less accurate than in the case of Chl, because it was possible to estimate reference conditions for biomass only by using the reconstructed Chl values, not the historical Secchi observations. An paleoecological approach was also applied to estimate reference conditions for Chl. In Laajalahti, an urban embayment off Helsinki, strongly loaded by municipal waste waters until 1986, reference conditions prevailed in the mid- and late 1800s. The recovery of the bay from pollution has delayed as a consequence of benthic release of nutrients. Laajalahti will probably not achieve the good quality objectives of the WFD on time.The third criterion (iii) was associated with coastal management including the resources it has available. Analyses of Chl are cheap and fast to carry out compared to the analyses of phytoplankton biomass and species composition; the fact which has an effect on number of samples to be taken and thereby on the reliability of assessments. However, analyses on phytoplankton biomass and species composition provide more metrics for ecological classification, the metrics which reveal various aspects of eutrophication contrary to what Chl alone does.