Kemijski profil sedimenata Plominskog zaljeva

Granulometric, chemical, and leaching properties of sediments dredged in the Plomin Bay (Northern Adriatic Sea, Croatia) were investigated in order to asses the risk of remobilisation of heavy metals into the water column. In total 65 samples from 65 sampling sites were taken from different sediment depths within the bay. Analysis of variance confirmed the homogeneity of granulometric and elemental composition of the investigated sediment throughout its volume. Granulometric analysis showed that all samples corresponded to a pelitic fraction (<0.063 mm). Bulk elemental mass fractions in the sediments were similar to literature data on relatively unpolluted areas of the Adriatic Sea. High sedimentation rate caused by constant infl ow of material from the Boljunčica River drainage may be responsible for low levels of heavy metals and negligible infl uence of fl y and bottom ash from a nearby disposal site on the chemical composition of the sediments. In contact with sea water only 0.29 mg kg-1 of V, 0.04 mg kg-1 of Cr, 0.07 mg kg-1 of Ni, 0.33 mg kg-1 of Cu, 0.67 mg kg-1 of Zn and 0.06 mg kg-1 of Pb could be remobilised from sediment material into the water column. However, these values increased three to ten times in case of leaching with organic acids.Granulometrijska i kemijska svojstva te mogućnost otpuštanja teških metala ispitivani su u sedimentima Plominskog zaljeva (Sjeverni Jadran, Hrvatska) u svrhu utvrđivanja rizika od remobilizacije teških metala iz sedimenta u stupac vode. Uzeto je 65 uzoraka s različitih točaka i dubina unutar zaljeva. Analizom varijance potvrđena je granulometrijska i kemijska homogenost cijelog volumena sedimenta, što upućuje na jedan prevladavajući izvor tijekom cijeloga sedimentacijskog razdoblja. Granulometrijskom analizom je utvrđeno da u svim uzorcima prevladava sitnozrnata frakcija (<0,063 mm). Koncentracije elemenata u ukupnim uzorcima sedimenata slične su literaturnim vrijednostima objavljenim za relativno onečišćena područja Jadranskog mora. Velika brzina sedimentacije uzrokovana konstantnim donosom materijala iz slijevnog područja Boljunčice vjerojatan je uzrok niskih koncentracija teških metala i slabo vidljivog utjecaja odlagališta šljake i pepela na sastav sedimenata. U kontaktu s morskom vodom moguća je remobilizacija samo 0,29 mg kg-1 V, 0,04 mg kg-1 Cr, 0,07 mg kg-1 Ni, 0,33 mg kg-1 Cu, 0,67 mg kg-1 Zn i 0,06 mg kg-1 Pb iz sedimenta u stupac morske vode. Ipak ove vrijednosti su tri do deset puta povećane u slučaju izluživanja s pomoću organskih kiselina

Massive Consumption of Gelatinous Plankton by Mediterranean Apex Predators

Stable isotopes of carbon and nitrogen were used to test the hypothesis that stomach content analysis has systematically overlooked the consumption of gelatinous zooplankton by pelagic mesopredators and apex predators. The results strongly supported a major role of gelatinous plankton in the diet of bluefin tuna (Thunnus thynnus), little tunny (Euthynnus alletteratus), spearfish (Tetrapturus belone) and swordfish (Xiphias gladius). Loggerhead sea turtles (Caretta caretta) in the oceanic stage and ocean sunfish (Mola mola) also primarily relied on gelatinous zooplankton. In contrast, stable isotope ratios ruled out any relevant consumption of gelatinous plankton by bluefish (Pomatomus saltatrix), blue shark (Prionace glauca), leerfish (Lichia amia), bonito (Sarda sarda), striped dolphin (Stenella caerueloalba) and loggerhead sea turtles (Caretta caretta) in the neritic stage, all of which primarily relied on fish and squid. Fin whales (Balaenoptera physalus) were confirmed as crustacean consumers. The ratios of stable isotopes in albacore (Thunnus alalunga), amberjack (Seriola dumerili), blue butterfish (Stromaeus fiatola), bullet tuna (Auxis rochei), dolphinfish (Coryphaena hyppurus), horse mackerel (Trachurus trachurus), mackerel (Scomber scombrus) and pompano (Trachinotus ovatus) were consistent with mixed diets revealed by stomach content analysis, including nekton and crustaceans, but the consumption of gelatinous plankton could not be ruled out completely. In conclusion, the jellyvorous guild in the Mediterranean integrates two specialists (ocean sunfish and loggerhead sea turtles in the oceanic stage) and several opportunists (bluefin tuna, little tunny, spearfish, swordfish and, perhaps, blue butterfish), most of them with shrinking populations due to overfishing

Eutrophication of the Izmit bay, Marmara Sea

The elongated Bay of Izmit is one of the most heavily polluted semienclosed basins in Turkey. From systematic data obtained during field studies between 1984 and 1988, it is clear that two distinct water masses are present throughout the year. The brackish water which originated in the Black Sea forms a 10 to 15 m thick surface layer. Its salinity and temperature vary from 22-24 ppt and 20-24 degrees C in summer, to 26 ppt and 7 degrees C, in winter. Marine water, which arrived from the Mediterranean, underlies the permanent pycnocline and has much more stable properties: salinity and temperature ranges are 37.5-38.5 ppt and 14-15 degrees C, respectively

Trophic characteristics of the Sapanca lake (Turkey)

Systematic measurements of optical properties, concentrations of major and minor chemicals and primary production throughout 1989-1992 enabled us to identify the oligotrophic state of Sapanca lake, Marmara region, Turkey. Lake waters which have low concentrations of major anions and cations (total = 49 mu M) overturn every February-March, ventilating the bottom waters and enriching the surface waters with nutrients. Surface waters cool down to 6.5 degrees C by late winter and then warm steadily to 26 degrees C by late summer, while temperatures in deep waters range between 6.5 and 10.0 degrees C throughout the year. When the seasonal thermocline develops, the dissolved oxygen profiles exhibit a subsurface maximum in the thermocline, while in the hypolimnion water, the content varies seasonally from 11.5-12.0 ppm (350-375 CIM) in March to 0.5-1.7 ppm (16-56 mu M) in late autumn. Surface nitrate concentrations vary markedly with season, from < 0.15 mu M in summer to 5.7 mu M in early March, whilst the bottom water concentrations range from 13.5-14.0 mu M in late autumn to 5.7 mu M after the winter overturn. Phosphate concentrations are always less than 0.1 mu M throughout the entire water column. Subsurface chlorophyll-a maximum descends in late summer to 20-25 m depths, where the Light intensity is less than 1% of the surface value. Below 10-15 m depths, corresponding to the upper thermocline, primary productivity is very low. The range was from 35 to 93 mg C/m(2) day(-1) during 1989-1991, consistent with the values in other oligotrophic lakes

Aleitamento e hábitos orais deletérios em respiradores orais e nasais Breast-feeding and deleterious oral habits in mouth and nose breathers

OBJETIVO: A amamentação promove vários benefícios na criança, entre eles o favorecimento da respiração nasal. Neste estudo verificou-se a relação do padrão respiratório com o histórico de aleitamento e hábitos orais deletérios. FORMA DE ESTUDO: clínico com coorte transversal. MATERIAL E MÉTODO: A população foi constituída por 62 crianças, de 3 anos e 3 meses a 6 anos e 11 meses, as quais foram submetidas à avaliação otorrinolaringológica, para definição dos grupos respiradores nasais e orais e entrevista fonoaudiológica. A avaliação otorrinolaringológica constituiu-se dos seguintes exames: rinoscopia anterior, oroscopia e exame radiológico. Os pais das crianças foram questionados em relação à forma (natural e/ou artificial), e ao período de aleitamento, além da presença de hábitos orais deletérios (sucção e mordida). O teste Exato de Fisher foi utilizado para comparar os grupos em relação à presença ou ausência de hábitos e diferentes períodos de aleitamento. RESULTADOS: O período de aleitamento materno foi maior nos respiradores nasais concentrando-se no período de 3 a 6 meses de idade. Quanto ao uso de mamadeira, os resultados mostraram que a maioria das crianças de ambos os grupos utilizou-se deste tipo de aleitamento nos primeiros anos de vida, não apresentando diferença estatística entre os grupos (p=0.58). A presença de hábitos orais deletérios ocorreu de maneira marcante nos respiradores orais, evidenciando diferença estatisticamente significativa, entre os grupos, para os hábitos de sucção (p=0.004) e hábitos de mordida (p=0.0002). CONCLUSÃO: As crianças respiradoras orais apresentaram um menor período de aleitamento materno e um histórico de hábitos orais presentes comparadas às crianças respiradoras nasais.<br>AIM: Breast-feeding promotes several benefits in childhood, among them favoring the nasal breathing. In the present study, the relationship between breathing pattern and the history of breast-feeding and of deleterious oral habits was determined. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: The study population consisted of 62 children ranging in age from 3 years and 3 months to 6 years and 11 months who were submitted to otorhinolaryngologic evaluation to determine nasal and mouth breathers and to a speech language pathologic interview. The otorhinolaryngologic evaluation involved the following exams: anterior rhinoscopy, oroscopy and radiologic examination. The parents of the children were questioned about the form of feeding (natural and/or artificial), the duration of breast-feeding and the presence of deleterious oral habits (suction and biting). The Fisher exact test was used to compare groups regarding the presence and absence of habits and the different periods of breast-feeding. RESULTS: The breast-feeding period was longer among nasal breathers and was concentrated in the period between 3 and 6 months of age. Regarding the use of bottle, the results showed that most of the children in both groups used this type of feeding during the first years of life, with no significant difference between groups (p=0.58). There was a marked presence of deleterious oral habits among mouth breathers, with a statistically significant difference between groups regarding suction (p=0.004) and biting habits (p=0.0002). CONCLUSION: Mouth breathing children were breast-fed for a shorter period of time and had a history of deleterious oral habits compared to nose breathers