Thesis (M. Sc.)--University of Western Sydney, Hawkesbury, 1996.

Abstract The principal objectives of this research are to investigate the distribution of fish larvae in relation to environmental factors in Chiku lagoon and the coastal waters of Tainan, Southwestern Taiwan during the period from August 1998 to June 1999 and during August 13~14, 1997. Seventy-six species of the fish larvae belonging to 65 genera were identified in Chiku lagoon and the mean numerical abundance of the fish larvae was 29 ¡Ó44 inds./100m3 during the sampling period between August 1998 and June 1999; and the dominant species were Omobranchus fasciolaticeps¡BGobiidae gen. sp.¡BSillago maculata and Engraulis japonica. Seventy-two species of the fish larvae belonging to 66 genera were identified in the coastal waters off Chiku lagoon during two cruises of December 1998 and June 1999, with the mean numerical abundance of 35 ¡Ó24 inds./100m3 ; and the dominant species were Myctophidae gen. sp., Ceratoscopelus warming, S. maculata and E. japonica. Eighty-three species of fish larvae belonging to 73 genera were identified and the mean numerical abundance was 35 ¡Ó49 inds./100m3 during the cruise of August 13~14, 1997 at 6 stations along a transect from the coastal waters near Tsengwen River to the waters south of Penghu Island, and the dominant species were Bothidae gen. sp., Stomioidae gen. sp. and Mullidae gen. sp.. The abundance, species number and species diversity of fish larvae were usually higher in the coastal waters of Tainan than in Chiku lagoon. The larval fish assemblages of Chiku lagoon was significantly different from that of the coastal waters of Tainan. The dominant species of fish larvae in the coastal water of Tainan were mostly meso-epipelagic species¡]Myctophidae, C. warningi, Diaphus sp., and Carangidae¡^, while Chiku lagoon was dominated by sandy benthic species¡]Blenniidae¡^and estuarine species ¡]Gobiidae and Engraulidae¡^. The species number and abundance of fish larvae in the coastal water of Tainan were found higher in wet season¡]June¡^than in dry season¡]December¡^. The abundance of fish larvae was significantly different among stations and seasons, but did not different between tides in Chiku lagoon. The abundance of fish larvae was higher at night than during the day in August, 1998 and was usually higher in spring ¡]April¡^and lower at the middle station of Chiku lagoon. The abundance of fish larvae was not significantly correlated with water temperature and salinity, but higher abundance of fish larvae was always found when temperature was between 26¢Jand 30¢J, and in higher salinity ¡]34‰ ~36‰¡^. In the transect study, the abundance of fish larvae was significantly different between surface and deep tows¡]p<0.05¡^, but not among stations and between day and night (p>0.05).

The species composition and numerical abundance of copepods related to tides, seasons and stations were investigated in Chiku lagoon and coastal waters of Tainan from August 1998 to June 1999. The grazing impact on phytoplankton by copepods in the study area was measured and the species composition and numerical abundance of copepods collected by two nets with different mashes (330&#x00B5;m and 100 &#x00B5;m) were compared and discussed. In total 72 species of copepods belonging to 14 families and 4 orders (42 Calanoids, 2 Harpacticoids, 19 Poecilostomatoids, and 8 Cyclopoids) were identified in the samples collected by 330&#x00B5;m mash net in the Chiku lagoon. The mean abundance of copepods was 1.5¡Ó3.5 ¡Ñ104 ind./100m3. The most dominant groups were Parvocalanus crasirostris, Oithona simplex, Oithona rigida and unidentified Copepodite, comprised 68 % of the total copepod numbers. The highest abundance of copepods was observed in October and February. Higher abundance and species number were found at station I than at station M, and were found more during high tide than at low tide. Thirty-eight species of the copepods belonging to 13 familis and 4 olders. (22 Calanoids, 2 Harpacticoids, 8 Poecilostomatoids and 6 Cyclopoids) were found in the samples collected by 100£gm mash net, with mean abundance of 1.1¡Ó1.9 ¡Ñ106 ind./100m3. The most dominant species were mostly small-sized and immature copepods, such as Parvocalanus crassirostris ¡BCopepodite¡BOithona rigida¡BOithona brevicornis ¡BOithona nana¡BNauplii¡BOithona simplex¡BEuterpina acutifrons and Acrocalanus gracilis, and comprised 90 % of the total numbers. Abundance and species number of copoeds varied seasonally, with highest abundance and species number found in February. The abundance of copoeds at M station was found higher than that at I station. Sixty-two species of the Copepod belonging to 13 families and 4 orders (36 Calanoids, 2 Harpacticoids, 20 Poecilostomatoids and 4 Cycloids) were found in the coastal watersof tainan, with mean abundance of 6.2 ¡Ó7.9 ¡Ñ104 ind./100m3. The most dominant copoepods in this area were warm-water and neritic species, such as Farranula gibbula, Acrocalanus gibber, Temora discaudata, A. gracilis, O. atlantica, Copepodite and T. turbinata, and comprised 62 % of the total catch. The abundance was significantly different among station, highest abundance found at station 3, that is the closest station to Chiku lagoon. The grazing impact of copepods on phytoplankton was minor, only < 2 % / day.

Evidence of Holocene sea-level changes along the Rio de Janeiro State Coast, and for the evolution of coastal lagoons and barriers in response to these sea- level movements, has been examined using stratigraphical and micropalaeontological techniques, radiocarbon dating and published data. Present-day diatom death assemblages have been studied in order to facilitate the interpretation of fossil assemblages, which has inter aha permitted the development of a simple statistical technique for the evaluation of the allochthonous diatom component. Modern lagoonal tide- gauge data have been used to establish a relationship between lagoonal water levels and tidal levels on the open coast. Evidence is presented which indicates that barriers which were previously believed to date from the mid-Holocene formed during the 'Last' Interglacial. The history of true Holocene barriers has been shown to be relatively complex, with some barriers having migrated by over-stepping and others by continous shoreface retreat. The published Holocene sea-level maximum for Rio de Janeiro State of -t- 4.8 m at 5100 BP is considered to be in error (approximately 3.0 m too high at this time) and a maximum Holocene sea level of -t- 3.0 m at c. 4000 BP is preferred. The evidence for sea-level maxima in other parts of Brazil at 5150 BP and for the migration of the geoid surface during the Holocene is questioned and shown to require further study. It is tentatively suggested that there may be evidence for an interglacial sea-level high at c. 35000 BP in Rio de Janeiro State.

[No abstract available] / Science, Faculty of / Zoology, Department of / Graduate

Abstract The Tapong Bay and the Chiku Lagoon are major lagoons in the south of Taiwan and are ideal sites to study the influence of coastal environment change on the ecosystem. Therefore, this study aims to evaluate the influence of oyster culture racks removal on biochemical processes of carbon, nutrients and mercury in the Tapong Bay, as well as to compare the status of mercury and trace-metal pollution in Tapong Bay and Chiku Lagoon. Before the removal of the oyster culture racks from the Tapong Bay, the annual mean of water exchange time is about 10 days that is longer than that of the present condition (7.1 days). This suggests that the flushing condition of lagoon water is improved after the racks were removed. The annual mean of each nutrient concentration is also lower at present than before, probably due to the enhanced water exchange rate and biological utilization. The annual mean of ∆POC/∆PN is 8.1 that is larger than that of the previous condition (7.3), possibly resulting from the increase of inputs of organic detritus. The Tapong Bay is an autotrophic system (p-r>0) both before and after the removal of oyster culture racks. However, the net ecosystem production (p-r) at present is twice as large as before the removal of oyster racks. After the removal of racks, the annual nitrogen fixation still exceeds the annual denitrification in the Tapong Bay with a magnitude of 5.35 mole N m-2 yr-1. Mercury (Hg) is a highly toxic metal with high affinity to biota. As the lack of Hg distribution data around the coastal zone of Taiwan, the study also aims to develop the analytical methods of Hg species and apply to study Hg biogeochemistry in Tapong Bay and Chiku Lagoon. Distributions of Hg species in the Tapong Bay are spatio-temporally variable, ranging from 6.66 to 12.40 ng/l (ave., 10.01 ng/l) for total Hg (unfilt.), from 1.79 to 3.75 ng/l (ave., 2.56 ng/l) for total dissolved Hg (filt.), from 1.59 to 2.67 ng/l (ave., 1.90 ng/l) for reactive Hg and from 2.51 to 9.45 ng/l (ave., 5.60 ng/l) for particulate Hg. Distributions of Hg species in the Chiku Lagoon are also spatio-temporally variable, ranging from 4.47 to 9.20 ng/l (ave., 6.22 ng/l) for total Hg (unfilt.), from 2.03 to 5.69 ng/l (ave., 4.54 ng/l) for total dissolved Hg (filt.), from 1.70 to 2.87 ng/l (ave., 2.12 ng/l) for reactive Hg and from 2.50 to 7.65 ng/l (ave., 4.79 ng/l) for particulate Hg. The abundance of particulate Hg is positively correlated with chlorophyll a, and total dissolved Hg and reactive Hg are negatively correlated with chlorophyll a. Such relationships imply that distributions of Hg species are primarily controlled by biological uptake and/or adsorption/desorption. Reactive Hg (Hg2+) is also correlated positively with dissolved oxygen concentration suggesting the biological redox effect in modulating the distribution of Hg2+. Particulate Hg also shows positive relationships with total suspended matter and particulate organic carbon, primarily due to biological absorption and particle adsorption/desorption. Enrichment factor (EF) are employed to evaluate trace metal pollution in Tapong Bay and Chiku Lagoon. The results show that the magnitudes of EF are larger in Tapong Bay than in Chiku Lagoon for most metals, particularly for Hg, indicating an thropogenic influence on metal distributions in both lagoons. On the other hand, particulate Hg is poorly correlated with particulate Fe, Mn and Al, strongly indicating relatively little influence of terrestrial detritus in modulating the distributions of particulate Hg.

Thesis (M.S.) -- Central Connecticut State University, 2005. / Thesis advisor: Timothy Rickard. "... in partial fulfillment of the requirements for the degree of Master of Science in International Studies." Includes bibliographical references (leaves 123-137). Also available via the World Wide Web.

The focus of this research is the study of lagoon ecosystem interaction and adjustment of the lagoon floor morphologies, water dynamics and sequences of change involving the motion of sediment. The aim of the study is to implement a functional mechanism to evaluate and analyse changes in the Lagos Lagoon and its ecosystem, with the objectives: (i) to investigate the extent and impact of urban expansion on the Lagoon coastline and its ecosystem; (ii) to quantify changes in the spatial extent of mangroves by use of satellite images from 1984 to 2016; (iii) to investigate the spatial dynamics of the Lagoon water floor and estimate its flushing time, (iv) to investigate the behaviour and relationship pattern of the Lagoon hydrodynamic parameters;, (v) to collect sediment samples from the Lagoon, analyse their settling behaviour and particle size distribution (PSD) in order to study their spatial evolution and characterisation; and (vi) to initiate a model that can predict the influence of sea level rise on the Lagoon ecosystem. The existing problem of an overcrowded human population in Lagos, the incessant repository of industrial effluence into its Lagoon, and increased flooding from the immediate watershed generate the research questions for this thesis. Lack of studies in the areas of morphodynamics and hydrodynamics on the Lagoon is a gap in the body of coastal knowledge, especially the temporal and long term dynamics of a significant Lagoon like that of Lagos. Understanding the dynamics of the Lagoon will enhance efficient monitoring, sustainable management and hence reveal the great importance the Lagoon preserves for the coastal region. Landsat images (1984 – 2016) of the study area (Lagos Lagoon) and its ecosystem were obtained for some specific data derivations. Land Surface Temperature (LST), NDVI and delineated Lagoon coastline were derived from the images. An Environment for Visualizing Images (ENVI) and a Geographic Information System (GIS) were used to extract land classification information, likewise, the GIS was used to develop a model for investigating the Lagoon coastline changes. With the use of ENVI and GIS software, land classification types were derived with the percentage of the coverage area for each land use classification for the years of study. A novel empirical method was designed to collect in-situ hydrodynamic data for both the dry and wet seasons in 2014, this was correlated and analysed using a case study approach. Also, in-situ bathymetric data was collected in 2014 to join the 2008 available data for studying the changes in the Lagoon water bed morphology. Functional models were used to examine the interaction of the various hydrodynamic information that was studied on the Lagoon. Results and inferences from the study show that the wetland of the system is depleting rapidly with increase urbanisation. In both lateral and vertical directions, the morphological shape of the Lagoon is reducing both in size and depth. The result from the model that investigated the system coastline indicates that reclamation and recession are taking place on the Lagoon coast at an approximate ratio of 4 to 1 whereas, the total surface area has reduced to approximately 204.51km2 as opposed to its approximate area of 208km2 as at the year 2010. The results from the analysis of the Lagoon salinity implies a wide salinity variation between the dry and the wet season; this confirms the system as brackish water in the dry season and freshwater in the wet season. Other inferences reveal the critical point of well-mixed water mass, significant vertical mixing during the wet season and a stable state during the dry season. In overview, the ratio of the Lagoon stratification during the dry season to that of the wet season is approximately 1 to 7 and flushing time of approximately 26 days and 22 days respectively. Lastly, the Lagoon possesses a varying settling velocity that is uniquely related to the diameter of its particles at various spatial locations. This research has been able to provide baseline investigations concerning the morphology and hydrodynamic study of the Lagos Lagoon.

Η λιμνοθάλασσα Πρόκοπος βρίσκεται στα βορειοδυτικά της Πελοποννήσου και αποτελεί μια πολύ σημαντική περιοχή με μοναδική πολιτιστική και οικολογική κληρονομιά όχι μόνο για τη συγκεκριμένη περιοχή, αλλά και για την Ελλάδα γενικότερα. Η λιμνοθάλασσα και ο υδροβιότοπο γύρω από αυτή έχει αναγνωριστεί από διεθνείς συνθήκες (RAMSAR), ευρωπαϊκά προγράμματα για την προστασία της φύσης (NATURA 2000) και της βιοποικιλότητας. Η λιμνοθάλασσα είναι ένας ενιαίος υγροβιότοπος, όμως το μεγαλύτερο μέρος της έκτασης της έχει μικρό βάθος (περίπου 30 cm) και καλύπτεται από πυκνούς καλαμιώνες, ιδιαίτερα κατά την θερινή περίοδο Στην εργασία αυτή παρουσιάζονται τα αποτελέσματα της μελέτης των ιζημάτολογικών χαρακτηριστικών της λιμνοθάλασσας μέσα από την ιζηματολογική και γεωχημική ανάλυση δειγμάτων ιζημάτων τα οποία συλλέχθηκαν από έξι θέσεις με πυρήνες βαρύτητας. Συνολικά 31 δείγματα αναλύθηκαν ως προς το κοκκομετρικό τους μέγεθος, τον ολικό οργανικό άνθρακα (TOC) και τα κύρια στοιχεία και ιχνοστοιχεία. Η κοκκομετρική ανάλυση πραγματοποιήθηκε για το αδρομερές υλικό με κόσκινα ενώ για το λεπτομερές κλάσμα χρησιμοποιώντας τον αναλυτή Malvern Mastersizer 2000 Hydro. Ο προσδιορισμός του ολικού οργανικού άνθρακα έγινε με την τροποποιημένη μέθοδο της τιτλοδότησης Walkley-Black ενώ ο προσδιορισμός των κυρίως στοιχείων και ιχνοστοιχείων, Al, Ca, Fe, K, Mg, Mn, Na, P, Cd, Cr, Cu, Ni, Pb, V και Ζn με φασματοσκοπία πλάσματος ατομικής εκπομπής Thermo Scientific iCAP 6000 ICP-OES. Για την αξιολόγηση των φυσικοχημικών παραμέτρων των υδάτων χρησιμοποιήθηκαν τα στοιχεία των σταθμών τηλεμετρίας (πολυαισθητήρας YSI6600), που έχουν εγκατασταθεί στην λιμνοθάλασσα του Πρόκοπου και τα οποία καλύπτουν περίοδο παρακολούθησης ενός έτους. Οι φυσικοχημικές παράμετροι οι οποίοι παρουσιάζονται και αξιολογούνται είναι το pH, θερμοκρασία (0C), διαλυμένο οξυγόνο (DO-mg/L) και αλατότητα (S ‰). Από την μελέτη των ανωτέρω παραμέτρων πρόεκυψε ότι τα ιζήματα της λιμνοθάλασσας αποτελούνται από πολύ πτωχά έως πτωχά ταξιθετημένη, πολύ λεπτόκοκκη άμμο έως αδρομερή πηλό και από υψηλές συγκεντρώσεις ολικού οργανικού άνθρακα >3%. Από τις εποχικές διακυμάνσεις των φυσικοχημικών παραμέτρων καταγράφηκαν περίοδοι με πολύ χαμηλές έως μηδενικές συγκεντρώσεις διαλυμένου οξυγόνου, τη θερινή περίοδο δείχνοντας υποξικές συνθήκες και ανοξικές κρίσης. Με βάση την θέση των σταθμών διακρίνουμε ότι η αλατότητα παρουσιάζει σημαντική διακύμανση, η οποία δημιουργείται από τη διαδικασία εισόδου-εξόδου του θαλάσσιου και γλυκού νερού στη λιμνοθάλασσα. Το pH παρουσιάζει μια φυσική ημερήσια διακύμανση του συντελεστή 0,5 το οποίο είναι ανάλογο προς τη θερμοκρασία και τη συγκέντρωση του οξυγόνου διαλύματος. Για την αξιολόγηση της περιβαλλοντικής κατάστασης της λιμνοθάλασσας από τις γεωχημικές αναλύσεις, χρησιμοποιήσαμε γεω-περιβαλλοντικούς δείκτες ώστε να προσδιορίσουμε τον εμπλουτισμό ή τον απεμπλουτισμό των ιζημάτων του πυθμένα σε βαρέα μέταλλα στην λιμνοθάλασσα. Για τον σκοπό αυτό χρησιμοποιήσαμε τον δείκτη γεω-συσσώρευσης (index of geo-accumulation), τον δείκτη μόλυνσης (contamination factor), τον δείκτη εμπλουτισμού (enrichment factor) που υπολογίσθηκαν σε σχέση με τιμές βάσεις των υπό εξέταση μετάλλων στα ιζήματα από την διεθνή βιβλιογραφία. Από την πιο πάνω ανάλυση φαίνεται ότι με βάση τους γεω-περιβαλλοντικούς δείκτες που υπολογίσθηκαν, τα υπό εξέταση ιζήματα στην περιοχή μελέτης δεν εμφανίζουν χαρακτηριστικά φαινόμενα ρύπανσης. / The Prokopos Lagoon is located in the north-western part of Peloponessus and is one of the most important ecological are of Greece. It is protected by the environmental international convention Ramsar and is listed in the Nature 2000 European network as special protected area. The lagoon is very shallow with mean depth of 30 cm while parts of it are consist of reed-bed forests and marshes. In this study we present the sedimentological characteristics of the bottom lagoon sediments using sedimentological and geochemical techniques. The analyzed samples were collected from six locations with gravity cores. A total number of 31 samples were analyzed for their grain size, total organic carbon (TOC) and major and trace elements. The particle size analysis was performed on the coarse material by sieving while the fine fraction was analyzed using the Malvern Mastersizer 2000 Hydro and moment measures were calculated using GRADISTAT software. The determination of the total organic carbon was made according to the modified titration method of Walkley-Black while the identification of the major and trace elements, Al, Ca, Fe, K, Mg, Mn, Na, P, Cd, Cr, Cu, Ni, Pb , V and Zn with plasma atomic emission spectroscopy Thermo Scientific iCAP 6000 ICP-OES. In order to evaluate the water physicochemical parameters, data from two telemetric stations (with multi parameter sensors YSI6600) were analyzed covering a period of one year monitoring. The physicochemical parameters that are presented and assessed are the pH, temperature (0C), dissolved oxygen (DO - mg/L) and salinity (S ‰). The study of the above parameters revealed that the bottom lagoon sediments consist of poorly to very poorly sorted, very fine sand to coarse silt and are characterized by high content of total organic carbon (>3%). The seasonal variations of physicochemical parameters indicate periods (summer) with very low to zero dissolved oxygen concentrations, showing hypoxic conditions and anoxic crisis. Salinity variations are the result of the process exchange of marine and freshwater into the lagoon via the narrow inlet. The pH variations follow proportionally the temperature and the oxygen concentration trend of the lagoon water. For the assessment of the environmental status of the lagoon and based on the geochemical analyses, we used geo-environmental indices to determine the enrichment or depletion of the bottom sediments heavy metals concentrations. For this purpose we used the geo-accumulation index, the index of contamination, the enrichment factor, compared to the bibliography values of baseline concentration. From the above analysis and based on thee geo-environmental indices we conclude that the bottom lagoon sediments are not polluted.

No description available.