1 RESUMO 5 GENERAL INTRODUCTION 9 Estuaries: drivers, pressures and responses 9 Estuarine fish fauna 11 Recruitment variability of marine species 13 Climate forcing and systems’ changes 16 Assessing ecological status of transitional waters 18 Study site – the Mondego estuary 21 References 24 GENERAL AIM AND THESIS OUTLINE 35 CHAPTER I The influence of an extreme drought event in the fish commun...

The environmental fate of herbicides in estuaries is poorly understood. Estuarine physical transport processes and the episodic nature of herbicide release into surface waters complicate interpretation of water concentration measurements and allocation of sources. Water concentrations of herbicides and two triazine degradation products (CIAT [6-amino-2-chloro-4-isopropylamino-s-triazine] and CE...

To describe the larval and juvenile fish fauna and to evaluate the relative contribution of the ocean and the estuary as settlement areas for benthic species, we compared the composition and abundance of larval fish supply to that of recently settled juvenile fishes in both ocean and an adjacent estuary habitats in southern New Jersey. The study was conducted from May to November 1992 in the Gr...

The Hudson River Benthic Mapping Project, funded by the New York State Department of Environmental Conservation, resulted in a comprehensive data set consisting of high-resolution multibeam bathymetry, sidescan sonar, and sub-bottom data, as well as over 400 sediment cores and 600 grab samples. This detailed data set made it possible to study the regional pattern and the local variations of the...

under the contemporary scenario of global climate change and increasing coastal eutrophication, baseline studies of phytoplankton diversity and distribution in relation to habitat conditions constitute the first approach to evaluate potential shifts at the base of the food webs. here we present data of phytoplankton species composition and environmental variables in winter 2006 in a temperate e...

benthic organisms have been studied in past to assess the health of an aquatic ecosystem. moreover, being sedentary forms they have been used as indicator organisms. in the present study, an attempt has been made to study the distribution and assemblage of major macrobenthic forms occurring in ponnani estuary. a total of 23 genera of benthic invertebrate fauna belonging to 6 groups viz., polych...

Flood/ebb-dominance in net sediment transport of shallow sandy estuaries with tidal flats and channels (typical around the U.K.) is investigated using a 2D model (TELEMAC). The micro-tidal Dyfi Estuary is used as a case study. The along-estuary net sediment transport in the Dyfi has been predicted and characterised as ebbor flood-dominant. The simulations illustrated that shallow waters (inner-...

In early summer 1995, we surveyed total system metabolism in the Plum Island estuary. Objectives included (1) estimation of ecosystem metabolism via open-water oxygen measurements, (2) determination of the autotrophic and heterotrophic regions of the estuary, and (3) comparison of the loading of organic carbon from the watershed to measurements of autochthonous production. Metabolism was calcul...

The net growth rate of marine zooplankton entering the Westerschelde estuary was investigated using an advective-dispersive transport model that simulates zooplankton biomass behaving conservatively in the estuary. Total biomass of marine zooplankters in the Westerschelde was much lower than what would be expected based on transport alone, indicating negative growth rates in the estuary. Includ...

Intra-tidal variability in the transport of materials through the Cochin estuary was studied over successive spring and neap tides to estimate the export fluxes of nutrients and chlorophyll a into the adjoining coastal zone. The results showed that there was a substantial increase in the freshwater flow into the estuary following heavy rains (~126 mm) prior to the spring tide observations. The ...