Abstract: Soil salinity in both coastal and inland, is known to affect vegetation structure and functions. Mangrove vegetation at Kala Oya estuary on the north western coast of Sri Lanka was selected to study the effect of soil salinity on structure, potential gross primary productivity and plant biomass of the ecosystems. Five belt-transects were laid perpendicular to the shoreline, covering 3.5 km upstream and approximately at 750 m intervals to collect data for the purpose. Vegetation structure was determined using data collected on plant species diversity, density, basal area, leaf area index and tree height. Biomass (total of above and below ground) of mangrove trees was estimated by allometric methods and potential gross primary productivity was calculated using leaf area index measured with terrestrial radiation sensor. Total of eight (8) true mangrove species were encountered in the area and highest density was recorded for Rhizophora mucronata (528 trees/ha), followed by Excoecaria agallocha (447 trees/ha) and Lumnitzera racemosa (405 trees/ha). Vegetation complexity index (CI), basal area, total tree biomass leaf area index and potential gross primary productivity measurements revealed an inverse correlation with soil salinity. Mangrove species were observed to possess varying salinity tolerance levels and Avicennia marina was the most salinity tolerant species, followed by Rhizophora mucronata, Ceriops tagal and Lumnitzera racemosa. Excoecaria agallocha was the least salt tolerant species in the area. Mangrove areas located around 2 km from the estuary mouth, where the soil salinity ranged from 8-12 mg/l, was observed to be with the highest species richness and diversity, indicating its’ ecological and conservation significance that may be considered in mangrove management decision-making for the area. Presence of a few species of terrestrial and freshwater plants among the mangroves indicates salinity changes that would have taken place due to trans-basin diversion of water to the area for irrigation purposes.

Abstract: Given the ecological significance of mysids in brackish and freshwater food chains and the potential importance in toxicity testing in estuarine systems, it is important to understand the distribution of these animals. However, to date, few studies have been undertaken on mysids in the Auckland region. DThe main focus of this study was to find out the distribution of estuarine mysids in this region. Reconnaissance surveys took place to locate mysid habitats in the estuarine waters entering the Manukau Harbour and the East Coast estuarine environments from May of 2006 to January 2009. The samples were taken using a hand held dip net with 500 µm mesh size along an eighty meter transect at the edge of the stream during day time at low tide. At each site four replicate surveys were undertaken (transects of 10 m length, 10 m apart). Five species of mysids have been identified from and are described for estuarine environments in the Manukau Harbour and along the Auckland East Coast: the sometimes sympatric Tenagomysis chiltoni and T. novaezealandiae, and the non-sympatric and patchily distributed Gastrosaccus australis, T. macropsis and a potentially new Tenagomysis sp.. The present distributional studies in the North Island reflects that the native mysid T. novaezealandiae is the dominant mysid species along the east coast, and the most geographically widespread species on both east and the west coasts, while T. chiltoni was equally dominant with T. novaezealandiae in the Manukau Harbour. G. australis and T. macropsis reported from North Island estuarine waters for the first time. The salinity ranges where species occurred were different: T. chiltoni 0-18‰, T. novaezealandiae 0-26‰ and G. australis 1.5-12.6‰. T. chiltoni, Tenagomysis sp. and T. novaezealandiae shows that the higher percentages of females than males.

Abstract: The trophic position of an organism can be determined by the stable isotope studies of nitrogen and carbon. The main objective of this study was to determine the trophic position of two mysid species, Tenagomysis chiltoni and T. novaezealandiae in the Kakamatua stream ecosystem in using ¹³C and ¹⁵N isotopes. Samples were collected during two weeks period in late December 2008 and early January 2009 including primary producers, leaf litter, aquatic invertebrates, fish species and sediment samples. Aquatic invertebrates and fish were collected from the stream using a hand net. Litter samples were collected randomly from the stream floor. Samples were sealed in plastic bags, and stored in a freezer until processing. All the samples were oven-dried, then ground to obtain a homogeneous powder. Three replicates of each sample were prepared. Samples were processed by the Waikato Stable Isotope Unit, of , . A trophic-level effect of ¹³C and ¹⁵N enrichment was clearly observed. Stable isotopic data indicated that T. chiltoni and T. novaezealandiae exhibited variety of feeding habits (feeding on the first and the second trophic levels) and can be considered as omnivores. Among the other invertebrates analysed, mysids seem to be an important invertebrate fauna which are capable of energy transferring towards the higher trophic level both from primary food sources and the secondary consumers as well. Differences in the isotopic composition were observed among same species depending upon the ontogenetic development.

Abstract: The accumulation of large and small plastic debris is a problem throught the world’s seas and coastlines. Azew gulf is an important southern West Mediterranean coast receiving discharges from many sources. Abundance and sizes of plastic debris in ten stations from intertidal sediments have been reported in this study. The results of the present study shows high plastic fragments accumulation in sediments up to 13.9 % and mostly debris were in size between 0.5 cm and 01 cm. The abundance of plastic debris could be associated with coastal urban centers and their anthropogenic activities (waste rejection). The high presence found can be explained too by the transport of plastic debris via the surface water circulation. This first quantitative and physical study contributes to the enrichment of data on plastic debris pollution and underscores further researches on ecological aspects of this pollution.

Abstract: Research work is focused on the taxonomic composition of macrobenthic in three marine water Shelf (Vadinar Shelf, Okha Shelf and Kandla Shelf) Gulf of Kutch Costal water during November 2011 to December 2012. In present investigation 39 species of macrobenthic were to the different groups i.e., Polychaetes, Crustaceans, Nematodes, Mollusca. Observation study period in the Shelf Vadinar, the macrobenthic was composed of nine taxa of Polychaetes, three taxa of Nematodes, three taxa of Crustaceans and three taxa of Mollusca a, while in Kandla Shelf ten taxa of Polychaetes, six taxa of Nematodes, three taxa of Crustaceans, three taxa of Mollusca and in Vadinar Shelf thirteen taxa of Polychaetes, nine taxa of Nematodes, three taxa of Crustaceans and three taxa of Mollusca, were encountered respectively. Comparison of the obtained results with those of earlier investigations occurred during November 2011 to December 2012 showed that changes have occurred in the interval. The total macrobenthic composition is significantly changed in all the three water bodies. Comparison of diversity and density in three Shelf was studied with diversity indices.