An assessment of water quality along the rivers loading to the Manado Bay, North Sulawesi, Indonesia

In the city of Manado, rivers are used for water drainage and sewer system of various wastewater discharges, including from toilets ; these rivers discharge their load to Manado Bay. Therefore it is extremely important to know the water quality of these rivers. In this study three selected rivers, Sungai Bailang (SB), S. Maasing (SM), and S. Tondano (ST), were assessed in regard to 5-days Biochemical Oxygen Demand (BOD_5), nitrate (NO_3^-), ortho phosphate (PO^_4), total coliform (TC), Escherichia coli (EC), and total mercury (Hg-tot) to indicate loads of organic matter, inorganic nutrients, bacteria, and metals, respectively. Existing concentrations, variations with seasons (dry and wet), and pollution status of the rivers, are presented and discussed in this paper. Except the levels of TC and EC, which were high in all rivers and seasons, these parameters varied according to space (within the river and among the rivers) and the seasons. Average levels loaded to the bay for (1) organic were 15.30 mg/l of BOD_5 in the dry season and 7.52 mg/l of BOD_5 in wet season ; (2) inorganic of NO^-_3 and PO^_4 were 2.01 mg/l of NO^-_3 and 1.71 mg/l of PO^_4 in the dry season, and 1.44 mg/l of NO^-_3 and 2.20 mg/l of PO^_4 in the wet season ; (3) Hg-tot in the water and the surface sediment of ST was 0.024 mg/l and 0.133 mg/kg in the dry season, and 0.081 mg/l and 0.130 mg/kg in the wet season. The level of Hg-tot accumulated in the marine bivalve, Soletellina sp., ranged between 0.012 and 0.124 mg/kg. Based on these results, the water quality of the rivers was assessed as polluted. This was perhaps attributable to the presence of input of wastewater discharging from residential sources of the city and from the hinterland agricultural area of Minahasa Regency (MR). This condition may further threaten the water quality of Manado Bay ; therefore, management measures are also identified and discussed

Coastal Aquaculture Development in Bangladesh: Un-sustainable and Sustainable Experiences

Coastal aquaculture in Bangladesh mainly consists of two shrimp species (Penaeus monodon and Macrobrachium rosenbergii). Currently, there are about 16,237 marine shrimp (P. monodon) farms covering 148,093 ha and 36,109 fresh water shrimp (M. rosenbergii) farms covering 17,638 ha coastal area. More than 0.70 million people are employed throughout the farmed shrimp sector in Bangladesh. In 2005-2006 the foreign currency earning were 403.5 million USD through exporting the frozen shrimp. Although coastal aquaculture contributes significantly in rural employment and economy its importance is overshadowed by negative social and ecological impacts. This paper reviews the key issues, constraints and opportunities of sustainable shrimp farming. In addition we present the results of two case studies from southwestern coastal areas where the shrimp farming originated and central coastal areas where shrimp especially M. rosenbergii farming sparked in recent years. Lessons learned from the review and case studies are considered in the context of recommendations to encompass a socially equitable and ecologically sound coastal aquaculture

A global phylogeny of Elysia Risso, 1818 (Gastropoda: Heterobranchia): molecular systematic insights focusing on European taxa and description of a new species

The genus Elysia comprises about one-third of the species richness in Sacoglossa. However, the species diversity in the genus remains poorly characterized in some areas like the north-eastern Atlantic and Mediterranean waters. To clarify the systematics of this genus and to characterize the species diversity in undersampled regions, we performed an integrative study based on a thorough literature review, molecular and morphological analyses, and species delimitation approaches. We conducted phylogenetic analyses of partial sequences of two mitochondrial genes (COI and 16S) and two nuclear genes (H3, 28S) using Bayesian inference and maximum likelihood methods, which confirmed the presence of five of the recognized European Elysia species: Elysia viridis, E. timida, E. flava, E. margaritae, and E. rubeni. Moreover, a new species (Elysia azorica sp. nov.) was identified in the Azores, and E. gordanae, currently considered a junior synonym of E. margaritae, was recovered as a distinct species. In addition, we consider E. hetta as a junior synonym of E. gordanae, and E. translucens as a taxon inquirendum. Finally, the tropical E. evelinae is recorded along European coasts for the first time. Our results demonstrate the value of integrative approaches in resolving taxonomic uncertainty surrounding polymorphism and unravelling potential cases of cryptic or pseudocryptic species complexes

Evolution of buccal apparatus and diet radiation in the Sacoglossa (Opisthobranchia)

Volume: 29Start Page: 147End Page: 17