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

Marine Strategy Framework Directive - Descriptor 2, Non-Indigenous Species, Delivering solid recommendations for setting threshold values for non-indigenous species pressure on European seas

Marine Non-Indigenous Species (NIS) are animals and plants introduced accidently or deliberately into the European seas, originating from other seas of the globe. About 800 marine non-indigenous species (NIS) currently occur in the European Union national marine waters, several of which have negative impacts on marine ecosystem services and biodiversity. Under the Marine Strategy Framework Directive (MSFD) Descriptor 2 (D2), EU Member States (MSs) need to consider NIS in their marine management strategies. The Descriptor D2 includes one primary criterion (D2C1: new NIS introductions), and two secondary criteria (D2C2 and D2C3). The D2 implementation is characterized by a number of issues and uncertainties which can be applicable to the Descriptor level (e.g. geographical unit of assessment, assessment period, phytoplanktonic, parasitic, oligohaline NIS, etc.), to the primary criterion D2C1 level (e.g. threshold values, cryptogenic, questionable species, etc), and to the secondary criteria D2C2 and D2C3. The current report tackles these issues and provides practical recommendations aiming at a smoother and more efficient implementation of D2 and its criteria at EU level. They constitute a solid operational output which can result in more comparable D2 assessments among MSs and MSFD regions/subregions. When it comes to the policy-side, the current report calls for a number of different categories of NIS to be reported in D2 assessments, pointing the need for the species to be labelled/categorised appropriately in the MSFD reporting by the MSs. These suggestions are proposed to be communicated to the MSFD Working Group of Good Environmental Status (GES) and subsequently to the Marine Strategy Coordination Group (MSCG) of MSFD. Moreover, they can serve as an input for revising the Art. 8 Guidelines