**2. LMP status in Bangladesh**

According to National report of the Bay of Bengal Large Marine Ecosystem (BOBLME), LMP is discharged directly into the Bay of Bengal through rivers, floods, tides, groundwater, or atmospheric deposition [18]. This report also identified two kinds of land-based sources of marine pollution in Bangladesh: point and non-point (**Table 1**). A point source of pollution is those for which a particular point of entry into the environment can be identified, whereas non-point sources are harder to identify and cannot be as readily identified as originating from a single source [19]. LMP can also inflict oil sewage and industrial waste, chemical fertilizer and pesticides, water from power stations, atmospheric discharges from vehicles, chimney fumes, and sprayed agricultural chemicals [20]. In Bangladesh, industrial wastes contain high organic pollutants, and most importantly, there is no waste treatment plant inside the industries [21]. Municipal garbage is also one of the leading factors for LMP in Bangladesh due to rapid urbanization, indiscriminately dumping into the drain, canal, or river directly [21]. Agriculture activities are also the reasons for LMP as pesticides and fertilizers are carried out by rivers, canals, or drains to the sea during the rainy season [21]. The causes of land-based sources of marine pollution are the same in other countries except for ship-breaking pollution because almost all shipyard in Bangladesh is located near the coast, and their recycling operation is done through the 'beaching' method. According to the National Program of Action (NPA), to protect the coastal and marine environment from land-based activities in Bangladesh, reported 'ship-breaking pollution' is one of the critical issues for landbased marine pollution at BOB [10].

Municipal waste comprises household, industrial, commercial, agricultural, street sweeping, construction debris, sanitation residues, etc. The total amount of municipal waste generated in the country appears to be related to socioeconomic factors, and also, the total amount of solid and liquid wastes of Bangladesh that could either directly or indirectly find their way to the coast of the BOB has not been estimated yet [22]. In 2005, the average per capita municipal waste generation rate was estimated to be 0.41 kg/capita/day, and it assumed that by 2025, the total waste generation would be 47,064 tons/day with a waste generation rate (WGR) of 0.6 kg/capita/day [23].

As Bangladesh has no domestic waste treatment facilities yet, effluents from city areas directly or indirectly enter the river. Increasing human settlement in the coastal


**Table 1.**

*Critical sources of LMP in Bangladesh [18].*

areas is also the factor for increasing pollutants in the coastal environment and, in general, dumping excreta in drains and canals that go to nearby rivers and ultimately falls into the Bay of Bengal. Septic tank effluents are also dumped into the rivers and canals directly or indirectly and cause localized water pollution surrounding the drainage outfalls. The rivers, including the Karnafuly and Passur, receive raw excreta daily from dense populations on both sides of these towns. Every day a considerable amount of blood and intestines of slaughtered animals from the Firringee Bazar slaughterhouse of Chittagong find their way into the River Karnafuly and hence to the Bay of Bengal. The most common system currently adopted for the disposal of solid wastes is to dump vast quantities of the collected solid wastes on the outskirts of townships as landfills, creating a breeding ground for houseflies and mosquitoes. The decomposition process pollutes the area emitting poisonous and obnoxious smells. The major channels that carry domestic wastes and spread into the coastal city areas cause pathogenic microbial pollution and severe health hazards during the rainy season, and the severity of floods is more in the Bay [24]. Solid waste is washed by rain, the leachate mixes with the water, goes to the river, then to the Sea, and ultimately pollutes the total water body.

Pathogenic organisms are usually present in the soil and solid wastes. These pathogens are causative agents of different diseases in human beings [25]. There is a very high abundance of oligochaetes and other pollution indicators of benthic organisms near sewage outfalls in the Karnaphuli River estuary, which indicates localized pollution in the estuary [26]. High BOD indicates oxygen depletion, endangering fish and aquatic species; deoxygenation induced by toxic waste occurs in the Sea. Harmful effects of the Chittagong Urea Fertilizer Limited (CUFL) effluents on aquatic organisms, particularly on plankton and fish [27]. The pollution caused by the tannery industry, which ranks fourth in earning foreign exchange, causes phenomenal environmental pollution to the soil, ecology, and human body [28]. Especially children and aged people suffer most from the emission of sulfur dioxide gas, which causes respiratory problems, and damages the lungs of the human body [29]. Toxic metals can pass through the food chain to human beings and damage the brain and nervous system. Mercury contamination on some commercially important shrimp and finfish species from the Bay of Bengal off the coast of Bangladesh [30]. The mercury concentrations show that in estuarine shrimp, contamination is higher than in the coastal or open sea shrimps. Heavy metals like mercury are serious pollutants because they are stable compounds that are not readily removed by oxidation, precipitation, or other natural processes. Lower concentrations of methyl mercury may kill aquatic organisms.

The reduction of oxygen in water affects aquatic flora and fauna [30]. As a result of ship scrapping activities, various refuse and disposable materials are being discharged and spilled from the scrapped ships and often get mixed with soil and seawater. Due to shipbreaking pollution, there is a significant difference in the physio-chemical properties of the beach soil within and outside of the areas [31]. Phytoplankton organisms and algae suffer from reducing light intensity beneath an oil film, which inhibits photosynthesis. Coating feathers with oil, which causes buoyancy and insulation losses, sometimes cause damage to the marine bird [29]. Persistent toxic metals that settle down on the sediment from various sources threaten the survival of health of all organisms and biodiversity, besides several environmental consequences resulting from coastal aquacultures such as Shrimp farming, hatcheries operation, and shrimp and fish processing units. Encroachment and unplanned expansion of shrimp farming within the coastal belt are responsible for the destruction of forest and agricultural land, thus reducing agricultural production and endangering biodiversity. Residues in seafood, along with those in paddy-cum-shrimp culture, salt-cum shrimp culture, and several agrochemicals used in the seashore culture, ultimately go to the Sea and have an adverse impact [32].
