Editing Bay of Bengal (section)

== Transboundary issues ==
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{{more citations needed |date=July 2020}}
A transboundary issue is defined as an environmental problem in which either the cause of the problem and/or its impact is separated by a national boundary; or the problem contributes to a global environmental problem and finding regional solutions is considered to be a global environmental benefit. The eight Bay of Bengal countries have (2012) identified three major transboundary problems (or areas of concern) affecting the health of the Bay, that they can work on together. With the support of the Bay Of Bengal Large Marine Ecosystem Project (BOBLME), the eight countries are now (2012) developing responses to these issues and their causes, for future implementation as the Strategic Action Programme.

=== Ecological degradation ===
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==== Fisheries overexploitation ====
[[File:Bay of Bengal 2.jpg|thumb|250px|Some small fishing boats are catching fish & sell them in local coastal markets.]]
[[Fisheries]] production in the Bay of Bengal is six million tonnes per year, more than seven percent of the world's catch. The major transboundary issues relating to shared fisheries are: a decline in the overall availability of fish resources; changes in species composition of catches; the high proportion of juvenile fish in the catch; and changes in [[marine biodiversity]], especially through loss of vulnerable and [[endangered species]]. The transboundary nature of these issues are: that many [[fish stocks]] are shared between BOBLME countries through the transboundary migration of fish, or [[Ichthyoplankton|larvae]]. Fishing overlaps national jurisdictions, both legally and illegally&nbsp;– overcapacity and [[overfishing]] in one location forces a migration of fishers and vessels to other locations. All countries (to a greater or lesser degree) are experiencing difficulties in implementing [[fisheries management]], especially the [[ecosystem approach to fisheries]]. Bay of Bengal countries contribute significantly to the global problem of loss of [[vulnerable species|vulnerable]] and endangered species.
The main causes of the issues are: open access to fishing grounds; government emphasis on increasing fish catches; inappropriate government subsidies provided to fishers; increasing fishing effort, especially from [[Fishing trawler|trawlers]] and [[purse seiners]]; high consumer demand for fish, including for seed and [[fishmeal]] for [[aquaculture]]; ineffective fisheries management; and illegal and destructive fishing.{{citation needed|date=December 2022}}

==== Marine habitats degradation ====
The Bay of Bengal is an area of high biodiversity, with many endangered and vulnerable species. The major transboundary issues relating to habitats are: the loss and degradation of [[mangrove]] habitats; [[Environmental issues with coral reefs|degradation of coral reefs]]; and the loss of, and damage to, [[seagrasses]]. The transboundary nature of these major issues are: that all three critical habitats occur in all BOBLME countries. [[Coastal development hazards|Coastal development]] for several varying uses of the land and sea are common in all BOBLME countries. Trade in products from all the habitats is transboundary in nature. [[Climate change]] impacts are shared by all BOBLME countries.
The main causes of the issues are: [[food security]] needs of the coastal poor; lack of [[Coastal management|coastal development plans]]; increasing trade in products from coastal habitats; coastal development and industrialization; ineffective [[marine protected area]]s and lack of enforcement; upstream development that affects water-flow; [[Nonpoint source pollution|intensive upstream agricultural practices]]; and increasing tourism.{{citation needed|date=December 2022}}

=== Environmental degradation ===
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==== Environmental hazards ====
The [[Asian brown cloud]], a layer of air pollution that covers much of South Asia and the Indian Ocean every year between January and March, and possibly also during earlier and later months, hangs over the Bay of Bengal. It is considered to be a combination of vehicle exhaust, smoke from
cooking fires, and industrial discharges.<ref>{{cite web |url=http://earthobservatory.nasa.gov/NaturalHazards/shownh.php3?img_id=13341 |title=EO Natural Hazards: Smog over the Bay of Bengal |website=NASA Earth Observatory |archive-url=https://web.archive.org/web/20071026204458/http://earthobservatory.nasa.gov/NaturalHazards/shownh.php3?img_id=13341 |archive-date=26 October 2007 |access-date=21 January 2007}}</ref> Because of this cloud, satellites attempting to track [[ocean acidification]] and other ocean health indicators in the Bay have difficulty obtaining accurate measurements.<ref>[https://www.firstpost.com/tech/science/ocean-acidification-in-bay-of-bengal-is-now-being-monitored-by-global-satellite-network-7787131.html Ocean acidification in Bay of Bengal is now being monitored] {{Webarchive|url=https://web.archive.org/web/20210929090907/https://www.firstpost.com/tech/science/ocean-acidification-in-bay-of-bengal-is-now-being-monitored-by-global-satellite-network-7787131.html |date=29 September 2021 }}. ''[[Firstpost]]''. 16 December 2019.</ref>

==== Pollution and water quality ====
The major transboundary issues relating to [[marine pollution|pollution]] and [[water quality]] are: sewage-borne pathogens and organic load; solid waste/marine litter; increasing nutrient inputs; oil pollution; persistent organic pollutants ([[Persistent organic pollutant|POPs]]) and persistent toxic substances (PTSs); sedimentation; and heavy metals.
The transboundary nature of these issues are: discharge of untreated/partially treated [[sewage]] being a common problem. Sewage and organic discharges from the [[Ganges]]-[[Brahmaputra]]-[[Meghna]] River are likely to be transboundary. Plastics and derelict fishing gear can be transported long distances across national boundaries. Around 4 million tonnes of [[microplastics]] are estimated to come from India and Bangladesh travelling into Sundurban and subsequently the Bay of Bengal.<ref>{{Cite journal |last1=Kumar |first1=Rakesh |last2=Sinha |first2=Rama |last3=Refat |first3=Md |last4=Rakib |first4=Jahan |last5=Padha |first5=Shaveta |last6=Ivy |first6=Nishita |last7=Bhattacharya |first7=Sayan |last8=Dhar |first8=Anjali |last9=Sharma |first9=Prabhakar |title=Microplastics pollution load in Sundarban delta of Bay of Bengal |doi=10.1016/j.hazadv.2022.100099 |journal=Journal of Hazardous Materials Advances |year=2022 |volume=7 |page=100099 |s2cid=249072350 |doi-access=free|bibcode=2022JHzMA...700099K }}</ref> High nutrient discharges from rivers could intensify largescale hypoxia. Atmospheric transport of nutrients is inherently transboundary. Differences between countries with regard to regulation and enforcement of shipping discharges may drive discharges across boundaries.<ref>{{Cite journal |last1=Gupta |first1=R.Sen |last2=Kureishy |first2=Tariq W. |date=September 1981 |title=Present state of oil pollution in the northern Indian Ocean |doi=10.1016/0025-326X(81)90079-5 |journal=Marine Pollution Bulletin |volume=12 |issue=9 |pages=295–301 |bibcode=1981MarPB..12..295S}}</ref> [[Tarball (oil)|Tar balls]] are transported long distances. POPs/PTSs and [[Mercury (element)|mercury]], including organo-mercury, undergo long-range transport. [[Sedimentation]] and most heavy metal contamination tend to be localized and lack a strong transboundary dimension.<ref>{{Cite journal |last1=Gong |first1=Chenglin |last2=Wang |first2=Haiqiang |last3=Shao |first3=Dali |last4=Wang |first4=Hongping |last5=Qi |first5=Kun |last6=Xu |first6=Xiaoyong |date=1 July 2022 |title=How did the world's largest submarine fan in the Bay of Bengal grow and evolve at the subfan scale? |doi=10.1306/02072219107 |journal=AAPG Bulletin |volume=106 |issue=7 |pages=1431–1451 |bibcode=2022BAAPG.106.1431G |s2cid=250063994}}</ref> The main causes of the issues are: increasing coastal population density and urbanization; higher consumption, resulting in more waste generated per person; insufficient funds allocated to waste management; migration of industry into BOBLME countries; and proliferation of small industries.{{citation needed|date=December 2022}} A pertinent issue is the rapid growth of the shrimp culture industry which requires use of antibiotics and chemicals for export-quality food safety but pollutes the Bay of Bengal.<ref>{{Cite journal |last1=Rashid |first1=Towhida |last2=Hoque |first2=Sirajul |last3=Akter |first3=Sharmin |date=28 November 2014 |title=Pollution in the Bay of Bengal: Impact on Marine Ecosystem |url=https://www.researchgate.net/publication/273346214 |journal=Journal of Marine Science |pages=55–63 |via=Scientific Research Publishing Inc.}}</ref>

=== Tropical storms and cyclones ===
{{main|Tropical cyclones in the Bay of Bengal}}
[[File:Sidr 2007-11-14 0445Z.jpg|thumb|right|[[Cyclone Sidr]] at its peak near Bangladesh]]
A tropical storm with rotating winds blowing at speeds of {{convert|119|km/h|mph|abbr=on}} is called a [[cyclone]] when they originate over the Bay of Bengal, and called a [[hurricane]] in the Atlantic.<ref>{{cite web |url=http://www.nationalgeographic.com/features/04/forcesofnature/resources/ |archive-url=https://web.archive.org/web/20090402110639/http://www.nationalgeographic.com/features/04/forcesofnature/resources/ |url-status=dead |archive-date=2 April 2009 |title=Forces of Nature—Natural Disaster Fast Facts |website=National Geographic |access-date=30 August 2016}}</ref> Between 100,000 and 500,000 residents of Bangladesh were killed because of the [[1970 Bhola cyclone]].
* 2023: [[Cyclone Mocha|Extremely Severe Cyclonic Storm Mocha]]
* 2021: [[Cyclone Yaas|Very Severe Cyclonic Storm Yaas]]
* 2020: [[Cyclone Nivar|Very Severe Cyclonic Storm Nivar]]
* 2020: [[Cyclone Amphan|Super Cyclonic Storm Amphan]]
* 2019: [[Cyclone Bulbul|Very Severe Cyclonic Storm Bulbul]]
* 2019: [[Cyclone Fani|Extremely Severe Cyclonic Storm Fani]]
* 2018: [[Cyclone Gaja|Very Severe Cyclonic Storm Gaja]]
* 2018: [[Cyclone Titli]]
* 2017: [[Cyclone Mora|Severe Cyclonic Storm Mora]]
* 2017: [[Cyclone Maarutha]]
* 2016: [[Cyclone Vardah|Very Severe Cyclonic Storm Vardah]]
* 2016: [[2016 North Indian Ocean cyclone season#Cyclone Nada|Cyclone Nada]]
* 2016: [[2016 North Indian Ocean cyclone season#Cyclone Kyant|Cyclone Kyant]]
* 2016: [[Cyclone Roanu]]
* 2015: [[Cyclone Komen]]
* 2014: [[Cyclone Hudhud|Very Severe Cyclonic Storm Hudhud]]
* 2013: [[Cyclone Phailin|Very Severe Cyclonic Storm Phailin]]
* 2013: [[Cyclone Viyaru]]
* 2012: [[Cyclone Nilam]]
* 2011: [[Cyclone Thane|Very Severe Cyclonic Storm Thane]]
* 2010: [[Cyclone Giri|Very Severe Cyclonic Storm Giri]]
* 2009: [[Cyclone Aila|Very Severe Cyclonic Storm Aila]]
* 2008: [[Cyclone Nargis|Very Severe Cyclonic Storm Nargis]]
* 2007: [[Cyclone Sidr|Very Severe Cyclonic Storm Sidr]]
* 2006: [[Cyclone Mala|Very Severe Cyclonic Storm Mala]]
* 1999: [[1999 Odisha cyclone|Odisha Super Cyclonic Storm 05B]]
* 1996: Konaseema Cyclone
* 1991: [[1991 Bangladesh cyclone|Super Cyclonic Storm 02B]]
* 1989: November [[Typhoon Gay (1989)|Typhoon Gay]]
* 1985: May Tropical Storm One (1B)
* 1982: April Cyclone One (1B)
* 1982: May Tropical Storm Two (2B)
* 1982: October Tropical Storm Three (3B)
* 1981: December Cyclone Three (3B)
* 1980: October Tropical Storm One (1B)
* 1980: December Unknown Storm Four (4B)
* 1980: December Tropical Storm Five (5B)
* 1977: [[1977 Andhra Pradesh cyclone|Andhra Pradesh Cyclone]] (6B)
* 1971: [[1971 Odisha cyclone|Odisha cyclone]]
* 1970: [[1970 Bhola cyclone|Bhola cyclone]]
* The [[1864 Calcutta Cyclone]]: caused a storm surge of 40 feet. Barometer 28.025 inches of mercury. 50,000 direct deaths and 30,000 from disease.<ref name="Tannehill">{{cite book |last=Tannehill |first=Ivan Ray |date=1969 |orig-date=First published 1945 |title=Hurricanes: Their Nature and History: Particularly Those of the West Indies and the Southern Coasts of the United States |edition=6th |url=https://books.google.com/books?id=schxAAAAMAAJ&q=bengal&pg=PA38 |publisher=Princeton University Press|pages=38–40|isbn=978-0-8371-2316-5 }}</ref>
* The [[Backergunge cyclone of 1876]]: 10 to 30 or 40 feet storm surge. 100,000 direct deaths and 100,000 indirect from disease.<ref name="Tannehill" />
* The [[Pre-1890 North Indian Ocean cyclone seasons|False Point cyclone of 1885]]: 22 feet of storm surge. Barometer 27.135 inches of mercury.<ref name="Tannehill" />