#we're all flustered like who tf posts their HOMEWORK for their friends to read???

[broodsys]

ik i said i wasnt gonna post it if i couldnt put it under a cut but im...... disproportionately proud of this essay lmao. we still imagine we’re gonna end up pursuing smth like being an essayist/article writer down the line cuz our voice is so our weapon, so it was nice to kinda use this to get a feel for what that process might look like

anyway, no pressure to read, but it’s abt dead zones & we found the content overall p interesting. death of marine life is discussed, and the random Personal Impact paragraph was an assignment requirement

Lake Toba is located in North Sumatra, Indonesia, and is the largest volcanic lake in the world(1). Yet its remarkable ecological history has not spared it from modern pollution, and as recently as 2016 the dead zone within the lake, described by photographer and essayist Binsar Bakkara as "meaning it has excessive nutrients [...] with low oxygen levels,"(2) led to a sudden, massive death of the aquatic animal life in the lake, the fish farmers waking to find their nets full of dead tilapia and carp. The waters of Lake Toba were teeming with aquatic plants - plants such as water hyacinth, milfoil, and algae - whose growth depleted the water of its oxygen, asphyxiating the fish overnight, and leading to 15,000 tons (or 30,000,000 pounds) of dead fish who locals had to remove over the course of days(1). Devastating both environmentally and culturally, the massive loss of fish and the high levels of pollutants have rendered the lake unreliable as both a water source and a source of income for the fish farmers.

Limited oxygen in a body of water is referred to as hypoxia(8), with anoxia being the total loss of oxygen, and both states do occur naturally, including with seasonal variance as increased light allows the algae to thrive, and areas of hypoxia or anoxia are referred to as the "dead zones" that Bakkara described. Despite their natural occurrence  the rising global levels of hypoxia and anoxia are being connected with human activities, such as "agriculture, [...] land transformation, groundwater drainage, urban stormwater runoff, sewage treatment, or atmospheric emissions through fossil fuel burning and volatilization of agricultural waste"(3) Among these pollutants are fertilizers or other nitrogen-rich substances, which lead to the expansive growth of aquatic plants that - as in Lake Toba - lead to massive, sudden loss of the aquatic animal life. The oxygen that aquatic life needs to survive is not the oxygen that is bonded with water to form H2O, but rather gaseous, water-soluble oxygen which form DO, or dissolved oxygen. Yet this dissolved oxygen is still subject to the surrounding waters saturation; decomposing organic matter contributes to the nutritional and chemical saturation, which necessitates a displacement of the dissolved oxygen. But all plants and animals require oxygen to breathe, even aquatic plants and animals, and if they cannot escape these areas of nutritional-saturation and oxygen-depletion, they end up asphyxiating as in the case of Lake Toba.(7) The nutrients and chemicals from both the fish's waste and the fish food decomposition would each have contributed to the saturation of the water content and the dispersal of the dissolved oxygen.

The National Academy of Sciences' Council for Agricultural Science and Technology issued a report in 1999 that said that hypoxic zones "are now one of the most widespread, accelerating, human-induced deleterious impacts in the world's marine environments."(3) The exact cause of Lake Toba's dead zones and the overnight death of so many fish is still contested; residents blame companies for run-off and for uneaten fish food pellets, which were used to feed their floating fish cages.(5) One floating cage fishery, PT Aquafarm Nusantara, "acknowledged the food pellets they scattered in a number of keramba [floating net cages] in Lake Toba had caused a decrease in water quality, but not significantly."(5) Professor Krismono was cited in Ayat S. Karokaro's article as saying the floating net "cages should only have 3,000-5,000 fish, but these cages had 10,000 fish,"(6) drawing attention to how overfishing could combine with overfeeding to fuel a hypoxic environment. Dead zones have seen some improvement, however, with concentrated efforts stopping the ongoing hypoxic processes. Certain localities have even seen improvements in non-algal aquatic life following these efforts. The 1987 campaign to clean the Chesapeake Bay, for instance, has seen improvements in biodiversity in the bay's contributing rivers.(3)

This subject is important to me as a fish-keeper, as problems with excess nitrate and nitrite production from uncleaned fish waste (or uneaten fish food!) can lead to something that, within the hobby, is called "toxic tank syndrome." This is when nitrate, nitrite, and eventually ammonia levels all reach toxic levels and is the source of the fish often seen gasping for air at the surface a few days or hours before dying. Obviously, the situation in Lake Toba was much more extreme and with much farther-reaching consequences than the loss of a pet fish, but the basic elements of it were familiar to me as warning signs of possible issues with my tanks. Despite that familiarity, the issues of a hypoxic or anoxic zone are much more difficult to solve and require a much more concerted and deliberate effort than, again, anything I will experience as a hobbyist.

Lake Toba's dead zone's overnight depletion of remaining dissolved oxygen, whether caused by industrial runoff, sewage, fish food, fish waste, overfishing, or a combination of the above factors, had significant financial and cultural impacts in 2016, but will likely have future complications for the residents, even if a complete overhaul of the contributing factors was implemented immediately. As demonstrated by the Chesapeake Bay efforts, halting the progress of hypoxia into anoxia is a difficult and time-consuming feat in and of itself, but restoring these dead zones to become oxygenated environments that are capable of supporting a diverse ecosystem is even more challenging. Yet restoration of these areas is important to the survival of any group of people who are dependent on their water, and globally the restoration of these dead zones - including many coastal areas - will undoubtedly have significant effects on global marine biodiversity.

1 = LakeNet - Lakes, www.worldlakes.org/lakedetails.asp?lakeid=8367. 2 = “How Pollution is Devastating an Indonesian Lake.” Yale E360, e360.yale.edu/features/how-pollution-is-devastating-an-indonesian-lake. 3 =  Joyce, S. "The Dead Zones: Oxygen-Starved Coastal Waters." Environmental Health Perspectives, vol. 108, no. 3, Mar. 2000, pp. A120-A125. EBSCOhost 4 = Web.archive.org. (2017). Water on the Web | Understanding | Water Quality | Parameters, https://web.archive.org/web/20121213101908/http://www.waterontheweb.org/under/waterquality/oxygen.html 5 = Gunawan, Apriadi (2015, May) The Jakarta Posthttp://www.thejakartapost.com/news/2015/05/22/jokowi-asked-handle-pollution-lake-toba.html 6 = Jacobson, P. (2017). Millions of fish die suddenly in Indonesia's giant Lake Toba. Conservation News, https://news.mongabay.com/2016/05/millions-fish-die-suddenly-indonesias-giant-lake-toba/ 7 = Lenntech.com. (2017). Oxygen (O) and water, https://www.lenntech.com/periodic/water/oxygen/oxygen-and-water.htm 8 = Eopugetsound.org. (2017). Section 4. Dissolved Oxygen (Hypoxia) | Encyclopedia of Puget Sound, https://www.eopugetsound.org/science-review/section-4-dissolved-oxygen-hypoxia