Featured articles
Is the X-Press pearl shipwreck real hazard of heavy metals?, Dhanushka Dilini, August 16, 2021
Ten Ecological benefits of protecting the Blue lagoon, Sulakkana Wanshapaly, July 27, 2021
What happens to oil spilled in the sea?, Chanaka Supun, July 16, 2021
The Mermaid Tears, Shobiya Paramasivam, July 5, 2021
Turtles versus nurdles, Suneetha Gunawickrama, June 17, 2021
Is the X-Press pearl shipwreck real hazard of heavy metals?, Dhanushka Dilini, August 16, 2021
Ten Ecological benefits of protecting the Blue lagoon, Sulakkana Wanshapaly, July 27, 2021
What happens to oil spilled in the sea?, Chanaka Supun, July 16, 2021
The Mermaid Tears, Shobiya Paramasivam, July 5, 2021
Turtles versus nurdles, Suneetha Gunawickrama, June 17, 2021
Is the X-Press pearl shipwreck real hazard of heavy metals?
Dhnaushka Dilini August 16,2021 Reviewer: Jorge Santos When the MV-X Press Pearl ship sank in June 2021, off Colombo harbor, close to fishery and nature areas, cargo such as copper slag, aluminum alloys, bars, ingot, automotive spare parts & accessories waterproofing materials, paints, inorganic chemicals, lubricants and, bunker oil dispersed. These are potential sources of heavy metals such as Cadmium, Copper, Aluminum, Mercury, Lead, Chromium, Nickel, Zinc and Arsenic. The fate of these elements as suspended or dissolved in the water will depend on complex chemical, physical and biological processes. The type and form of the metal, its adsorption, deposition, temperature, and water circulation will determine their dilution and deactivation. Dissolved or suspended metals are taken up by organisms through the skin or membrane from water, food and sediments. Heavy metals are naturally available in trace amounts in seawater, sediments and organisms, but above small bioavailability levels they become toxic for many animals. Heavy metals, and their complexes can cause serious health problems and damage to the kidney, reproductive system, immune system, nervous system when they accumulate in tissues or bones., There is particular concern about their uptake, concentration, and biomagnification along the food chain leading to human food. Seafood consumption has raised public concern when some predatory fish species, bottom-dwelling species and shellfish such as tuna, mullet, crabs contain heavy metals above the reference level set by European Union. Hence, certain species become unsuitable for human consumption while others are routinely monitored for heavy metals. There are records of similar accidents, such as the the Bahamas shipwreck in 1998 in the Rio Grande harbor, Brazil. The vessel transported 12 thousand tons of concentrated sulfuric acid, which reacted with the remaining cargo and hull. This lead to contamination of the bottom sediment and estuarine water with mercury and cadmium [1]. Another study performed in the Persian Gulf, an area heavily trafficked by ships, found that high metal concentration (Cd, Cu, Pb) in sediments may lead to toxicity in bottom-dwelling fish species. The study of heavy metals in bottom sediments and mullet proved that. The research strongly advised against the consumption of mullet (Liza klunzingeri) by humans [2]. The presence of high concentration of metals in sediments and water can be an indirect toxicological risk to fish and human health. Historical information from shipwrecks around the world teaches us that trace metals in general cargo, bunker oil and lubricants may affect seawater quality over the years from immediate and chronic leaks. The quality of the seawater in Negombo harbor basin, monitored by National Aquatic Resources Research and Development Authority in 2011, was relatively good. Many metals appeared in concentrations below the critical toxicity levels set by the European Union, despite some elevated values for Chromium, Copper and Nickel [3]. These measurements can be used as baseline values for comparison. Monitoring of the long-term concentrations of trace metals in sediments, filter-feeding organisms and commercial fish, particularly tuna, is warranted to secure the confidence of domestic and international consumers of our fish. References [1] Mirlean, N., Baraj, B., Felipe, L., Baisch, P., & Robinson, D. (2001). The effects of accidental Sulphuric acid leaking on metal distribution in estuarine sediment of Potos lagoon. Marine pollution bulletin, 1114-1117. https://doi.org/10.1016/S0025-326X(01)00099-6 [2] Bastami, K. D., Afkhami, M., Mohammadizaedeh, M., Eshanpour, M., Chambari, S., Aghaei, S., Lagzaee, F. (2015). Bioaccumulation and ecological risk assessment of heavy metals in the sediments and mullet Liza klunzingeri in the nothern part of the Persian Gulf. Marine pollution bulletin, 329-334. https://doi.org/10.1016/j.marpolbul.2015.01.019 [3] Jinadasa, B. (2013). A study of trace metal levels in selected fisheries harbours in South and West coast of Sri Lanka. Journal of National Aquatic Resources Research and Development Agency, 42.DOI: 192.248.96.4 |
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Ten Ecological benefits of protecting the Blue lagoon
Sulakkana Wanshapaly July 27, 2021 Reviewer: Jorge Santos The accident with the X-Press Pearl in May 2021 took place only 10-11 km away from the Negombo lagoon. This caused much concern, because this lagoon provides many of important services. Negombo lagoon is famous as the ‘’Blue lagoon’’, and hosts many species of fish, shrimp and crabs [1]. The bottom of this shallow lagoon is very rich in invertebrate animals, including 36 species of polychaete worms, 13 species of crustaceans, 24 species of snails and 16 species of clams [2]. Mangroves, reeds, filamentous algae and the productive seagrass beds cover 22 % of the lagoon area [3]. The lagoon offers also nesting areas for thousands of turtles and a breeding place for large numbers of migratory birds. The Negombo lagoon provides a number of benefits to society and make it worth to protect it from the immediate and long-tern effects of the accident: 1- Provides raw materials and food, such as timber, flavouring agents, textiles, mats, paper, housing, baskets, boats and tapa cloth, fish and fruits of the mangrove trees. 2- Attenuates wind and waves and provides coastal protection 3- Mangroves and seagrasses control erosion brought about by tides and sea-level rise 4- The vegetation helps controlling eutrophication (green water without oxygen) by regeneration of sewage nutrients 5- Provides shelter and nursery grounds for commercial fish species caught offshore 6- Hosts small-scale aquaculture farms and an important fishing activity, contributing with over one thousand tons a year, of which one third are valuable prawns [4] 7- Sequestration of carbon in the air and water, helping reducing climate change 8- The sheltered water boosts leisure activities and tourism 9- The great diversity of species is important for nature education 10- Is an important site for research. The knowledge can be used in many other similar systems in Sri Lanka [5]. These are among the benefits for society that make coastal ecosystems, particularly estuaries and nearby corals, the most economically valuable in the world [5]. The Negombo lagoon is situated right in the outskirts of the capital of the country and has thereby a large symbolic value that adds to all these ecosystem services and benefits. References [1] Silva, E.I.L., Katupotha, J., Amarasinghe, O., Manthrithilake, H. and Ariyaratna, R., (2013). Lagoons of Sri Lanka: from the origins to the present. IWMI DOI: 10.5337/2013.215 [2] Dahanayaka, D.D.G.L., Jayamanne, S.C. and Wijeyaratne, M.J.S., (2008). Benthic invertebrates of a tropical estuary in the western coast of Sri Lanka. Journal of Environmental Biology,vol.3,pp.59. http://repository.kln.ac.lk/handle/123456789/5028 [3] Samaranayake, R.A.D.B., (2006), September. Pre-and post-tsunami coastal planning and land-use policies and issues in Sri Lanka. In Proceedings of the Workshop on Coastal Area Planning and Management in Asian Tsunami-affected Countries. Bangkok, Thailand (pp. 27-29). DOI: 10.15274/tpj.2017.02.02.24. [4] Jayawardane, P.A.A.T., (2001). Fishery biology and population dynamics of shrimps (Penaeus indicus and Metapenaeus dobsoni) in the lagoon and the coastal area of Negombo, Sri Lanka. Unpublished Ph.D. Thesis, University of Stirling, Scotland, UK. 178 pp [5] Barbier, E.B., Hacker, S.D., Kennedy, C., Koch, E.W., Stier, A.C. and Silliman, B.R., (2011). The value of estuarine and coastal ecosystem services. Ecological monographs, 81(2), pp.169-193. DOI 10.1890/10-1510.1 |
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What happens to oil spilled in the sea? Chanaka Supun July 16, 2021 Reviewer: Jorge Santos The X-Press Pearl ship disaster can have long-lasting pollution impact in the coast of Sri Lanka. Pollution is defined as contamination of the ecosystem to such a level that results in harmful effect upon the organisms. Depending on the location and conditions of the wreck and cargo, weather, other stress factors and the success of the salvaging operations, pollution may affect ocean and coasts for months to decades in acute or periodic manners. The harshness of impact of oil spills typically depends on the quantity and type of the oil spilt and the region or ecosystem of occurrence. The X-Press Pearl carried 278 tonnes of bunker fuel oil, 50 tonnes of gas oil and 20 containers full of different types of lubricating oil. Common to all these petroleum-based products is that they are composed of complex and variable mixtures of alkanes, cycloalkanes and aromatics, which exist in many different size and configurations (Figure 1). Lubricants contain 90% base oil (most often petroleum fractions) and 10% additives. These additives are normally rich in heavy metals, like nickel or molybdenum and these represent concerns of their own. When oil slicks are composed of light hydrocarbons like gasoline or diesel, the fraction of short chain alkanes dominate. These are strongly irritating to membranes (like the eyes and gills of fish) or toxic in high concentrations to air breathers, like turtles [1]. However, these oil slicks tend to evaporate in a matter of weeks in tropical regions. In the present case of low-grade bunker oil, however, long-chain alkanes predominate and these tend to form thick layers, which develop into emulsions and tar-balls with time. This thick oil smears the protective feather of sea birds, resulting in loss of body heat, starvation and drowning of thousands of birds [2]. Whales and dolphins may risk from suffocation, but they normally move quickly away from impacted areas. Fish only seem to be affected when they are entrapped in heavy polluted areas like small bays. Polycyclic components of oil (like PAH’s), which become more abundant after combustion of petroleum products (fires), have the potential to cause mutations and cancer in fish, but do not seem to accumulate along the food chain [3]. Periodic leaks of petroleum products from the X-press Pearl wreck may have acute effects that last for weeks. The currents, agitation and high temperature of the seawater in Sri Lanka and the strong sun exposure may lead to chemical, physical and UV degradation of the oil products, and finally sinking of the tar balls offshore. Monitoring of total hydrocarbons in important food fish is necessary, as well as remediation actions to save iconic species. More importantly, oil should not enter systems where wave-energy is low, like lagoons, seagrass beds, salt marshes and mangroves. The direct and indirect effects of heavy oil in these habitats may last for many years and become a sad souvenir of the accident. References [1]Farrington, J. W. (2014). Oil Pollution in the Marine Environment II: Fates and effects of Oil Spills. tandf, 16-31, https://doi.org/10.1080/00139157.2014.922382. [2] Huang, Y. J., Jiang, Z. B., Zeng, J. N., Chen, Q. Z., Zhao, Y. q., Liao, Y. b., Xu, X. q. (2011). The chronic effects of oil pollution on marine phytoplankton in a subtropical bay, China. Environ monit assess, 517-530, https://dx.doi.org/10.1007/s10661-010-1601-6. [3] Albers, P. H., Hoffman, D. J., Rattner, B. A., Burton, G. A., & Cairns, J. (2003). Petroleum and individual polycyclic aromatic hydrocarbons. Boca Raton, FL: Lewis Publishers, https://doi.org/10.1201/9781420032505.ch14. |
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The Mermaid Tears Shobiya Paramasivam July 5, 2021 Reviewer: Jorge Santos The X - Press Pearl accident brought "plastic snow" to Sri Lanka's west coast. The beaches became white-carpeted by plastic pellets. Those are the pre-production plastic pellets or nurdles, also known as “mermaid tears”. Our lifestyles have become increasingly reliant on plastics. They are light weight, ease to use, and low cost. Owing to a great demand worldwide, global plastic production totaled 370 million tons in 2019 [1]. How are plastics produced? The original polymers, derived normally from oil or coal, are transformed into pellets. These are the raw material melted down and molded into plastic products. The pellets have a regular shape and a diameter of 2–5 mm, and are also known as primary micro plastics [2,3]. Polyethylene, polypropylene, nylon and other polymers have different densities, and additives can give them different colors and other properties [3]. Waves and currents have the ability to transport low-density plastic pellets. These small, lightweight, and persistent particles are non-biodegradable, but can break down into smaller particles due to physical, biological, and chemical processes. Like other small particles in the sea, they can absorb toxic chemicals from the surrounding environment. Plastic pellets might be spilled at any point during the plastic manufacturing and transportation process, for instance as a result of ship accidents [2, 3]. Every year, an estimated 230 thousand tons of plastic pellets are washed into waterways [4]. The first scientific reports documenting the negative environmental impact of plastic pellets were published in the 1970s [2]. Plastic pellets have been discovered in surface water samples and on beaches all around the world since then [2]. The accident in Negombo, is in the same scale of the highly publicized nurdle spills in Hong Kong port in 2012 and Durban harbor in South Africa in 2017, both of which caused by bad weather. The MV X-Press Pearl carried 78 metric tons of linear low density plastic pellets. Owing to their density, these plastic pellets floated and washed up on beaches and coasts. The disaster occurred during a period of heavy winds and waves. These precluded their collection and lead to the flow of pellets along 300 kilometers of Sri Lanka's west and south west beaches. Wind and coastal countercurrents brought also the nurdles to the beaches of Mannar (Vankalai and Silavathurai) in Northern Sri Lanka. The presence of plastic pellets in the beaches increases the risks of accidental ingestion by marine organisms and lead to chocking or lethal obstruction. We know little about the health risks of bioaccumulation and biomagnification of nano-plastics, as well as of adsorbed toxicants, in the food web, leading to humans [5]. We must have a precautionary attitude. For sure, the plastic snow reduces the aesthetic value of beaches and constrain their recreational benefits and tourism. Reducing the reliance on plastic is a difficult and global task today. Our first step is to ban single-use plastics. Simultaneously, we must develop replacing technology and change attitudes. Therefore, adopt the 4Rs: refuse, reduce, reuse and recycle. References [1] PlasticsEurope, E.P.R.O., (2020). Plastics—the facts 2020. An analysis of European plastics production, demand and waste data. Plastics Europe. [2] Karlsson, T.M., Arneborg, L., Broström, G., Almroth, B.C., Gipperth, L. and Hassellöv, M.,(2018). The unaccountability case of plastic pellet pollution. Marine pollution bulletin, 129(1), 52-60. https://doi.org/10.1016/j.marpolbul.2018.01.041 [3] Fanini, L. and Bozzeda, F., (2018). Dynamics of plastic resin pellets deposition on a microtidal sandy beach: informative variables and potential integration into sandy beach studies. Ecological Indicators, 89, 309-316. https://doi.org/10.1016/j.ecolind.2018.02.027 [4] Sherrington,C.,(2016).Plastic in the marine environment. Eunomia Research & Consulting Ltd, 13. [5] Miller,M.E., Hamann,M., & Kroon, F.J.(2020). Bioaccumulation and biomagnification of microplastics in marine organisms: a review and meta-analysis of current data. PLoS One, 15(10). https://doi.org/10.1371/journal.pone.0240792 |
Turtles versus nurdles
Suneetha Gunawickrama June 17, 2021 Reviewer: Jorge Santos More than 50 turtles, some fish and dolphins have been washed up dead along the Western and Southern coastline in the days following the X-Press Pearl wreckage nine nautical miles from the shore. Such news on dead turtles were rare before the disaster. The cause of death is yet to be disclosed by the relevant authorities. We do not know if there is a direct or indirect cause-effect but cannot reject the hypothesis that chemicals or plastics released to the water from the ship were involved. Is it possible that creatures like sea turtles die of eating up tiny nurdles? Some sea turtles, including the loggerhead and leatherback, eat smaller animals like jellyfish, crabs and conchs so are carnivorous. Those, like adult green sea turtle, that graze on coral reefs, algae, seagrass and other plant material are herbivorous. Smaller turtles feed on various small particles of both animal and plant origin. Turtles don’t have teeth at all! But the strong beak and jaws can crush their relatively bigger shelled food such as crabs and urchins. Can turtles distinguish plastic particles from their food? Small plastic nurdles when afloat may mimic small sea creatures which are typical food of carnivorous sea turtles. It is possible that mistakenly they may feed on look-alike food items (1). Therefore, the possibility of omnivorous or carnivorous turtles eating floating debris cannot be disregarded. What may happen if they ingest large amount of plastic? Most plastics are non-biodegradable, and no biological process can break them down. Then, the plastics can accumulate and obstruct the stomach of the turtles. Strangely enough, plastic accumulation can kill turtles! EcoWatch, based on SUN-Sentinel 2019 news report, revealed that a small turtle washed ashore in Florida had died from accumulation of 104 small pieces of plastic. Turtle death from obstruction is more likely where the densities of drifting nurdles are high, and that is close to the sinking ship, or in concentration areas offshore like the Great Pacific Garbage Patch. The south and southwest coasts of Sri Lanka, to where the nurdles will start flowing in this season of the year, have vast areas of coral reefs, sea grass beds and sandy beaches. These provide important nesting and foraging grounds to sea turtles. Five of the seven living turtle species nest in southern Sri Lanka, but Green turtles and Olive turtles dominate, with nearly 98% of the nests (2). The young of these two species feed on drifting particles, and are obviously at risk. In general, one can expect that turtles close to the wreck are vulnerable to chemical pollution, but those along the southern coast are in the mid-term more exposed to physical damage by stomach obstruction with the nurdles or by weathered oil. This comes in addition to other occurrences, like damage in fishing gear, egg poaching and natural predation, which are little investigated. Against the efforts to increase the survival of turtle eggs in artificial rookeries, grounding of this ship did not come as a blessing for turtles! References: 1) Takuya Fukuoka, Misaki Yamane, Chihiro Kinoshita et al. (2016). The feeding habit of sea turtles influences their reaction to artificial marine debris. Sci Rep. doi: 10.1038/srep28015 2) Jayathilaka, R. A. M., Perera, H. A. C. C., & Haputhanthri, S. S. K. (2017). Marine Turtles of Sri Lanka; Status, Issues, Threats and Conservation Strategies. IOTC-2017-WPEB13-36 Rev_1 https://www. iotc. org/meetings/13th-working-party-ecosystems-andbycatch-wpeb13. |