A National Marine Debris Management Strategy to Conserve Marine Ecosystems
Total Page：16
File Type：pdf, Size：1020Kb
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CMFRI Digital Repository Mar. Fish. Infor. Serv., T & E Ser., No. 228, 2016 3 A National Marine Debris Management Strategy to conserve marine ecosystems V. Kripa, P. Kaladharan, D. Prema, R. Jeyabaskaran, P. S. Anil Kumar, G. Shylaja, K. K. Sajikumar, A. Anasu Koya, Preetha G. Nair, K. S. Abhilash, A. M. Dhanya, John Bose, T. V. Ambrose, N. D. Divya P. G. Vishnu and Jishnu Mohan ICAR-Central Marine Fisheries Research Institute, Kochi Introduction Types of marine debris Marine debris which is defined as any persistent, Since the major source of marine debris is land, manufactured or processed solid material discarded, an evaluation of the solid waste generated on land disposed of or abandoned in the marine and coastal and the effectiveness of waste management can environment is one of the most pervasive, yet indicate the threat to the coastal ecosystem of the potentially solvable, pollution affecting the world’s specific area. In most cities, there is no complete oceans, coastal ecosystems and rivers. Whereas waste management system in place and the threat impacts of most anthropogenic activities are usually to coastal and riverine ecosystem from marine found near the point source, marine debris has been debris is evident. Indiscriminate dumping of solid found to impact even distant locations, often waste on land reaches the drains, rivers and estuaries and finally ends up in the sea. During this affecting uninhabited areas also. According to process, these may sink and spread on the river bed United Nations Joint Group of Experts on the or estuaries, can clog small canals and ultimately Scientific Aspects of Marine Environmental affect the aquatic habitats and its functioning which Protection (GESAMP), 60 to 80%, of the global litter supports the local fauna. From the coastal waters, found in the coastal and marine ecosystems has they are also transported to distant places by wind originated from land and only the rest from sea and water currents. They may either remain based activities. The slow degradable nature of floating, trapped in gyres or eddies or sink and marine litter and the potential to pollute all spheres settle or become washed ashore as beach litter. For of oceans irrespective of point source has raised wastes originating at sea, usually from ships, the the alarm bells. The UNEP has recently initiated a fate of the litter is the same. Studies have shown special program ‘Global Initiative on Marine Litter’. that debris can also lead to water stagnation thereby Three main industries which are affected by marine creating a breeding ground for mosquitoes and flies debris are fisheries, shipping and tourism and the that spread diseases to humans. Discarded litter estimated damage to these sectors in Asia-Pacific has thus become a concern for human life and Economic Co-operation (APEC) region is US$1.265 health. million annually. In India, occurrence of marine In India, estimates of Municipal Sewage Waste debris along the Indian coast has been studied by (MSW) in 2008 was about 48134 ton per day from the ICAR-Central Marine Fisheries Research Institute, 299 cities across the country with the per capita since 2007. The study indicates that marine debris production being 0.376 kg per day. In a report on has affected the ecosystem and livelihood of fishers. Municipal Solid Wastes in India based on the data In this article, the impacts of marine debris on the from CPCB, it is stated that the major MSW is ecosystem are explained briefly followed by the compostable waste (43 %) followed by ash and fine possible solutions for controlling and reducing sand (41%). Paper which is degradable forms 5.7%. marine debris in the country and the need for a The other items which are non-degradable and semi- Nation at Marine Debris Management Strategy. degradable were plastics, leather, glass, metal and 4 Mar. Fish. Infor. Serv., T & E Ser., No. 228, 2016 Solid wastes dumped in the Cochin Backwater Clogged canals impacting local biodiversity textile. Of these, plastics consisted of 32% followed fishers and beach goers. In bivalve fishing areas of by textile (28.7%) glass (17.2%), metal (15.6%) and Vembanad Lake, especially where the clams are leather (6.6%). The dominance of semi-degradable handpicked from intertidal/subtidal areas, fishers material which can be recycled clearly indicates have indicated that broken glass pieces are a threat the potential we have to move towards a zero-waste to their health and plastic covers and other debris situation with proper waste management. Also, in have led to low catch per hour of fishing. the marine and coastal areas there are large biomass Foamed plastics that include thermocol are of floating weeds and sea grasses which are commonly used in packaging industry and as use- degradable and can be readily composted, but very and- throw plates. Being light, the thermocol debris little effort is currently made to effectively manage floats and is carried away by wind and currents and these. was one of the most common litter item in all The UNEP guidelines for assessing litter, list surveys conducted by CMFRI in beaches and fishing seven types of materials such as plastics, foamed areas. Tyres, footwear, bags and toys made of plastics, cloth, glass and ceramics, metal, rubber, rubber, semi degradable textile material and wood and others (electronic items, paraffin wax, mattresses are also common in the marine debris etc) with a total of 77 individual codes for items in almost all beaches and waterways. These actually coming under these categories (UNEP Regional Seas degrade the habitats and reduce the functions of Reports and Studies, No. 186; IOC Technical Series the ecosystems. Apart from this, these macro items No. 83:). This is mainly meant for uniformity in data soak and settle on the bottom affecting the benthic collection and comparison of data under the substrate and impacting the breeding and nursery Regional Sea Programme. The non- degradable and grounds in critical habitats like mangroves, sea semi-degradable items commonly found in India are grasses and coral reefs. E-waste like used CDs, parts varieties of plastics (hard / foamed), rubber, metal, of computer and mobiles are also found in the thermocol, textile and glass. In India, the quantity marine debris but comparatively less. of litter on the beaches has been found to vary Abandoned, lost, or otherwise discarded fishing (CMFRI Annual Reports in Eprints.cmfri.org.in) with gear (ALDFG) is one of the most dangerous types of plastics being the major pollutants. marine debris. These nets called 'Ghost nets' can Though the percentage occurrences of glass, go on fishing, trapping, or entangling other fauna ceramics and metal debris are much lower and act as a collecting entity of other debris thereby compared to plastics, broken glass pieces and other degrading habitats and reducing functional values sharp objects lying on the beach pose a threat to of ecosystem services. Increased use of synthetic Mar. Fish. Infor. Serv., T & E Ser., No. 228, 2016 5 material in fishing gear manufacture and range suratensis) which are the major fishery resources extension of fishing activities have led to presence there. of ghost nets in the oceanic and coastal ecosystems. Plastic products ranging from small ice cream In India, ghost nets sometimes get washed ashore. spoons to large sheets and crates are dumped as There is a need to create awareness among litter on the beaches and obtained along with fish fishermen on the harmful effects of ghost nets on catch in gears like bag nets and trawls. In the the marine fauna as well as navigators and other estuaries, these occur in gill nets and drift nets. users of the marine ecosystem like divers and Even critical habitats like coral reefs of tourists. Countries like Australia which had severe Lakshadweep have plastic litter. In a survey problems due to ghost nets have devised several conducted the mean litter density was estimated methods to tackle the problem. GhostNets Australia as 7.71 g m-2 and in the 4 inhabited islands the litter is an alliance of 22 indigenous communities from density ranged from 2 to 11 g m-2. Similar situation coastal northern Australia established in 2004. This occurred in the ecologically sensitive, sea grass beds program has trained and supported indigenous at Mandapam, Kilakkarai, Erwadi and groups in removing ghost nets on shore and at sea. Periyapattinam, which are habitats of dugong. Such exercises are strenuous and these groups Plastics are a transport vector of persistent organic undertake cleanups of fishing gear and other debris pollutants (POP) and heavy metals as well as a at sea for periods extending to three weeks. source of chemical pollutants themselves such as Discarded lobster and other fishing traps are also a phthalate plasticisers, polybrominated diphenyl major concern in Australia and it is mandatory that ether flame retardants (PBDE; which are known to traps are made with rot cord that decays in cause infertility in human beings) and bisphenols approximately six months. (endocrine disrupter). Depending on the size, Several reports on seabirds, turtles, seals, sea plastics are classified into macro(>5mm) and micro lions, whales and fishes that have suffered from plastics (<5mm) that includes particles as small as entanglement or ingestion of marine debris are 10 nanometers. Micro-plastics are used as abrasive available. Plastic bags are mistaken by sea turtles for jellyfish, their prey and when they try to feed on it, the bag gets entangled and most often the turtle moves around with this. Recent studies show that plastics can act as a source of toxic substances which can affect the fauna when ingested, bio- accumulate and then be transported up the food web to humans.