PLASTIC MARINE DEBRIS: Importance to Aquatic Environment and Human Health
Over the years the importance of plastics for different purposes especially packaging has been emphasized but its adverse effect on the aquatic environment and human health makes it less desirable. Aquatic animals feed on plastic marine debris and sometimes get a sense of satiety. This false satiety results in starvation as these animals no longer have the need to feed. Most often, tiny plastic materials contain or attract toxic Endocrine-like Estrogen Disrupting Chemicals (EEDC) like Polychlorinated Biphenyls (PCBs) and BisphenolA (BPA) from the environment. These toxic chemicals pass to humans indirectly when they feed on the contaminated fish or other aquatic animals; or directly by exposure to the toxic chemicals in plastics. Hence the need to inform, orient and educate the general public on proper waste management and disposal; and proffer solutions.
Plastics in various forms (bottles, bags, cigarette butts and utensils) make up a category of marine debris; they are non-biodegradable, and persist in the environment for a long period of time. Cigarette butt, a plant based plastic also persist in the environment for a long time. Plastics in the aquatic environment entangle fish and other aquatic animals. The frequent indiscriminate disposals of trash on streets and beaches eventually carried into water bodies (lagoon, rivers, seas and oceans) through run-offs are the major cause of plastic contamination in Nigeria’s waters. There is high rate of diseases in humans as a result of direct or indirect consumption of EEDC like PCBs present or leached from plastics beyond WHO Provisional Tolerable Monthly Intake (PTMI) for dioxins, and PCBs (70 picogram per kilogram of body weight).
Aquatic organisms ingest plastic particles directly in water while humans ingest plastics directly through exposure to toxic chemicals in plastic, or indirectly by feeding on contaminated fish or other aquatics. Controlling of challenges of plastic debris requires effective information and orientation. Highlights of the efforts of Government, Individuals and Non Governmental Organisations towards debris free environments are of paramount importance. Government sets regulations and partners with NGO to raise awareness on management of wastes. Meanwhile, the discarded plastics can be re-utilized for other economic uses without recycling. For instance, in fisheries and aquaculture, the discarded plastic bottle corks can be useful for nitrification of aquaculture waste water while the discarded plastic bottles can be used for building fish farm houses.
In conclusion, beneficial uses of discarded plastics can reduce health risks in aquatic environments. All individuals must be sensitized to be involved in ensuring a debris free environment in order to conserve aquatic lives, improve local economies through beaches and recreational centers, and secure safe human health.
3.1 7 Most Common Plastics and Typical Uses of Each 6
3.2 Plastic Consumption and Disposal 6
3.3 Lifespan of Some Common Plastic Debris 7
3.4 Biodegradability of Plastic Marine Debris 7
3.5 Demerits of Plastic Marine Debris 9
3.5.1 Demerits to wildlife (aquaculture) 9
3.5.2 Demerits to local economies 12
3.5.3 Demerits to humans 13
3.6 How Humans Feed Indirectly on Plastic Marine Debris 13
3.6.1 Polychlorinated Biphenyls (PCBs) 14
3.6.2 Bisphenol A (BPA) 16
3.7 Reducing Direct Exposure to Toxic Chemicals in Plastics 18
3.8 Merits of Plastic Debris 18
3.8.1 Merits to aquaculture, nitrification of aquaculture waste water 19
3.8.2 Merits to humans 19
3.8.3 Merits to local economies as Source of employment 21
3.9 Recycled Uses of Plastic 22
4.1 Policies by Governments Addressing Debris in Nigeria 23
4.2 Efforts by Individuals and NGO’s Addressing Debris in Nigeria 23
4.2.1 Clean Coast Nigeria (CCN) 23
4.2.2 Living Earth Foundation Waste to Wealth 26
4.3 Control of Plastic Marine Debris 26
5.1 Conclusion 27
5.2 Recommendations 27
List of Tables
Table 1: Plastic Debris and their breakdown time 8
Table 2: Comparison of laboratory/toxicity studies of BisphenolA exposure
effects on wildlife 11
Table 3: 7 Common Plastics, Typical Uses, EEDC Present or Leached and Effects
in Humans 17
List of figures
Figure 1: The flow chain of plastic debris ingested indirectly by humans 14
Figure 2: Trickling System, Nitrification of waste water using plastic corks
as filter blocks 19
List of Plates
Plate 1: indiscriminate disposal by citizens 5
Plate 2: Seal trapped in marine plastic debris 9
Plate 3: bird filled with plastics 10
Plate 4: Baby bottles labelled BPA 16
Plate 5: house being built with discarded plastic bottles in Nigeria 20
Plate 6: chair made from discarded polytethylene bags 21
Plate 7: Result of marine debris got from the Lagos cleanup at the Lagos Bar Beach 24
Plate 8: Volunteers campaign for Green Environment with Placards during CARNIRIV
Kids Carnival PHC 24
Plate 9: A kid’s description of harmful effects of debris to aquaculture 25
Plate 10: Volunteers filling trash data cards at middle Ogunpa River during Ibadan 2014 25
Marine debris includes any form of manufactured or processed material discarded, disposed of or abandoned in the marine environment. It consists of items made or used by humans that enter the sea, whether deliberately or unintentionally, includingtransport of these materials to the ocean by rivers, drainage, sewage systems or by wind (Galgani et al. 2010). Once in the water, itcan blow around, remain floating on the water surface, drift in the water column, get entangled in algae on shallow bottoms, sink to the deeper seabed, or be washed up onto beaches sometimes many miles away.
Theyare items and materials that are either discarded directly (thrown or lost directly into the sea), brought to the sea indirectly by rivers, sewage, storm water or winds, or left by people on beaches and shores.
Marine debris is a major global threat to biodiversity. For instance, more than six million tons of fishing gear alone is estimated to be lost in the ocean each year (Derraik 2002). Despite this staggering amount of marine waste, fishing gears form only a small percentage of the total volume of debris in the ocean, not even making the list of the top 10 most common items found during coastal cleanup operations (Ocean Conservancy 2010).
The coastal areas of Nigeria have been in the limelight in recent times due the heavy environmentalpollution resulting from oil prospecting activities. The coastal states in Nigeria are Akwa-Ibom, Bayelsa, Cross-River, Delta,Edo, Lagos, Ogun, Ondo and Rivers states. For certain reasons, development, job opportunities, government attention and commercial activities are concentrated in coastal locations than inland locations all over the world. This phenomenon, which is best explained by anthropologists and sociologists, is also the case in Nigeria.
It is estimated that one-quarter ofthe Nigerian population live in the coastal zone represented by nine states (UNEP, 2007). However, going by the 2006 census (FRN, 2007), 37.2 million representing 26.6% of the total population live in the coastal zone.
Two-thirds of Earth’s surface is covered by ocean. The ocean is our planet’s life support system. It drives our climate and provides food, water and oxygen. No matter where one lives, we all depend on the ocean in some way and we all have a responsibility to care for it.
After all, you can’t “go green” if you don’t “live blue”.
1.1 PROBLEM STATEMENT
Marine debris is a major global threat to biodiversity. For instance, more than six million tons of fishing gear alone is estimated to be lost in the ocean each year (Derraik 2002).The coastal areas of Nigeria have been in the limelight in recent times due the heavy environmental pollution and oil prospecting activities. However, oil pollution is not the only environmental threat to these coastal States. Other forms of solid and liquid wastes equally threaten the livelihood of residents of these areas. Plastics in various forms (bottles, bags, cigarette butts and utensils) make up a category of marine debris; they are non-biodegradable, and persist in the environment for a long period of time. Cigarette butt, a plant based plastic also persist in the environment for a long time.
1.2JUSTIFICATION OF STUDY
Discarded plastics can be re-utilized for other economic uses without recycling. For instance, in fisheries and aquaculture, the discarded plastic bottle corks can be useful for nitrification of aquaculture waste water while the discarded plastic bottles can be used for building fish farm houses amongst other uses as discussed in this work.
Beneficial uses of discarded plastics can reduce health risks in aquatic environments. All individuals must be sensitized to be involved in ensuring a debris free environment in order to conserve aquatic lives, improve local economies through beaches and recreational centers, and secure safe human health.
1.3 OBJECTIVES OF STUDY
1. To inform about the hazardous effects of plastic marine debris
2. To enlighten about the useful utilization of plastic marine debris
3. To highlight the relevance of plastic marine debris to Aquaculture especially its useful utilizations before recycling
4. To educate on role of stake-holders in ensuring environmental safety from marine debris.