Marine Water Pollution Research Paper

View sample Marine Water Pollution Research Paper. Browse other  research paper examples and check the list of research paper topics for more inspiration. If you need a religion research paper written according to all the academic standards, you can always turn to our experienced writers for help. This is how your paper can get an A! Feel free to contact our custom writing service for professional assistance. We offer high-quality assignments for reasonable rates.

This research paper will briefly define the term marine pollution and then go on to consider the historic growth of problems in this area and the perception of those problems. The main areas of concern in terms of marine pollution are then outlined and the international methods of regulating marine pollution problems are considered.

1. Introduction

The term pollution is used widely and rather loosely. In the context of the oceans the UN sponsored Joint Group of Experts on the Scientific Aspects of Marine Pollution (GESAMP) offered the following definitions (GESAMP 1982):

Contamination is the presence of elevated concentrations of substances in water sediments and organisms. Pollution is the introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries) resulting in deleterious effects such as harm to living resources, hazards to human health, hindrance of marine activities, including fishing, impairing quality for use of seawater and reduction of marine amenities.

These definitions are extremely valuable because they draw an important distinction between human-induced changes in the concentrations of a substance somewhere in the marine environment (contamination) and actual damage resulting from this introduction (pollution). The oceans in total are vast and have a huge capacity to dilute, and in some cases break down, a discharge if time and physical processes allow this dilution and degradation capacity to be utilized. Acknowledgment of this capacity should not imply complacency about problems arising from human impacts on the ocean, but rather help focus concern on the most important issues.

2. Historical Developments

Major public health problems in developing cities in the Middle Ages led to the construction of primitive sewers to discharge wastes to local estuaries. Such discharge of wastes improved public health but caused pollution in estuaries such as the Thames in London from the fourteenth century onwards, promoting the earliest development of sewage treatment systems. However, until the twentieth century technological development was such that only the immediate coastal environment was significantly contaminated by human activity. Despite this, the tragedy of the decimation of the great marine mammals by hunting demonstrates major and global human impacts on the marine environment from the eighteenth century onwards.

Concern over marine pollution grew from the 1950s onwards as it became clear that the ability of the marine environment to absorb discharges was not infinite and that real damage was being done by human activity. Incidents such as the mercury poisoning at Minamata in Japan, the global contamination of the oceans by radioactive debris from bomb testing and by persistent pesticides such as DDT, and the effects of the first large-scale oil spills from sinking of the new giant oil tankers changed for ever the public perception of the vulnerability of the oceans to damage from human activity.

Investigations into these incidents also began to reveal the complexity of marine contamination and pollution issues. The saga of DDT illustrates that some contaminants can very effectively become globally dispersed and furthermore can be concentrated up the food chain to cause major ecological damage far from source to nontarget organisms.

By contrast, while the effects of an oil spill are locally catastrophic in the short term, the bacteria in the marine environment have the capacity to degrade such hydrocarbon material and hence the problem is relatively localized and short term. It is also now known that the biggest sources of hydrocarbons to the marine environment are not the rare catastrophic oil spills, but rather the chronic low-level operational discharges of oil, although the impacts of the two different sorts of discharge are very different. These examples illustrate that contaminants of the marine environment can be broadly classified into several groups.

Nondegradable. Elements such as lead and cadmium cannot be degraded, although they may become stored in sediments and largely removed from biological interactions.

Slowly degraded. Some organic compounds such as DDT and PCBs are only very slowly degraded over timescales of decades or longer. Radioactive material introduced to the marine environment decays over timescales controlled by radioactive half-lives which range from seconds to millions of years. In the case of both persistent organic and radioactive contaminants, intermediate decay products can also be toxic. As with nondegradable material, these compounds may be buried in sediments and effectively taken out of the system long before they are fully degraded.

Readily degraded. The marine environment is a natural biological system containing a wealth of micro-organisms able to break down many organic compounds including substances such as sewage and oil. As noted later, however, the breakdown process itself and the products of that breakdown can cause serious environmental problems.

Since the 1950s there has been enormous growth in the scientific understanding of how the oceans function as a physical, chemical, and biological system. This has allowed a much better assessment of the local and global scale of marine contamination and pollution problems. However, it was still not until the early 1970s that the natural distributions of some important contaminants, such as cadmium, in the oceans were described. A basic understanding of the natural distribution of an element is clearly a vital prerequisite to assessing the likely contamination of the oceans from human impacts. In the case of entirely manmade substances such as DDT or artificial radionuclides, the situation is rather different since their detection in the environment at any level implies contamination, although not necessarily pollution.

In recognition of the growing impact of human activity on the oceans, discharge controls on degradable and nondegradable materials have been introduced in many countries. These aim to minimize harmful impacts, based on the best available scientific understanding of likely effects. There is clear evidence that these controls have had beneficial effects in many areas. The resulting declines in levels of lead and some radionuclides in the oceans, for instance, have been documented. However, the pollution arising from the use of tributyl tin (TBT) as an antifouling agent in the 1980s provides a warning that our control procedures are still far from being entirely effective. Every year hundreds of new organic compounds are synthesized and used in industries around the world. The effects of the inevitable resultant discharge are rarely known with certainty and there is growing concern over their possible effects. The issue of possible estrogenic effects of chemicals discharged to the environment represents an example of a new and disturbing pollution problem that we are a long way from understanding.

3. Current Concerns

A series of reviews of the marine environment have discussed the changing nature of pollution threats to the oceans and also suggested a broad consensus on the nature of current threats to the oceans (McIntyre 1995, Goldberg 1995, Huber 1999). The major issues of current and likely future concern center on the effects of sewage and nutrient discharge, and the release of organic compounds including pesticides. The issue of marine litter is also still of concern, with evidence of damage to bird and marine life from the indiscriminate discharge particularly of plastic wastes from ships and the loss of drift nets. Regulations to reduce these problems exist, but policing such regulations on the high seas is almost impossible.

The global population is growing and the proportion of that population living near the sea is also growing. The waste discharges from that population will inevitably enter the marine environment, although this will hopefully be after basic treatment. Furthermore, the agricultural and industrial activity to sustain that population will inevitably result in discharges to the marine environment, even if these are minimized by the use of the best available technology. Thus it is the insidious effects of this population growth that may pose the biggest threat to the oceans.

3.1 Sewage

Sewage wastes contain many harmful micro-organisms. The public health effects of coming into contact with these organisms either directly, via bathing, or in foodstuffs such as shellfish, where they can become concentrated, is increasingly being recognized. Sewage wastes are rather quickly broken down by natural micro-organisms in the marine environment to release nutrients such as nitrogen and phosphorus. However, the breakdown of organic wastes such as sewage requires oxygen, or some other oxidizing agent. If the rate of breakdown of waste and associated oxygen consumption exceeds the rate at which oxygen is supplied, oxygen concentrations in the water will fall, leading, in the extreme case, to oxygen depletion and the loss of almost all animals as well as the production of noxious odors. This happened in the Thames estuary as London’s population grew and overwhelmed primitive waste treatment facilities. Improvements in waste treatment since the 1950s have restored the health of the Thames. Similar stories of damage from waste discharge and subsequent recovery with improved waste treatment can be told for industrialized estuaries around the world. They illustrate that we have the technology to mitigate the effects of sewage discharges and to reverse the damage done.

3.2 Nutrients

Human perturbations have approximately doubled the fluxes of the nutrients nitrogen and phosphorus through the environment, while the perturbation for the nutrient silicon is much less. Thus fluxes and the relative proportions of the nutrients have changed as a result of human activity. Nitrogen and phosphorus fluxes are projected to continue to increase in the future. The resulting inputs to the oceans have already led to eutrophication problems in some areas, although on a global scale human impact has done little to increase the vast natural nutrient inventory of the deep ocean. Problems are therefore focused on the coastal environment. Eutrophication describes the process of increased nutrient load stimulating the growth of phytoplankton, the microscopic algae that form the base of the food chain. A modest stimulation of phytoplankton growth has the potential to increase the phytoplankton stock and thereby provide more food for animals further up the food chain. However, excessive nutrient inputs coupled to inadequate dilution can lead to excessive algal growth which can settle into deeper water after death and consume all the available oxygen leading to the death of animals living in deep waters. The extent of such deep-water oxygen depletion depends critically on the physical water exchange processes which promote oxygen supply to the deep waters. Thus in areas of restricted mixing, such as the Baltic or Adriatic Sea, there are serious problems, while in the much more open North Sea the problem is less significant, although all these areas receive major discharges of nutrients via rivers and the atmosphere.

Large-scale algal growth, or blooms, can also involve undesirable or toxic species and have a range of highly undesirable effects. There is some evidence that such blooms may be increasing worldwide, although systematic studies to confirm this are not available. Indeed, on an oceanic scale, or even a regional scale, it is often difficult to quantify the level of human perturbation of the marine system, particularly since coastal and near-surface environments are characterized by great natural variability. Systematic studies of the marine environment are relatively recent, so we often do not have sufficient a time series of data to identify with confidence concentration trends for many contaminants.

3.3 Pesticides

Pesticide use has many benefits to human society, particularly in terms of increased food production. However, the release of chemicals into the environment which are designed to produce harmful biological effects is inevitably a cause for concern. The use of some pesticides such as DDT and TBT are now severely restricted, although the extent and effectiveness of such regulation varies widely from country to country. In developing countries the use of other pesticides is continuing to increase. These will inevitably escape into the wider environment and the effect of low levels of these compounds individually or in mixtures is very poorly understood. The input of other potentially harmful organic compounds is also of continuing concern, as noted earlier.

3.4 Global Issues

In addition to these concerns over the direct contamination of the oceans, recently attention has turned to the role of the oceans within the larger global climate-regulating system. Heat and CO exchange between the ocean and the atmosphere are key elements in this system. The emission of gases, such as dimethyl sulfide (DMS), from the ocean also plays a major role in climate regulation. The response of these exchange processes to climate change represents a series of poorly understood feedbacks in the global climate system. This makes predicting the effects of increasing concentrations of CO and other greenhouse gases particularly difficult. Thus it is important to recognize that the oceans play a key role in the control of the whole planetary system, and hence that atmospheric pollution is linked to marine pollution.

3.5 Loss Of Marine Habitats

Marine pollution is usually considered in terms of inputs of chemical wastes to the marine environment. However, there are two major issues that represent simpler and more direct threats to the marine environment. First, there is clear evidence that almost all fisheries worldwide are fully or overexploited. In the North Sea, for example, the clearest trend of environmental change is not of chemical contamination, but the vast decline in fish stocks. Globally half of the individual fish stocks are fully exploited and another 22 percent are overexploited.

The second issue is the physical degradation of coastal environments. In some cases this takes the form of total loss of habitat to reclamation. For instance, in the Humber estuary, the largest English estuary draining to the North Sea, more than 90 percent of the intertidal area has been lost to reclamation over the last 300 years. Similar losses have occurred in many other estuaries. In tropical areas half the mangrove forests have been lost to developments of some sort. These represent a massive loss of ecologically important wetlands and also loss of nutrient-processing potential. In other cases the habitat loss is not complete but involves a major reduction of ecological value. This problem is illustrated by the loss of many inshore coral reef systems to sedimentation. This occurs as changing land use patterns increase erosion and hence turbidity in the coastal waters, blocking light to the coral community and ultimately killing the corals. Eutrophication can have similar effects. Intertidal areas and coral reefs also represent important components of coastal defense against erosion and flooding. The destruction of these areas therefore represents economic as well as ecological losses.

4. Research And Regulation

Long-range transport is a feature of marine pollution issues, and hence national regulation alone is inadequate to protect the marine environment. There have been a series of initiatives focused on regional seas such as the Baltic, the North Sea, and the Mediterranean to achieve coordinated international action to manage the area. The United Nations Convention on the Law of the Sea entered into force in 1994, providing an international framework for the exploitation of the marine environment and also a requirement on states to ‘use the best practical means at their disposal’ to prevent and control marine pollution. While imperfect, these initiatives represent a growing realization that the oceans need to be managed at an international level to ensure their continued value for future generations.

There has also been a growing recognition that progress in managing the marine environment requires interdisciplinary scientific study involving chemists, biologists, physicists, and geologists. An important recent development has been the integration of social scientists in this work to describe the human pressures on the marine system and to consider future management options for the marine environment. An example is the recent valuation of the whole marine ecosystem at $20 billion dollars, although the methodology used is controversial. Most of the value assigned to the marine environment in this analysis is associated with the cycling and storage of nitrogen and phosphorus, and hence intimately linked to nutrient and sewage pollution issues. Huber (1999) noted ‘Environmental degradation impedes economic and social development and diminishes human welfare.’ Thus the true cost of indiscriminate discharges to the marine environment are now beginning to be considered.

Control of marine pollution problems does not necessarily require sophisticated regulation but rather rigorous and effective planning control that assigns an appropriate value to the marine environment. It also implies controls not only of direct discharges to the marine environment, but also throughout the river catchment draining to the marine environment and of atmospheric sources upwind.

Thus several areas of real concern in terms of potential marine pollution problems can be identified, although the evidence for large-scale effects in the open ocean is modest. The oceans have a very large capacity to dilute and degrade wastes. Marine pollution problems are most evident where this capacity is not effective, such as in coastal areas with restricted circulation or for contaminants that float, such as oil or plastics. The assessment of the nature of these threats has changed somewhat over the years as we have come to understand the marine system better and also to regulate human discharges into the system. Indeed, in a recent report GESAMP noted: ‘While the resolution of these issues is neither simple nor easy, in most cases the nature of the ocean’s environmental problems is understood, the knowledge to solve them is available and the necessary management tools exist. What is lacking is the determination and political will to act’ (Huber 1999).


  1. Andrews J, Samways G, Dennis P, Maher B 2000 Origin, abundance and storage of organic carbon and sulphur in the Holocene Humber Estuary. In: Shennan I, Andrews J E (eds.) Holocene Land–Ocean Interaction and Environmental Change Around the North Sea. Geological Society of London Special Publication, London, pp. 145–70
  2. Botsford L W, Castilla J C 1997 The management of fisheries and marine ecosystems. Science 277: 509–15
  3. Clark R 1989 Marine Pollution. Oxford Science, Oxford, UK
  4. Constanza R, Arge R, De Groot R, Farber S, Grasso M, Hannon B, Limburg K, Naeem S, O’Neill R, Paruelo J, Raskins R, Sutton P, Den Belt M 1997 The value of the world’s ecosystem services and natural capital. Nature 387: 253–60
  5. Goldberg E D 1995 Emerging problems in the coastal zone for the twenty-first century. Marine Pollution Bulletin 31: 152–8
  6. Henrichsen D 1994 Life on the margin. People and the Planet 3: 3–35
  7. Houghton J, Meira Filho L, Callander B, Harris N, Kattenberg A, Maskell K 1996 Climate Change 1995. Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, UK
  8. Huber M E 1999 Oceans at risk. Marine Pollution Bulletin 38: 435–8
  9. Jickells T 1998 Nutrient biogeochemistry of the coastal zone. Science 281: 217–22
  10. McIntyre A D 1995 Human impact on the oceans: the 1990s and beyond. Marine Pollution Bulletin 31: 147–51
  11. North Sea Task Force 1993 North Sea Quality Status Report. Oslo and Paris Commissions, London
  12. The Open University Course Team 1991 Case Studies in Oceanography and Marine Affairs. The Open University and Pergamon, Oxford, UK
  13. O’Riordan T 1995 Environmental Science for Environmental Management. Longman, Harlow, UK
  14. Richardson K 1997 Harmful or exceptional phytoplankton blooms in the marine ecosystem. Advances in Marine Biology 31: 302–85
  15. Turner B L, Clark W C, Kates R W, Richards J F, Mathews J T, Meyer W B 1990 The Earth as Transformed by Human Action. Cambridge University Press, Cambridge, UK
  16. Turner R K, Adger W N, Lorenzoni I 1998 Towards Integrated Modelling and Analysis in Coastal Zones: Principles and Practices. LOICZ International Project Office, Texel, The Netherlands
  17. United Nations Joint Group of Experts on the Scientific Aspects of Marine Pollution 1982 The Review of the Health of the Oceans. GESAMP Reports and Studies no. 15, UNESCO, Paris
  18. United Nations Joint Group of Experts on the Scientific Aspects of Marine Pollution 1990 The State of the Marine Environment. GESAMP NEP Regional Seas Reports and Studies no. 115, UNEP, Nairobi, Kenya
Groundwater and Terrestrial Water Pollution Research Paper
History of Warfare Research Paper


Always on-time


100% Confidentiality
Special offer! Get discount 10% for the first order. Promo code: cd1a428655