Research Project Title

(Effect of oil spillage on aquatic ecosystem)

Research project submitted to the department of (Chemistry) inpartial fulfilment of the requirements for the

degree of BSc in (Chemistry)

By:Piroz khdir

Supervised byDr Suad Najmaldin Mohiaedin

Academic year 2019-2020 / May 2020

1

Table of Content Content------------------------------------------------------------------PageAbstract 3

Key word 4

Introduction 5

Optimum environmental conditions for fish and aquatic life 6

Marine environments 8

Long term damage 12

Toxic Effects 12

Restoration, reinstatement and remediation 13

Summary and Conclusion 15-16

References 17-18

2

Abstract

Dealing with a major oil spill is a huge effort, sometimes requiring billions of dollars and

involving hundreds, even thousands of people. Yet, oil is a natural material that seeps from the

ground or into the ocean in many locations around the world.

So why is it so important to respond to an oil spill, anyway? The main reason is that oil is also

a toxic material that can cause environmental damage where it spills. The central purpose of oil spill

response is to reduce that damage.

The physical effects of freshly spilled crude oil are all too obvious. When oil washes ashore, it can

completely cover and smother the plants and animals living there.

Crude oil not only destroys the insulating properties of animal fur and bird feathers, which can lead

to hypothermia, but it also impairs animals' abilities to fly and swim, sometimes causing oiled

animals to drown.

Spilled oil also can harm life because its chemical constituents are poisonous. As we previously

learned, petroleum-derived oil is a complex mixture of thousands of chemical compounds. Given

oil's chemical complexity, we need to consider how these different components—and their very

different effects on living things—cause harm.

It is important components of crude oil: volatile organic compounds (VOCs) and polycyclic aromatic

hydrocarbons (PAHs). In terms of how long they remain in the environment, they represent two ends

of a spectrum.

All crude oil contains VOCs, which readily evaporate into the air, giving crude oil a distinctive

odour. Some VOCs are acutely toxic when inhaled, in addition to being potentially cancer-causing.

At the site of a fresh oil spill, these VOCs can threaten nearby residents, responders working on the

spill, air-breathing marine mammals, and sea turtles at the water surface. However, VOCs are

generally a response concern only right after oil is spilled, because oil floating on the sea surface

quickly loses its VOCs.

In contrast, polycyclic aromatic hydrocarbons PAHs can persist in the environment for many years,

in some cases continuing to harm organisms long after the oil first spills. How PAHs in oil do that is

an active area of research.

3

 Lab researchers conducted a series of studies that continued for more than a decade. They found that

even though the levels of PAHs leaching from weathered oil buried in beach sediments were very

low, the PAHs still caused negative effects to incubating herring and salmon eggs. The good news

from these studies is that over the years, the concentration of PAHs has declined in the Sound's

beach sediments, to the point that those particular toxic effects on fish eggs have diminished as well.

However, at a few sites in the Sound, sea otters are eating clams that may continue to be

contaminated by leaching PAHs in buried oil.

The researchers found that some PAHs in oil inhibit proper heart development in fish embryos,

which can either kill the fish outright or make them more susceptible to predation and disease.

With so many varying factors coming into play, predicting the impacts of an oil spill can be quite

challenging. It’s important to know the specific chemical makeup of an oil (and how that makeup

changes over time as the oil weathers). This information will give us clues about how that oil will

interact with organisms and the environment and, hopefully, will help us figure out how to keep

those impacts low.

Key word:Oil: crude oil or fossil fuel

VOC: volatile organic compound

PAH: polycyclic aromatic hydrocarbon

Aquatic: water

Ecosystem: all the plants and animals that live in a particular area

Toxic: poison

DO: Dissolved Oxygen

BOD: Biological Oxygen Demand

Oil spill: run out of oil container by accident

Environment: surrounding atmosphere

Odour: smell

4

IntroductionAn oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially the

marine ecosystem, due to human activity, and is a form of pollution. The term is usually given to

marine oil spills, where oil is released into the ocean or coastal waters, but spills may also occur on

land. Oil spills may be due to releases of crude oil from tankers, offshore platforms, drilling rigs and

wells, as well as spills of refined petroleum products (such as gasoline, diesel) and their by-products,

heavier fuels used by large ships such as bunker fuel, or the spill of any oily refuse or waste oil. [1]

Oil spills penetrate into the structure of the plumage of birds and the fur of mammals, reducing its

insulating ability, and making them more vulnerable to temperature fluctuations and much less

buoyant in the water. Clean-up and recovery from an oil spill is difficult and depends upon many

factors, including the type of oil spilled, the temperature of the water (affecting evaporation and

biodegradation), and the types of shorelines and beaches involved.(1)Spills may take weeks, months

or even years to clean up.[2]

Oil spills can have disastrous consequences for society; economically, environmentally, and socially.

As a result, oil spill accidents have initiated intense media attention and political uproar, bringing

many together in a political struggle concerning government response to oil spills and what actions

can best prevent them from happening. [3]

Environmental pollution caused by petroleum is of great concern. This is because petroleum

hydrocarbons are toxic to all forms of life and harm both aquatic and terrestrial ecosystems. The

pollution of marine habitats has caught the attention of researchers and environmentalists. This is due

to the serious impact of oil spills on marine life, as well as on people whose career relies on the

exploitation of the sea’s resources. Additionally, marine life may be affected by clean-up operations.

It may also be indirectly affected by the physical damage to the habitats in which plants and animals

live. Within the period of 2010-2014, 5,000 tons of the average in. 10,000 billion tons of crude oil

transported by sea yearly was spilled due to accidents, cleaning operations or other causes. For

example, washing ballast tanks account for 36,000 metric tons (11.2 million gallons) of oil entering

the oceans globally every year; human induced activities and non-tank vessels. The marine

ecosystem comprises of various animals from microorganism, vertebrates (fish, birds, mammals, and

turtles), and invertebrates (copepods, mollusks, crustaceans, and echinoderm). These organisms are

5

exposed to various degree of impact during an oil spill accident. Various research has detailed the

toxicological effects of oil (such as increased

mortality or as sub-lethal injury, impaired feeding and reproduction and avoiding predators) on fish

communities, estuarine communities, mammals, birds and turtles, deep-water corals, plankton,

foraminifera, and microbial communities. Oil spills can seriously affect the marine environment both

as a result of physical smothering and toxic effects. The severity of impact typically depends on the

quantity and type of oil spilt, the ambient conditions and the sensitivity of the affected organisms and

their habitats to the oil.

Optimum environmental conditions for fish and aquatic life

1. According to Damaskos [15] and Papadopoulos (1983), the generally accepted indicators of water

quality are dissolved oxygen (DO) and the biochemical oxygen demand (BOD). High oxygen

depletion can be so severe as to affect fish life. If DO value falls below the minimum oxygen

requirement for the particular species of fish, they are subjected to stress, which can result in

mortality. The oxygen content of natural waters varies with temperature, salinity, turbulence, the

photosynthetic activity of algae and plants, and atmospheric pressure. Chapman and Kimstach

(1992) noted that DO concentrations below 5mg/1 adversely affect the functioning and survival

of biological communities, and below 2 mg/1 may lead to the death of most fish. The optimum

concentration of DO for fish and other aquatic life is given in Table.

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2. The BOD is estimated by the amount of oxygen required for the aerobic microorganisms (in the

case of oil pollution, hydrocarbon degraders) present in the water body to oxidize the organic matter

to a stable inorganic form. Thus, when we say that a water body has a BOD value of đ mg/1 we

mean that the concentration of biodegradable organic matter in one litre of it is such that the micro-

organisms need đ mg of oxygen in order to be able to oxidize it. The result of a study carried out by

Chattopadhyay (5) et al. (1988) indicated 10 – 20 mg/1 as the optimum BOD range for fish culture in

effluent or polluted waters. The addition of significant quantities of crude oil to any water body

causes an immediate rise in the BOD due to the activities of hydrocarbon degraders and the blockade

of oxygen dissolution.

3. Changes in pH (or the hydrogen ion activity) can indicate the presence of certain pollutants,

particularly when continuously measured and recorded, together with the conductivity of a water

body. The pH of 1 unit could result in an increase of lead by a factor of 2.1 in the blood of an

exposed organism (Sheehan et al., 1984). What is known, of course, is that pH changes can

drastically affect the structure and function of the ecosystem, both directly and indirectly by, for

example, increasing the concentration of heavy metals in the water through increased leaching from

sediments.

4. Helz )(9,17)et al. (1975) found out that cadmium, which is toxic to many organisms, could be readily

remobilized from sediments. It is important to note that the pH of any water body is dependent on its

temperature. And temperature affects physical, chemical and biological processes in water bodies

and, therefore, the concentration of many variables. According to Chapman and Kimstach (13) (1992),

increased temperature increases the rate of chemical reactions and decreases the solubility of gases

(especially oxygen) in water. Respiration rates of aquatic organisms increase leading to increased

oxygen consumption and increased decomposition of organic matter.

5. Crude oil is associated with some toxic heavy metals most of which contaminate the oil through

underground deposits, especially lead and chromium. Iron is in great abundance in tropical and

subtropical aquifers and is also associated with crude oil deposits. High iron concentrations in

groundwater are widely reported from developing countries, where iron is often an important water

quality issue. Some metals also get into oil due to pipeline ageing and corrosion. Metal-induced

depression of productivity most certainly occurs and may persist in polluted aquatic systems. Certain

organisms have been shown to have some ability to regulate levels of copper and zinc in muscle

(Sheehan et al., 1984). However, bioaccumulation of metals such as lead and chromium by fish is

7

expected, and this spells danger to the human populations consuming such fish. Results obtained by

Rai and Chandra (1992) show marked accumulation of copper, manganese, lead, and iron by the alga

Hydrodictyon reticulatum under both field and laboratory conditions. Fish usually preys upon algae

and other planktonic and benthic organisms; and when there is bioaccumulation of heavy metals in

fish, there is likelihood of morbidity and mortality in man along the food chain. Usually

bioaccumulation of toxic metals can occur to certain extent before chronic- effects thresholds are

reached.

Marine environments

The following sections consider the different types of damage caused by ship-source oil spills in

various environments.

A. Offshore and coastal waters

Most oils float on the sea surface and are spread over wide areas by waves, wind and currents. Some

low viscosity oils may disperse naturally within the top few metres of the water column, particularly

in the presence of breaking waves, where they are rapidly diluted.

Kelp after an oil spill

B. Plankton

The pelagic zones of seas and oceans support a myriad of simple planktonic organisms, comprising

bacteria, plants (phytoplankton) and animals (zooplankton).

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plankton

C. Fish

Despite the susceptibility of juvenile stages of fish to relatively low concentrations of oil in the water

column, adult fish are far more resilient and effects on wild stock levels have seldom been detected.

Free-swimming fish are thought to actively avoid oil.

D. Seabirds

Seabirds are the most vulnerable open water creatures and in major incidents large numbers may

perish. Sea ducks, auks and other species which raft together in flocks on the sea surface are

particularly at risk.

A bird covered in oil from the Black Sea oil spill

E. Marine mammals and reptiles

Whales, dolphins and other cetaceans may be at risk from floating oil when surfacing to breathe or

breach. Harm to nasal tissue and eyes from oil has been postulated. However, where mortalities have

been recorded, necropsies have generally concluded death resulted from causes other than the oil.

Dead sea lion due to oil spill

F. Corals

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Coral reefs provide an extremely rich and diverse marine ecosystem, are highly productive and offer

coastal protection to otherwise exposed shorelines. Corals are highly sensitive organisms that can

take a long time to recover from oiling. Dispersed oil presents the greatest risk of damage to coral

reefs. This risk is highest where increased turbulence from breaking waves encourages natural

dispersion of spilt oil and where dispersants are used. In addition to the coral themselves, the

communities which the habitat supports are also sensitive to oil.

Reef corals

G. Shorelines

Line where water meets land place where the meets sea dry land. Shorelines are exposed to the

effects of oil more than any other part of the marine environment.

H. Soft sediment shores

They often support large populations of migrating birds and indigenous sediment dwelling

invertebrates, including bivalves, and are also nursery areas for some species. Pollutants that do

penetrate fine sediments can persist for many years, increasing the likelihood of longer-term effects.

I. Saltmarshes

The upper fringe of soft sediment shores is often dominated by saltmarsh vegetation comprising

woody perennials, succulent annuals and grasses. Saltmarshes are usually associated with temperate.

J. Mangroves

Mangroves are salt-tolerant trees and shrubs growing at the margins of sheltered tropical and sub-

tropical waters. Mangrove stands provide a valuable habitat for crabs, oysters and other invertebrates

as well as important nursery areas for fish and shrimp. Their location means that mangroves are

highly vulnerable to oil spills. Mangroves are also considered to be extremely sensitive to

contamination by oil, dependent to a large extent on the substrate in which the mangroves are

growing.

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Mangroves tre

K. Shallow inshore waters

Damage in shallow waters is most often caused by oil becoming mixed into the water column by

strong wave action or by the inappropriate use of dispersants too close to the shore.

Spilt oil can pollute streams, rivers and, if it soaks through the soil and rock, groundwater

L. Rocky and sandy shores

Exposure to the scouring effects of wave action and tidal currents means that rocky and sandy shores

are the most resilient to the effects of a spill (Figure). This scouring also usually enables natural and

rapid self-cleaning to take place.

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Figure: Rocky shorelines are commonly exposed to wind and waves and may rapidly self-clean.

Biota including limpets may be affected by oil. Significant mortality may result in the subsequent

abundance of opportunistic flora (algae and seaweed) that would otherwise be kept under control

through grazing. Over time, species re-establish and equilibrium will be restored.

Long term damage

An effective clean-up operation usually includes removal of bulk oil contamination, reducing the

geographical extent and duration of pollution damage, and allowing natural recovery to commence.

However, aggressive clean-up methods can cause additional damage and natural cleaning processes

may be preferable. Over time, several factors reduce the toxicity of oil so that the contaminated

substrate can support new growth (Figure). For example, oil can be flushed away by rain and tides

and as the oil weathers the volatile fractions evaporate, leaving less toxic residual oil.

Figure:Intrusive clean-up of the marsh has caused

additional damage over and above that caused by the oil.

Toxic Effects:

12

We call something toxic if it harms living things. The amount of harm caused depends on how an or-

ganism is exposed and to how much oil. For example, crude oil is considered toxic and causes two

main kinds of injury: physical and biochemical.

The physical effects of freshly spilled crude oil are all too obvious. You've likely seen the disturbing

images of birds and other animals coated in crude oil, struggling to survive. When oil washes ashore,

it can completely cover and smother the plants and animals living there.

Crude oil not only destroys the insulating properties of animal fur and bird feathers, which can lead

to hypothermia, but it also impairs animals' abilities to fly and swim, sometimes causing oiled anim-

als to drown.

During the months after the 1989 Exxon Valdez oil spill, researchers collected about 30,000 dead

birds—ranging over 90 different species—from the oiled areas, and they estimated that perhaps ten

times as many birds died. Spilled oil also can harm life because its chemical constituents are poison-

ous. As we previously learned, petroleum-derived oil is a complex mixture of thousands of chemical

compounds. Given oil's chemical complexity, we need to consider how these different components—

and their very different effects on living things—cause harm.

Dr. Brian Stacy, NOAA veterinarian, prepares to clean an oiled Kemp's Ridley turtle during the response to the 2010

Deepwater Horizon/BP oil spill. Veterinarians and scientists from NOAA, the Florida Fish and Wildlife Commission,

and other partners worked under the Unified Command to capture heavily-oiled young turtles 20 to 40 miles offshore as

part of animal rescue and rehabilitation efforts. (NOAA and Georgia Department of Natural Resources.

Restoration, reinstatement and remediation

Restoration, also known as reinstatement or remediation, is the process by which measures are taken

to restore the damaged environment to conditions where it is functioning normally more quickly than

might be expected from natural recovery processes alone. The terms are often used interchangeably

13

in the context of environmental damage. However, in comparing environmental law in the United

States and European Union with the international regime of the 1992 Civil Liability and Fund

Conventions (CLC & FC), the interpretation of the terms can be different. Guidance provided by the

1992 Fund Claims Manual** indicates that within the international regime, reinstatement measures

should have a realistic chance of significantly accelerating natural recovery without adverse

consequences for other natural or economic resources. The measures should also be in proportion to

the extent and duration of the damage and the benefits likely to be achieved. Damage is considered

as the impairment of the marine environment, where impairment in this context can be described as

the abnormal functioning or absence of organisms within a biological community, caused by the

spill.

The US regulations promulgated under the 1990 Oil Pollution Act (OPA ‘90) also acknowledge

natural recovery as a key mechanism for restoration but introduce two concepts: primary and

compensatory restoration. Compensatory restoration is intended to compensate for environmental

services ‘lost’ during the period that the environment is undergoing recovery, whereas primary

restoration refers to actions taken to restore or accelerate recovery and is equivalent to reinstatement

under the international regime. The 2004 EU Environmental Liability Directive (ELD) also includes

these concepts in terms of remediation. However, the international regime does not recognise the

concept of compensatory restoration or remediation.

Following a clean-up operation, further active steps may be justified to restore damaged resources

and encourage natural recovery, especially in circumstances where recovery would otherwise be

relatively slow. An example of such an approach following an oil spill would be the replanting of

saltmarsh or mangrove plants. Once the new growth has become established other forms of

biological life return and the potential for erosion of the area is minimised.

Designing meaningful reinstatement strategies for fauna is a much greater challenge. Damaged

habitats may be protected and recovery of ecosystems may be enhanced, for example, by restricting

access and human activity, by placing controls on fishing to reduce competition for a limited food

source, as

is the case with sand eels and puffins, or by closing beaches used by turtles during the nesting

season. In some cases, protection of a natural breeding population at a nearby, un-oiled site may be

warranted, for example by predator control, to provide a reservoir from which re-colonisation of the

damaged areas can occur. However, many complex biological, ecological and environmental factors

are likely to govern the ability of adjacent populations to re-colonise a polluted area.

14

In reality, the complexity of the marine environment means that there are limits to the extent to

which ecological damage can be repaired artificially. In most cases natural recovery is likely to be

relatively rapid and will only rarely be outpaced by reinstatement measures.

Years after the Exxon Valdez oil spill, heavy residual oiling remains in sediments of Smith Island in

Prince William Sound, Alaska, June 2011. (David Janka, R/V Auklet, NOAA)

Clean-up efforts after the Exxon Valdez oil spill

Summary and Conclusion:

This study addressed the impact of an oil spill on the aquatic eco system it shows the greatest impact

on marine animals’ fish and other marine mammals and coral reef and plekton.

Dealing with a major oil spill is a huge effort, sometimes requiring billions of dollars and involving

hundreds, even thousands of people. Yet, oil is a natural material that seeps from the ground or into

the ocean in many locations around the world.

Therefor there are many reasons makes it so important to respond to an oil spill. The main reason is

that oil is also a toxic material that can cause environmental damage where it spills. The central

purpose of oil spill response is to reduce that damage. Let’s look at two important components of

crude oil: volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). In

terms of how long they remain in the environment, they represent two ends of a spectrum.

All crude oil contains VOCs, which readily evaporate into the air, giving crude oil a distinctive

odour. Some VOCs are acutely toxic when inhaled, in addition to being potentially cancer-causing.

15

At the site of a fresh oil spill, these VOCs can threaten nearby residents, responders working on the

spill, air-breathing marine mammals, and sea turtles at the water surface. However, VOCs are

generally a response concern only right after oil is spilled, because oil floating on the sea surface

quickly loses its VOCs.

In contrast, PAHs can persist in the environment for many years, in some cases continuing to harm

organisms long after the oil first spills. How PAHs in oil do that is an active area of research.

The Auke Bay Lab researchers conducted a series of studies that continued for more than a decade.

They found that even though the levels of PAHs leaching from weathered oil buried in beach

sediments were very low, the PAHs still caused negative effects to incubating herring and salmon

eggs. The good news from these studies is that over the years, the concentration of PAHs has

declined in the Sound's beach sediments, to the point that those particular toxic effects on fish eggs

have diminished as well. However, at a few sites in the Sound, sea otters are eating clams that may

continue to be contaminated by leaching PAHs in buried oil.

he Northwest Fisheries Science Centre, another NOAA [2] research laboratory in Seattle, Wash., has

studied the chemical physiology of how PAHs harm developing fish. The researchers found that

some PAHs in oil inhibit proper heart development in fish embryos, which can either kill the fish

outright or make them more susceptible to predation and disease. With so many varying factors

coming into play, predicting the impacts of an oil spill can be quite challenging. It’s important to

know the specific chemical makeup of an oil (and how that makeup changes over time as the oil

weathers). This information will give us clues about how that oil will interact with organisms and the

environment and, hopefully, will help us figure out how to keep those impacts low.

16

REFRENCES

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17

6. H. C. (1988), A Study on Optimun BOD Levels for Fish Culture in Wastewater Ponds.

Biological Wastes, 25(2), 79-85.

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Oceanogr Mar Res 6: 179. doi: 10.4172/2572-3103.1000179 Copyright: © 2018 Adzigbli L,

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Attribution License, which permits unrestricted use, distribution, and reproduction in any

medium, provided the original author and source are credited

13. A-Chapman, D; Kimstach, V.(1992), The Selection of Water Quality Variable In: Water

Quality Assessments(Chapman, D. Ed.) Chapman and Hall Ltd., London pp. 51-119

14. Chattopadhyay, G N; Saha, PK; Gosh, A; Karmakar H C (1988), A Study on Optimun BOD

Levels for Fish Culture in Wastewater Ponds. Biological Wastes, 25(2), 79-85.

15. Damaskos, S. D. and Papadopoulos, A. S. (1983); A General Stochastic Model for Predicting

BOD and DO in Streams. International Journal of Environmental Studies, 21(2), 229 – 237.

16. DPR (1991); Guidelines and Standards for Petroleum Industry in Nigeria. The Department of

Petroleum Resources, The Federal Ministry of Petroleum and Mineral Resources.

18

17. Helz, G. R., Hugget, R. J. and Hill, J. M. (1975); Behaviour of Mn, Fe, Cu, Zn, Cd, and Pb

Discharged from a Wastewater Treatment Plant into an Estuarine Environment. Water

Research, 9, 631 – 636.

18. Ilangovan, K and Vivekanandan, M. (1992); Effectsof oil Pollution on Soil Respiration and

Growth of Aquatic Oil Pollution.

19