How human activities effect Marine life

1. Presentation topic:
How Human
Activities Affect the
Marine life.
PRESENTED BY: NASEER AHMAD
PRESENTED TO: DR. ZAWAR HUSSAIN

2. Marine Ecosystem:
 Marine ecosystem are the largest of earth’s aquatic ecosystems and exist in
waters that have high salt content.
 Besides serving as a source of economic, recreation, and food, surface
waters are also home to tens of thousands of sea creatures across the
globe. These ranges from the smallest microscopic algae to the biggest
whale,
 Unfortunately, Human activities such as overfishing, oil spillage, plastic
dumping, agricultural and industrial wastes, amongst other harmful
practices account for the death of trillions of marine lives every year.

3. Human Activities:
1. Ocean Acidification:
 Our water bodies suffer from the activities we do on land. Take burning of
fossil fuel, for example.
 It also increases the pH level of surface waters.
 When these chemicals fall from the atmosphere into water bodies. This
shift in the pH of water bodies makes it difficult for marine life to survive,
thus, leading to the death of many sea creatures.

4. Excessive Fishing:
 Fishing the oldest way humans used the oceans. While this is a great
opportunity for food and as a means of earning a living.
 excessive fishing is soul-wrenching.
 Over the years, humans have exploited this means aggressively, resulting in
the death of tons of fishes in surface waters.
 Besides reducing the fish population drastically, the equipment and
techniques used in modern-day have a negative impact on other marine
life.
 Don’t get me wrong, I am not saying humans should stop fishing,

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6. Eutrophication:
 It is caused by the release of excess nutrients into coastal areas via streams
and rivers.
 These nutrients come from fertilisers.
 Additional nutrients in the sea can lead to
excessive phytoplankton growth that results in ‘blooms’.
 Decomposition of the dead organisms by bacteria decrease the oxygen
level in water which cause the death of large numbers of other
organisms such as fish.

8. Water Pollution:
 Pollution account for the highest death toll in the marine ecosystem.
 Being the broadest of all human activities affecting marine life, I decided to
outline each source of water pollution below.
 Industrial waste:
 Disposing of industrial wastes such as chemicals and hot water used for
cooling industrial machines is very common in our world today. The
temperature of the water is way higher than that of the sea or ocean, thus
disrupting the balance in the marine ecosystem.
 Oil Spillage:
 Although large scale oil spills do not occur often, however, when it is
highly disastrous when it does.

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 Crude oil spillage can last several years in the sea, suffocating thousands
of sea creatures throughout its stay.
 Land runoff:
 Harmful chemicals on land, especially agricultural wastes, are washed into
water bodies once it rains. Therefore, introducing excessive nutrients,
pesticides and other noxious chemicals that are detrimental to the health
of marine life.
 Plastics:
 The list of water pollutants will be incomplete without addressing the
devastating impact of plastics in water bodies.
 Humans introduce plastics to surface waters directly by dumping them
into water bodies.

10. …
 Another way plastics get into the ocean is through runoff.
 Chemicals from these plastics are toxic to marine life.
 When mistaken as food by aquatic animals, these chemicals poison
the animals and eventually kill them.
 Research shows that plastic is one of the top causes of death in the
marine ecosystem. Sadly, the plastics in water bodies continue to
increase every day.

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