Biodiversity of species (Secondary) - Lesson Four
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Lesson duration is: 45 minIntroduction
Lesson Four – What is threatening biodiversity?
This lesson covers how the ocean is being overfished, including the issues of illegal fishing and by-catch,
Learning activities:
Investigate an example of overfishing and its impacts on biodiversity.
Create a poster or infographic explaining the issue of overfishing.
Instructions
Time: 45 minutes
Contact: education@seashepherdglobal.org
© Sea Shepherd 2022
Items in this lesson
Slide 1 - Slide
This lesson is provided by Sea Shepherd. Sea Shepherd was founded in 1977 and is a marine conservation organisation working to protect the oceans and marine wildlife. Sea Shepherd works globally on a range of issues impacting the oceans, running numerous direct action campaigns each year.
Slide 2 - Slide
During the lesson we will use these icons to identify the learning actions.
Slide 3 - Slide
The next issue we are going to look at is overfishing and the impact of illegal fishing.
Ask students: “What do you think we mean by overfishing?”
Overfishing – means the depletion of fish numbers by excessive fishing.
Overfished populations - means the depletion of the numbers of fish in specific area) by excessive fishing ultimately leading to the collapse of fisheries.
Ask students: “What do you think we mean by overfishing?”
Overfishing – means the depletion of fish numbers by excessive fishing.
Overfished populations - means the depletion of the numbers of fish in specific area) by excessive fishing ultimately leading to the collapse of fisheries.
Why is overfishing happening?
Slide 4 - Open question
Ask students “Why do you think overfishing is occurring?”
Slide 5 - Slide
Overfishing is occurring due to the large demand for fish, as a result of:
Growing populations
Increased popularity of fish as a “healthier” choice. Fish is seen as a good source of Omega 3’s, however fish don’t produce omega 3, it comes from the algae they eat. This also does not take into account the chemical contamination in fish.
Growing populations
Increased popularity of fish as a “healthier” choice. Fish is seen as a good source of Omega 3’s, however fish don’t produce omega 3, it comes from the algae they eat. This also does not take into account the chemical contamination in fish.
Slide 6 - Slide
The result of this demand is:
Increased size of the global commercial fleet
Size of the vessels used to catch fish has increased, which means larger nets are used.
Increased size of the global commercial fleet
Size of the vessels used to catch fish has increased, which means larger nets are used.
Fisheries are being overfished to meet the demand.
What do you think the impacts of this might be for marine species?
Slide 7 - Slide
Illegal fishing means that the fishermen enter the territorial waters of a country or regulated marine zone without permission or without a license for the fish they intend to catch. In basic terms they are stealing from these waters.
It is estimated around 30% of the global commercial fishing catch is caught illegally. The demand for fish encourages vessels to operate illegally. Taking more than their quota, or catching fish they are not licensed to.
It is estimated around 30% of the global commercial fishing catch is caught illegally. The demand for fish encourages vessels to operate illegally. Taking more than their quota, or catching fish they are not licensed to.
Slide 8 - Slide
By-catch is basically anything that is caught in fishing nets or on lines, that the fishermen don’t want or are not allowed to legally catch.
Generally, by-catch is removed from the nets and dumped back into the ocean. Many of these animals will have already died before they are freed. By-catch may include fish, turtles, dolphins, sharks and even whales.
An estimated 26% of the global commercial fishing catch is by-catch.
Ask students: “What do you think the implications of this are going to be on marine wildlife?”
Generally, by-catch is removed from the nets and dumped back into the ocean. Many of these animals will have already died before they are freed. By-catch may include fish, turtles, dolphins, sharks and even whales.
An estimated 26% of the global commercial fishing catch is by-catch.
Ask students: “What do you think the implications of this are going to be on marine wildlife?”
Slide 9 - Video
This video (2.35 min) shows the impacts of purse seine fishing, used by the tuna fishing industry. It explains by-catch and overfishing.
https://www.youtube.com/watch?v=TsmA0gX2qNk&list=PLx1pnhQVtbbBnH1BBXzQtknEROG73UNO9&index=14
https://www.youtube.com/watch?v=TsmA0gX2qNk&list=PLx1pnhQVtbbBnH1BBXzQtknEROG73UNO9&index=14
Slide 10 - Slide
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Slide 11 - Slide
Refer Lesson Guide for activity suggestions.
