How are humans causing extinction of species? (Secondary) - Lesson One

• Social Studies
• History
• +3
• 11th,12th Grade

Introduction

Lesson One – Are we in the 6th mass extinction event? This lesson covers previous mass extinction events and what the key indicators are of an extinction event. Learning activities:  Discuss key changes that are occurring and what species are disappearing.  Research previous extinction events, their causes and species impacted.

Instructions

Time: 45 minutes

Contact: [e-mail]
© Sea Shepherd 2022

Lesson 1 - Are we in the 6th mass extinction event?

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. 

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During the lesson we will use these icons to identify the learning actions.

What do we mean by mass extinction?

Ask students what the term mass extinction means to them?

Illegal Fishing

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.

They are stealing from these waters.

MASS EXTINCTION

Defined as a loss of over 50% of all species in existence on the entire planet, during a geological period, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt.

Mass extinction is usually defined as a loss of over 50% of all species in existence on the entire planet, during a geological period, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt.

Introduction to IUU fishing and the impact of overfishing.

Mass extinction events

Scientists believe that there have been five previous mass extinction events on our planet.
450 million years ago - Ordovician-Silurian
-    Wiped out approximately 85% of all species.
-    The planet experienced cooling events, changing atmosphere, and melting glaciers.
-    What triggered this event is not clearly known.
374 million years ago - Devonian
-    Three quarters of species were killed, including most marine invertebrates.
-    Many environmental changes occurred, including global warming and cooling, sea levels and reduction in oxygen.
-    The cause is unknown
250 million years ago - Permian also called the Great Dying
-    95% of marine species went extinct.
-    Some scientists believe an asteroid hit Earth which caused dust particles to block out the sun, others think a large volcanic explosion increased carbon dioxide levels.
200 million years ago - Triassic
-    80% of all species including dinosaurs went extinct.
-    30% of marine species went extinct.
-    Believed to have been caused by colossal geological activity that increased carbon dioxide levels and temperatures.
65 million years ago - Cretaceous
-    78% of all species killed.
-    Most likely caused by an asteroid hitting Earth and volcanism that was occurring.

Source: Natural History Museum, London.

Illegal Fishing

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.

They are stealing from these waters.

SIGNS OF EXTINCTION EVENT

• Climate change
• Ocean warming and acidification
• Changes in sea levels
• Loss of land masses
• Movement in tectonic plates
• Super Volcanos were active
• Invasive species were thriving
• Extinction of species was at higher than normal rates

From previous extinction events scientists believe some of the key changes included:
    Climate change
    Ocean warming and acidification
    Changes in sea levels
    Loss of land masses
    Movement in tectonic plates
    Super Volcanos were active
    Invasive species were thriving
    Extinction of species at higher than normal rates
Discuss with students, which of these they believe are occurring now and what examples they can think of?

Introduction to IUU fishing and the impact of overfishing.

Rate of extinction of species 1,000 x higher than normal

Research has shown that the current rates of extinction of species have increased, showing that they are running at 1,000 times higher than the natural background rate of extinction.

Current data sources/articles:
https://www.nytimes.com/2020/06/01/science/mass-extinctions-are-accelerating-scientists-report.html
https://www.iflscience.com/plants-and-animals/current-extinction-rate-10-times-worse-previously-thought/

Over 100 million tons of fish caught each year.

International Union for the Conservation of Nature (IUCN)

The International Union for the Conservation of Nature (IUCN) have evaluated  140,000+ species, including plants, corals and animals, with over 35.000 of those listed as threatened with extinction.  Some are vulnerable to extinction, through to those that are critically engendered and on the verge of disappearing.  Over 8.000 species are currently listed as critically endangered.

www.seashepherdglobal.org

LEARNING ACTIVITIES

Refer Teachers Guide for Learning Activities.