IB MYP 4-5 Biology-Over exploitation- Study Notes - New Syllabus
IB MYP 4-5 Biology-Over exploitation- Study Notes – New syllabus
IB MYP 4-5 Biology-Over exploitation- Study Notes – IB MYP 4-5 Biology – per latest IB MYP Biology Syllabus.
Key Concepts:
- Overfishing and fishing quotas
- Illegal wildlife trade
- Deforestation for agriculture
- Water resource depletion
Overexploitation: Overfishing and Fishing Quotas
What Is Overexploitation?
Overexploitation occurs when natural resources are used faster than they can renew. This includes overfishing, overhunting, deforestation, and overharvesting of plants or animals.
What Is Overfishing?
Overfishing is catching too many fish too quickly, before they can reproduce.
Result: Fish populations collapse, harming marine ecosystems and human livelihoods.
Causes of Overfishing
| Cause | Explanation |
|---|---|
| Advanced fishing tech | Large trawlers, sonar, and nets catch more fish than ever |
| High demand | Fish is a staple food globally |
| Weak regulations | Lack of laws or enforcement in some regions |
| Bycatch | Unwanted species like turtles and dolphins are caught and die |
| Illegal fishing | Unlicensed boats overfish without limits |
Consequences of Overfishing
| Problem | Result |
|---|---|
| Fish population drop | Tuna, cod, and salmon numbers fall dangerously |
| Predator-prey imbalance | Fewer sharks = more jellyfish, disrupting the food web |
| Economic loss | Communities lose income and jobs |
| Harm to marine life | Turtles, seabirds, and dolphins are killed as bycatch |
| Food shortage | Future generations may have no fish to eat |
What Are Fishing Quotas?
Fishing quotas are legal limits on how many fish (or how much weight) can be caught per species over a set period.
They are part of sustainable fishing – helping fish populations recover and ensuring long-term food security.
Benefits of Fishing Quotas
- Allow fish time to grow and reproduce
- Prevent extinction of overfished species
- Protect jobs and food supply over time
- Encourage sustainable, low-impact fishing methods
Real-World Examples
| Region | What Happened |
|---|---|
| North Atlantic | Cod populations collapsed in the 1990s |
| Japan | Bluefin tuna overfished due to sushi demand |
| India (Kerala) | Seasonal fishing bans protect breeding cycles |
| EU & Norway | Strict quotas helped recover herring stocks |
Other Solutions to Overfishing
- Create Marine Protected Areas (MPAs) where fishing is banned
- Use selective gear to avoid catching unintended species (bycatch)
- Promote seafood with certified eco-labels (e.g., MSC)
- Educate fishermen on sustainable practices
- Ban illegal, unregulated fishing (IUU fishing)
Overexploitation through overfishing is harming marine life and food security.
Fishing quotas, marine reserves, and sustainable practices are key tools for preserving our oceans for future generations.
Illegal Wildlife Trade
What Is Illegal Wildlife Trade?
Illegal wildlife trade is the buying and selling of wild animals, plants, or their parts in violation of national or international laws. It is one of the biggest modern threats to biodiversity.
What Is Traded Illegally?
| Traded Item | Used For |
|---|---|
| Elephant tusks (ivory) | Decoration, carvings |
| Rhino horns | Traditional medicine (falsely believed to cure diseases) |
| Tiger skins & bones | Luxury items, medicines |
| Pangolins | Meat and scales |
| Exotic birds and reptiles | Pet trade |
| Rare orchids, cacti | Collection, ornamental use |
Why Does It Happen?
| Cause | Explanation |
|---|---|
| High market demand | Rare species are highly valuable |
| Poverty in local areas | Poaching becomes a source of income |
| Weak enforcement | Lack of strict laws or corrupt systems |
| International trade | High demand in foreign luxury markets |
| Cultural beliefs | Animal parts used in rituals or traditional medicine |
Impacts of Illegal Wildlife Trade
- Extinction of Species: Tigers, pangolins, rhinos, and birds are pushed toward extinction
- Loss of Biodiversity: Removing one species harms entire ecosystems
- Animal Cruelty: Smuggling causes suffering and death
- Health Risks: Spreads zoonotic diseases (e.g. COVID-19)
- Criminal Activity: Links with illegal global trafficking networks
Examples from Around the World
| Species or Region | What Happened |
|---|---|
| Pangolins (Asia & Africa) | World’s most trafficked mammal |
| Indian Star Tortoises | Smuggled in large numbers for pet trade |
| African Elephants | Killed for ivory every year |
| Amazon Rainforest Birds | Captured and sold in black markets |
Laws and Agreements to Stop It
| Protection Tool | What It Does |
|---|---|
| CITES | Regulates international trade in endangered species |
| Wildlife Protection Act (India) | Bans poaching and illegal trade |
| National Parks & Reserves | Provide protected habitats for species |
| Customs and Border Checks | Stop trafficking at ports and borders |
How Can We Stop Illegal Wildlife Trade?
- Enforce wildlife protection laws strictly
- Run awareness campaigns for public and travelers
- Educate communities on conservation
- Use technology to track poaching and trade routes
- Involve local people in protecting their environment
- Never buy animal parts, exotic pets, or illegal souvenirs
Illegal wildlife trade pushes species to extinction, spreads diseases, and funds crime. With strict laws, global teamwork, and public awareness, we can protect nature and save our wildlife for future generations.
Deforestation for Agriculture
What Is Deforestation for Agriculture?
Deforestation for agriculture is the removal of forests to make space for farming, plantations, or grazing. It is one of the main drivers of habitat loss and biodiversity decline worldwide.
Why Does It Happen?
| Agricultural Activity | How It Causes Deforestation |
|---|---|
| Crop farming | Forests cleared to grow crops like rice, wheat, soy |
| Animal grazing | Trees removed for cattle and livestock pastures |
| Plantations | Rainforests cut for palm oil, tea, coffee, rubber |
| Shifting cultivation | Temporary use of forest land then moving to new areas |
Where Is It a Major Problem?
- Amazon Rainforest (Brazil): Cleared for soy and cattle ranching
- Indonesia & Malaysia: Palm oil plantations destroy orangutan habitats
- Central Africa: Slash-and-burn farming damages rainforests
- India (North-East, Western Ghats): Hill forests cleared for crops and tea estates
What Are the Impacts?
- Loss of Biodiversity: Forest species like tigers and orangutans lose habitats
- Soil Erosion: Tree roots hold soil; without them, land becomes infertile
- Climate Change: Fewer trees = more CO₂ in the air → global warming
- Water Cycle Disruption: Less transpiration = reduced rainfall and more drought
- Conflict with Communities: Indigenous people lose land, homes, and culture
What Can Be Done?
| Solution | How It Helps |
|---|---|
| Agroforestry | Grow trees and crops together sustainably |
| Ban illegal clearing | Stops unauthorized deforestation |
| Smart farming | Crop rotation reduces pressure on new land |
| Protected zones | Preserves forests and biodiversity hotspots |
| Farmer education | Teaches eco-friendly methods and soil care |
Real Example: Brazil’s Soy Problem
Deforestation for agriculture feeds today’s population but risks tomorrow’s ecosystems. Through sustainable farming, protection laws, and awareness, we can meet food demands while saving forests and biodiversity.
Water Resource Depletion
What Is Water Resource Depletion?
Water resource depletion is when freshwater from rivers, lakes, and underground sources is used faster than it can naturally be replaced. It leads to shortages, poor water quality, and environmental stress.
Why Is It Happening?
| Cause | Explanation |
|---|---|
| Over-irrigation | Using large volumes of water for crops, especially in dry areas |
| Domestic wastage | Long showers, leaking taps, and water misuse in homes |
| Industrial overuse | Factories use excessive water for cooling and cleaning |
| Urbanization | More people increase demand; cities reduce space for rain to soak in |
| Climate change | Reduced rainfall and higher evaporation dry up sources |
| Groundwater overuse | Pumping water from underground faster than it can refill |
What Are the Effects?
| Impact | What Happens |
|---|---|
| Drying lakes and rivers | Affect drinking water, farming, and animal life |
| Water scarcity | Many areas lack clean, reliable water supply |
| Groundwater depletion | Wells dry up; deeper drilling is costly and unsustainable |
| Crop failure | Farmers can’t irrigate fields, food production drops |
| Aquatic life loss | Fish and wetland species disappear as habitats shrink |
| Pollution concentration | Less water = less dilution = more toxicity in rivers |
Case Studies
- India (Punjab & Haryana): Over-irrigation for rice → groundwater tables falling
- Aral Sea (Central Asia): Once the world’s 4th largest lake; now shrunk drastically due to cotton irrigation
- Cape Town (South Africa): Faced “Day Zero” water crisis in 2018 due to poor rainfall and overuse
How Can We Solve It?
| Solution | How It Helps |
|---|---|
| Rainwater harvesting | Stores rainwater for use in homes, schools, farms |
| Water-saving habits | Reduces daily water waste in homes and offices |
| Drip irrigation | Delivers water directly to plant roots, saving large amounts |
| Native crops | Require less water, suited to local conditions |
| Recycled water | Factories reuse treated water, reducing freshwater demand |
| Urban planning | Green areas and recharge zones allow rain to seep into the ground |
Water Usage by Sector
| Sector | % of Global Use |
|---|---|
| Agriculture | ~70% |
| Industry | ~20% |
| Households | ~10% |
Agriculture is the largest consumer – so water-saving in farming is critical.
Water is precious and finite. With rising demand and climate stress, protecting water is urgent. Smart farming, rainwater harvesting, and public awareness can ensure clean water for all now and in the future.