- Applied Ecology Outline: 1. Human Impact on the Environment 2. Pollution Control 3. Conservation 4. Global Issues I Human Impact ! "e Env#!ment Human Population Growth Depletion of natural resources Environmental degradation -Pollution -Natural habitat destroyed Population control -Government policies（Adopting policies / Birth-control education/Family planning services / Provide advantages for small families） :Use of resources Natural resources -Renewable - Produced by nature continuously . Soil/air/freshwater • Plant ok Animal -Non-renewable - Will not be replenished in our • lifetimes ga Fossil fuel • Mineral ores Fishery IEEE -Methods ooo Drift net fishing / Dredging / Bottom trawling / Cyanide fishing / Dynamite fishing -Impacts ooo Overexploitation - fish population harvested at a higher rate than it can be recovered → extinct → ↓biodiversity • Harming non-target species non-discriminatory → juvenile fish + by-catch → injured or dead Destruction of habitats : Cyanide: kill coral reefs • Dynamite: heavy fishing gears → damage the sea bed • Disturbance of ecological balance Agriculture ⇐¥⇐¥¥aoE¥¥EE -Overgrowing → soil erosion ** . -Pesticide BEEN • Toxic → allergies / food-poisoning •• Bioaccumulation - x broken down / excreted → biomagnification pesticide resistance pests -Chemical fertilizers sooooo Organic FA Hormones Pollution Consumed by human → health risk ④ Antibodies → antibiotic resistance •• Inorganic the Reach to rivers/lakes → ↑nutrients → eutrophication → algal bloom → depletion of O2 → die of suffocation *Effects on Urbanization and Industrialization Land Clearance & Reclamation -Habitat destruction → ↓biodiversity -Habitat fragmentation → over-crowding & ↑competition -Destroy coastal habitats → ↑ suspended particles → ↓ sun exposure → toxins disposal Pollution -Air → e.g. CO2 / SO2 / NOx / RSP -Water • Organic pollutants (excretions/debris) BE More nutrition for bacteria → Bacterial population↑ → Depletion of O2 (hypoxia) → Other organisms die AK Decomposition → [NO3-]↑ → Eutrophication → Harmful algal bloom Inorganic pollutants FED Pesticides (DDT) me Leached chemical fertilizers [N]/[P]/[K]↑ = more nutrients for algal growth → Eutrophication → Harmful algal bloom •@ Thermal effluent (discharge from powerplant) FE Fishes are poikilotherm → Body temperature easily deviate because of environmental change → heat denature enzymes • Acid/Alkali (electroplating/Acid mine drainage (AMD)) DE pH↑/↓ → enzyme denature FE AMD contains toxic metal e.g. Aluminum/Zinc/Iron/. Copper/Arsenic •• Oil Leakage THE Less dense → floating → reflect light → light penetration↓ Nea Not permeable to O2 → [O2]↓ FE Lipophilic (fat-soluble) toxicant → difficult to metabolize or excrete → Bioaccumulation/biomagnification II Poli! C!&ol i * 4Rs Reduce: ↓ unnecessary materials *ssmi Recycle: recovering waste materials/ make other items Reuse: using an item for 1+ times Replace: use alternative to replace non-renewable resources Air Pollution Control Street-level pollution -Standards for vehicles emissions -Replace diesel vehicles Regional smog -HK + Pearl River Delta region - reduce emission Solid Waste Management -Waste separation/ recycling -Environment levy on plastic bags -Development of eco-park Water Pollution Control -Law: control discharge of sewage -Sewage treatments • Primary : screening / degritting / sedimentation • Secondary: biological treatment • Tertiary: remove nutrients / suspended solids • Sludge digestion: centrifuge / anaerobic digestion → decomposed → methane Sewage treatment graphic (Next page) Raw tSewage Screening ÷ To Landfill Site Preliminary Treatment Degritting Transportation Primary Primary Sedimentation Primary Treatment Sludge Dewatered Sludge Biological Sludge Treatment Return Dewatering Secondary Activated Treatment Sludge Final Sedimentation Sludge Digestion Tolo Effluent Harbor Effluent Effluent Export Surplus Export Pumping Activated Scheme Effluent Station Sludge Export Sludge Tunnel Thickening iii.Victoria Harbour III C!v'sai! = maintain quality of natural environment and biodiversity Importance -Economic: species have direct/indirect economic values -Ecological: maintain balance & genetic variation -Aesthetic: appreciate beauty of nature + recreational activities -Ethical: right to survive → ethical responsibility to look after them Conversation of Species -Extinction -Endangered species → e.g. Romer’s tree frog & black-faced spoonbill & pitcher plant -Measures Be Registration / Insitu / Exsitu / Seed banks Conversation- of Habitat -Sites of special specific interests -County parks -Marine parks -Ecological mitigation Ramsar site → ecological restoration → reforestation + stream restoration IV. Global Issues * Global Warming Temp ↑ Sea level ↑ Extreme weather Spread disease Acid Rain SO2 → H2SO4 / NOx → HNO3 Impacts -Lake acidification → reduction of fish -Forest damage -Buildings and monuments damage :Eutrophication & Algal Boom Oligotrophic: Low nutrient content → clear water and low biological productivity Eutrophic: rich in nutrients and organic materials → high turbidity, high biological activity Human activities accelerated eutrophication = cultural eutrophication (vs. natural eutrophication/lake aging) Eutrophication Nitrogen Phosphorus Sun These nutrients cause an increase in phytoplankton Sediments Algae Bloom from land block sunlight Algae Die Oxygen Phytoplankton Decay growth on . ¥7Sedgegrass Sedgegrass Lose: Food, Habitat & Oxygen Production I S!"hing Ex#a XD: Micr$las%c Poli( We consume about 2000 microplastic particles each week, equivalent to the weight of a credit card!! • • ••••oc B. 00 • Oooo oooo • Microplastics = tiny synthetic polymers with a size of 5mm or below • Source - Primary = as directly released to the environment as small particles Oo E.g. microfibers from launderings of synthetic clothes & micro-beads in personal care products - Secondary = originated from the degradation of larger plastics objects • E.g. degradation of fishing nets, and plastic bottles Effects - not biodegradable → enter marine, freshwater, and terrestrial wildlife → enter the food chain → bioaccumulation lethal and sublethal effects, as the particles translocate across the cell membrane into biological systems, like the circulatory, lymphatic, and respiratory system : Possible solutions Biodegradable polymer substitutes • E.g. a biotech company, Biofase, found that Avocado seeds contain biopolymers that can mimic plastics after proper processing • E.g. Our project :) Hagfish Slime - Bacterial enzymes • E.g. A bacteria, Ideonella sakaiensis, is found to be able to digest PET. They can split the chemical bonds and eat the smaller carbon molecules as a food source.