Lecture 3 - Environmental stressors

what are the 11 types of environmental stressors?

• Deforestation and Air Pollution

• Climate Change (Sea Surface Warming)

• Ocean Acidification

• Extreme Weather Events

• Chemical Pollution

• Eutrophication

• Plastic Pollution

• Invasive Species

• Overfishing

• Loss of Biodiversity

• Habitat Destruction

what is deforestation?

the temporary or permanent clearance of large expanses of forest for agriculture or other uses

why is deforestation bad?

• Clearing trees leads to increased soil erosion & warmer stream temperatures

  • Harms aquatic animals adapted to colder temperatures

  • Increased sedimentation and runoff can smother coral

Less trees = less CO2 absorbed = increased effects of climate change (e.g., ocean acidification)

what is air pollution?

air, indoor or outdoor, is contaminated by substance that can cause harm to living organisms and the environment 

• pollutants can include gases, particulate matter (e.g., dust, soot), or aersols

why is air pollution bad?

• Large amounts of atmospheric CO2 can lead to increased climate change effects (e.g., increased temperatures, decreased ocean pH)

  • These changes in water parameters can put
    physiological stress on marine animals and
    plants

what is climate change? 

• long-term shifts in temperature and weather patterns, primarily caused by human activities that release greenhouse gases into the atmosphere

what are the consequences of climate change?

• sea surface warming

• ocean acidification

what is sea surface warming?

• marine heat waves

• more intense storms and hurricanes

• sea ice melt

• sea level rise

what is ocean acidification?

• increased acidity

• decreased carbonate

• increased challenges for calcifying organisms

• altered ocean chemistry

what type of effects do sea surface warming and ocean acidification have in common?

• widespread ecosystem change

• food web disruptions

• degradation of marine habitats, including coral reefs

what are the effects of climate change on extreme weather?

• marine heat waves

• heat extremes

• wildfires

• droughts

• hurricanes, typhoons, and tropical cyclones

• heavy precipitation

• floods

• high-tide flooding

what are the consequences of extreme weather?

• property damage 

• habitat destruction

• disrupt ecosystems 

• devastating impacts on communities and agriculture 

• sometimes result in death 

what is eutrophication?

• Accumulation of nutrients in a body of water that results in the increased growth of microorganisms (algae) and depletes oxygen

  • Nutrients: nitrogen and phosphorus

where does eutrophication gain its nutrients?

• Nutrients come from pollution from wastewater from industry and municipal sewage (point pollution) or water from irrigation or surface water containing fertilizer (non-point pollution)

what are the effects of eutrophication?

• causes harmful algal blooms, dead zones, and fish kills

what are the causes of eutrophication?

• natural runoff

• erosion

what is natural runoff causes?

• nutrients from soil/weathering of rocks

• manure from farms

• fertilizers

what is erosion causes?

• animal waste

• detergent discharge

• treated or untreated sewage

• industrial waste

what are the consequences from eutrophication?

• harmful algal blooms

• fish kills

• dead zones

what are the harmful agal blooms consequences?

• nutrients increases algae growth

• algae block the sun which can harm other plants

• algae eventually dies and bacteria uses up remaining oxygen to break down algae

• little to no oxygen remaining

what are the fish kills consequences?

• without oxygen fish die also

what are dead zones consequences?

• if plants and animal die, there is no life in the area

• some animals may leave if there is no oxygen or food

how does plastic pollution enter the oceans?

• enter the water from garbage dumps, storm impacts on the shore, littering, and other sources

  • approx. 200 mil tons produce annually - 10 mil. tons enters ocean system

how is plastic moved?

moved by ocean circulation and is transported all over the the world

what are types of chemical pollution?

• fertilizers

• pesticides and herbicides

• detergent and other household products

• industrial chemicals

• sewage

• oil

what are the consequences of chemical pollution?

• excessive toxins/poisons

  • ex. Metals like zinc, copper, or mercury

• Physiological issues

  • ex. fertility problems in fishes

• excessive nutrients (eutrophication)

what are invasive species?

• non-native species introduced into a new habitat, successfully establishing itself

how do invasive species get introduced?

by ballast water, accidental release, or by people

what are the consequences of invasive species?

• causes ecological or economic harm

• Consequences include:

  • extinction of native plants and animals

  • compete with native organisms for limited resources

  • destroy biodiversity

  • permanetly alter habitats

what is overfishing?

Case in which a high degree of fishing results in a decline of a fish population to unsustainable levels

what is the main cause of elf overfishing?

poor fishing management

what are the consequences of overfishing? 

• creates imbalance that can alter the food web 

• can lead to loss of other important marine life 

what is habitat destruction?

The elimination or alteration of the conditions necessary for animals and plants to survive

What are the results/effects of all these stressors from marine habitat destruction?

• low oxygen concentration 

• food reduction 

• extinction of plant and animal species 

• migration of animals (they will leave)

what are the consequences of losing biodiversity?

• ecosystem service decline

  • reduced biodiversity compromises ecosystem services like pollination, water purification, and soil fertility

• food security

  • loss of species can affect food sources and agricultural stability

• health impacts

  • reduced biodiversity can lead to the emergence and spread of diseases

• economic costs

  • biodiversity loss affects industries like agriculture, fisheries, and tourism

what are potential solutions for climate change?

• renewable energy in place of fossil fuels, both solar and wind

• non-renewable energy: nuclear (fusion energy) and natural gas

• sustainable transportation

• sustainable buildings

• electric cars 

• plant trees or kelp

what are the pros of nuclear energy?

• low-cost energy

• reliable power source

• creates jobs

• zero carbon emissions

• high energy density

what are the cons of nuclear power?

• environmental impact

• water intensive

• risk of nuclear accidents

• radioactive waste

• non-renewable energy source

what are the pros of fusion energy?

• clean energy source that produces no greenhouse gases 

• limitless amount of fuel available, deuterium and tritium easy to produce 

• fusion, unlike fission, does not involve a chain reaction so the process can be stopped eliminating the risk of a meltdown 

• fusion does not produce nuclear waste only the core of the reactors remains radioactive and only for 100yrs 

• fusion had the potential to fuel the entire world for relatively low costs compared to todays fuel 

what are the cons to fusion energy?

• only occurs at extremely high temperatures (10-15mil K) making it difficult to contain 

• the energy required to make fusion work could be greater Thant the output of energy by fusion itself 

• the current research and experimentation is going to cost billions of dollars, money that could be invested in renewable green fuels 

• cold fusion may be the only way to make fusion efficient and cold fusion has yet to been successfully developed

what are the pros of natural gas?

• ample supplies

• high net energy yield 

• less air pollution than other fossil fuels 

• lower CO2 emissions 

• easily transported by pipeline 

• good fuel for fuel cells and gas turbines

what are the pros of natural gas?

• nonrenewable resource use

• release CO2 when burned 

• methane (greenhouse gas) can leak from pipeline 

• highly explosive 

• requires pipelines

what are the pros of electric cars?

• environment friendly

• durable

• ideal for urban driving 

• cost effective 

• driving dynamics 

• extra storage 

what are the cons of electric cars?

• requires charging stations 

• range issue 

• price

• negative impact on the environment 

what are potential solutions for eutrophication?

1. nutrient management 

2. wetland restoration

3. riparian buffers 

4. algae control 

5. sustainable land use practices 

6. climate change mitigation

7. reduced fossil fuel emissions 

8. responsible recreational activities 

what are potential solutions for plastic pollution?

1. avoid single-use plastics 

2. use reusable bottles, cups, and straws 

3. use reusable shopping bags 

4. recycle 

5. join a beach or park clean up 

6. individually pick up trash

how do all our actions have consequences when trying to help improve the environment?

• Our climate solutions are not 100% without consequence

• The goal is to mitigate our impact on the environment as much as
  possible

• Some solutions have unexpected side effects – noise pollution

• The solution is to investigate these consequences and see how we can reduce our impact

• Individually, we can make small changes (i.e., reusable bottles, turning off the lights, etc.) and spread awareness

so what is the solution?

• keep researching and work with the environment

• Mitigate climate change

• Environmental conservation policies

• Control pollution

• Control fishing processes/practices

• Restrict aggressive coastal development

• Environmental education

• Research

• Be creative and never give up!

what are sponges (phylum Porifera)?

• Cellular animals with no distinct tissues or organs

• No nervous system

• Specialized cells: choanocytes

  • Flagellated collar cells that drive water and food particles through pores and cavities

• Number of species: 8,000

• Important bioeroders of coral reefs

•  Symbiotic relationship with dinoflagellates

• Skeleton made of needle-like spicules

  • Silica (glass) - siliceous

    • Calcium carbonate (CaCO3) - calcareous

• Expected to be OA “winners”

what is bioerosion?

Biological processes that break down hard substances

what are corals (phylum cnidaria)?

• Animals consisting of two tissue layers – blind gut and body cavity

• Nervous system consists of a network of nerves

• Specialized cells: nematocysts

  • Stinging cells

• Approx. 6,000 of the 9,000 cnidarian species

•  Have a symbiotic relationship with photosynthetic zooxanthellae

• Skeleton made of calcium carbonate (CaCO3)

• Expected to be defeated by a combination of climate change and OA

how does climate change impact sponges?

• Resistant to OA

• Symbionts can burrow deeper in presence of stressor

• Temp/OA reduces spicule size (skeleton)

• Can break down corals – may dominate coral reefs

( more on page 14-15 in lecture notes)

how does climate change impact corals?

• Vulnerable to increasing temperatures and OA

• Symbionts expelled in presence of stressor

• OA reduces carbonate ions to produce coral skeleton

• Old corals broken down – may provide new space for heat-resistant corals

( more on page 14-15 in lecture notes)

what is the outcome of corals V. sponges?

it can go either way

what are jellies?

• Cnidarian form: medusa

• Free living

• 95% water

  • Environmental indicators

• Ecological importance:

  • Controls species populations

    • Feed on fish larvae and eggs

  • An important food source for other marine organisms

    • Sea turtles, sunfish, and
      spadefish

• Medical importance:

  • Anti-cancer venom

  • Prevagen

• Economic impact:

  • Large colonies of jellies can affect power plants and fisheries

what are anemones?

• Cnidarian form: polyp

• Sessile, unmoving

• Ecological importance:

  • Provide shelter and food for various species

  • Recycles nitrogen waste produced