Pollutants Flashcards
What is the difference between a toxicant and a toxin?
toxicant = synthesized (manmade) toxic chemicals
toxins = harmful substances produced biologically (i.e biotoxins, HABs)
How can risk be determined (i.e ___ x ____)?
exposure x toxicity
What are some factors behind a pollutant’s risk?
- chemical activity
- dose
- exposure route
- ability to be absorbed
- species exposed
- age of individual exposed
- metabolism of exposed
- excretion rate
- interactions with other chemicals
What are some sources of contaminants?
- runoff (road and agricultural)
- shipping leakage
- wastewater
- disposal at sea
- agriculture
What are some examples of contaminants?
- oil
- POPs (persistent organic pollutants)
- metals
What are some sources of oil?
- natural leakage
- marine transportation
- runoff from land
- air pollution
- jettisoned fuel
- offshore oil extraction
What are the steps of contamination from an oil spill?
- spreading along the surface of the water
- partial evaporation into the atmosphere
- dissolving into deeper water
- emulsifying from water movement
- dispersion of smaller oil particles
- biodegradation from microorganisms
- breakdown from photo-oxidation
- adsorption
- sinking/sedimentation
What animals were most acutely affected by the Exxon Valdez oil spill?
- seabirds (largest # impacted)
- killer whales
- marine mammals (otters, seals)
What long term effects did the Exxon Valdez spill have on ecosystems?
- loss of some algae species (primary producers)
- loss of some herbivorous gastropods (primary consumers)
- loss of some carnivorous gastropods (secondary consumers)
- increase in some barnacles (primary consumers)
What effects did the Deepwater Horizon spill have on ecosystems?
- affected 2000km of wetlands
- negatively affected mussel recruitment for several years
- large mortality of seabirds, dolphins and sea turtles
What are POPs?
- persistent organic pollutants
- bioaccumulative (lipophilic = can store easily inside cells)
- can be transported far from origin via atmospheric movement
- strong health concerns for both humans and environment
Name two examples of POPs and desribe them
DDT
- pesticide (insecticide)
- metabolized form DDE can cause eggshells to thin out
- banned use
PCB
- found in transformer fluids
- heat resistant
- carcinogenic/immunotoxic
In which marine organism are PCBs the most concentrated?
Biggs and SR killer whales
What pollutant is found in marine mammal’s milk?
POPs
How do POPs affect wildlife?
- altered behaviour
- impairs reproduction
- can cause deformities/birth defects
- endocrine disruption
- can affect immune system
What three metals are prevalent in marine pollution and where are they found?
cadmium
- byproduct from zinc mining
- found in batteries, paints, cigarettes, fertilizers
mercury
- found in mining, coal combustion, batteries, older medical instruments
lead
- found in some gases, alloys, paints and ammunition
Which metal has a high risk of bioaccumulation in the arctic?
mercury
What is 6PPD-quinone?
- additive in car tires to make them stronger against wear
- ozonation releases chemical
- rain can transport chemical via runoff and reach aquatic ecosystems
- responsible for mortalities of coho salmon
How did mercury affect the animals and residents of Minamata, Japan?
- inorganic mercury was released from a chemical processing plant into the bay
- mercury binded with carbon to become methylmercury
- methylmercury bioaccumulated in plants and fish before being consumed by cats and humans
- caused uncontrollable spasms, numbness, loss of some senses and death
Define eutrophication/nutrient enrichment
- increase in primary productivity and organic matter accumulation
- caused by increased concentrations of limiting nutrients like N and P
- can cause excess growth of algae/phytoplankton
- can increase turbidity and create hypoxic conditions
Which nutrient makes up the bulk of global fertilizers?
nitrogen
What region of the world uses the most fertilizer?
Asia
Where can some deadzones be found?
- Gulf of Mexico/SE coast of USA
- western Europe
- Japan/Korea coast
Why does the Gulf of Mexico have strong dead zones?
- runoff from Mississippi river (drains 40% of USA’s agricultural land) deposits fertilized nutrients into the water
- bacteria consume nutrients and depletes water of oxygen at lower depths
How are dead zones formed (based on the Oregon DFO video)
- upwellings occur seasonally and bring in low oxygen but high nutrient water
- nutrients get consumed by phytoplankton, who eventually sink to bottom and decompose using the little remaining oxygen in water
What are some natural and anthropogenic sources of sedimentation?
natural
- erosion
- storms
- river deposits
- desert sand
anthropogenic
- trawling
- deforestation
- runoff
- coastal development
- industrial dumping
How can sedimentation affect sponges?
reduces/blocks filter feeding
What consequences can sedimentation have on corals?
- reduced fecundity and fertilization
- large reduction in settlement, juvenile and adult growth/survival
- reduction in coralline and macroalgae
What are plastics?
- synthetic polymers
- oil/natural gas based
- can leech
- can float and be transported
What consequences can plastics have in the ocean?
- entanglement
- ingestion
- toxic health
- transport invasive species
- ghost fishing pollution
How big are macroplastics, microplastics and nanoplastics?
macro = >5 mm
micro = 1 um - 5 mm
nano = <1 um
Where does plastic accumulate in the oceans?
along coasts and stuck in gyres
What are some sources of artificial light?
temporary = light fisheries (uses light to attract fish), ships
permanent = cities, harbours, oil rigs (runs 24/7)
What are some consequences of light pollution?
- disorientation (i.e turtle hatchlings)
- affects activity patterns (i.e vertical migration of zooplankton)
- spawning asynchrony (if light is a signal)
- altered habitat choice
- altered interactions (i.e advantages for predators)
Why are LED lights so impactful for marine life?
wavelengths of light focused in LED lights are blue/green, which penetrate deeper in the ocean
What are some sources of noise in the ocean?
- ships
- seismic guns
- SONAR
- drilling
What are some consequences of noise pollution?
- interference with natural frequency range
- behavioural responses
- physical impairments (i.e affects the function of otoliths)
- physiological changes
What were the effects of seismis air guns on plankton?
there were more dead captured plankton closer to the range of the air gun versus farther away, and less caught overall
How do boats affect the behaviour of cleaning fish?
more cleaner fish “cheated” and bit off chunks of their clients after hearing a boat nearby
What were the main findings of the paper by Martin et al. (2022)?
- marine sediment is a greater sink for plastics than the open ocean (2-3x higher)
- greatest abundance of plastics found around Europe/Mediterranean and China
- mangroves/seagrass meadows held highest amount of plastics in coastal environments
- continental slope held highest amount of plastics in open water
What were the main findings in the paper by Fakan and McCormick (2019)?
- noise pollution from boats can affect fish growth/development, predator avoidance and behaviour; can cause stress
- ## exposure to motorboat sounds increased heart rate in embryonic damselfish
