Lecture 15 Flashcards
Types of marine pollution
Sewage Pesticides Heavy metals Radioactive waste Thermal pollution Oil Plastics Noise Invasive species
Example of large oil spill in ocean
Deepwater horizon, 2010
Gulf of Mexico
4.9 million barrels
What forms of oil pollution are more common than big oil spills seen on the news?
Natural seeps
Up in smoke
Down the drain
Routine maintenance
Variables determining the scale of impact of oil spills into the environment?
- Volume of the spill
- Speed of the spill
- Inshore or offshore (cost of shoreline clean up 5x more)
- Dispersant use (can suppress oil-degrading microorganisms)
- Sea conditions and currents
- Habitats present (rock, sand)
Impact of oil on organisms
- Oil floats so organisms that pass through air-water interface most affected
- Ingestion
- Accumulation of contaminants in tissues
- DNA damage
- Immune function
- Mass mortality of pelagic eggs/larvae
- Loss of buoyancy/insulation
- Recovery rates depend on habitat and species
What size is a micro plastic?
Less than 5mm
What areas do micro plastics accumulate in?
In coastal areas where a great number of people live
What causes the release of microplastics?
Degradation of large plastic
Direct release e.g. through cosmetic products
Laundry
What are the effects of microplastics?
- Energy reserves: decreased feeding activity, increased phagocytosis, fewer egestion, reduced energy reserves
- Pollution transfer: PVC absorbs pollutants, and these pollutants accumulate in tissues when ingested by organisms
- Effects on reproduction: decreased oocyte production, decreased sperm velocity, lower larval production and growth, shifts in gene expression
What are causes of marine noise?
Boat noise Military activity (anti-submarine measures, loud short pulses of sound) Seismic surveys (oil and gas exploration) Construction noise (e.g. pile driving for wind farms)
How are right whales affected by boat noise?
Increased stress levels with more boat traffic
How can noise pollution kill fish?
Ambon damselfish (prey) cannot hear dusky dottyback (predator) over noise so increased predation
Greatly reduced survivorship of newly settled fry on patch reefs
More oxygen depletion, less likely to startle when predator present and slower response times
Examples of invasive species
Lion fish (Pterois sp.) European shire crab Caulerpa taxifola Sea walnut Zebra mussel (Dreissena polymorpha)
What is the method by which the most invasive species are introduced?
Through shipping (via ballast water)
Spread of lionfish
Rapid spread throughout the Caribbean from aquaria
Extremely predatory
Pterois volitans and Pterois miles