marine pollution Flashcards
pollution definition
impurity caused by contamenation
4 routes of pollution
Dumping – direct release
Runoff – land, farms
Aerosols – released into atmos
Sewage
Point source pollution definition
any discrete conveyance from which pollutants are or may be discharged
Non-point source pollution definition
multiple sources rather than a single discrete source
Xenobiotics definition
foreign materials not produced in nature + not normally a component of biological systems
Bioaccumulate definition
does not break down + accumulates in the organism over its lifetime
Biomagnify definition
does not break down – increases as you move up the food chain
Biomarkers definition
aspect of the body used to measure the effects of the pollutants e.g. enzymes
8 Types of marine pollution
Oil spills and runoff
Nutrient
Heavy metals
pesticides / herbicides
Endocrine disrupting compounds (EDCs)
Sewage
plastics
noise
explain nutrients as a type of marine pollution
Eutrophication = increase in primary productivity + organic matter in aquatic systems caused by excess nuts e.g. N + P
where does excess N + P come from
- Farm runoff – fertilizer, farm animal faeces
- Sewage discharge
- N fixation by legumes
- Atmospheric deposition of N from fossil fuel combustion
3 Eutrophication consequences
- Increased algal growth + habitat loss
- Harmful algal blooms (HABs) - brown and red tides
- Hypoxia (< 2-3 mg/L) / anoxia - sessile can’t move out of the area + mobile fauna displacement
explain heavy metals as a type of marine pollution
- Mining
- Mercury – atmos, coral burning, waste incineration, Cl- production, ore + mining, batteries, light bulbs, methymercury – microbes
- Bioaccumulates + biomagnifies
- Minemata disease
Effects of heavy metals in marine environment
Mortality
Elevated metabolic rates
Liver damage
Impaired feeding ability
Reproduction
explain pesticides / herbicides as a type of marine pollution
Atrazine + diazanon
DDT – banned in US in 70s
Bioaccumulate + biomagnify
explain EDCs as a type of marine pollution
- Compounds which in sufficient concs cause elicit responses under cotnrol of endocrine hormones
- LD50 – 50% of organisms die
- Include: Hormones, organohalogenes (PCBs), pesticides, food antioxidants, phthalates, surfactants, styrenes, metals
- Lipophilic + hydrophobic – accumulate in fats + don’t dissolve in water
- Sources: aerosoles, landfill leakage, industrial waste, sewage discharge
effects of EDCs on fishes
- Thin eggs in birds – egg membrane in fishes (zona radiata)
- Abnormal gonad morphology
- Reduced rates of gamete production + release
- Reduced quality of gametes
- Gender reversals e.g. chinook salmon - can effect gender ratios
- Changes in repro behavior
explain sewage as a type of marine pollution
Contributes:
Nutrients
Pharmaceuticals
Chemicals
Sewage sludge
explain plastics as a type of marine pollution
- 5.8mmt oceans/yr
- Light weight – floats, concentrates
- Strong – entangled
- Endurable – long time to biodegrade
- Cheap – a lot of it
- Tend to concentrate chemicals – stick to it e.g. EDCs
- Nurdles = microplastics
explain noise as a type of marine pollution
- Fishes – altered behavior, loss of hearing
- Mammals – use sound for navigation
- Croakers, drums, toadfish
- Larvae use reef sounds to find its way back and recruit there
