MCQ2 Flashcards
How much faster does sound travel in water than air?
5 times
Light travels how deep in water?
200m depth
Sound is a
pressure wave, measured by frequency
Low frequencies travel further or less than high?
further than high frequencies
Low frequency can travel…. (metres)
thousands
Sound propagation is dependent on
Water, Salinity, Temp and pH
Shipping noises
flow over hull, engine noise and dynamic positioning
Shipping noise is what frequency?
5-500Hz
Shipping noise has increased by…?
3db/year (doubling every year)
Seismic survey noise is
Airguns
Seismic survey sound is around what frequency?
<300Hz but spills into higher frequencies
Seismic surveys test where?
Continental shelf
Naval sonar uses what frequencies?
100-500Hz and 2-8kHz
Science surveys are used to:
Map seabed, finding sea temperature and tagging
Construction and pile driving cause what?
temporary mammal displacement
Fisheries use what to confuse mammals and keep them at a distance?
banana tags
Marine organisms use sound to:
find prey, attract mates and socialise
Impacts of noise can be:
Death, increased stress, changing behaviour and masking
PTS
Permanent Threshold Shift
TTS
Temporary threshold shift
PTS and TTS limits for cetaceans
PTS - 5m and TTS - 10m
PTS and TTS limits for pinnipeds
PTS - 20m and TTS 40m
Stress in small crustaceans has lead to:
Reduced growth and reproduction
Level of displacement of porpoises around pile driving?
22km radius
Masking is
being unable to hear conspecifics to mate, or predators
Legislation with some thresholds for marine noise
MSFD Descriptor 11
Climate change can change sound in water by:
increased transparency to low frequencies (decreased salinity and increased pH)
Crocodiles 1800s
Large scale harvest of skins
Crocodiles 1820s
Demand dropped (leather came up)
Crocodiles 1860s
Civil war lead to higher demand again
Crocodiles 1930s
Fashion in Europe leading to decline in 60s
Louisiana Crocodilians killed
3.5 million alligators 1880-1933
Brazil Crocodilians killed
7.5 million caiman 1950-1965
Colombia Crocodilians killed
<1980 11.65 million caiman
1975 trade of croc skins prohibited by
CITES
Alligators removed form endangered species list in
1987
Managed harvests for crocodilians now in
USA, Zimbabwe and Papua New Guinea
Louisiana now makes ____ in croc trade
$25 million/year
Venezuela has made ____ in export of croc skins since 1990
$25 million
Countries that advocate whaling
Japan, Iceland, Norway
IWC
International Whaling Commision
IWC established in
1946
Catch limit on whales in 1986
Zero, except for some aboriginal quotas
How many critically endangered species of cetacean?
2
How many endangered species of whale
7
How many least concern species of whale?
22
Russian soviet whalers could kill:
200 sperm, 100 humpbacks or 30 blue whales/day
How many Russian ships in whaling fleet?
7 factory fleet and 5 whaling stations
How many whales hidden by Russians?
152,000 whales
Russians caused population crashes of:
Antarctic humpbacks and North Pacific right whale
Green turtles, there are now:
300,000 (0.33% left)
Hawksbill turtles, there are now:
30,000 (0.27% left)
Oil is formed due to:
anaerobic decomposition of small organisms over years and years under compression and heat
Hydrocarbons are found mainly on:
continental shelf
Demand for oil is highest in
USA, China the Europe
Main reserve of oil are in:
Canada, Saudi Arabia, Russia, Venezuela
Hydrocarbons are found using
Seismic surveys
Oil is seen in surveys using
seismic stratigraphy
Rigs are used to
drill to correct layer and ensure there is oil
Static oil platform is used for
taking up oil when commercially viable
FPSO
Floating production storage and offloading vessel
FPSO role is
holding oil to be taken away by oil tankers
Oil tankers take the oil…
to refineries to convert into fractions
Torrey Canyon
1967, 60,000 tonnes of oil spilt
How to track where oil might spread
Radar and GNOME (software)
How can you clean up oil?
Booms and skimmers, dispersants, burning and coastal removal
Disperants contain
PAHs
PAHs
Polycyclic Aromatic Hydrocarbons
Physical impacts on wildlife of oil
feeding behaviour, impaired breathing, changes to preening, heat regulation failing, displacement, predation
Physiological impacts on wildlife of oil
Direct lethal toxicity, Sub-lethal disruption of behaviour, Downstream effect on progeny, Bioaccumulation
Seabird worst effected by oil
Auks
Effects on seabirds of oil
Waterproofing, ingestion from preening, lack of feeding (toxic effect on organs)
Impact of oil on turtle hatchlings
fewer and more deformed scutes, can digest tar balls
impact of oil on turtles
failing of salt glands, epithelium breakdown