AMSO - Nautica Flashcards
Why does the Arabian Peninsula have a unique marine biodiversity?
- seasonal upwelling (causing some species to stop migrating -> humpback whale)
- natural culdesac, water cannot move northward in the Arabian Gulf
Characteristics of the Arabian Gulf
shallow + heat -> a lot of evaporation
- no freshwater inputs, but nutrients are added which causes some areas to become eutrophic
Characteristics of the Red Sea
- oligotrophic (nutrient poor)
- deeper than Arabian Gulf (much)
Oligotrophic
nutrient poor
JNCC
Joint Nature Conservation Committee (UK)
Source of noise pollution underwater (biological, non-biological, and anthropogenic)
Biological:
- communication between species (mammals, fish, shrimps)
Non-biological:
- lightning, earthquakes, volcanic eruptions
Anthropogenic
- seismic exploration (+ VSP)
- pile driving
- explosives
- sonar
- dredging
- development
What are the three main features of sound waves?
frequency, amplitude, and wavelength
Frequency
the number of pressure waves that pass by a reference point overtime
- higher frequency = higher pitch
Amplitude
the height of the sound waves
Wavelength
distances between the peaks of sound waves
Sound moves _ faster underwater
4 x
Why does sound move faster in warmer water?
because the medium (water) is less dense
_ refract sound allowing it to travel over even greater distances
thermoclines
What are the loudest anthropogenic underwater sound sources?
sonar and seismic
Seismic exploration
- used to find oil and gas in the sea bed + sediments
- sound is produced by seismic airguns, travels from the surface to the seabed, and then hydrophones receive the echo of the sounds
VSP
Vertical seismic profiling (into a well-hole)
Pile driving
placing a foundation into the sea bed, done during offshore development
2 groups of whales
Mysticetes and Odontocetes
Odontocetes
Toothed whales
Mysticetes
Baleen whales
Why is sound important for marine mammals?
prime sense
- communication
- hunting
- echolocations
- navigation
Sharks and rays are attracted by _
low pulses, but deterred by loud sounds
Masking
when noise pollution prevents marine animals from hearing and communicating properly
Tissue damage in marine mammals from noise disturbances
- gas-filled tissue
- decompression sickness (N in tissue)
- growth of microscopic bubbles
- change in behaviour
- damaged hearing
Like humans marine mammals have _ in their ears
hairs
2 thresholds of damaged hearing from underwater noise pollution
temporary
permanent
Sharks and rays use _
electric and magnetic cues
subsea cables and pipeline deployments attract some species
ALAN
artificial light at night
How are turtles disturbed by light pollution?
- nesting females look for the darkest beach spots
- light may cause females to lay their eggs in less-favorable spots
- the light produced by the moon also guides adults and hatchlings, ALAN may guide them in the wrong direction
How are corals disturbed by light pollution?
disrupts the photosynthetic cycle of symbiotes
Marine mammals are classified into 4 taxonomic groups:
- Cetacea (mysticetes and odontocetes)
- Sirenia (manatees and dugong)
- Pinnipedia (seals and walruses)
- Fissipedia (polar bears and marine otters)
How many blow holes does a baleen whale have?
2
How many blow holes does a toothed whale have?
1
Ventral pleats
creases that run vertically down the underside of a whale’s jaw all the way to its stomach. When feeding, the ventral pleats expand like an accordion to accommodate a huge amount of food-rich water
What are the 5 dorsal fin shapes?
- Falcate
- Triangular
- Humped
- Rounded
- Non-existant
Rostrum
the upper jaw or “snout” of the whale.
Caudal peduncle
one of a whale’s strongest muscles, right before the fluke
Fluke
whale tail
A taller blow means a _ whale
larger
What are some characteristics of mysticete feeding?
- jaw opens 90°
- when mouth is closed the whale’s body is very streamline
Which behavior in marine mammals indicates disturbance?
- turning away
- shielding young
- grouping together
- suddenly diving or moving away
- flipper, tail, or jaw slapping
- dugongs swim in a figure of 8 and then make a sharp turn
Carapace
hard, upper shell of a turtle
Plastron
lower shell of a turtle
5 marine turtles found around the Arabian Peninsula
Most common
- green turtle
- hawksbill turtle
- loggerhead turtle
- olive ridley turtle
- leatherback turtle
Coastal scutes
largest scutes on the carapace of a sea turtle
Prefrontal scutes
number of scutes on a turtle’s forehead
turtles can’t see _ light wavelengths
red
Female turtles can _ _ more than once per season
successfully nest but also often have multiple nesting attempts until it is successful
Elasmobranchs
sharks and rays (cartilaginous fish)
What are the main sense of elasmobranchs?
smell and sensing magnetic fields
sharks and rays
PAM
passive acoustic monitoring
- hydrophones used to detect and identify marine mammal vocalizations
Exclusion zone (seismic surveys)
500m zone around the center of the source (air guns)
Soft-start (seismic surveys)
slowly introducing sound into the environment (20-40 minutes)
Pre-shooting search (seismic surveys)
30 - 60 minutes (depending on water depth) search before the soft-start to insure that no marine species are present
What should be done when a turtle covered in barnacles is found?
DO NOT remove them, but place it in freshwater
What should or should not be done when an injured turtle is found?
Do’s
- reduce stress and noice
- cover the head and eyes
- keep in shade
- protect plastron (usually soft)(place towel under)
- ensure that the turtle’s head is above the surface
- hold on the sides of the carapace
- place turtle head first into water and let go
- if a turtle is unconscious, place its hind legs higher so water is drained from the lungs and check its reflexes (eyes, flipper)
Don’ts
- remove encrustations
- give food
- throw nets back into ocean (ghost nets)
