Dolpin (8) Flashcards
(30 cards)
- How do dolphins swallow their food?
- Why do they do it this way?
Dolphins swallow their fishy food head first - this is so that bones don’t get stuck in their thoats.
What major impact do fisheries have on UK cetaceans?
Fisheries can significantly affect the status and distribution of various UK cetaceans.
Which fish stocks have shown marked changes in population due to fishing pressure (6 Points maximum)?
- Sprats
- Sand eels
- Herring
- Whiting
- Mackerel
- Haddock
What is the consequence of over-exploitation of fish stocks on marine mammals?
Over-exploitation leads to dramatic declines in fish stocks, imposing major pressures on marine mammals that depend on them for food.
What was the status of North Sea herring stocks by 1977?
North Sea herring stocks collapsed to about 5% of post-war levels by 1977.
Do dolphins give each other gifts?
- Yes - a male may present a female with a gift to earn her love.
- A nice sea sponge will do.
Do dolphins have culture?
Yes - the act of wearing a sponge to protect one’s beak when foraging is learned, with baby dolphins learning the ability from their mothers.
What led to the near extinction of most great whales in the world’s oceans?
Centuries of hunting
Which country was one of the leaders in causing the demise of great whales?
Britain
Which group is the leader in dolphin research?
The US Navy
- Why was the US Navy so interested in dolphins in the 1950s?
- What did this lead to the discovery of?
- Because they thought that they could be trained to retrieve items that were lost at sea.
- This led to the discovery that they were possibly the second most smartest animal alive.
Which whale species are mentioned as being very rare in UK waters?
- Northern right whale
- Humpback whale
- Blue whale
What signs of recovery have been observed after thirty years of protection in the North Atlantic?
Some signs of recovery for blue whales and humpbacks
What type of whaling resumed in the 1990s?
Scientific whaling
How many minke whales did Norway take in waters north of Shetland in the 1990s?
Around 800 minke whales
Which country has joined Norway in resuming whaling as a commercial activity during the 1990s?
Iceland
True or False: The whaling activity mentioned has completely ceased.
False
Other than your name, date, and email address, what else do you need to record before starting a land watch survey (Hint: L and L)?
Longitude and latitude.
When doing a land watch survey, how often do you record environmental data?
Every 15 minutes
What five environmental conditions should you record when doing a land watch survey?
SSWVB
- Swell
- Sea state
- Wind direction
- Visibility
- Boat activity
When doing a land watch survey, what are the three mammals you’re most likely to see?
- Seals
- Bottlenose dolphins
- Harbour porpoises
What is logging?
When marine mammals rest at the the surface of the water (they look like logs).
Some long-finned pilot whales logging.
For how long do dolphins sleep each day?
Eight hours.
What does it mean when dolphins are milling (3 Points)?
- Group frequently changes travel direction (no consistent travel direction).
- Individuals may surface facing different directions.
- Dolphins have slow movements with variable, but frequent, dive intervals and often remain floating at the surface for a short amount of time between dives.
