Dolpin (17) Flashcards
(30 cards)
What do scientists refer to the ‘the Great Whale Conveyor Belt’ as?
The largest long-distance nutrient transport on Earth
- What two key elements are transported by baleen whales from polar feeding grounds?
- Where are they moved to?
- Nitrogen and carbon
- These nutrients are moved to nutrient-poor tropical and subtropical breeding areas.
By what percentage has the Great Whale Conveyor Belt diminished since pre-whaling times?
Approximately two-thirds
What could be disrupted by the reduction of whale populations (something quite broad)?
Marine ecosystem dynamics - the loss of nutrient transport by whales may lead to significant changes in marine life and habitats.
What type of whales are primarily involved in the Great Whale Conveyor Belt?
Baleen whales
Name four species of baleen whale that play a key role in the Great Whale Conveyor Belt
- Humpback whales
- Gray whales
- Northern and southern right whales
What do baleen whales build-up duing the summer?
They gorge in cold, food-rich waters near the poles and build up energy reserves in the form of blubber.
How are nitrogen and carbon released by whales as they migrate (and eventually die) (4 Points)?
- Poopy-poo-poo and pee (especially nitrogen-rich urea)
- Afterbirth (placentas)
- Lactation
- Dead babies :(
How much biomass do baleen whales transport?
Approximately 46,500 tons of biomass.
What is the amount of carbon transported in the Great Whale Conveyor Belt?
4,900 tons of carbon.
How much nitrogen is transported in the Great Whale Conveyor Belt?
3,800 tons of nitrogen.
- What is the significance of whale nitrogen contribution in some locations?
- Give an example of where this happens
- It exceeds what’s naturally available through physical processes such as ocean currents.
- An example is Hawaii’s Humpback Whale National Marine Sanctuary.
Baleen whales are essentially _______ the base of the marine food web.
Fertilizing the base of the marine food web (by promoting phytoplankton growth).
What is the average number of calves a single female humpback whale could produce over her lifetime?
10 calves
Approximately how much nitrogen does a female humpback whale transport on each calving journey?
77 kg of nitrogen
How do the distances over which whales transport nutrients compare to those of seabirds?
Whales move nutrients much farther distances – across thousands of kilometers
Where does much of the nutrient deposition by seabirds occur?
On land rather than in ocean ecosystems
Why is 2050 a significant year for whales?
Due to climate change, it’s predicted that some whale populations (e.g., right whales) will peak in 2050 and then decline.
- What do baleen whales typically do in winter and during migration in regards to eating?
- What did whalers notice in regards to this?
- They don’t eat/they fast, with an associated change in body condition.
- Whalers noted that whales killed at the end of the breeding season often weighed significantly less than those killed on the feeding grounds.
Give one reason why baleen whales migrate to tropical waters to give birth (Hint: orca).
Pregnant females migrate to reduce the likelihood of their newborn calves being attacked by killer whales.
What is one advantage of warmer waters for newborn whale calves (Hint: not orcas) (2 Points)?
- Maintaining body temperatures before developing their insulative blubber layer.
- This may allow for faster growth.
What type of breeders are most baleen whales?
Capital breeders - organisms that use stored energy (like fat reserves) to finance reproduction, rather than relying on food intake during the breeding period.
How much larger are the energy stores of pregnant baleen whales compared to nonpregnant females and males?
25% larger than nonpregnant females and 37% more than males
What role do adult whale carcasses play in marine ecosystems?
They represent large nutrient pulses to areas they migrate to
