Lecture 17

Question 1

What is ranging behaviour?

Answer 1

Where they go to forage

Question 2

What is foraging itself?

Answer 2

What they do when they get there e.g. who do the animals actually catch their prey. Depend on the species

Question 3

What are the issues of foraging in the sea?

Answer 3

. Navigating in a featureless environment
. Spatial distribution of prey (not evenly distributed)
. Environmental factors e.g. tide, ocean currents (could be faster than they can swim- to have to contend with this or poss utilise)
. Prey disturbed vertically as well as horizontally
. Prey are not normally visible from the surface
. Physiological limitations (related to the fact that they are diving- have to hold their breath- limit to how long they can stay submerged for)

Question 4

Why is oceanography important?

Answer 4

Determines the location of the food:
- sides of primary production (plants)
. Winter vs summer (changes in productivity and sunlight levels) (south vs north)
. Depth in water column (deeper=less likely to have primary produces)
. Stratification
- nutrients
. N, Si, Ph, Fe
- where food gets aggregated or concentrated
. Prey isn’t homogenous
. Prey is patchy
. Need to locate optimal prey patches (if predator- come back to the same place/ remember)

Question 5

What is the oceans surface circulation major current dominated by?

Answer 5

. Gyres

. Wind patterns e.g. build up, could use this if you were a bird

Question 6

Give some oceanographic features

Answer 6

. Coastal upwelling 
. Bathymetry 
. Fronts 
. Eddies 
(Impact whether the nutrients are coming up to the herbivores)

Question 7

What are coastal upwellings driven by?

Answer 7

Wind

Question 8

What is the oceanographic feature bathymetry? (What is it caused by, where)

Answer 8

Upwelling caused by currents and bottom structure- changes in the underlying topography of the marine landscape
. Galapagos
. Seamounts
. Continental shelf edge

Question 9

What is the oceanographic feature fronts? Explain

Answer 9

Temperature salinity discontinuously
Is different bodies of water coming together
If you have a low and high salinity water coming together the low salinity will sit on top because it is less dense

Question 10

What is the oceanographic feature eddies? (What are they and what are they a result of)

Answer 10

. Result from circulation patterns

. Warm and cold core rings and jets

Question 11

Where do upwellings tend to be? What are they linked to?

Answer 11

Coastal regions

Linked to tidal features and wind

Question 12

What do gyres transport?

Answer 12

Nutrients to shallow waters- primary production here and brings lots of animals (predictable)

Question 13

What does sea surface temperature link to?

Answer 13

The availability of resources for the primary producers

more in cold water then warm

Question 14

How often do El Niño events take place?

Answer 14

Every 5-10 years

Question 15

What is La Niña closes to?

Answer 15

Normal surface temperature and currents (cold water extends from South America to the Pacific- opposite in El Niño. Impacts cold formation)

Question 16

Give an example of species that’s breeding season fails in El Niño years

Answer 16

Seals and birds

Question 17

What is a time-depth recorder used for?

Answer 17

Records pressure- at the surface the pressure in 1atmosphere less than when animals dive down. So if you can monitor that change in pressure then you can monitor how deep the animals are going (usually have a gps)

Question 18

As shown by time-depth recorders how does sea surface temperature affect seal behaviour? Give an example of a year when this happened

Answer 18

When they had a warm water anomaly in 2005 seals changed where they went and at what time and how deep they dived- went further out

Question 19

What does oceanographic features affect?

Answer 19

(. Work at different scales
. Wide variety of oceanographic features)
. Linked to productivity
. Ultimately linked to food- drive the food chain

Question 20

What is the new idea for how we can sample the water column at great depths?

Answer 20

Using animals such as elephant seals and attaching devices to them (movements of higher predators in the Pacific Ocean)

Question 21

Define the diving behaviour diving

Answer 21

Period of submersion- 3 components:
. Descent
. Bottom time = foraging time (some sea floor, some not)
. Ascent

Question 22

Define the diving behaviour surface

Answer 22

Time spent at surface between dives (maybe the breath or rest- elephant seals rest under water) (missed foraging time)

Question 23

Define the diving behaviour dive cycle

Answer 23

Dive plus surface

Question 24

Define the diving behaviour dive bout

Answer 24

A group of dives (before taking a break) (recovering/ preparing for a dive)