IGCSE Marine science 3.7 Vertical Migration

 The syllabus states that:


1 Describe migration and give reasons for it 

2 Describe that migration of marine organisms occurs in a three-dimensional environment and can be horizontal or vertical, and can be over short or very long distances 

3 Explain why many organisms, such as plankton, fish, squid and shrimp, undertake daily vertical migration between the twilight zone and sunlight zone

4 Explain why some organisms, such as tuna, turtles and whales, undertake very long horizontal migration

 5 Outline the methods used by organisms during migration to find their way

My notes:

Horisontal migration is seen in many types of populations. Some of you might have seen it in "Finding nemo", where the sea turtles uses the ocean currents for Horisontal migration

Migration is usually either for finding food (as we see when big animals like whales move to feeding grounds), finding mates/breeding/spawning (we see turtles returning and laying eegs on the same beaches as they came from themself) and avoiding predation.

Migration can be short range and short times or extreme long range.

Among mammals, the North Pacific grey whale holds the record for the longest migration. At a confirmed 12,400 miles round trip, its route is the longest of any marine creature migration. Their journey starts in the Bering Sea in October when the sea ice begins to build and ends in the Gulf of California.

Orcas, leathercack turtles, Blue marlins  and elephant seals also have long and impressive migration routes.

Other organisms have a short vertical migration in a dailey cycle, where they stay further down at day and go to the surface to eat during the night

You can find more about animals and how they navigate in the ocean here.