Alot of animals migrate or are constantly moving,
Water dwellers are no different, they also have migratory patterns
and migrate following pretty much the same course every year or few years
depending on the  reason they are on the move.
Most water dwelling animals Migrate due to weather conditions,
food resources, tidal conditions or for breeding purposes.

Salmon
Juvenile salmon memorize the odor of the stream
in which they were born.
Years later they use this knowledge to navigate
from the ocean back to the mouth of their home river;
they then follow its distinctive odor upstream.

Plovers
The American golden plover travels about 8,000 miles
from nesting areas in the Arctic
to the southern tip of South America--
one of the longest migrations known.
The trip includes about 2,000 miles over open ocean.

 Eels
Freshwater eels spend most of their lives in North American
and British lakes and rivers,
but to reproduce they swim from each side of the Atlantic
to an area of the Sargasso Sea between Bermuda and Puerto Rico.
Land barriers are no problem:
The eels just slither overland through dewy grass.
After breeding, they return to their freshwater homes.

 Turtles
Each year thousands of female green turtles swim more
than 1,000 miles from the coast of Brazil to
tiny Ascension Island in the South Atlantic Ocean.
There they haul themselves onto the sandy beaches,
scrape out shallow nests, and deposit their eggs.
Then they swim back to Brazil.

Lobsters
Each year, the spiny lobster makes an astounding migration.
Individual lobsters join large numbers of others to march
single file across the ocean's floor.
Scientists don't fully understand why the spiny lobsters do this,
but it is believed to have something to do with their reproductive
cycle.

Bluefish
Known for their sharp teeth and insatiable appetites,
bluefish migrate in dense packs each spring,
preying on other fish that come inshore to spawn.
Bluefish often leave a trail of blood for miles as
they consume other fish in a feeding frenzy.

Whales
In autumn whales move from subpolar to subtropical seas to reproduce,
returning to colder, food-rich waters in late spring.
They may be guided by a magnetic substance (called magnetite)
in their brains that functions as a magnetic compass.