See the Light: Cap­ture Sun­beams in Your Im­ages

Al­though dwarfed in size by the mighty blue whale, hump­backs are record break­ers in their own right

Sport Diver - - Front Page - BY DR. RICHARD SMITH


The hump­back whale makes the long­est mi­gra­tion be­tween sea­sonal feed­ing and breed­ing ar­eas of any mam­mal.


Or­cas and dusky sharks are among known preda­tors of hump­back whale calves.


One dis­puted es­ti­mate sug­gests that there were

al­most 250,000 hump­backs in the North At­lantic be­fore whal­ing be­gan. There are now 12,000.


Fol­low­ing the 1986 global mora­to­rium on whale

hunt­ing, hump­backs have moved from En­dan­gered to Vul­ner­a­ble, and in 2008, to Least Con­cern, with an es­ti­mated pop­u­la­tion of more than 60,000 an­i­mals.


Male hump­backs are the Pavarot­tis of the ocean realm. It’s been sug­gested that singing at­tracts fe­males to birthing and mat­ing ar­eas by males, which lead the way dur­ing mi­gra­tion.


Fe­male hump­backs are preg­nant for up to one year. New­born calves can swim im­me­di­ately.


From the 17th cen­tury, hump­backs were hunted for their meat, oil and baleen.


The en­dan­gered Ara­bian Sea sub­pop­u­la­tion of hump­backs is the only non­mi­gra­tory group in the world. They ap­pear to have been iso­lated from other pop­u­la­tions for 70,000 years.


At 15 feet in length,

the hump­back’s flip­pers are the long­est ap­pendage of any ver­te­brate.


Hump­backs can weigh up to 40 tons, six times heav­ier than a bull ele­phant and three times heav­ier than a school bus.


The 10,000 hump­backs that over­win­ter in Hawai­ian wa­ters travel around 3,000 miles to their sum­mer feed­ing grounds off Alaska.


The hump­back whale is a fil­ter feeder, us­ing huge sieve-like baleen plates to trap

plank­ton and small an­i­mals, such as krill and fish. Sadly, in mod­ern oceans this also in­cludes mi­croplas­tics.


Adult fe­males can reach 60 feet in length, which is equal to a bowl­ing

lane but only twothirds the length of a blue whale.


The hump­back’s av­er­age life span is 50 years.


Hump­backs are di­vided into three

sub­species: North Pacific, North At­lantic and South­ern Hemi­sphere.

Fol­low Richard Smith’s un­der­wa­ter ad­ven­tures at ocean­realm im­

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