Good afternoon everyone.Well,with some of youabout to go out on field work it's timely that in thisafternoon's session I'll be sharing some ideas aboutthe reasons why groups of whales and dolphinssometimes swim ashore from the sea right onto thebeach and,most ofter,die in what are know as 'massstrandings'.
Unfortunately,this type of event is a frequentoccurrence in some of the locations that you'll be travelling to,where sometimes the tide goesout suddenly,confusing the animals.However,there are many other theories about the causesof mass strandings.
The first is that the behaviour is linked to parasites.It's often found that stranded animals wereinfested with large numbers of parasites.For instance,a type of worm is commonly found in theears of dead whales.Since marine animals rely heavily on their hearing to naviqate this type ofinfestation has the notential to be very harmful.
Another theory is related to toxins,or poisons.These have also been found to contribute tothe death of many marine animals.Many toxins,as I'm sure you're aware,originate fromplants,or animals.The whale ingests these toxins in its normal feeding behaviour but whetherthese poisons directly or indirectly lead to stranding and death,seems to depend upon thetoxin involved.
In 1988,for example,fourteen humpback whales examined after stranding along the beaches ofCape Cod were found to have been poisoned after eating tuna that contained saxitoxin,thesame toxin that can be fatal in humans.