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HowMarineDivingMammals

ManageDecompressionScienceDailyDecember21,2011

MargaretJillW.Tinsay

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WHATISDECOMPRESSIONSICKNESS(DCS)?

-rapidascentfromtheoceandepths(largepressuregradient)duringdivingthatmay

causenitrogenbubblestoforminthebody

-manysymptoms:jointpain,rashes,paralysis,unconsciousness,evendeath

-"bends"-jointorskeletalpain

"chokes"-breathingproblems

"staggers"-neurologicalproblems^[3]

-Type1(skin,musculoskeletalsystemorlymphaticsystem)

Type2(CNS)

BUTHOWDOMARINEMAMMALS,WHOSEVERYSURVIVALDEPENDSONREGULARDIVING,

MANAGETOAVOIDDCS?DOTHEYINDEEDAVOIDIT?

April2010

28researchersfromWoodsHoleOceanographicInstitution'sMarineMammalCenter(MMC)

discusseddivingmarinemammalgaskinetics(theratesofthechangeintheconcentrationof

gasesintheirbodies

Newtechnologies:

-CTscanner{toexaminemarinemammalcadaversatdifferentpressures}

-Portableveterinaryultrasoundunits{tolookatthepresenceorabsenceofgasinlive,strandeddolphins}

"Untilrecentlythedogmawasthatmarinemammalshaveanatomicalandphysiologicaland

behavioraladaptationstomakethebendsnotaproblem.."-MMCDirectorMichaelMoore

BUT

RecentstudiessuggestthatmammalsareACTIVELYAVOIDINGDCSratherthansimplynot

experiencingdecompression

MOREQUESTIONSTOBEANSWERED:

-dotheyhavecirculatingbubblesintheirsystemsthattheyaremanaging?

-howdonoiseimpactsandotherstressorsaffectthismanagement?

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Examplesofrecordedincidents:

1)BeakedwhalesstrandedontheCanaryIslandsin2002:

-Necropsyshowsdamagefromgasbubbles

-thisledscientiststothinkthatdivingmarinemammalsmighthavegreatervariationintheirnitrogenlevelsintheirbloodandhave'strategies'tomanageit

2)AsphericallesionfoundinaribofadeadspermwhalethatbeachedonNantucketwaslikely

causedbynitrogenbubblesthatformedwhenthewhalerosetoorapidlyfromhigh-pressure

depths.Thebubblesobstructbloodflowandleadtobonedamage.(Credit:PhotobyTom

Kleindinst,WoodsHoleOceanographicInstitution)

Whenahumandiverhasbubbleissueshemay:

-climbintoarecompressionchamber-gobacktooceandepthsandletthebubblesdisappear

FORMARINEMAMMALS

Whentheyaresurfaced,theywouldneedtodiveagain.

Theycan'tdothatinSHALLOWWATERorwhentheyareBEACHED.

"...noiseimpactsandotherstressors[that]pushtheanimalfromanormalmanagement

situationtoanabnormalsituation[becomemoreofaconcern]...."-Moore,MMC

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Resources:

[1]http://www.thedivingblog.com/decompression-theory/

[2]http://www.sciencedaily.com/releases/2011/12/111221151721.htm

[3]http://en.wikipedia.org/wiki/Decompression_sickness

[4]Deadlydiving?Physiologicalandbehaviouralmanagementofdecompressionstressindiving

mammals,"whichwaspublishedDec.21,2011,onlineintheProceedingsoftheRoyalSocietyB.

http://www.oceanquestdivecenter.com/?cat=25

http://www.mudgeediveandtravel.com/images/group_of_scuba_divers_hc.gif?202

http://www.la-sirena.net/imagenes-

lasirena/gif/scuba_diver_with_underwater_camera_hg_clr.gif