Yoji Okatopulledonhisdivegear.Theunderwaterphotographergatheredhiswaterproofcameras.ThenhedoveintotheseaoffsouthernJapan.
Whenhereachedtheseafloor,he sawsomethingodd.Itwasagiantcircleinthesandthatwastwometers(sixfeet)wide.Thesandinthecenterlookedsmooth.Apatternofsymmetricalridgespileduparoundtheedgeofthe circle.
Okatotookpicturesofthesandsculpture.Whenhesharedhisphotos,otherdiverssaidthey’dseenthesemysteriouscircles,too.Yet,noonehadeverseenwhat
madethem.
Searching
foraCause
Soon,peoplecameupwiththeoriesabouttheseseacircles.SomesaidtheyformedwhenaUFOlandedontheseafloor.Thespaceshipleftamarkinthesand,
they said.
Othersthoughtoceancurrentssculptedthesand.Themovingwatercouldpushthesandintoridges.But,thecirclesseemtooperfectlyroundtobeformedbyshiftingwater currents.
Tosolvethemystery,Okatoteamedupwithscientistsandfilmmakers.Timeaftertime,theyreturnedtothedivesitewherehefirstsawasand circle.
Theteamwatchedandwaitedtoseehowthecirclesformed.Diveafterdive,theysawnothingandswamawaywithout
any clues.
Asia
Japan
Apufferfishmovessandasitflapsitsfinsandswimsalongthe seafloor.
SeeingIsBelieving
Finally,theteamcaughttheartistintheact.Itwasn’tanalien,anditwasn’tanoceancurrent.Itwasamalepufferfishsmallenoughtofitinaperson’s
cupped hands.
Thefishswambackandforth.Hismotionmadetinywavesinthewater.Thesewavesmovedthesand,formingacircle.Thenthefishusedhisfinstodigintothesand.Heflippedfinesandintothecenterofthecircle.Hedugdipsandbuiltridgesaroundtheedge.Finally,hecollectedbitsofshellsinhismouthandcarefullyplacedthemonthe ridges.
Thepufferfishworkedonhisprojectformorethanaweek.Bitbybit,hebuiltasandsculpturehundredsoftimesbigger
than him.
MysterySolved
Okato’steamdidn’tjustfindoutwhatbuildsthemysteriousseacircles.Theylearned whythepufferfishbuilds it.
Whenafemalepufferfishswamby,themalezippedbackandforthinsidethecircle.Hestirredupthefinesand.Hetriedtogetthefemalefish’sattention.Itworked.Shedecidedtolayhereggsinthecenterofthe circle.
Ittookpatienceandalotofobservation.Yet,yearsafterhisdiscovery,Okatofinallysolvedthemysteryofthesea circles.
Apufferfishswimsbackandforthasitmakesasand circle.