Shark ba­bies re­main strong de­spite acid­i­fi­ca­tion

Port Douglas & Mossman Gazette - - SPORT -

AN Aus­tralian study pub­lished this week has found that cer­tain baby sharks are able to cope with the level of ocean acid­i­fi­ca­tion pre­dicted for the end of this cen­tury.

Dr Jodie Rum­mer from the ARC Cen­tre of Ex­cel­lence for Co­ral Reef Stud­ies (Co­ral CoE) at James Cook Univer­sity (JCU) and her co-au­thors stud­ied epaulette shark em­bryos as they were de­vel­op­ing.

“Over­all, there were no dif­fer­ences be­tween growth and sur­vival in sharks reared un­der cur­rent day con­di­tions ver­sus those reared un­der ocean acid­i­fi­ca­tion con­di­tions pre­dicted for the year 2100,” Dr Rum­mer said.

How­ever, she also con­veys cau­tion. Shark gills play an im­por­tant role in help­ing cor­rect pH dis­tur­bances – the team thinks that the risk of death un­der ocean acid­i­fi­ca­tion con­di­tions may be high­est be­fore the em­bryo’s gills are fully de­vel­oped.

Those that got past this stage though, were able to carry on with busi­ness as usual.

Epaulette shark eggs nor­mally in­cu­bate for 3–4 months be­fore they hatch.

Over the course of the study, the re­searchers raised epaulette shark eggs from 10 days af­ter they were laid un­til 30 days af­ter they hatched.

Dur­ing this time, the sharks were raised in one of two groups: to­day’s cur­rent ocean con­di­tions or con­di­tions meant to sim­u­late ocean acid­i­fi­ca­tion pre­dicted for the year 2100.

The re­searchers counted gill and tail move­ments of the de­vel­op­ing em­bryos. They mea­sured how much yolk the em­bryo was con­sum­ing and how much the em­bryo was grow­ing.

And, upon hatching, they fur­ther mon­i­tored sur­vival and growth.

Car­bon diox­ide emis­sions into the at­mos­phere have been in­creas­ing dra­mat­i­cally since the in­dus­trial rev­o­lu­tion.

The oceans are ab­sorb­ing ap­prox­i­mately 30 per cent of this car­bon diox­ide, caus­ing ocean acid­i­fi­ca­tion.

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.