De­formed dol­phins

Dol­phins in bad shape af­ter oil spill.

The Star Malaysia - Star2 - - ECOWATCH - By KERRY SHERIDAN

BOT­TLENOSE dol­phins with miss­ing teeth, lung dis­ease and ab­nor­mal hor­mone lev­els were found swim­ming in the Gulf of Mex­ico a year af­ter the BP oil spill, US re­searchers say.

Pneu­mo­nia, liver dis­ease and a preg­nant fe­male car­ry­ing a dead fe­tus were also re­ported in the first ma­jor study of dol­phin health af­ter the 2010 Deep­wa­ter Hori­zon oil rig ex­plo­sion that spilled 4.9 mil­lion bar­rels of oil into the Gulf of Mex­ico.

Half of the 32 dol­phins stud­ied off the coast of Louisiana in Au­gust 2011 – a year and four months af­ter the worst oil spill in US his­tory be­gan – were judged to be se­ri­ously ill or in dan­ger of dy­ing.

“I’ve never seen such a high preva­lence of very sick an­i­mals,” said lead au­thor Lori Schwacke, a re­searcher with the Na­tional Oceanic and At­mo­spheric Ad­min­is­tra­tion (NOAA).

The wild dol­phins were cap­tured in the cen­tral Louisiana wa­ters and held briefly for health checks be­fore be­ing re­leased.

“There is dis­ease in any wild pop­u­la­tion. We just haven’t seen an­i­mals that were in such bad shape as what we saw in Barataria Bay,” she said.

Their health was com­pared to 27 bot­tlenose dol­phins in Sara­sota Bay, Florida, an area also in the Gulf that was un­af­fected by the oil spill.

The Barataria Bay dol­phins had sig­nif­i­cantly lower lev­els of adrenal hor­mones, which are crit­i­cal to an an­i­mal’s stress re­sponse. Mod­er­ate to se­vere lung dis­ease was five times more com­mon in the Louisiana dol­phins than in their Florid­ian coun­ter­parts.

Three of the Barataria Bay dol­phins had also lost nearly all their teeth, and three oth­ers had just half of their nor­mal num­ber of teeth left. Dol­phins typ­i­cally have be­tween 78 and 106 teeth.

Sickly dol­phins

“There were sev­eral dol­phins that were in such bad shape that the vet­eri­nar­i­ans who ex­am­ined them did not ex­pect them to live very long,” said Schwacke, an ex­pert on dol­phins in the south­ern United States.

Dol­phins that were stud­ied also suf­fered from pneu­mo­nia, anaemia, low blood su­gar and el­e­vated liver en­zymes.

Oil gi­ant BP said the re­port, which ap­peared in De­cem­ber in the jour­nal En­vi­ron­men­tal Sci­ence and Tech­nol­ogy, was “in­con­clu­sive as to any cau­sa­tion as­so­ci­ated with the spill”.

BP spokesman Ja­son Ryan di­rected AFP to a com­pany state­ment that read in part: “Symp­toms ob­served in the study have been seen in other dol­phin mor­tal­ity events that have been re­lated to con­tam­i­nants and con­di­tions found in the north­ern Gulf, such as poly­chlo­ri­nated biphenyls (PCBs), DDT and pes­ti­cides.”

NOAA re­searchers ad­mit­ted that their study can­not prove that the dol­phin’s health prob­lems were caused by the BP oil spill be­cause there were no stud­ies of dol­phin health in that area prior to the spill.

How­ever when com­par­ing blub­ber, the Louisiana dol­phins have lower lev­els of pes­ti­cides and flame re­tar­dant chem­i­cals than the Florida group, sug­gest­ing that agri­cul­tural run-off and com­mon pol­lu­tion were not the cause of their dis­eases.

“We feel like it is highly un­likely that the toxic ef­fects that we ob­served in Barataria Bay dol­phins were as­so­ci­ated with ex­po­sure to other en­vi­ron­men­tal con­tam­i­nants,” said Schwacke. “What we are see­ing is con­sis­tent with oil ex­po­sure,” she said.

Un­ex­plained die-offs

NOAA said it is still try­ing to de­ter­mine why 1,082 dol­phins have been stranded in the north­ern Gulf of Mex­ico since Fe­bru­ary 2010. An un­usu­ally high num­ber of dol­phins and whales started wash­ing up on shore prior to the April 20 Deep­wa­ter Hori­zon rig ex­plo­sion that sparked the un­der­wa­ter spill.

Be­tween Fe­bru­ary and the end of April 2010, 114 dol­phins and whales were stranded. Nearly 1,000 more were stranded be­tween April 30, 2010 and Jan 26, 2014. Those in­cluded 86 baby dol­phins that washed ashore dead from Louisiana to western Florida be­tween Jan­uary and April 2011.

NOAA sci­en­tist Teri Rowles said that nei­ther the measles-like mor­bil­livirus – blamed for killing bot­tlenose dol­phins along the US East Coast – nor the bac­te­rial in­fec­tion bru­cel­losis ap­pear to be the cause of the Gulf of Mex­ico deaths.

“At this time we don’t have a fac­tor that we can pin­point as a causative agent and we cer­tainly at this point can­not rule out the role of the BP oil spill in the mor­tal­ity event,” said Rowles.

Craig Harms, a vet­eri­nar­ian that helped check the dol­phin’s health, said that their symp­toms mir­rored those seen in lab an­i­mals ex­posed to oil.

“Crude oil ex­po­sure is the most rea­son­able ex­pla­na­tion for adrenal in­suf­fi­ciency and lung dis­ease in the Barataria Bay dol­phins,” said Harms, an as­so­ciate pro­fes­sor at the North Carolina State Univer­sity Col­lege of Vet­eri­nary Medicine. – AFP

Vic­tims of pol­lu­tion: dol­phins in the Gulf of Mex­ico may feel the ef­fects of the bP oil spill for years to come. — MCT

Newspapers in English

Newspapers from Malaysia

© PressReader. All rights reserved.