Im­pact of di­luted bi­tu­men on young sock­eye salmon deadly: study

Calgary Herald - - CITY + REGION -

VIC­TO­RIA A spill of di­luted bi­tu­men puts the sur­vival of young salmon at risk, even if the fish end up in clean wa­ter fol­low­ing ex­po­sure to the oil prod­uct, says new re­search from the Univer­sity of Guelph.

Re­searchers said they made the con­clu­sions af­ter ex­pos­ing four groups of sock­eye salmon eggs to four dif­fer­ent amounts of wa­ter sol­u­ble di­luted bi­tu­men, and ob­served the young fish af­ter the eggs hatched for up to eight months in clean wa­ter.

“We saw a lot of changes dur­ing the ex­po­sure,” said Sarah Al­der­man, a post-doc­tor­ate re­searcher at the Univer­sity of Guelph’s depart­ment of in­te­gra­tive bi­ol­ogy. “We found a whole suite of ef­fects, from de­layed hatch­ing to in­creased mor­tal­ity, in­creased de­vel­op­men­tal de­for­mi­ties and changes in growth and en­ergy stores in the fish.”

She said al­most 50 per cent of the salmon ex­posed to the high­est amount of bi­tu­men died dur­ing the first two months af­ter they were moved to clean wa­ter.

The re­search was pub­lished this month in the peer-re­viewed jour­nal Aquatic Tox­i­col­ogy.

About 1,000 sock­eye eggs were used in each of the tests, with the amounts rang­ing from four mi­cro­grams of di­luted bi­tu­men per litre of wa­ter to 35 mi­cro­grams per litre to 100 mi­cro­grams per litre, Al­der­man said. The fourth group of eggs was not ex­posed to the prod­uct.

Al­der­man said the largest ex­po­sure amount of 100 mi­cro­grams per litre re­flected the level of oil prod­ucts mea­sured along the shore­line of the Gulf of Mex­ico fol­low­ing the Deep Wa­ter Hori­zon spill in 2010.

She said mor­tal­ity among the un­ex­posed sock­eye eggs was less than two per cent.

In the ex­posed fish, the re­searchers also found changes in brain de­vel­op­ment and over­all per­for­mance lev­els in the young sock­eye that sur­vived the di­luted bi­tu­men ex­po­sure, said Al­der­man. “It’s re­ally af­fect­ing mul­ti­ple body sys­tems in lots of dif­fer­ent ways.”

The re­sults from the study come as fed­eral and pro­vin­cial gov­ern­ments, First Na­tions, en­vi­ron­men­tal groups and en­ergy com­pa­nies are locked in a con­tentious de­bate over the en­vi­ron­men­tal and eco­nomic vi­a­bil­ity of the pro­posed ex­pan­sion of the Trans Moun­tain pipe­line from north­ern Al­berta to Burn­aby, B.C.

The Canadian As­so­ci­a­tion of Pe­tro­leum Pro­duc­ers did not com­ment on the Guelph re­search, but in a state­ment it said it is part of a sep­a­rate and on­go­ing in­de­pen­dent study to “pro­vide a bet­ter un­der­stand­ing of the be­hav­iour of oil in the un­likely event of a spill on wa­ter.”

It’s re­ally af­fect­ing mul­ti­ple body sys­tems in lots of dif­fer­ent ways.


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