Detailed visual seabed survey at drilling site 7218/11-1
Detailed visual seabed survey at drilling site 7218/11-1
Detailed visual seabed survey at drilling site 7218/11-1
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
For example,spongesare sensitiveto physicaldamage(suchas trawling or anchor handling)and<br />
smothering(suchasfrom passingtrawls or depositionof <strong>drilling</strong> muds),but they are only vulnerable<br />
in areaswheretheseactivitiesactuallyoccur.<br />
Assessingsensitivity to <strong>drilling</strong> cuttings requires further research on sponge metabolism and<br />
responsesto various disturbances(see below). Sensitivity and vulnerability can therefore be<br />
measured<strong>at</strong> an individual scale,but for environmentalmanagementand conserv<strong>at</strong>ionissues,an<br />
ecosystemperspectiveusuallyis adopted.<br />
Arisingquestionsaretherefore:<br />
Howmuchimpactswill be causedby plannedactivities<br />
Amountof spongeseradic<strong>at</strong>edor reducedin function;<br />
Howlongwill the effectsremainvisibleon the sea-floor<br />
Arethe impactsshort,middleor long-term?<br />
Will remedialactionshaveother undesirableenvironmentalside-effects<br />
Disposalin marinehabit<strong>at</strong>sversustransportto coastalor terrestrialzone<br />
Disposalof solidwasteversusemissionsto air<br />
To d<strong>at</strong>e, we do not havereal answersto these questionsin rel<strong>at</strong>ion to spongeassemblagesin the<br />
Barents Sea.In responseto emerging needs, a number of researchiniti<strong>at</strong>ives are taking place<br />
(Akvaplan-niva,Institute for MarineResearchandIRIS;seealsobelow).<br />
5.5.2 Ongoing and planned experimental and in situ work on assessing<br />
sensitivit y of sponges to <strong>drilling</strong> cuttings.<br />
Recently(05.09.2012),Akvaplan-niva submitted a researchproposal to the NorwegianResearch<br />
CouncilPROOFNYprogramme,on the impacts of <strong>drilling</strong> cuttings on spongeassemblagesin the<br />
south-westernBarentsSea.RENAS, together with EniNorgeand Lundin,hasgivenan expressionof<br />
interest to function as an end-user to this research. In addition, these companieswill guide the<br />
selectionof experimentalexposureparameters,and, where possibleor practical,offer assistancein<br />
collection/ in-situ studyof sponges,shouldan opportunity ariseduringanyfuture <strong>visual</strong>surveillance<br />
or stand-by missionswhereROVservicescanbe usedto mutual benefit.<br />
Thisreal link betweenexperimentalresearchand industrialneedsis a major stepforwards,towards<br />
answeringsomeof the urgentquestionsraisedduringthis, andrel<strong>at</strong>eddetailed<strong>site</strong> <strong>survey</strong>s.<br />
Howmuchsediment<strong>at</strong>ionislethal to sponges?<br />
o Andwhichsedimentfractioncausesmost stressto sponges?<br />
How do spongesreact to exposureof someof the substancesusedduring oper<strong>at</strong>ions(e.g.<br />
BariteandBentonite)?<br />
How is the metabolism/respir<strong>at</strong>ion/ generalperformanceof spongesaffectedby sub-lethal<br />
exposureto <strong>drilling</strong>discharges?<br />
How fast do spongesgrow, and therefore wh<strong>at</strong> is the expected recovery period after<br />
depositionof <strong>drilling</strong>mud/cuttings?<br />
o note – another question arises- do spongesreadily recolonize,despitechangesin<br />
the grainsizecomposition<strong>at</strong> the sedimentsurface?<br />
<strong>Detailed</strong> <strong>site</strong> <strong>survey</strong> <strong>at</strong> PL531 Darwin<br />
Akvaplan-niva AS Rapport 6051 - 1 57
Change language