BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Antarctic krill: Life is all about balance in a high CO2 world - J
 essica Ericson\, University of Tasmania
DTSTART:20170620T123000Z
DTEND:20170620T130000Z
UID:TALK73100@talks.cam.ac.uk
CONTACT:Claire Waluda
DESCRIPTION:Ocean acidification is caused by sequestration of atmospheric 
 CO2 into ocean surface waters\, a process that increases ocean pCO2 and de
 creases ocean pH. Present day levels of atmospheric CO2 have reached 400 p
 pm\, and are predicted to rise as high as 2000 ppm by the year 2300\, equa
 ting to a decrease in ocean pH of up to 0.7 pH units. Organisms from Polar
  regions are particularly vulnerable to ocean acidification\, due to the i
 ncreased rate of CO2 sequestration in colder seawater.\nAntarctic krill we
 re reared for 11 months in a flow-through seawater system at the Australia
 n Antarctic Division’s Krill Aquarium in Tasmania\, under five pCO2 leve
 ls (400\, 1000\, 1500\, 2000 and 4000 ppm). We examined the effects of inc
 reased seawater pCO2 on the lipid and fatty acid composition\, respiration
  rate\, growth\, mortality\, intermoult period\, haemolymph pH and maturit
 y of adult Antarctic krill. \nHaemolymph pH decreased with increasing seaw
 ater pCO2 but it appears that krill were compensating for this decrease\, 
 possibly through the transport of bicarbonate ions into their extracellula
 r space. Maturation was delayed in krill exposed to CO2 levels of 1500 ppm
  and above. Seawater pCO2 had no effect on the lipid and fatty acid compos
 ition\, respiration rate and intermoult period of krill. \nOur research su
 ggests that the adult life stages of Antarctic krill have the capacity to 
 tolerate levels of near-future acidification\, when elevated pCO2 is asses
 sed as a single stressor. However\, the energetic costs of maintaining phy
 siological acid-base balance over the long term are unknown\, and previous
  studies have shown that krill eggs and embryos may be vulnerable to pCO2 
 levels predicted for the year 2100 and beyond.\n
LOCATION:British Antarctic Survey\, Room 307
END:VEVENT
END:VCALENDAR