Ocean acidification is predicted to lead to global oceanic decreases in pH of up to
0.3 units within the next 100 years. However, those levels are already being reached
currently in coastal regions due to natural CO2 variability. Squid are a vital component of
the pelagic ecosystem, holding a unique niche as a highly active predatory invertebrate
and major prey stock for upper trophic levels. This study examined the effects of a range
of ocean acidification regimes on the early life history of a coastal squid species, the
Atlantic longfin squid, Doryteuthis pealeii. Eggs were raised in a flow-through ocean
acidification system at CO2 levels ranging from ambient (400ppm) to 2200ppm. Time to
hatching, hatching efficiency, and hatchling mantle lengths, yolk sac sizes, and statoliths
were all examined to elucidate stress effects. Delays in hatching time of at least a day
were seen at exposures above 1300ppm in all trials under controlled conditions. Mantle
lengths were significantly reduced at exposures above 1300 ppm. Yolk sac sizes varied
between CO2 treatments, but no distinct pattern emerged. Statoliths were increasingly
porous and malformed as CO2 exposures increased, and were significantly reduced in
surface area at exposures above 1300ppm. Doryteuthis pealeii appears to be able to
withstand acidosis stress without major effects up to 1300ppm, but is strongly impacted
past that threshold. Since yolk consumption did not vary among treatments, it appears
that during its early life stages, D. pealeii reallocates its available energy budget away
from somatic growth and system development in order to mitigate the stress of acidosis.
Date of Award | Dec 2013 |
---|
Original language | English (US) |
---|
Awarding Institution | - Biological, Environmental Sciences and Engineering
|
---|
Supervisor | Michael Berumen (Supervisor) |
---|
- squid
- ocean acidification
- paralarvae
- energy budget
- statolith
- CO2 stress