Research database

Project information
Project title
WP2-OA-3: Effects of Ocean Acidification and temperature on Arctic vs. boreal zooplankton species and populations
Year
2013/2014
Project leader
Haakon Hop, NPI
Participants
  • Haakon Hop, NPI-Leader
  • Howard Browman (IMR)-Co-leader
  • Peter Thor (NPI-post doc)
  • Claudia Halsband (Akvaplan-niva-reseacher)
  • Anne Berit Skiftesvik (IMR - researcher)
  • Caroline Durif (IMR - researcher)
  • Reidun Bjelland (IMR – senior engineer)
  • David Fields (IMR and Bigelow Laboratory for Ocean Science - researcher)
  • Jeffrey Runge (Gulf of Maine Research Institute - researcher)
  • Padmini Dalpadado (IMR-researcher)
  • Anders Mangor Jensen (IMR-engineer)
  • Erik Sperfeld (IMR-post doc)
Funding Source
Fram Centre, NRC
Summary of Results

Studies on the effects of OA, both acute physiological effects and evolutionary trans-generational effects, were conducted on Pseudocalanus acuspes at Sven Lovén Centre for Marine Science, Kristineberg, Sweden. Significant differences were found in both ingestion rates and respiration rates in acute tests with the copepod P. acuspes from Kongsfjorden. The OA-effects on ingestion and respiration differed between copepods from the Arctic and a boreal population from the Gullmar fjord, on the Swedish west coast. It seems that Arctic copepods may react differently to OA than copepods at lower latitudes.

Evolutionary changes were also detected in P. acuspes. Egg clutch size and production rate was reduced by 30% in 2nd generation females from populations exposed to 900 and 1500 µatm CO2 (pH 7.75 and pH 7.54, respectively) compared to a population exposed to 550 µatm (pH 7.95). Reciprocal transplant tests of females transplanted between these two high OA-treatments and control showed that these changes resulted from phenotypic plasticity at pH 7.75 and from selection at pH 7.54.

Experiment on effects of OA on growth and development on Calanus finmarchicus were conducted at IMR-Austevoll. Females (500-850) collected near Austevoll, in April 2013, were maintained on a diet of mixed algae and then used to inoculate triplicate control and treatment tanks. Treatments at 12 oC included ambient (400 ppm, pH 7.935; 900 ppm, pH 7.608; 1200 ppm, pH 7.495). Automated pumps maintained a minimum food level of 600 µg C L-1 from a mixed algae stock of: Rhodomonas baltica, Isochrysis, Chaetocerous sp., and  Skeletonema sp . Temperature, pH, salinity, and food levels were measured daily, and samples for pH, total alkalinity and nutrients were taken twice a week. Staging, size and lipid content were determined on a minimum of 25 animals from photographs of anesthetized copepods. Dry weight was measured for eggs, N6, all copepodid stages and adult females. The developmental stages appeared healthy and displayed normal respiration rates, feeding, and swimming and avoidance behaviors.

Body mass varied among treatments, particularly for stage C5. However, this was influenced by variability in age at time of sampling. Growth rates were not significantly different for C5’s between 27 and 29 d old. Lipid volume increased exponentially with prosome length as the copepods developed. Similar to the growth rates, there were some differences between treatments, but no significant difference between the lipid volume or slope against prosome length for C5’s that were 29 days old. Results are consistent with the hypothesis that growth and development rates of the species do not need to be reparameterized for ocean acidification in population dynamics models under climate change scenarios.

A cold water OA- facility has been established at IMR-Austevoll to accommodate experiments on Calanus glacialis during 2014. The facility is able to simulate 3 different levels of ocean acidification at temperatures down to 0 degrees in 12 × 50 L flow-through microcosms. Regulation of pH and temperature is computer-controlled and measurements of alkalinity are run regularly according to IPCC guidelines to achieve precise calculations of pCO2. Calanus glacialis were caught near Rijpfjorden, Svalbard and transported to the facility where they are being kept in culture. Incubations for OA will start December 2013. A PhD student, Allison Bailey, has started 2013-08-01. Supervisor is Peter Thor, with assistant supervisors Claudia Halsband and Haakon Hop. Internal supervisor at the University of Tromsø is Camilla Svensen.

Experimental investigations were carried out at IMR-Austevoll to evaluate OA-effects on euphausiids (krill). The krill, Nyctiphanes couchii, caught in light traps near Austevoll, was subjected to pCO2 levels, 430, 800, 1100 and 1700 µatm for about a month. In the experimental set-up, 6 × 1L jars containing individual krill were kept in a 50 L tank, subjected to the specific pCO2 levels, with continuous flow. Three replicates for each pCO2 level were applied. The krill were frequently fed with a mixture of three types of algae and Artemia. Carbon chemistry (Total alkalinity, pH, and DIC) was measured regularly. Mortality, moulting frequency and swimming performance were monitored daily. Results indicated no significant OA-effects on mortality, inter-moult period, growth or swimming performance at pCO2 levels predicted for the end of the century (ca. 1000 µatm). However, the experiments indicated an increasing frequency of deaths related to moulting with increasing pCO2 levels, and swimming performance was reduced at unrealistically high pCO2 of 1700 µatm. It was concluded that N. couchii will not suffer dramatically from near future changes in pCO2. Further experiments are needed in order to investigate whether those results are also valid for other northern krill species, such as Meganyctiphanes norvegica, or Thysanoessa inermis, given that Arctic waters will be more affected by future changes in OA.

For the Management

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Published Results/Planned Publications

Halsband, C., Kurihara, H. (2013). Potential acidification impacts on zooplankton in Carbon Capture & Storage leakage scenarios. Marine Pollution Bulletin, Special Issue (doi:10.1016/j.marpolbul.2013.03.013).

McConville, K., Halsband, C., Fileman, E., Somerfield, P.J., Findlay, H.S., Spicer, J.I. (2013). Effect of elevated CO2 on the reproduction of two calanoid copepods. Marine Pollution Bulletin, Special Issue (doi:10.1016/j.marpolbul.2013.02.010).

Thor, P., Oliva Oliver, E. (in prep). Arctic and boreal populations of the copepod Pseudocalanus acuspes show different metabolic responses to ocean acidification.

Thor, P., Dupont, S. (in prep). Importance of evolutionary selection and phenotypic plasticity for metabolic changes in the copepod Pseudocalanus acuspes during ocean acidification.

Thor, P., de Wit, P. (in prep). Influence of near future ocean acidification on expression rate and allelic frequencies of expressed genes in the copepod Pseudocalanus acuspes.

Communicated Results

Thor, P., Dupont, S. (2013). Importance of evolutionary selection and phenotypic plasticity for metabolic changes in the copepod Pseudocalanus acuspes during ocean acidification. Nordic Marine Sciences Conference 2013, Oslo.

Interdisciplinary Cooperation

OA studies demand close collaboration between chemists and biologists. Naturally we are collaborating within the flagship with Melissa Chierici (IMR) and Agneta Fransson (NPI) during our studies.

Budget in accordance to results

The funding from Fram represents approximately half of the total funding for the project and is essential. Part of the funds covers Peter Thor’s salary and he is central to the continuation of the studies. Moreover, conducting experiments such as these requires expensive specialized facilities, equipment and materials and is also very labour intensive.

Funds from the Fram Centre supported collaboration with V. Thiyagarajan at the University of Hong Kong who works on global proteome expression, a skill not available in the Fram-IMR team. Similarly, funds have also facilitated collaboration with P. de Wit (Univ. of Gothenburg), which enabled another extension of our research into full genome expression.

Could results from the project be subject for any commercial utilization
No
Conclusions

The copepod studies continue on true arctic species (Calanus glacialis and, potentially, C. hyperboreus). A cold water OA facility has been established at IMR- and we are initiating long- term studies on C. glacialis and P. acuspes there. It is our intention to study evolutionary trans-generation effects should we succeed in culturing the copepods for two generations. We will conduct various acute OA tests on several other arctic pelagic species (extending beyond copepods) during the summer 2014. Moreover, we will be involved in the RV Lance freeze- in during the winter 2014-15. During the expeditions, it is our intention to monitor effects of natural changes in sea water pH during the winter-spring transition north of Svalbard. This may provide important information on the resilience of planktonic animals to natural fluctuations in pH in the Arctic.