Effects of temperature elevation and glucose addition on prokaryotic production and respiration in the mesopelagic layer of the western North Pacific
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Incubation experiments were conducted to determine whether, and to what extent, heterotrophic prokaryotic production (HPP), prokaryotic respiration (PR), and prokaryotic growth efficiency (PGE) vary in response to the addition of dissolved organic carbon (DOC; glucose at a final concentration of 0.5 µmol C L−1) and elevation of water temperature (+5 °C) in the upper mesopelagic layer of the subarctic and subtropical western North Pacific. The addition of DOC or temperature elevation generally enhanced HPP and PR. Synergistic effects of water temperature and DOC were also found, suggesting that prokaryotic consumption of DOC in the mesopelagic layer is partly regulated by water temperature. Despite the large variability in HPP and PR, PGE varied only moderately, yielding an average value of 0.066 (standard deviation = 0.027, n = 8).
KeywordsDissolved organic carbon Mesopelagic layer Prokaryotic growth efficiency Prokaryotic production Prokaryotic respiration Seawater temperature
We are grateful to the captain and crew of the R/V ‘Mirai’, and the staff of Global Ocean Development Inc. and Marine Works Japan Inc. for their support during the cruises. We also thank M. Honda for his coordination of the cruises and H. Fukuda for his assistance with the laboratory analyses on land. This study was financially supported by a Japan Society for the Promotion of Science Grant (JSPS KAKENHI 24241003) awarded to TN. Financial support was also provided by the JSPS Research Fellowship for Young Scientists awarded to MU. We appreciate the constructive comments provided by the Editor and two anonymous reviewers.
- Buesseler KO, Lamborg CH, Boyd PW, Lam PJ, Trull TW, Bidigare RR, Bishop JKB, Casciotti KL, Dehairs F, Elskens M, Honda M, Karl DM, Siegel DA, Silver MW, Steinberg DK, Valdes J, Van Mooy B, Wilson S (2007) Revisiting carbon flux through the ocean’s twilight zone. Science 316(5824):567–570CrossRefGoogle Scholar
- del Giorgio PA, Cole JJ (2000) Bacterial energetics and groth efficiency. In: Kirchman DL (ed) Microbial ecology of the oceans, 1st edn. Wiley-Liss Inc, New York, pp 289–325Google Scholar
- Dickson AG (1994) Determination of dissolved oxygen in sea water by Winkler titration. WOCE operations manual: the observational programme, section 3.1: WOCE hydrographic programme, part 3.1.3: WHP operations and methods, vol 3. WHP Office Report WHPO 91-1, WOCE Report No. 68/91 November 1994, Woods Hole. https://www.nodc.noaa.gov/woce/woce_v3/wocedata_1/whp/manuals.htm
- Honda MC, Matsumoto K, Fujiki T, Siswanto E, Sasaoka K, Kawakami H, Wakita M, Mino Y, Sukigara C, Kitamura M, Sasai Y, Smith SL, Hashioka T, Yoshikawa C, Kimoto K, Watanabe S, Kobari T, Nagata T, Hamasaki K, Kaneko R, Uchimiya M, Fukuda H, Abe O, Saino T (2015) Overview of study of change in ecosystem and material cycles by the climate change based on time-series observation in the western North Pacific: K2S1 project. J Oceanogr (submitted)Google Scholar
- Kirchman DL (2001) Measuring bacterial biomass production and growth rates from leucine incorporation in natural aquatic environments. In: Paul JH (ed) Methods in microbiology, vol 30. Academic Press, San Diego, pp 227–237Google Scholar
- Kirchman DL (2012) Progresses in microbial ecology. Oxford University Press, New YorkGoogle Scholar
- Montegut CD, Madec G, Fischer AS, Lazar A, Iudicone D (2004). Mixed layer depth over the global ocean: an examination of profile data and a profile-based climatology. J Geophys Res 109 (C12). doi: 10.1029/2004JC002378
- Robinson C, Steinberg DK, Anderson TR, Aristegui J, Carlson CA, Frost JR, Ghiglione JF, Hernandez-Leon S, Jackson GA, Koppelmann R, Queguiner B, Ragueneau O, Rassoulzadegan F, Robison BH, Tamburini C, Tanaka T, Wishner KF, Zhang J (2010) Mesopelagic zone ecology and biogeochemistry—a synthesis. Deep Sea Res II 57(16):1504–1518CrossRefGoogle Scholar