Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Supplemental Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Shell quality of pteropods held for 1-14 days in three CO2 treatments with pteropods collected with a Reeve net during R/V Tioga cruises in the Gulf of Maine from 2014 to 2015.

These data were published in Maas et al. (2018) and Maas et al. (in review).

Related Datasets: 
* Pteropod abundance and distribution: https://www.bco-dmo.org/dataset/780874
* Pteropod respiration experiments: https://www.bco-dmo.org/dataset/780886

Methodology:

Pteropod adult (>0.5 mm, with fully developed wings/parapodia) were captured for experiments using a Reeve net with 333-m mesh and a large cod end that was deployed at slow speeds, for a short duration (< 1 h) with the aim of gently sampling live, undamaged specimens on various cruises. Tows were conducted at multiple stations in the Gulf of Maine (C42 22.1’ - 42 0.0’ N and 69 42.6’ - 70 15.4’ W). Individuals for respiration experiments were returned via coolers to a walk-in cold-room facility at the Woods Hole Oceanographic Institution within 8 h of collection. The cold-room was set at a constant temperature of 8C for all experiments. During each experimental period, water had been collected from an offshore site concurrent to pteropod sampling and had been returned to the lab in advance for filtration (0.2-m) and thermal equilibration. It had been bubbled with ambient air, which ranged from a calculated 380 to 440 atm over the seasonal cycle, for ~12 h prior to the arrival of the pteropods. Upon arrival, pteropods were placed in 1-L beakers of water containing the filtered in situ water (15 ind L-1) for 8-12 h to allow for further temperature acclimatization and gut clearance. After this period, healthy looking individuals (actively swimming or with parapodia extended) were placed into glass respiration chambers (containing optode spots; OXFOIL: PyroScience, Aachen Germany) with 2-3 mL fresh 0.2-m filtered water. A control chamber, without a pteropod, was set up for every fourth chamber to determine background bacterial respiration. The oxygen concentration was measured non-invasively at the start of the experiment and 24 h later using a FireStingO2 optical oxygen meter (PyroScience, Aachen Germany). At the conclusion of the experiment, each organism was visually inspected to confirm survival, briefly rinsed with DI water, placed in a pre-weighed aluminum dish, and weighed on a Cahn microbalance (C-33; 1 g precision) for wet mass. They were then dried for 3-7 days in a drying oven at 60C and weighed again to obtain dry mass. Final oxygen consumption rates were calculated based on the change in oxygen between the final and initial oxygen measurements, corrected for the bacterial respiration from the control chambers (mol O2 h-1).

Sampling and analytical procedures:

Temperature in the experiments was continually monitored using the Pyrosciences temperature logger that comes with the Firesting meter and are reported for only the ~24 duration of the respiration experiments.

Carbonate chemistry parameters are calculated as the average (over the course of the whole 14 day experiment) of measured pH, DIC and TA values using CO2sys. To monitor the carbonate chemistry during the experiments, subsamples of water (50 mL) from each carboy were taken every 2–3 days and measured spectrophotometrically for pH as described in White et al. (2013). To more fully characterize the carbonate chemistry of the experimental treatments, discrete samples for analysis of dissolved inorganic carbon (DIC) and total alkalinity (TA) were also collected from the pre-equilibrated water at weekly intervals, prior to its transfer to the carboys (day 0 and 7) and from the water in each carboy right before it was replaced during water transfers (day 7 and 14). This provided both the starting and ending DIC and TA of each batch of water for the first two weeks, and the starting conditions for week 3. DIC was measured using an Apollo SciTech DIC auto-analyzer, while TA was measured using an Apollo SciTech alkalinity auto-titrator, a Ross combination pH electrode, and a pH meter (ORION 3 Star) based on a modified Gran titration method (detailed in Wang et al., 2017). pH is reported on the seawater scale (pHsw). Salinity was measured with a Hannah refractometer.

CO2sys_v2.1

Matlab processing script "transparency_code.m" was used (see Supplemental Files section for full description and download access).

There are no temperature and salinity values for 2015 in this dataset.

BCO-DMO Data Manager Processing Notes:
* Excel file exported as csv
* added a conventional header with dataset name, PI name, version date
* modified parameter names to conform with BCO-DMO naming conventions
* blank values in this dataset are displayed as "nd" for "no data." nd is the default missing data identifier in the BCO-DMO system.

This project will involve a series of five short cruises in 2013 and 2014, during which a variety of hydrographic, chemical, and biological data and samples will be collected, as well as a number of laboratory experiments examining pteropod physiology and gene expression.

From NSF proposal abstract:

Dissolution of excess anthropogenic CO2 into the ocean is causing the marine environment to decrease in pH. This "ocean acidification" is predicted to threaten a broad variety of marine organisms, particularly calcifying animals such as the thecosome (i.e., shelled) pteropods. These pelagic gastropods form an aragonite shell, are prey for a number of commercially important fish, and are significant contributors to carbon biogeochemistry. Their ecosystem importance, abundance, and sensitivity to dissolution position them as an important group for investigating the impacts of acidification. Our understanding of the effect of high CO2 on pteropods and the pelagic ecosystem, however, is limited primarily to short-term studies of adult calcification and respiration response in the polar ecosystems. There have been no seasonal studies of sensitivity and our understanding of the effect of CO2 on pteropod early life stages is limited. Limacina retroversa is a particularly abundant thecosome pteropod in the North Atlantic, where it is prey for a number of fisheries species and other top predators. This species is also the most common pteropod in the Gulf of Maine (GoM) where it is present year round. L. retroversa thus offers the prospect of a useful model pteropod species, given both its ecological importance and its abundance in readily accessible waters. The investigators will conduct a series of short cruises to sample L. retroversa on a seasonal basis from local waters of the GoM near Cape Cod. The carbonate chemistry of the GoM fluctuates seasonally, providing the opportunity to assess the response of wild caught pteropods to natural changes in CO2. By characterizing the carbonate chemistry of the water column and measuring the metabolic rate, shell quality, and gene expression of pteropods throughout the year, the researchers will achieve a time series of pteropod sensitivity to CO2. Subsequently, using experimental manipulations the investigators will explore the effect of seasonal acclimation on pteropod response to short- and medium-term exposure to enhanced CO2. Pteropods frequently lay eggs in captivity, and at WHOI there is institutional expertise in maintaining these individuals in the laboratory. Building on these strengths, the researchers will also study the effect of CO2 on embryonic and larval development in L. retroversa. These earliest life-stages of marine calcifiers are thought to be especially sensitive since initial shell precipitation and the highly energetic processes of growth and development are impeded by CO2 exposure. They will also document mortality, shell production, abnormality, and developmental rate of clutches of pteropod embryos exposed to increased CO2.

Intellectual Merit: Thecosome pteropods are an abundant group of calcifying zooplankters that have been chronically understudied, particularly in temperate regions. Due to its accessibility and ecological importance, L. retroversa can be developed as a valuable model, interesting both as the dominant pteropod in the commercially-important GoM region and also an abundant pteropod in the temperate waters of the North Atlantic. The goal of this research is to augment our knowledge of the distribution of L. retroversa, to attain an understanding of their seasonal sensitivity to natural variability in CO2, and to see how this exposure impacts responses to both short- and medium-term CO2 exposure. Using powerful transcriptomic technologies, the research will transform our understanding of this group by investigating the molecular mechanisms of response in L. retroversa to both seasonality and varying durations and intensities of acidification, contextualized by ecosystem- and organism-level metrics. Furthermore the study will examine the effect of CO2 on the eggs of pteropods for the first time, providing insight into their sensitivity to an acidifying environment.

NSF Climate Research Investment (CRI) activities that were initiated in 2010 are now included under Science, Engineering and Education for Sustainability NSF-Wide Investment (SEES). SEES is a portfolio of activities that highlights NSF's unique role in helping society address the challenge(s) of achieving sustainability. Detailed information about the SEES program is available from NSF (https://www.nsf.gov/funding/pgm_summ.jsp?pims_id=504707).

In recognition of the need for basic research concerning the nature, extent and impact of ocean acidification on oceanic environments in the past, present and future, the goal of the SEES: OA program is to understand (a) the chemistry and physical chemistry of ocean acidification; (b) how ocean acidification interacts with processes at the organismal level; and (c) how the earth system history informs our understanding of the effects of ocean acidification on the present day and future ocean.

Solicitations issued under this program:
NSF 10-530, FY 2010-FY2011
NSF 12-500, FY 2012
NSF 12-600, FY 2013
NSF 13-586, FY 2014
NSF 13-586 was the final solicitation that will be released for this program.

PI Meetings:
1st U.S. Ocean Acidification PI Meeting(March 22-24, 2011, Woods Hole, MA)
2nd U.S. Ocean Acidification PI Meeting(Sept. 18-20, 2013, Washington, DC)
3rd U.S. Ocean Acidification PI Meeting (June 9-11, 2015, Woods Hole, MA – Tentative)

NSF media releases for the Ocean Acidification Program:

Press Release 10-186 NSF Awards Grants to Study Effects of Ocean Acidification

Discovery Blue Mussels "Hang On" Along Rocky Shores: For How Long?

Discovery nsf.gov - National Science Foundation (NSF) Discoveries - Trouble in Paradise: Ocean Acidification This Way Comes - US National Science Foundation (NSF)

Press Release 12-179 nsf.gov - National Science Foundation (NSF) News - Ocean Acidification: Finding New Answers Through National Science Foundation Research Grants - US National Science Foundation (NSF)

Press Release 13-102 World Oceans Month Brings Mixed News for Oysters

Press Release 13-108 nsf.gov - National Science Foundation (NSF) News - Natural Underwater Springs Show How Coral Reefs Respond to Ocean Acidification - US National Science Foundation (NSF)

Press Release 13-148 Ocean acidification: Making new discoveries through National Science Foundation research grants

Press Release 13-148 - Video nsf.gov - News - Video - NSF Ocean Sciences Division Director David Conover answers questions about ocean acidification. - US National Science Foundation (NSF)

Press Release 14-010 nsf.gov - National Science Foundation (NSF) News - Palau's coral reefs surprisingly resistant to ocean acidification - US National Science Foundation (NSF)

Press Release 14-116 nsf.gov - National Science Foundation (NSF) News - Ocean Acidification: NSF awards $11.4 million in new grants to study effects on marine ecosystems - US National Science Foundation (NSF)