Month: November 2018

[Publication] Meta-analysis of silverside CO2 experiments published!

28 November 2018. Hannes, Emma, and Chris are happy to announce that Biology Letters just published our latest study, a meta-analysis of 20 standard CO2 exposure experiments conducted on Atlantic silverside offspring between 2012-2017. All these years of sustained experimental work resulted in the most robustly constrained estimates of overall CO2 effect sizes for a marine organism to date.
The study demonstrated:

  • A general tolerance of Atlantic silverside early life stages to pCO2 levels of ~2,000 µatm
  • A significant overall CO2 induced reduction of embryo and overall survival by -9% and -13%, respectively
  • The seasonal change in early life CO2 sensitivity in this species
  • The value of serial experimentation to detect and robustly estimate CO2 effects in marine organisms

Baumann, H., Cross, E.L., and Murray, C.S. Robust quantification of fish early life CO2 sensitivities via serial experimentation. Biology Letters 14:20180408

This figure shows the summary of early life responses to high CO2 conditions in Atlantic silversides across all experiments conducted between 2012-2017. Effect size was estimated using the log-transformed response ratio (A-D). Error bars are 95% confidence intervals. The responses are considered significant if the confidence interval does not include zero. Panels E-F: seasonal decomposition of response ratios, showing that silverside early life stages are most sensitive to high CO2 at the beginning and end of their spawning season.

[Research news] Sandlance are spawning on Stellwagen Bank again!

15 November 2018. After a stretch of foul weather kept us from going out to Stellwagen Bank last week, this time all the stars aligned for Emma and Mackenzie. Due to their success in catching spawning ripe Northern sandlance, we are now embarking on our third year of CO2 x temperature experiments on this species!

Here is how Mackenzie Blanusa experienced her first trip to these enigmatic waters:
“This particular sandlance cruise was a day filled with firsts and is definitely a trip to remember. I accompanied Emma, Hannes’ postdoc, up to Scituate the night before the cruise and was given a rundown of what needed to be accomplished. I was a bit overwhelmed at first, because I’ve never dealt with sandlances before and did not know a lot about these fish. Nevertheless, I was eager to learn something new and was ready to help out wherever needed.

The goal of the sandlance cruise was to collect running ripe males and females to do a fertilization via strip spawning. Emma and I were a bit doubtful at first because we got less than 10 sandlance on the first two trolls. However, things got much better by the afternoon, and our most successful trawl caught 147 sand lance. I helped out with the fertilization and deploying the trawl, two things I have never done before. The most exciting part of the day was getting to see humpback whales. Usually they are in the distance but today they were right next to the boat. Everyone on board said that this never happens and it was very unusual so I felt very lucky to have seen whales at such a close proximity.”

Overall, the trip was a huge success and it was very refreshing to see everything go as planned. The only downside to the day was driving back home through a snowstorm. I later found out that there was a 73% fertilization success and we got 27,000 embryos for Emma’s experiment. I am very grateful to have gotten the opportunity to help out on this sampling cruise and am looking forward to doing this again in the future!

Emma on the makeshift spawning station for sand lance on board the RV Auk
Mackenzie strip-spawning sand lance on the ship

Stellwagen whales
Added perks of doing research on Stellwagen Bank …

Exactly 0.5ml of sand lance eggs (~ 600) were distributed into each replicate per treatment
Emma and Julie pipetting sand lance eggs