On 26 February 2016, H. Baumann was invited to give a seminar at the Biological & Environmental Sciences Colloquium Series at the University of Rhode Island, featuring the recently published e-lecture on “Combined effects of ocean acidification, warming, and deoxygenation on marine organisms”
His host, David Bengston has been a renowned fisheries and aquaculture biologist for the past 40 years.
For the last 6 weeks, we housed about 100 adult sand lance (Ammodytes dubius) in our lab that Chris and Jake brought from a research cruise on Stellwagen Bank (Massachusetts Bay). We watched them visibly ripen in our tanks, and today managed to strip-spawn 10 males and 10 females, obtaining several thousands of eggs and having them develop under different CO2 conditions now.
Thumbs up, and fingers crossed for the next steps!
Sand lance embryos 1h post-fertilization
Sand lance embryos 1h post-fertilization
Squeezing milt from a running ripe male sand lance
Squeezing eggs from a running ripe female sand lance
Novel experiments on wild Atlantic silversides Menidia menidia suggest that parents are capable of pre-conditioning their offspring to the naturally occurring, seasonal acidification in their spawning habitat (shape depicts the annual pattern of pH mean, minimum and maximum.)
How vulnerable are marine organisms to unfolding ocean acidification? Apart from being species- and habitat-specific, the answer may even differ between times of the year. Other than open ocean species, most coastal organisms naturally experience large seasonal pH fluctuations, to which they have adapted. Murray and co-workers monitored pH conditions in the spawning habitat of a common coastal marine fish, while sampling wild spawning adults repeatedly over the season and conducting standardized CO2 exposure experiments on their offspring. This demonstrated that offspring CO2 sensitivity is not constant, but decreases seasonally with the increasing acidification in their habitat. These findings imply that realistic assessments of species CO2 sensitivities should account for the pH/CO2 variability in the parental environment.
