On 15 March, Hannes gave a lecture at Mitchell College in New London, talking about the combined effects of ocean warming, acidification, and hypoxia on marine organisms. The entire lecture is publicly available at Limnology & Oceanography e-lectures.
“It was such a pleasure to have you present to the class today; your lecture was excellent – engaging with just the right amount and level of information. I’m glad that you intend to continue to provide outreach/education to the community on this topic.”
…it’s time to thoroughly prep our rearing system for the first real experimental season on Atlantic Silversides. Jake can be seen applying Iodine to water circling through all rearing units.
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.
Check out the awesome picture of M. beryllina embryos that Chris took today. The red dot means trouble, which really is the proverbial elephant in the room.
Elephant? See?
120 hours old embryos of Menidia beryllina. The red dot in the middle is the yolk of an unfertilized infected with a ruby-red pathogen, a gram-negative but otherwise unknown bacterium.
A suite of parallel anthropogenic changes affects contemporary marine ecosystems. Excessive carbon dioxide (CO2) pollution results in warmer, more acidic oceans with lower dissolved oxygen (DO) levels, meanwhile the emission of reactive nitrogen/phosphorus results in eutrophication, excessive microbial degradation and thus metabolic hypoxia and acidification. Despite decades of empirical research how each individual stressor of the ‘climate-change syndrome’ (i.e., temperature, CO2, DO) affects the fitness of marine organisms, we still know little about the combined effects of these stressors. This lecture gives an overview over the nascent field of multi-stressor approaches evaluating the climate sensitivity of marine organisms across taxa. In most studied cases, combined effects of these stressors exceeded those observed individually. Effects of combined warming, acidification, and deoxygenation have mostly been additive (no stressor interaction) or synergistically negative (stressor interaction). The occurrence and strength of synergistic stressor interactions in some species, life history stages, and traits comprises a vexing challenge but hints at potentially greater sensitivities of organisms to marine climate change than previously recognized. This lecture is intended for post-secondary students, providing them with illustrated examples from the most resent literature, while aiding in communicating the urgent need for empirical data from multi-stressor approaches.
…in the true sense has kept biologist’s head scratching for quite some time, and matters have only gotten more complex since the thunderous advent of genetic methods. Yet the distinction between a species and – say – an ecotype of a species is more than just academic quibble.
In the case of the key silverside, Menidia conchorum, a species that is only found in the hypersaline ponds on the Florida Keys, it’s quite literally an existential question. So far, the protocols and steps of protection apply only in cases of threatened species, which is perhaps something that ought to change.
O’Leary et al. went down to the Florida Keys and sampled the silversides in order to compare them morphologically and genetically to the ‘parent’ species, the tidewater silverside Menidia peninsulae. Their findings show that key silversides are distinct, but not quite their own species yet. In addition, the study revealed the large amount of inbreeding and genetic drift that is happening in each of these small hypersaline ponds.
The paper concludes that although ‘only’ an ecotype, the key silverside is threatened by loss of habitat and therefore still needs our protection!
Depiction of morphometric landmarks (upper left) and distinguishing shapes (lower left) between tidewater and key silverside (M. peninsula & M. conchorum). Key silversides are an ecotype that can only be found in hypersaline ponds on the Florida Keys (right: lead and co-authors seining).
Roughly once a month, somebody from our lab has to hop on a small institute boat and drive the 20 min over to our local field site, Mumford Cove, to exchange the sensors on our monitoring buoy. Depending on water temperature, the Eureka Probes recording temperature, salinity, pH, and oxygen in 30 min intervals are getting exchanged with another newly calibrated one with a fresh set of batteries.
As usual, Jake’s seeing this a great occasion to bring his GoPro along and have a new underwater look at the cove. What’s interesting, the dense seagrass meadows that cover the Cove’s bottom have become spotty this time of the year, and there’s much more sand visible.
We are happy to announce the continued support of the National Science Foundation, Division of Biological Oceanography, which just started to fund our project about multi-stressor effects on the early life stages of fish. This is collaborative work with Prof. Janet Nye’s lab at Stony Brook University, NY, which will strengthen ties between UConn and Stony Brook Marine Sciences. The work has already started and we’re looking forward to new discoveries!
Baumann, H. and Nye, J. 2015. Collaborative research: Understanding the effects of acidification and hypoxia within and across generations in a coastal marine fish. NSF Project# 1536336 (3 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
Chris Murray checking for sand lance caught by the sediment grab. RV Auk (Photo credit: Jacob Snyder)
By Jacob Snyder:
Chris and I meet up, grab the supplies we need (buckets, bags, coolers, aerators, etcetera), and start making our way to Scituate, Mass. Today we are going out on the NOAA vessel “Auk,” with a few members from NOAA and the USGS. Our goal? To collect approx. 200 Northern Sand Lance, Ammodytes dubius.
We boarded the ship …
Read the whole post and see all the pictures on Jake’s blog @Red Skies Photography
Check out the footage from the day, thanks to Jake and his GoPro. Check-out the video from the second sampling trip about one month later, too!
