[Campus Talk] H. Baumann talks at Avery Point Global Cafe

“Nets versus Nature: Have we indadvertedly made our fish smaller?”

Avery Point Global Cafe

April 9th 2015. H. Baumann contributed to Avery Point’s Global Cafe Series “The Omnivore at Sea” by talking about the topic of fisheries-induced evolution.
When hearing and talking about sustainable seafood, issues such as overfishing, fishing-related habitat destruction (e.g., trawls tearing through bottom habitat, dynamite fishing) or changes to the architecture of marine ecosystems (‘fishing down the foodweb’) often come to mind. Baumann talked about another potential effect of heavy decade-long commercial fishing, which is less clear but perhaps even more insidious. Nature’s age-old rule of survival in the ocean, i.e., that faster growing fish have better chances of survival, is suddenly reversed when size-selective fishing becomes the dominant agent of mortality. Because in fishing, a faster growing fish will just be susceptible sooner to get caught by the meshes of a fishing trawl. We instinctively know that life on earth has adjusted before to changing selection pressures, and there’s little reason to suspect that this case might be different. Commercial fishing may trigger fisheries-induced evolution, and this may mean smaller, earlier maturing fish and less total biomass for centuries to come. The brief talk will summarize the problem as we know it, explore alternative explanations and look at examples, which show that the issue is also inextricably linked to all the other natural and man-made changes (warming, food web) that affect fish stocks. A cautionary approach that considers evolutionary processes within the framework of sustainable fisheries is surely warranted.

[Talk] 5th International Otolith Symposium

Combining otolith microstructure + microchemistry: What can we learn about juvenile Pacific Bluefin Tuna migration?

Baumann et al. Otolith Symposium
H.Baumann presented findings about juvenile tuna otolith microstructure & -chemistry
From 19 – 24 October 2014, H. Baumann participated in the 5th International Otolith Symposium (Mallorca, Spain), a focused gathering of researchers worldwide analyzing calcified structures of fishes (otoliths = ear bones, scales, spines fin rays), mollusks and corals to infer age in days or years, isotopic or trace elemental composition, or to review the quality control measures in place in various production aging labs.
Dr. Baumann presented a study that combined daily ring analyses (=microstructure) in juvenile tuna otoliths with trace elemental analysis, showing that the otoliths likely record the entry of these fish into the California Current Ecosystem after their transpacific migration as juveniles.

[Talk] “Restore America’s Estuaries” Conference

“Combined effects of low pH and low O2 on coastal organisms”

Baumann et al. talked about combined effects of acidification and hypoxia on coastal marine organisms
Baumann et al. talked about combined effects of acidification and hypoxia on coastal marine organisms
H.Baumann was invited to be one of four panel speakers during a session called “Acidifying our Estuaries – Global Problems, local effects” chaired by Dr. Denise Breitburg (SERC) during the “7th National Summit on Coastal and Estuarine Restoration” in Washington D.C. (1-5 November 2014, Gaylord Hotel & Convention Center). The talk covered recent results from work on early larval silversides and bivalves, showing that the combined negative effects of acidification and hypoxia need to be better understood and can at times be greater than additive (i.e., synergistic).In biology, sometimes 1 + 1 is greater than 2.