More Like this

1. Diel and tidal pCO2 × O2 fluctuations provide physiological refuge to early life stages of a coastal forage fish

   https://doi.org/10.1038/s41598-019-53930-8  

   Cross, Emma L.; Murray, Christopher S.; Baumann, Hannes (December 2019, Scientific Reports)

   null (Ed.)

   Abstract Coastal ecosystems experience substantial natural fluctuations in p CO 2 and dissolved oxygen (DO) conditions on diel, tidal, seasonal and interannual timescales. Rising carbon dioxide emissions and anthropogenic nutrient input are expected to increase these p CO 2 and DO cycles in severity and duration of acidification and hypoxia. How coastal marine organisms respond to natural p CO 2  × DO variability and future climate change remains largely unknown. Here, we assess the impact of static and cycling p CO 2  × DO conditions of various magnitudes and frequencies on early life survival and growth of an important coastal forage fish, Menidia menidia . Static low DO conditions severely decreased embryo survival, larval survival, time to 50% hatch, size at hatch and post-larval growth rates. Static elevated p CO 2 did not affect most response traits, however, a synergistic negative effect did occur on embryo survival under hypoxic conditions (3.0 mg L −1 ). Cycling p CO 2  × DO, however, reduced these negative effects of static conditions on all response traits with the magnitude of fluctuations influencing the extent of this reduction. This indicates that fluctuations in p CO 2 and DO may benefit coastal organisms by providing periodic physiological refuge from stressful conditions, which could promote species adaptability to climate change. 

   more » « less
2. You Better Repeat It: Complex CO2 × Temperature Effects in Atlantic Silverside Offspring Revealed by Serial Experimentation

   https://doi.org/10.3390/d10030069  

   Murray, Christopher; Baumann, Hannes (September 2018, Diversity)

   null (Ed.)

   Concurrent ocean warming and acidification demand experimental approaches that assess biological sensitivities to combined effects of these potential stressors. Here, we summarize five CO2 × temperature experiments on wild Atlantic silverside, Menidia menidia, offspring that were reared under factorial combinations of CO2 (nominal: 400, 2200, 4000, and 6000 µatm) and temperature (17, 20, 24, and 28 °C) to quantify the temperature-dependence of CO2 effects in early life growth and survival. Across experiments and temperature treatments, we found few significant CO2 effects on response traits. Survival effects were limited to a single experiment, where elevated CO2 exposure reduced embryo survival at 17 and 24 °C. Hatch length displayed CO2 × temperature interactions due largely to reduced hatch size at 24 °C in one experiment but increased length at 28 °C in another. We found no overall influence of CO2 on larval growth or survival to 9, 10, 15 and 13–22 days post-hatch, at 28, 24, 20, and 17 °C, respectively. Importantly, exposure to cooler (17 °C) and warmer (28 °C) than optimal rearing temperatures (24 °C) in this species did not appear to increase CO2 sensitivity. Repeated experimentation documented substantial inter- and intra-experiment variability, highlighting the need for experimental replication to more robustly constrain inherently variable responses. Taken together, these results demonstrate that the early life stages of this ecologically important forage fish appear largely tolerate to even extreme levels of CO2 across a broad thermal regime. 

   more » « less
3. Consequences of elevated CO2 exposure across multiple life stages in a coastal forage fish

   https://doi.org/10.1093/icesjms/fsw179  

   Murray, Christopher S.; Fuiman, Lee A.; Baumann, Hannes (October 2016, ICES Journal of Marine Science)

   Browman, Howard (Ed.)

   Ocean acidification may impact the fitness of marine fish, however, studies reporting neutral to moderate effects have mostly performed short-term exposures to elevated CO2, whereas longer-term studies across life stages are still scarce. We performed a CO2 exposure experiment, in which a large number (n > 2200) of Atlantic silverside Menidia menidia offspring from wild spawners were reared for 135 days through their embryonic, larval, and juvenile stages under control (500 µatm) and high CO2 conditions (2300 µatm). Although survival was high across treatments, subtle but significant differences in length, weight, condition factor and fatty acid (FA) composition were observed. On average, fish from the acidified treatment were 4% shorter and weighed 6% less, but expressed a higher condition factor than control juveniles. In addition, the metrics of length and weight distributions differed significantly, with juveniles from the high CO2 treatment occupying more extreme size classes and the length distribution shifting to a positive kurtosis. Six of twenty-seven FAs differed significantly between treatments. Our results suggest that high CO2 conditions alter long-term growth in M. menidia, particularly in the absence of excess food. It remains to be shown whether and how these differences will impact fish populations in the wild facing size-selective predation and seasonally varying prey abundance. 

   more » « less
4. Larval rockfish growth and survival in response to anomalous ocean conditions

   https://doi.org/10.1038/s41598-023-30726-5  

   Fennie, H. William; Grorud-Colvert, Kirsten; Sponaugle, Su (December 2023, Scientific Reports)

   Abstract Understanding how future ocean conditions will affect populations of marine species is integral to predicting how climate change will impact both ecosystem function and fisheries management. Fish population dynamics are driven by variable survival of the early life stages, which are highly sensitive to environmental conditions. As global warming generates extreme ocean conditions (i.e., marine heatwaves) we can gain insight into how larval fish growth and mortality will change in warmer conditions. The California Current Large Marine Ecosystem experienced anomalous ocean warming from 2014 to 2016, creating novel conditions. We examined the otolith microstructure of juveniles of the economically and ecologically important black rockfish ( Sebastes melanops ) collected from 2013 to 2019 to quantify the implications of changing ocean conditions on early growth and survival. Our results demonstrated that fish growth and development were positively related to temperature, but survival to settlement was not directly related to ocean conditions. Instead, settlement had a dome-shaped relationship with growth, suggesting an optimal growth window. Our results demonstrated that the dramatic change in water temperature caused by such extreme warm water anomalies increased black rockfish growth in the larval stage; however, without sufficient prey or with high predator abundance these extreme conditions contributed to reduced survival. 

   more » « less
5. Abalone populations are most sensitive to environmental stress effects on adult individuals

   https://doi.org/10.3354/meps13320  

   Aalto, EA; Barry, JP; Boch, CA; Litvin, SY; Micheli, F; Woodson, CB; De Leo, GA (June 2020, Marine Ecology Progress Series)

   null (Ed.)

   Marine organisms are exposed to stressors associated with climate change throughout their life cycle, but a majority of studies focus on responses in single life stages, typically early ones. Here, we examined how negative impacts from stressors associated with climate change, ocean acidification, and pollution can act across multiple life stages to influence long-term population dynamics and decrease resilience to mass mortality events. We used a continuous-size-structured density-dependent model for abalone ( Haliotis spp.), calcifying mollusks that support valuable fisheries, to explore the sensitivity of stock abundance and annual catch to potential changes in growth, survival, and fecundity across the organism’s lifespan. Our model predicts that decreased recruitment from lowered fertilization success or larval survival has small negative impacts on the population, and that stock size and fishery performance are much more sensitive to changes in parameters that affect the size or survival of adults. Sensitivity to impacts on subadults and juveniles is also important for the population, though less so than for adults. Importantly, likelihood of recovery following mortality events showed more pronounced sensitivity to most possible parameter impacts, greater than the effects on equilibrium density or catch. Our results suggest that future experiments on environmental stressors should focus on multiple life stages to capture effects on population structure and dynamics, particularly for species with size-dependent fecundity. 

   more » « less