ALBERT

Description: Many shallow coastal systems experience diel fluctuations in dissolved oxygen (DO) and pH that can intensify throughout the summer season and expose estuarine organisms to repeated episodes of coastal hypoxia and acidification. In temperate regions, larval release of the economically important blue crab Callinectes sapidus occurs in the summer, and while the earliest stage (zoea I) larvae are susceptible to persistent low DO and low pH conditions, their sensitivity to diel fluctuations is unknown. Here, a series of short-term (〈=96 h) experiments were conducted to investigate the survival of C. sapidus zoea I larvae exposed to a range of diel cycling hypoxic and acidified conditions and durations. Two experiments comparing a diel cycling DO/pH treatment (fluctuating from 30% air saturation to 103% averaging 66%/and from pH 7.26 to 7.80 averaging 7.53) to a static low DO/pH treatment (43%/7.35), a static moderate DO/pH treatment (68%/7.59), and a static control treatment (106%/7.94) indicated that survival in the diel cycling treatment was significantly lower than the moderate treatment (p 〈 0.05) by 75 and 48% over 96 and 48 h, respectively, despite comparable mean experimental DO/pH values. Three other experiments aimed at identifying the effective minimum duration of low DO/low pH to significantly depress larval survival under diel cycling conditions revealed that 8 h of low DO/low pH (28%/7.43) over a 24-h diel cycle consistently decreased survival (p 〈 0.05) relative to control conditions by at least 55% regardless of experimental duration (72-, 48-, and 24-h experiments). An increase in DO beyond saturation to supersaturation (160%) and pH beyond normocapnic to highly basified (8.34) conditions during the day phase of the diel cycle did not improve survival of larvae exposed to nocturnal hypoxia and acidification. Collectively, these experiments demonstrate that diel cycling does not provide newly hatched C. sapidus larvae a temporal refuge capable of ameliorating low DO/pH stress, but rather is more lethal than chronic exposure to comparable average DO/pH conditions. Given that larvae exposed to a single nocturnal episode of moderate hypoxia and acidification experience significantly reduced survival, such occurrences may depress larval recruitment.

Description: Coastal zones can be focal points of acidification where the influx of atmospheric CO2 can be compounded by additional sources of acidity that may collectively impair calcifying organisms. While the photosynthetic action of macrophytes may buffer against coastal ocean acidification, such activity has not been well-studied, particularly among aquacultured seaweeds. Here, we report on field and laboratory experiments performed with North Atlantic populations of juvenile hard clams (Mercenaria mercenaria), eastern oysters (Crassostrea virginica), and blue mussels (Mytilus edulis) grown with and without increased CO2 and with and without North Atlantic kelp (Saccharina latissima) over a range of aquaculture densities (0.3 – 2 g/L). In all laboratory experiments, exposure to elevated pCO2 (〉1,800 µatm) resulted in significantly reduced shell- and/or tissue-based growth rates of bivalves relative to control conditions. This impairment was fully mitigated when bivalves were exposed to the same acidification source but also co-cultured with kelp. Saturation states of aragonite were transformed from undersaturated to saturated in the acidification treatments with kelp present, while the acidification treatments remained undersaturated. In a field experiment, oysters grown near aquacultured kelp were exposed to higher pH waters and experienced significantly faster shell and tissue based growth rates compared to individuals grown at sites away from kelp. Collectively, these results suggest that photosynthesis by S. latissima grown at densities associated with aquaculture increased pH and decreased pCO2, fostering a carbonate chemistry regime that maximized the growth of juvenile bivalves. As S. latissima has been shown to benefit from increased CO2, growing bivalves and kelp together under current or future acidification scenarios may be a synergistically beneficial integrated, multi-trophic aquaculture approach.

Description: Digitalisation has transformed the way we communicate and collaborate with friends, family, and colleagues. In a similar vein, digitalisation in industry – the so-called industry 4.0 – is expected to transform the way firms and their suppliers collaborate in global supply chains. Considering that 25 percent of global emissions in 2021 were generated by industry (IEA): Can industry 4.0 play a role in greening industrial supply chains? Researchers at the Research Institute for Sustainability (RIFS) at the Helmholtz Centre Potsdam explored the opportunities and risks of digital supply chains for environmental sustainability. In short: sustainability does not simply occur as a by-product of digitalization. Firms should aim to increase sustainability levels in their supply chain – whether through digital or non-digital means.

Description: What to expect of the incoming Lula government’s environmental policy

Description: As we start off the new year and set our sights on new goals and projects, we also want to take stock of the many activities and achievements of the RIFS “Justice in Sustainability” focal topic team during 2022.

Description: The term “triple crisis” loomed large in 2022: The interlinking crises of the pandemic, the climate and energy crises, and the war in Ukraine took many people to their existential limits this past year. Geopolitically, we now face a fragmented world in which power relations are increasingly contested. This was evident at the Sharm el-Sheikh Climate Change Conference (COP 27) in November, where familiar lines of conflict shaped negotiations. Tensions between countries of the Global North and South, for example: Who bears how much responsibility for the climate change that is already occurring (not least of all financial responsibility!) and who (still) counts as a developing country and should be granted support? Debate also continues to rage around the exploitation and use of fossil fuels, which many countries wish to continue for as long as possible – even under the Paris Agreement.

Description: Let's close our eyes for a moment and travel back in time to childhood. Try to remember a time when you felt scared or devastated, the feeling of losing someone you truly love. And now, let’s imagine that these moments begin to multiply and persist. They stay in our minds for days and weeks.

Description: For years now the international community has been negotiating an agreement that will cover more than half of the Earth's surface and establish rules for the conservation and sustainable use of marine biodiversity. Will they succeed?