Climate Change, Ocean Acidification, and Ocean Warming

Changes in Sea-Ice Protist Diversity With Declining Sea Ice in the Arctic Ocean From the 1980s to 2010s

Hop H, Vihtakari M, Bluhm BA, Assmy P, Poulin M, Gradinger R, Peeken I, von Quillfeldt C, Olsen LMork, Zhitina L, et al. Changes in Sea-Ice Protist Diversity With Declining Sea Ice in the Arctic Ocean From the 1980s to 2010s. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00243/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1334659_45_Marine_20200521_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The large declines in Arctic sea-ice age and extent over the last decades could have altered the diversity of sea-ice associated unicellular eukaryotes (referred to as sea-ice protists). A time series from the Russian ice-drift stations from the 1980s to the 2010s revealed changes in community composition and diversity of sea-ice protists from the Central Arctic Ocean. However, these observations have been biased by varying levels of taxonomic resolution and sampling effort, both of which were higher in the early years at drift stations on multiyear sea ice (MYI) in the Central Arctic Ocean. We here combine the Russian ice-drift station data with more recent data to (1) identify common sea-ice protists (in particular diatoms) in drifting sea ice of the Central Arctic Ocean; (2) characterize the potential change in such communities over 35 years in terms of species number and/or community structure; and (3) relate those shifts to relevant environmental factors. In terms of relative abundance, pennate diatoms were the most abundant sea-ice protists across the Arctic, contributing 60% on average of counted cells. Two pennate colony-forming diatom species, Nitzschia frigida and Fragilariopsis cylindrus, dominated at all times, but solitary diatom species were also frequently encountered, e.g., Cylindrotheca closterium and Navicula directa. Multiyear sea ice contained 39% more diatom species than first-year ice (FYI) and showed a relatively even distribution along entire sea-ice cores. The decrease in MYI over the last decades explained the previously reported decreases in sea-ice protist diversity. Our results also indicate that up to 75% of diatom species are incorporated into FYI from the surrounding sea ice and the water column within a few months after the initial formation of the ice, while the remaining 25% are incorporated during ice drift. Thus, changing freeze-up scenarios, as currently witnessed in the Central Arctic, might result in long-term changes of the biodiversity of sea-ice protists in this region.

European policies and legislation targeting ocean acidification in european waters - Current state

Galdies C, Bellerby R, Canu D, Chen W, Garcia-Luque E, Gašparović B, Godrijan J, Lawlor PJ, Maes F, Malej A, et al. European policies and legislation targeting ocean acidification in european waters - Current state. Marine Policy [Internet]. 2020 ;118:103947. Available from: https://www.sciencedirect.com/science/article/pii/S0308597X19309054
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Ocean acidification (OA) is a global problem with profoundly negative environmental, social and economic consequences. From a governance perspective, there is a need to ensure a coordinated effort to directly address it. This study reviews 90 legislative documents from 17 countries from the European Economic Area (EEA) and the UK that primarily border the sea. The primary finding from this study is that the European national policies and legislation addressing OA is at best uncoordinated. Although OA is acknowledged at the higher levels of governance, its status as an environmental challenge is greatly diluted at the European Union Member State level. As a notable exception within the EEA, Norway seems to have a proactive approach towards legislative frameworks and research aimed towards further understanding OA. On the other hand, there was a complete lack of, or inadequate reporting in the Marine Strategy Framework Directive by the majority of the EU Member States, with the exception of Italy and the Netherlands. We argue that the problems associated with OA and the solutions needed to address it are unique and cannot be bundled together with traditional climate change responses and measures. Therefore, European OA-related policy and legislation must reflect this and tailor their actions to mitigate OA to safeguard marine ecosystems and societies. A stronger and more coordinated approach is needed to build environmental, economic and social resilience of the observed and anticipated changes to the coastal marine systems.

Projected Economic Impact of Climate Change on Marine Capture Fisheries in the Philippines

Suh D, Pomeroy R. Projected Economic Impact of Climate Change on Marine Capture Fisheries in the Philippines. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00232/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1320398_45_Marine_20200505_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Climate change and its impact on fisheries is a key issue for fishing nations, particularly the Philippines. The Philippines is highly vulnerable to the impacts of climate change on fisheries and it can lead to economic shock on the nation's economy. This paper examines the impact of climate change on marine capture fisheries in the Philippines using a computable general equilibrium (CGE) model to elaborate and project impacts on the national economy. In the simulation, one baseline scenario and two climate change scenarios based on greenhouse gas concentration—RCP 2.6 and RCP 8.5—were considered. The model focuses on Gross Domestic Product (GDP) and income distribution by region, which can represent economic conditions in terms of economic growth and distribution. Results show that there will be a negative change on both the fisheries and economic variables where more extreme changes in climate occur.

Detect coastal disturbances and climate change effects in coralligenous community through sentinel stations

García-Gómez JC, González AR, Maestre MJ, Espinosa F. Detect coastal disturbances and climate change effects in coralligenous community through sentinel stations Bianchi CNike. PLOS ONE [Internet]. 2020 ;15(5):e0231641. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0231641
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

This study was implemented to assess the Sessile Bioindicators in Permanent Quadrats (SBPQ) underwater environmental alert method. The SBPQ is a non-invasive and low-cost protocol; it uses sessile target species (indicators) to detect environmental alterations (natural or anthropic) at either the local or global (i.e., climate change) scale and the intrusion of invasive species. The SBPQ focuses on the monitoring of preselected sessile and sensitive benthic species associated with rocky coralligenous habitats using permanent quadrats in underwater sentinel stations. The selected target species have been well documented as bioindicators that disappear in the absence of environmental stability. However, whether these species are good indicators of stability or, in contrast, suffer variations in long-term coverage has not been verified. The purpose of this study was to assess the part of the method based on the hypothesis that, over a long temporal series in a highly structured and biodiverse coralligenous assemblage, the cover of sensitive sessile species does not change over time if the environmental stability characterising the habitat is not altered. Over a ten-year period (2005–2014), the sublittoral sessile biota in the Straits of Gibraltar Natural Park on the southern Iberian Peninsula was monitored at a 28 m-deep underwater sentinel stations. Analyses of the coverages of target indicator species (i.e., Paramuricea clavata and Astroides calycularis) together with other accompanying sessile organisms based on the periodic superimposition of gridded images from horizontal and vertical rocky surfaces allowed us to assess the effectiveness of the method. We conclude that no alterations occurred during the study period; only minimal fluctuations in cover were detected, and the method is reliable for detecting biological changes in ecosystems found in other geographical areas containing the chosen indicator species at similar dominance levels.

European policies and legislation targeting ocean acidification in european waters - Current state

Galdies C, Bellerby R, Canu D, Chen W, Garcia-Luque E, Gašparović B, Godrijan J, Lawlor PJ, Maes F, Malej A, et al. European policies and legislation targeting ocean acidification in european waters - Current state. Marine Policy [Internet]. 2020 ;118:103947. Available from: https://www.sciencedirect.com/science/article/pii/S0308597X19309054
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Ocean acidification (OA) is a global problem with profoundly negative environmental, social and economic consequences. From a governance perspective, there is a need to ensure a coordinated effort to directly address it. This study reviews 90 legislative documents from 17 countries from the European Economic Area (EEA) and the UK that primarily border the sea. The primary finding from this study is that the European national policies and legislation addressing OA is at best uncoordinated. Although OA is acknowledged at the higher levels of governance, its status as an environmental challenge is greatly diluted at the European Union Member State level. As a notable exception within the EEA, Norway seems to have a proactive approach towards legislative frameworks and research aimed towards further understanding OA. On the other hand, there was a complete lack of, or inadequate reporting in the Marine Strategy Framework Directive by the majority of the EU Member States, with the exception of Italy and the Netherlands. We argue that the problems associated with OA and the solutions needed to address it are unique and cannot be bundled together with traditional climate change responses and measures. Therefore, European OA-related policy and legislation must reflect this and tailor their actions to mitigate OA to safeguard marine ecosystems and societies. A stronger and more coordinated approach is needed to build environmental, economic and social resilience of the observed and anticipated changes to the coastal marine systems.

Can prior exposure to stress enhance resilience to ocean warming in two oyster species?

Pereira RRC, Scanes E, Gibbs M, Byrne M, Ross PM. Can prior exposure to stress enhance resilience to ocean warming in two oyster species? Vengatesen T. PLOS ONE [Internet]. 2020 ;15(4):e0228527. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0228527
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Securing economically and ecologically significant molluscs, as our oceans warm due to climate change, is a global priority. South eastern Australia receives warm water in a strengthening East Australia Current and so resident species are vulnerable to elevated temperature and marine heat waves. This study tested whether prior exposure to elevated temperature can enhance resilience of oysters to ocean warming. Two Australian species, the flat oyster, Ostrea angasi, and the Sydney rock oyster, Saccostrea glomerata, were obtained as adults and “heat shocked” by exposure to a dose of warm water in the laboratory. Oysters were then transferred to elevated seawater temperature conditions where the thermal outfall from power generation was used as a proxy to investigate the impacts of ocean warming. Shell growth, condition index, lipid content and survival of flat oysters and condition of Sydney rock oysters were all significantly reduced by elevated seawater temperature in the field. Flat oysters grew faster than Sydney rock oysters at ambient temperature, but their growth and survival was more sensitive to elevated temperature. “Stress inoculation” by heat shock did little to ameliorate the negative effects of increased temperature, although the survival of heat-shocked flat oysters was greater than non-heat shocked oysters. Further investigations are required to determine if early exposure to heat stress can enhance resilience of oysters to ocean warming.

Marine heatwaves exacerbate climate change impacts for fisheries in the northeast Pacific

Cheung WWL, Frölicher TL. Marine heatwaves exacerbate climate change impacts for fisheries in the northeast Pacific. Scientific Reports [Internet]. 2020 ;10(1). Available from: https://www.nature.com/articles/s41598-020-63650-z
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Marine heatwaves (MHWs) have occurred in all ocean basins with severe negative impacts on coastal and ocean ecosystems. The northeast Pacific 2013–2015 MHW in particular received major societal concerns. Yet, our knowledge about how MHWs impact fish stocks is limited. Here, we combine outputs from a large ensemble simulation of an Earth system model with a fish impact model to simulate responses of major northeast Pacific fish stocks to MHWs. We show that MHWs cause biomass decrease and shifts in biogeography of fish stocks that are at least four times faster and bigger in magnitude than the effects of decadal-scale mean changes throughout the 21st century. With MHWs, we project a doubling of impact levels by 2050 amongst the most important fisheries species over previous assessments that focus only on long-term climate change. Our results underscore the additional challenges from MHWs for fisheries and their management under climate change.

Ocean warming and acidification may drag down the commercial Arctic cod fishery by 2100

Hänsel MC, Schmidt JO, Stiasny MH, Stöven MT, Voss R, Quaas MF. Ocean warming and acidification may drag down the commercial Arctic cod fishery by 2100 Tsikliras AC. PLOS ONE [Internet]. 2020 ;15(4):e0231589. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0231589
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The Arctic Ocean is an early warning system for indicators and effects of climate change. We use a novel combination of experimental and time-series data on effects of ocean warming and acidification on the commercially important Northeast Arctic cod (Gadus morhua) to incorporate these physiological processes into the recruitment model of the fish population. By running an ecological-economic optimization model, we investigate how the interaction of ocean warming, acidification and fishing pressure affects the sustainability of the fishery in terms of ecological, economic, social and consumer-related indicators, ranging from present day conditions up to future climate change scenarios. We find that near-term climate change will benefit the fishery, but under likely future warming and acidification this large fishery is at risk of collapse by the end of the century, even with the best adaptation effort in terms of reduced fishing pressure.

Heat Waves Are a Major Threat to Turbid Coral Reefs in Brazil

Duarte GAS, Villela HDM, Deocleciano M, Silva D, Barno A, Cardoso PM, Vilela CLS, Rosado P, Messias CSMA, Chacon MAlejandra, et al. Heat Waves Are a Major Threat to Turbid Coral Reefs in Brazil. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00179/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1302118_45_Marine_20200416_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Coral reefs are threatened by climate change on a global scale with thermal stress events and mass coral bleaching being widely reported. The reefs off the east coast of Brazil (and other turbid areas) have, however, historically escaped such thermal stress events, with relatively low levels of background coral mortality (5–10%). This has recently changed. Here we show that, in 2019, degree heating weeks (DHW) of 19.65 coincided with catastrophic declines in coral cover, especially in the major reef building hydrocoral Millepora alcicornis. The decline was due to bleaching associated with exposure to high temperature stress culminating in DHW values exceeding 15 for a period of 50 days. At two independent sites, surveys showed upwards of 83.5 ± 9.0 and 89.1 ± 3.9% mortality, and a third site showed relatively lower (albeit still high) mortality rates of 43.3 ± 12.0%. The mass die-off in 2019 is unprecedented in the South Atlantic reefs and coincides with increased heating events.

Assessing Perception of Climate Change by Representatives of Public Authorities and Designing Coastal Climate Services: Lessons Learnt From French Polynesia

Terorotua H, Duvat VKE, Maspataud A, Ouriqua J. Assessing Perception of Climate Change by Representatives of Public Authorities and Designing Coastal Climate Services: Lessons Learnt From French Polynesia. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00160/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1286267_45_Marine_20200331_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

 Institutional actors have a crucial role in adaptation to climate change, especially for highly vulnerable territories such as small tropical islands. Here, we emphasize their major role in the co-design of tailored coastal climate services (CCS) based on a case study of French Polynesia. In this perspective, we assessed climate change perceptions by public authorities and identified their needs with regard to climate-related science. This assessment included an analysis of the decision-making context, semi-structured interviews with practitioners representing 23 administrative divisions directly or indirectly involved in climate change issues, and a workshop dedicated to discussing needs in terms of CCS. Generally, respondents did not identify climate change as a major current issue in French Polynesia; they showed more concern for economic growth, pollution, land tenure, and land use planning. However, interviewees were concerned about future impacts of sea-level rise (SLR) and ocean warming and acidification, mentioning in particular their detrimental impacts on marine ecosystems, shoreline position, economy (especially agriculture and the blue economy), and freshwater resources. The interviewed practitioners showed particular interest in SLR projections for future decades up to a century, and for knowledge on expected impacts to critical infrastructure, coastal systems, and natural resources. Practitioners’ needs made it possible to co-define four CCS to be developed: (1) the design of sea-level-rise-compatible critical infrastructures (airports and ports); (2) adapting to the risk of destabilization of beaches and reef islands; (3) professional training on climate change impacts and adaptation, including an analysis of potentially emerging new jobs in the SLR context; and (4) the development of participatory approaches for observing climate change impacts. While the co-development of these CCS will require a multi-year engagement of stakeholders concerned with climate change adaptation, our results already shed light on specific needs for salient CCS in highly vulnerable tropical island territories.

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