Description: Highlights: • Effects of microplastic on marine biota reflect the quality of experimental research. • The quality of published experiments can be quantified from an “ideal” experiment. • Previously published experiments have significantly deviated from “ideal”. • Implementation of proposed criteria can improve future microplastic experiments. Abstract: This article presents a novel conceptual blueprint for an ‘ideal’, i.e., ecologically relevant, microplastic effect study. The blueprint considers how microplastics should be characterized and applied in laboratory experiments, and how biological responses should be measured to assure unbiased data that reliably reflect the effects of microplastics on aquatic biota. This ‘ideal’ experiment, although practically unachievable, serves as a backdrop to improve specific aspects of experimental research on microplastic effects. In addition, a systematic and quantitative literature review identified and quantified departures of published experiments from the proposed ‘ideal’ design. These departures are related mainly to the experimental design of microplastic effect studies failing to mimic natural environments, and experiments with limited potential to be scaled-up to ecosystem level. To produce a valid and generalizable assessment of the effect of microplastics on biota, a quantitative meta-analysis was performed that incorporated the departure of studies from the ‘ideal’ experiment (a measure of experimental quality) and inverse variance (a measure of the study precision) as weighting coefficients. Greater weights were assigned to experiments with higher quality and/or with lower variance in the response variables. This double-weighting captures jointly the technical quality, ecological relevance and precision of estimates provided in each study. The blueprint and associated meta-analysis provide an improved baseline for the design of ecologically relevant and technically sound experiments to understand the effects of microplastics on single species, populations and, ultimately, entire ecosystems.

Description: Research so far has provided little evidence that benthic biogeochemical cycling is affected by ocean acidification under realistic climate change scenarios. We measured nutrient exchange and sediment community oxygen consumption (SCOC) rates to estimate nitrification in natural coastal permeable and fine sandy sediments under pre-phytoplankton bloom and bloom conditions. Ocean acidification, as mimicked in the laboratory by a realistic pH decrease of 0.3, significantly reduced SCOC on average by 60% and benthic nitrification rates on average by 94% in both sediment types in February (pre-bloom period), but not in April (bloom period). No changes in macrofauna functional community (density, structural and functional diversity) were observed between ambient and acidified conditions, suggesting that changes in benthic biogeochemical cycling were predominantly mediated by changes in the activity of the microbial community during the short-term incubations (14 days), rather than by changes in engineering effects of bioturbating and bio-irrigating macrofauna. As benthic nitrification makes up the gross of ocean nitrification, a slowdown of this nitrogen cycling pathway in both permeable and fine sediments in winter, could therefore have global impacts on coupled nitrification-denitrification and hence eventually on pelagic nutrient availability.

Description: Ocean warming and acidification affect species populations, but how interactions within communities are affected and how this translates into ecosystem functioning and resilience remain poorly understood. Here we demonstrate that experimental ocean warming and acidification significantly alters the interaction network among porewater nutrients, primary producers, herbivores and burrowing invertebrates in a seafloor sediment community, and is linked to behavioural plasticity in the clam Scrobicularia plana. Warming and acidification induced a shift in the clam's feeding mode from predominantly suspension feeding under ambient conditions to deposit feeding with cascading effects on nutrient supply to primary producers. Surface-dwelling invertebrates were more tolerant to warming and acidification in the presence of S. plana, most probably due to the stimulatory effect of the clam on their microalgal food resources. This study demonstrates that predictions of population resilience to climate change require consideration of non-lethal effects such as behavioural changes of key species.

Description: The combined effect of ocean acidification and warming on the common cockle Cerastoderma edule was investigated in a fully crossed laboratory experiment. Survival of the examined adult organisms remained high and was not affected by elevated temperature (+3 °C) or lowered pH (-0.3 units). However, the morphometric condition index of the cockles incubated under high pCO2 conditions (i.e. combined warming and acidification) was significantly reduced after six weeks of incubation. Respiration rates increased significantly under low pH, with highest rates measured under combined warm and low pH conditions. Calcification decreased significantly under low pH while clearance rates increased significantly under warm conditions and were generally lower in low pH treatments. The observed physiological responses suggest that the reduced food intake under hypercapnia is insufficient to support the higher energy requirements to compensate for the higher costs for basal maintenance and growth in future high pCO2waters.

Description: In the effort towards a decarbonised future, the local effects of a proliferating offshore wind farm (OWF) industry add to and interact with the global effects of marine climate change. This study aimed to quantify potential ecophysiological effects of ocean warming and acidification and to estimate and compare the cumulative clearance potential of suspended food items by OWF epifauna under current and future climate conditions. To this end, this study combined ecophysiological responses to ocean warming and acidification of three dominant colonising species on OWF artificial hard substrates (the blue mussel Mytilus edulis, the tube-building amphipod Jassa herdmani and the plumose anemone Metridium senile). In general, mortality, respiration rate and clearance rate increased during 3- to 6-week experimental exposures across all three species, except for M. senile, who exhibited a lower clearance rate in the warmed treatments (+3 °C) and an insensitivity to lowered pH (−0.3 pH units) in terms of survival and respiration rate. Ocean warming and acidification affected growth antagonistically, with elevated temperature being beneficial for M. edulis and lowered pH being beneficial for M. senile. The seawater volume potentially cleared from suspended food particles by this AHS colonising community increased significantly, extending the affected distance around an OWF foundation by 9.2% in a future climate scenario. By using an experimental multi-stressor approach, this study thus demonstrates how ecophysiology underpins functional responses to climate change in these environments, highlighting for the first time the integrated, cascading potential effects of OWFs and climate change on the marine ecosystem.

Description: This study investigated the effects of experimentally manipulated seawater carbonate chemistry on several early life history processes of the Baltic tellin (Macoma balthica), a widely distributed bivalve that plays a critical role in the functioning of many coastal habitats. We demonstrate that ocean acidification significantly depresses fertilization, embryogenesis, larval development and survival during the pelagic phase. Fertilization and the formation of a D-shaped shell during embryogenesis were severely diminished: successful fertilization was reduced by 11% at a 0.6 pH unit decrease from present (pH 8.1) conditions, while hatching success was depressed by 34 and 87%, respectively at a 0.3 and 0.6 pH unit decrease. Under acidified conditions, larvae were still able to develop a shell during the post-embryonic phase, but higher larval mortality rates indicate that fewer larvae may metamorphose and settle in an acidified ocean. The cumulative impact of decreasing seawater pH on fertilization, embryogenesis and survival to the benthic stage is estimated to reduce the number of competent settlers by 38% for a 0.3 pH unit decrease, and by 89% for a 0.6 pH unit decrease from present conditions. Additionally, slower growth rates and a delayed metamorphosis at a smaller size were indicative for larvae developed under acidified conditions. This may further decline the recruit population size due to a longer subjection to perturbations, such as predation, during the pelagic phase. In general, early life history processes were most severely compromised at ~pH 7.5, which corresponds to seawater undersaturated with respect to aragonite. Since recent models predict a comparable decrease in pH in coastal waters in the near future, this study indicates that future populations of Macoma balthica are likely to decline as a consequence of ongoing ocean acidification.

Description: Anthropogenic CO2 emissions are rapidly changing seawater temperature, pH and carbonate chemistry. This study compares the embryonic development under high pCO2conditions across the south-north distribution range of the marine clam Limecola balthicain NW Europe. The combined effects of elevated temperature and reduced pH on hatching success and size varied strongly between the three studied populations, with the Gulf of Finland population appearing most endangered under the conditions predicted to occur by 2100. These results demonstrate that the assessment of marine faunal population persistence to future climatic conditions needs to consider the interactive effects of co-occurring physico-chemical alterations in seawater within the local context that determines population fitness, adaptation potential and the system resilience to environmental change.

Description: There is growing evidence that climate change could affectmarine benthic systems. This review provides information of climate change-related impacts on the marine benthos in the North Atlantic. We cover a number of related research aspects, mainly in connection to two key issues. First, is the relationship between different physical aspects of climate change and the marine benthos. This section covers: (a) the responses to changes in seawater temperature (biogeographic shifts and phenology); (b) altered Hydrodynamics; (c) ocean acidification (OA); and (d) sea-level rise-coastal squeeze. The second major issue addressed is the possible integrated impact of climate change on the benthos. This work is based on relationships between proxies for climate variability, notably the North Atlantic Oscillation (NAO) index, and the long-term marine benthos. The final section of our review provides a series of conclusions and future directions to support climate change research on marine benthic systems.

Description: © The Author(s), 2018]. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Global Ecology and Biogeography 27 (2018): 760-786, doi:10.1111/geb.12729.

Description: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community‐led open‐source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2). BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.

Description: European Research Council and EU, Grant/Award Number: AdG‐250189, PoC‐727440 and ERC‐SyG‐2013‐610028; Natural Environmental Research Council, Grant/Award Number: NE/L002531/1; National Science Foundation, Grant/Award Number: DEB‐1237733, DEB‐1456729, 9714103, 0632263, 0856516, 1432277, DEB‐9705814, BSR‐8811902, DEB 9411973, DEB 0080538, DEB 0218039, DEB 0620910, DEB 0963447, DEB‐1546686, DEB‐129764, OCE 95‐21184, OCE‐ 0099226, OCE 03‐52343, OCE‐0623874, OCE‐1031061, OCE‐1336206 and DEB‐1354563; National Science Foundation (LTER) , Grant/Award Number: DEB‐1235828, DEB‐1440297, DBI‐0620409, DEB‐9910514, DEB‐1237517, OCE‐0417412, OCE‐1026851, OCE‐1236905, OCE‐1637396, DEB 1440409, DEB‐0832652, DEB‐0936498, DEB‐0620652, DEB‐1234162 and DEB‐0823293; Fundação para a Ciência e Tecnologia, Grant/Award Number: POPH/FSE SFRH/BD/90469/2012, SFRH/BD/84030/2012, PTDC/BIA‐BIC/111184/2009; SFRH/BD/80488/2011 and PD/BD/52597/2014; Ciência sem Fronteiras/CAPES, Grant/Award Number: 1091/13‐1; Instituto Milenio de Oceanografía, Grant/Award Number: IC120019; ARC Centre of Excellence, Grant/Award Number: CE0561432; NSERC Canada; CONICYT/FONDECYT, Grant/Award Number: 1160026, ICM PO5‐002, CONICYT/FONDECYT, 11110351, 1151094, 1070808 and 1130511; RSF, Grant/Award Number: 14‐50‐00029; Gordon and Betty Moore Foundation, Grant/Award Number: GBMF4563; Catalan Government; Marie Curie Individual Fellowship, Grant/Award Number: QLK5‐CT2002‐51518 and MERG‐CT‐2004‐022065; CNPq, Grant/Award Number: 306170/2015‐9, 475434/2010‐2, 403809/2012‐6 and 561897/2010; FAPESP (São Paulo Research Foundation), Grant/Award Number: 2015/10714‐6, 2015/06743‐0, 2008/10049‐9, 2013/50714‐0 and 1999/09635‐0 e 2013/50718‐5; EU CLIMOOR, Grant/Award Number: ENV4‐CT97‐0694; VULCAN, Grant/Award Number: EVK2‐CT‐2000‐00094; Spanish, Grant/Award Number: REN2000‐0278/CCI, REN2001‐003/GLO and CGL2016‐79835‐P; Catalan, Grant/Award Number: AGAUR SGR‐2014‐453 and SGR‐2017‐1005; DFG, Grant/Award Number: 120/10‐2; Polar Continental Shelf Program; CENPES – PETROBRAS; FAPERJ, Grant/Award Number: E‐26/110.114/2013; German Academic Exchange Service; sDiv; iDiv; New Zealand Department of Conservation; Wellcome Trust, Grant/Award Number: 105621/Z/14/Z; Smithsonian Atherton Seidell Fund; Botanic Gardens and Parks Authority; Research Council of Norway; Conselleria de Innovació, Hisenda i Economia; Yukon Government Herschel Island‐Qikiqtaruk Territorial Park; UK Natural Environment Research Council ShrubTundra Grant, Grant/Award Number: NE/M016323/1; IPY; Memorial University; ArcticNet. DOI: 10.13039/50110000027. Netherlands Organization for Scientific Research in the Tropics NWO, grant W84‐194. Ciências sem Fronteiras and Coordenação de Pessoal de Nível Superior (CAPES, Brazil), Grant/Award Number: 1091/13‐1. National Science foundation (LTER), Award Number: OCE‐9982105, OCE‐0620276, OCE‐1232779. FCT ‐ SFRH / BPD / 82259 / 2011. U.S. Fish and Wildlife Service/State Wildlife federal grant number T‐15. Australian Research Council Centre of Excellence for Coral Reef Studies (CE140100020). Australian Research Council Future Fellowship FT110100609. M.B., A.J., K.P., J.S. received financial support from internal funds of University of Lódź. NSF DEB 1353139. Catalan Government fellowships (DURSI): 1998FI‐00596, 2001BEAI200208, MECD Post‐doctoral fellowship EX2002‐0022. National Science Foundation Award OPP‐1440435. FONDECYT 1141037 and FONDAP 15150003 (IDEAL). CNPq Grant 306595‐2014‐1

Description: Low-frequency noise (LFN), or sound waves with frequencies between 10 Hz to 500 Hz, has increased substantially in coastal and shelf waters over the last decades. This is in large part due to the escalation in human activities such as shipping, wind farming, and pile-driving. Concern over how LFN affects marine mammal and fish welfare (eg. foraging efficiency, acoustic communication interference) has led the European Marine Strategy Framework Direction to include noise as a descriptor for achieving “good” environmental status. While the effects of anthropogenic noise on marine mammals and fish are by no means well documented, the effects of such noise on marine benthic invertebrates, crucial ecosystem engineers that continually rework sediment, are even less understood. Here, we present how LFN affects the behavior and sediment reworking activities of select macrobenthic invertebrate species from the North Atlantic in controlled laboratory setups. The polychaete Lanice conchilega, an abundant benthic invertebrate, exhibited behavioral responses to LFN in the form of modified pumping behavior. The amphipod crustacean Corophium volutator was negatively affected by LFN, exhibiting lower bioturbation rates and shallower burial depths compared to controls. The effect of LFN on the polychaete Arenicola marina and the bivalve Limecola balthica remained inconclusive, though A. marina displayed greater variability in bioirrigation rates when exposed to LFN. Benthic macroinvertebrates may be in jeopardy alone with the crucial ecosystem-maintaining services they provide, thus more research is urgently needed to understand, predict, and manage the impacts of anthropogenic noise pollution on marine fauna and their associated ecosystems.