Affect Marine Ecosystems Research Articles

Sediment archives reveal irreversible shifts in plankton communities after World War II and agricultural pollution

To evaluate the stability and resilience1 of coastal ecosystem communities to perturbations that occurred during the Anthropocene,2 pre-industrial biodiversity baselines inferred from paleoarchives are needed.3,4 The study of ancient DNA (aDNA) from sediments (sedaDNA)5 has provided valuable information about past dynamics of microbial species6-8 and communities9-18 in relation to ecosystem variations. Shifts in planktonic protist communities might significantly affect marine ecosystems through cascading effects,19-21 and therefore the analysis of this compartment is essential for the assessment of ecosystem variations. Here, sediment cores collected from different sites of the Bay of Brest (northeast Atlantic, France) allowed ca. 1,400 years of retrospective analyses of the effects of human pollution on marine protists. Comparison of sedaDNA extractions and metabarcoding analyses with different barcode regions (V4 and V7 18S rDNA) revealed that protist assemblages in ancient sediments are mainly composed of species known to produce resting stages. Heavy-metal pollution traces in sediments were ascribed to the World War II period and coincided with community shifts within dinoflagellates and stramenopiles. After the war and especially from the 1980s to 1990s, protist genera shifts followed chronic contaminations of agricultural origin. Community composition reconstruction over time showed that there was no recovery to a Middle Ages baseline composition. This demonstrates the irreversibility of the observed shifts after the cumulative effect of war and agricultural pollutions. Developing a paleoecological approach, this study highlights how human contaminations irreversibly affect marine microbial compartments, which contributes to the debate on coastal ecosystem preservation and restoration.

Ocean acidification but not elevated spring warming threatens a European seas predator

Ocean acidification has the potential to negatively affect marine ecosystems by influencing the development and metabolism of key members of food webs. The garfish, Belone belone, is an ecologically important predator in European regional seas and it remains unknown how this species will be impacted by projected changes in climate. We artificially fertilized and reared garfish embryos until hatch at present (400 μatm) and future (1300 μatm) pCO2 levels within three temperature treatments, i.e. two daily warming regimes and one constant high temperature (17 °C). For the two warming treatments, embryos were fertilized at 13 °C and experienced 0.1 or 0.3 °C/day warming. The 0.1 °C/day treatment served as control: 13 °C was the in situ temperature of parental fish in the Southwest Baltic Sea and 0.1 °C/day is the average warming rate experienced by embryos of this population in nature. Survival was drastically reduced at both future pCO2 and at the constant high temperature while the highest survival in any treatment was observed at 0.3 °C/day warming. The proportion of embryos with morphological deformities increased with elevated pCO2 but not temperature. Hatch characteristics and physiological measures such as heart rate and critical thermal ranges, however, were not affected by pCO2 but were influenced by temperature. Our results suggest that garfish in the Baltic Sea will benefit from projected increased rates of spring warming but not the concomitant increase in pCO2. Previous studies on the impacts of ocean acidification on resident fishes in the Baltic Sea indicate that this piscivorous fish is at higher risk compared to its prey which may have broader implications for the future trophodynamic structure and function of the coastal food web.

Rising Temperature Is a More Important Driver Than Increasing Carbon Dioxide Concentrations in the Trait Responses of Enhalus acoroides Seedlings

Increasing temperature and CO2 concentration are among the most important factors affecting marine ecosystems under climate change. We investigated the morphological, biochemical, and physiological trait responses of seedlings of the tropical seagrass Enhalus acoroides under experimental conditions. Trait responses were greater under temperature effects than increasing CO2 concentration. Seedlings under rising temperatures showed enhanced leaf growth, lower leaf nutrient content, and stimulated down-regulating mechanisms in terms of photo-physiology. Increasing CO2 concentrations did not show any significant effects independently. There was a significant interaction for some of the trait responses considered, such as leaf number and carbon content in the roots, and trends of higher starch concentrations in the leaves and lower rETRmax under combined enriched CO2 and high temperature, even though none of these interactions were synergistic. Understanding the single and interactive trait responses of seagrass seedlings to increasing temperature and CO2 concentration is of importance to determine the relative responses of early life stages of seagrasses, which may differ from adult plants, in order to form a more holistic view of seagrass ecosystem health under climate change.

Shifts in marine invertebrate bacterial assemblages associated with tissue necrosis during a heat wave

Marine heat waves (MHWs) are periods of extremely high seawater temperature that affect marine ecosystems in several ways. Anthozoans (corals and gorgonians) and Porifera (sponges) are usually among the taxa most affected by MHWs. Both are holobiont entities that form complex interactions with a wide range of microbes, which are an essential part of these organisms and play key roles in their health status. Here, we determine microbial community changes suffered in two corals (Cladocora caespitosa and Oculina patagonica), one gorgonian (Leptogorgia sarmentosa) and one sponge (Sarcotragus fasciculatus) during the 2015 MHW. The microbial communities were different among hosts and displayed shifts related to host health status, with a higher abundance in necrosed tissues of Ruegeria species or of potential pathogens like Vibrio. We also carry out a meta-analysis using 93 publicly accessible 16S rRNA gene libraries from O. patagonica, C. caespitosa and L. sarmentosa to establish a Mediterranean core microbiome in these species. We have identified one Ruegeria OTU that maintained a stable and consistent association with these species, which was also related to tissue necrosis in their hosts. Therefore, Ruegeria sp. could play an important and still underexplored role in the health status of its hosts.

Immediate social and economic impacts of a major oil spill on Brazilian coastal fishing communities

In August 2019, a major oil spill hit nine Brazilian coastal states, affecting marine ecosystems and fishing communities. In this study, we assess the immediate social and economic impacts of this oil spill on fishing communities of the northeast coast. We conducted semi-structured interviews and focal meetings with 381 fishers and shellfish gatherers to understand the perceived socioeconomic impacts on different types of fishing. We also obtained information on fish consumption after the oil spill, which we compared with data prior to the oil spill from the same communities. Sales decreased by more than 50% for all types of fishing, strongly impacting local income generation. These communities, which are already social-ecologically vulnerable, have had their subsistence, food security and cultural maintenance strongly compromised. We argue that there is a clear need for coordinated state interventions to mitigation the impacts, considering it's environmental, social, economic, human health and political dimensions.

The impact of the risk perception of ocean microplastics on tourists' pro-environmental behavior intention

Microplastic pollution has been recognized as an emerging concern that negatively affects marine ecosystems. Given the situation, the government and environmental groups have emphasized the seriousness of microplastics to the public and encouraged them to reduce the use of microplastics. However, very few studies have examined how individuals perceive microplastics. Thus, this study aims to identify the relationship between peoples' risk perception of microplastic and pro-environmental behavioral intention. To conduct an empirical study, we used a total of 445 samples collected from online survey and adopted the partial least squares path modeling method to test the causal relationship between variables in the conceptual model. The results indicated that risk perception significantly affects pro-environmental behavioral intention and is influenced by knowledge as an environmental trigger. In addition, we highlighted that feelings of guilt and social responsibility play important mediating roles in the relation between risk perception and pro-environmental behavioral intention. This study has meaningful implications for practitioners to encourage the public's eco-friendly behavior by suggesting ways to inform knowledge of microplastics and stimulate individuals' responsibility on environment.

Global Drivers on Southern Ocean Ecosystems: Changing Physical Environments and Anthropogenic Pressures in an Earth System

The manuscript assesses the current and expected future global drivers of Southern Ocean (SO) ecosystems. Atmospheric ozone depletion over the Antarctic since the 1970s, has been a key driver, resulting in springtime cooling of the stratosphere and intensification of the polar vortex, increasing the frequency of positive phases of the Southern Annular Mode (SAM). This increases warm air-flow over the East Pacific sector (Western Antarctic Peninsula) and cold air flow over the West Pacific sector. SAM as well as El Niño Southern Oscillation events also affect the Amundsen Sea Low leading to either positive or negative sea ice anomalies in the west and east Pacific sectors, respectively. The strengthening of westerly winds is also linked to shoaling of deep warmer water onto the continental shelves, particularly in the East Pacific and Atlantic sectors. Air and ocean warming has led to changes in the cryosphere, with glacial and ice sheet melting in both sectors, opening up new ice free areas to biological productivity, but increasing seafloor disturbance by icebergs. The increased melting is correlated with a salinity decrease particularly in the surface 100 m. Such processes could increase the availability of iron, which is currently limiting primary production over much of the SO. Increasing CO2is one of the most important SO anthropogenic drivers and is likely to affect marine ecosystems in the coming decades. While levels of many pollutants are lower than elsewhere, persistent organic pollutants (POPs) and plastics have been detected in the SO, with concentrations likely enhanced by migratory species. With increased marine traffic and weakening of ocean barriers the risk of the establishment of non-indigenous species is increased. The continued recovery of the ozone hole creates uncertainty over the reversal in sea ice trends, especially in the light of the abrupt transition from record high to record low Antarctic sea ice extent since spring 2016. The current rate of change in physical and anthropogenic drivers is certain to impact the Marine Ecosystem Assessment of the Southern Ocean (MEASO) region in the near future and will have a wide range of impacts across the marine ecosystem.

Decadal variability and recent summer warming amplification of the sea surface temperature in the Red Sea.

Under climate change, regional Sea Surface Temperature (SST) changes are a crucial factor affecting marine ecosystems, which thrive only within a certain thermal limit. Thirty-seven years of monthly gridded Optimum Interpolation SST data from 1982 to 2017 were used to investigate the decadal variability of this parameter in the Red Sea during the summer season, in relation to large-scale climate variability. We identified a non-uniform warming trend beginning around the mid-1990s over the whole basin, with a predominant amplified warming over the northern half (0.04°C year-1), which is approximately four times higher than the global warming trend, but much weaker warming over southern end (0.01°C year-1). It was found that the Atlantic Multi-Decadal Oscillation (AMO) and the Silk Road Pattern (SRP) are shaping the RS SST, since their phase shift concurs with the timing of the significant non-uniform warming over the basin. The AMO triggers the SRP-related vertical and horizontal temperature advection that leads to opposite changes in the SST. We suggest that warming is amplified over the basin due to an overlap with global warming signals. Our results have important implications for interannual and decadal SST predictions based on the predictability of AMO and SRP patterns.

Twenty-first century ocean warming, acidification, deoxygenation, and upper-ocean nutrient and primary production decline from CMIP6 model projections

Abstract. Anthropogenic climate change is projected to lead to ocean warming, acidification, deoxygenation, reductions in near-surface nutrients, and changes to primary production, all of which are expected to affect marine ecosystems. Here we assess projections of these drivers of environmental change over the twenty-first century from Earth system models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) that were forced under the CMIP6 Shared Socioeconomic Pathways (SSPs). Projections are compared to those from the previous generation (CMIP5) forced under the Representative Concentration Pathways (RCPs). A total of 10 CMIP5 and 13 CMIP6 models are used in the two multi-model ensembles. Under the high-emission scenario SSP5-8.5, the multi-model global mean change (2080–2099 mean values relative to 1870–1899) ± the inter-model SD in sea surface temperature, surface pH, subsurface (100–600 m) oxygen concentration, euphotic (0–100 m) nitrate concentration, and depth-integrated primary production is +3.47±0.78 ∘C, -0.44±0.005, -13.27±5.28, -1.06±0.45 mmol m−3 and -2.99±9.11 %, respectively. Under the low-emission, high-mitigation scenario SSP1-2.6, the corresponding global changes are +1.42±0.32 ∘C, -0.16±0.002, -6.36±2.92, -0.52±0.23 mmol m−3, and -0.56±4.12 %. Projected exposure of the marine ecosystem to these drivers of ocean change depends largely on the extent of future emissions, consistent with previous studies. The ESMs in CMIP6 generally project greater warming, acidification, deoxygenation, and nitrate reductions but lesser primary production declines than those from CMIP5 under comparable radiative forcing. The increased projected ocean warming results from a general increase in the climate sensitivity of CMIP6 models relative to those of CMIP5. This enhanced warming increases upper-ocean stratification in CMIP6 projections, which contributes to greater reductions in upper-ocean nitrate and subsurface oxygen ventilation. The greater surface acidification in CMIP6 is primarily a consequence of the SSPs having higher associated atmospheric CO2 concentrations than their RCP analogues for the same radiative forcing. We find no consistent reduction in inter-model uncertainties, and even an increase in net primary production inter-model uncertainties in CMIP6, as compared to CMIP5.

Potential toxicity of polystyrene microplastic particles

Environmental pollution arising from plastic waste is a major global concern. Plastic macroparticles, microparticles, and nanoparticles have the potential to affect marine ecosystems and human health. It is generally accepted that microplastic particles are not harmful or at best minimal to human health. However direct contact with microplastic particles may have possible adverse effect in cellular level. Primary polystyrene (PS) particles were the focus of this study, and we investigated the potential impacts of these microplastics on human health at the cellular level. We determined that PS particles were potential immune stimulants that induced cytokine and chemokine production in a size-dependent and concentration-dependent manner.

Abundance and distribution of small microplastics (≤ 3 μm) in sediments and seaworms from the Southern Mediterranean coasts and characterisation of their potential harmful effects.

Microplastics (MPs) are an uncontrolled contaminant affecting marine ecosystems. Studying their undesirable effects has been an attractive field for scientists in recent years. This study is the first to investigate the uptake and distribution of small microplastics (≤3 μm) from several sites in the Southern Mediterranean coasts. This work primarilyaims to provide a qualitative and quantitative analysis of microplastics in sediments as well as in the seaworms (Hediste diversicolor) from eight sites from the Tunisian coasts using Fourier transform infrared spectroscopy and Raman microspectroscopy. The second aim is to evaluate the potential toxic effects of environmental microplastics using a set of biomarkers such as Catalase, Glutathione-S-Transferase, Malondialdehyde and Acetylcholinesterase. Our findings showed that microplastics (1 mm–1.2 μm) were present in all sediments with its abundance ranging from 129 to 606 items kg−1. Microplastic accumulation in seaworms (3 μm–0.22 μm) was 0.5–3.7 items g−1. The predominant polymer was polyethylene. Results also revealed a significant variation among sites in the parameters associated with oxidative stress. Thus, size abundance of microplastics in seaworms was mainly correlated with oxidative stress biomarkers. Our data should be carefully considered in view of the microplastic presence with several types and sizes in Tunisian coastal sites, their potential toxic effects, and their transfer into food web.

Haloxyfop-P-methyl induces developmental defects in zebrafish embryos through oxidative stress and anti-vasculogenesis

Haloxyfop-P-methyl, an aryloxyphenoxypropionate herbicide, is widely used to eliminate unwanted plants by inhibiting lipid synthesis and inducing oxidative stress. Since haloxyfop-P-methyl targets are limited within plants, few negative side effects on non-target crops have been reported. However, dissolved haloxyfop-P-methyl in rain or groundwater contaminates aquatic environments and affects marine ecosystems. In the present study, treatment with haloxyfop-P-methyl for 48 h induced developmental deficiencies in the eyes and bodies of the zebrafish embryos as a whole and was also linked to increases in the incidence of pericardial edema. Additionally, haloxyfop-P-methyl treatment decreased hatching ratio, embryo viability, and heart rate, while simultaneously increasing the expression levels of apoptotic and inflammatory genes. Moreover, haloxyfop-P-methyl hampered vasculogenesis in the embryos through down-regulation of functional genes, and disruption of vessel formation caused neurodegeneration in the olig2-positive notochord. Collectively, this study newly discovered the oxidative stress-related toxic mechanism of haloxyfop-P-methyl during embryonic development through anti-vasculogenesis, which suppresses neurogenesis of the notochord. This toxicity assessment of haloxyfop-P-methyl on embryogenesis may contribute to establishment of safety profiling of herbicide and to support hazard control in aquatic environment.

Surface modification of rubber seed shell activated carbon with malic acid for high CO2 adsorption

Carbon dioxide (CO2) has been stated as one of major contributor to climate change and affects marine ecosystems. Among other CO2 capturing technology, adsorption is widely used due to its numerous advantages. Rubber seed shell (RSS), an agriculture waste from rubber plantation was used as precursor for preparing activated carbon (AC) by chemical activation using Malic acid as activating agent for CO2 adsorption. In this research, the AC was characterized and analysed by SEM, Micrometric ASAP 2020, TGA and FTIR instruments. The optimum condition was found at activation temperature of 600 °C, sample A. Results from specific surface and porosity analyzer shows the AC total pore volume, specific surface area and diameter were 0.2635 cm3/g, 480.5692 m2/g and 2.1937 nm, respectively. The CO2 adsorption studies showed the CO2 uptake for the AC was 2.26 mmol/gwhich is better most agricultural wastes’ and commercial AC. It was found that malic acid helps to prolong the thermal stability of AC. The presence of a new FTIR peak in samples indicated N-H stretching and C=N stretching might due to remaining malic acid on the surface which increased the CO2 affinity and was an attractive source for CO2 adsorption applications.

Standing genetic variation fuels rapid adaptation to ocean acidification

Global climate change has intensified the need to assess the capacity for natural populations to adapt to abrupt shifts in the environment. Reductions in seawater pH constitute a conspicuous global change stressor that is affecting marine ecosystems globally. Here, we quantify the phenotypic and genetic modifications associated with rapid adaptation to reduced seawater pH in the Mediterranean mussel, Mytilus galloprovincialis. We reared a genetically diverse larval population in two pH treatments (pHT 8.1 and 7.4) and tracked changes in the shell-size distribution and genetic variation through settlement. Additionally, we identified differences in the signatures of selection on shell growth in each pH environment. Both phenotypic and genetic data show that standing variation can facilitate adaptation to declines in seawater pH. This work provides insight into the processes underpinning rapid evolution, and demonstrates the importance of maintaining variation within natural populations to bolster species’ adaptive capacity as global change progresses.

Dynamics of a stochastic phytoplankton-toxin phytoplankton\u2013zooplankton model

Environmental fluctuations and toxin-producing phytoplankton are crucial factors affecting marine ecosystems. In this paper, we propose a stochastic phytoplankton-toxin phytoplankton–zooplankton model to study the effect of environmental fluctuations on extinction and persistence of the population. The results show that large environmental fluctuations may lead to the extinction of the population, and small environmental fluctuation can keep population weakly persistent in the mean. We also find that the noise-induced extinction of one phytoplankton population may lead to the density increase of the other phytoplankton population in two competitive phytoplankton populations. By constructing appropriate Lyapunov functions, we obtain the sufficient conditions for the existence of an ergodic stationary distribution of the model. Finally, numerical simulations are carried out to support our main results.

Predicting marine futures

Marine Management The ability to predict how climate variations will affect marine ecosystems would allow better economic and ecosystem planning and management. Park et al. found that a global Earth system model skillfully predicted seasonal to multiannual ocean chlorophyll fluctuations in many regions. This could allow annual fish catches in some regions to be forecast 2 to 3 years in advance. Science , this issue p. [284][1] [1]: /lookup/doi/10.1126/science.aav6634

Seasonal to multiannual marine ecosystem prediction with a global Earth system model.

Climate variations have a profound impact on marine ecosystems and the communities that depend upon them. Anticipating ecosystem shifts using global Earth system models (ESMs) could enable communities to adapt to climate fluctuations and contribute to long-term ecosystem resilience. We show that newly developed ESM-based marine biogeochemical predictions can skillfully predict satellite-derived seasonal to multiannual chlorophyll fluctuations in many regions. Prediction skill arises primarily from successfully simulating the chlorophyll response to the El Niño-Southern Oscillation and capturing the winter reemergence of subsurface nutrient anomalies in the extratropics, which subsequently affect spring and summer chlorophyll concentrations. Further investigations suggest that interannual fish-catch variations in selected large marine ecosystems can be anticipated from predicted chlorophyll and sea surface temperature anomalies. This result, together with high predictability for other marine-resource-relevant biogeochemical properties (e.g., oxygen, primary production), suggests a role for ESM-based marine biogeochemical predictions in dynamic marine resource management efforts.

An assessment of the toxicity of polypropylene microplastics in human derived cells

Environmental pollution caused by plastic waste is a growing global problem. Discarded plastic products and debris (microplastic particles) in the oceans detrimentally affect marine ecosystems and may impact human. Humans are exposed to plastic debris via the consumption of seafood and drinking water, contact with food packaging, or inhalation of particles. The accumulation of microplastic particles in humans has potential health risks such as cytotoxicity, hypersensitivity, unwanted immune response, and acute response like hemolysis. We investigated the cellular responses of secondary polypropylene microplastics (PP particles) of approximately ~20 μm and 25–200 μm in different condition and size to normal cells, immune cells, blood cells, and murine immune cells by cytokine analysis, ROS assay, polarization assay and proliferation assay. We found that PP particles showed low cytotoxicity effect in size and concentration manner, however, a high concentration, small sized, DMSO method of PP particles stimulated the immune system and enhanced potential hypersensitivity to PP particles via an increase in the levels of cytokines and histamines in PBMCs, Raw 264.7 and HMC-1 cells.

Banggai cardinalfish and its microhabitats in a warming world: a preliminary study

Global changes in the Anthropocene are affecting marine ecosystems in many ways, including alterations in long-established inter-species relationships. The Banggai cardinalfish Pterapogon kauderni, a species of global conservation concern, is highly dependent on benthic organisms serving as microhabitat. The objective of this study was to evaluate the effects of global change, in particular rising sea temperature, on P. kauderni and three key associated microhabitats: hard corals (Scleractinia), sea urchins (Diadematidae), and sea anemones (Actinia). Data collected before, during, and after the 2016 global coral bleaching event from P. kauderni habitat in the Banggai Archipelago, including coral bleaching (by genus) and P. kauderni (by life stage) microhabitat association (species or genus, coral life-form), were complemented by a literature review. While coral bleaching and mortality was less severe than in many other regions, hard coral genera and life-forms preferred by P. kauderni were disproportionately affected, and P. kauderni hosting sea anemones also bleached. Coral, sea urchin and sea anemone reproduction, larval development, and recruitment may be negatively affected. Likely post-settlement effects on sea urchin and sea anemone growth and survival are unclear. Direct impacts on P. kauderni are likely, including metabolic rate change with consequences for growth and longevity. Indirect impacts (e.g. changes in plankton composition and abundance, increased storm frequency/severity) will affect P. kauderni and all its microhabitats. This evaluation for P. kauderni, its key microhabitat groups, and their association, points towards increased need for both conservation action and research to fill identified knowledge gaps.

Decreasing pH affects Seagrass Epiphyte Communities

Increasing CO2 in the atmosphere is affecting marine ecosystems, including seagrass beds. Epiphytes are a component of seagrass ecosystems. Epiphytes make a significant contribution as important primary producers in the food chain. Increasing atmospheric CO2 leads to a decrease in oceanic pH that can result in an unfavorable environment for the epiphytic community. This study was conducted to determine the effect of increasing CO2 on seagrass epiphytic communities and biomass. Using a field experiment, we manipulated dissolved carbon dioxide to 800 - 1000 ppm in line with the forecast increase in atmospheric CO2 levels in the year 2100. In situ C02 manipulations were conducted using an open-top mesocosm. The CO2 enrichment was conducted by adding CO2 at a concentration around 800 - 1000 ppm. This CO2 was injected directly using a pump and hose to the acrylic mesocosm chamber. Epiphyte community structure was affected, with an increase in the abundance of filamentous algae but a decrease in the coralline algae community in the CO2 enriched treatment units. Overall, CO2 enrichment had no effect on epiphyte biomass.