Posts Tagged 'review'

A Polar outlook: potential interactions of micro- and nano-plastic with other anthropogenic stressors

Highlights

  • MP/NP at the poles should be addressed with chemical and climate stressors.
  • MP/NP and anthropogenic stress interactions may vary seasonally and locally.
  • MP/NP research should focus on polar species enduring high anthropogenic stress.

Abstract

Polar marine ecosystems may have higher sensitivity than other ecosystems to plastic pollution due to recurrent physical and biological features; presence of ice and high UV radiation, slow growth rates and weak genetic differentiation of resident biota, accumulation of persistent organic pollutants and heavy metals, and fast rates of warming and global ocean acidification. Here, we discuss potential sources of and exposure to micro- and nano-plastic in polar marine ecosystems and potential mixture effects of micro- and nano-plastic coupled with chemical and climate related stressors. We address the anthropogenic contaminants likely to be ‘high risk’ for interactions in Arctic and Antarctic waters for reasons such as accumulation under sea-ice, a known sink for plastic particulates. Consequently, we address the potential for localised plastic-chemical interactions and possible seasonal fluctuations in interactions associated with freeze-thaw events. The risks for keystone polar species are also considered, incorporating the behavioural and physiological traits of biota and addressing potential ‘hotspot’ areas. Finally, we discuss a possible direction for future research.

Continue reading ‘A Polar outlook: potential interactions of micro- and nano-plastic with other anthropogenic stressors’

Ocean and coastal indicators: understanding and coping with climate change at the land-sea interface

The U.S. Exclusive Economic Zone (EEZ) encompasses approximately 3.4 million square nautical miles of ocean and a coastline of over 12,300 miles. Along with the Great Lakes, this vast area generates ~US 370 billion of U.S. gross domestic product, 617 billion in sales and 2.6 million jobs each year. These ocean and coastal ecosystems also provide many important non-market services including subsistence food provisioning, health benefits, shoreline protection, climate regulation, conservation of marine biodiversity, and preservation of cultural heritage. As climatic changes occur, these benefits or ecosystem services may be significantly reduced or in some cases enhanced. These services are also under an array of pressures including over-exploitation of natural resources, pollution, and land use changes that occur simultaneously in synergistic, multiplicative, or antagonistic ways. This results in direct and indirect impacts that are often unpredictable across spatial and temporal scales. Here, we discuss a set of indicators designed in close collaboration with the U.S. National Climate Indicators System. Tracking the impacts via indicators will be essential to ensure long-term health of the marine environment and sustain the benefits to stakeholders who depend on marine ecosystem services.

Continue reading ‘Ocean and coastal indicators: understanding and coping with climate change at the land-sea interface’

Antarctic ecosystems in transition – life between stresses and opportunities

Important findings from the second decade of the 21st century on the impact of environmental change on biological processes in the Antarctic were synthesized by 26 international experts. Ten key messages emerged that have stakeholder-relevance and/or a high impact for the scientific community. They address (i) altered biogeochemical cycles, (ii) ocean acidification, (iii) climate change hotspots, (iv) unexpected dynamism in seabed-dwelling populations, (v) spatial range shifts, (vi) adaptation and thermal resilience, (vii) sea ice related biological fluctuations, (viii) pollution, (ix) endangered terrestrial endemism and (x) the discovery of unknown habitats. Most Antarctic biotas are exposed to multiple stresses and considered vulnerable to environmental change due to narrow tolerance ranges, rapid change, projected circumpolar impacts, low potential for timely genetic adaptation, and migration barriers. Important ecosystem functions, such as primary production and energy transfer between trophic levels, have already changed, and biodiversity patterns have shifted. A confidence assessment of the degree of ‘scientific understanding’ revealed an intermediate level for most of the more detailed sub-messages, indicating that process-oriented research has been successful in the past decade. Additional efforts are necessary, however, to achieve the level of robustness in scientific knowledge that is required to inform protection measures of the unique Antarctic terrestrial and marine ecosystems, and their contributions to global biodiversity and ecosystem services.

Continue reading ‘Antarctic ecosystems in transition – life between stresses and opportunities’

Chapter: Manipulation of seawater carbonate chemistry

Different culture methods to grow microalgae could lead to different physical (light) and chemical environments in culture vessels. Photosynthetic carbon sequestration by the algae in light and their respiratory CO2 release in darkness, can affect stability of carbonate systems (pH, various forms of inorganic carbon, total alkalinity) in culture systems. Usually, pH could increase during light period with active photosynthesis, and decrease during dark period. Such changes in pH and associated carbonate chemistry depend on culture methods and cell biomass or densities of microalgae in water body. The greater the amount of carbon fixation in the water, the greater the changes of the carbonate system. In experiments on the influence of other environmental factors on algae, controlling pH and other carbonate system parameters within known stable ranges is one of the keys to obtain reliable data. This section introduces the seawater carbonate system, compares the existing several kinds of carbonate system control methods, and provides basic suggestions for ocean acidification simulation experiments on marine organisms.

Continue reading ‘Chapter: Manipulation of seawater carbonate chemistry’

Establishing ocean acidification monitoring system for tropical waters of Indonesia facing regional climate variability

Emission of greenhouse gasses, including high CO2 and other materials, initiating global warming and climate change. Atmospheric CO2 that affect the carbonate system of seawater cause ocean acidification. Indonesian sea with a unique geolocation has important role in this emerging phenomenon. Ocean acidification (OA) not only affect marine organism as a direct effect but also economic and ecological for the human being. Considering the high impact of OA and following the global responsibility on Sustainable Development Goals, it is necessary to conduct systematic research and monitoring on OA in Indonesia. In this review, we are informing the urgency of the OA monitoring system and suggest the carbonate system monitoring as well as carbon biogeochemistry studies for OA. We also introduce an initiative of biogeochemical monitoring for OA at Lombok island with the established protocols. Improvement of many aspects including analysis instrumentations, analysis method, sample treatment, and sampling frequency will be a new insight in conducting further research and monitoring of OA.

Continue reading ‘Establishing ocean acidification monitoring system for tropical waters of Indonesia facing regional climate variability’

Chapter: Volcanic past cycles indicators: paleoclimatology and extinctions using benthic and planktonic forams community dynamics

The Benthic and planktonic foraminiferal communities’ dynamics as volcanic past cycles indicators are very well placed within the Paleoclimatology and extinctions studies. We have showed a bit, of what is available to explain how communities have evolved in the past. The past volcanic activity has released as much carbon dioxide into the atmosphere as anthropogenic as predicted emissions projections for the twenty-first century and they are linked to increases in carbon dioxide emissions and with faunal patterns, with marine extinctions observed sediment cores after volcanic episodes, and this increase in carbon dioxide and other volcanic gaseous influences on global warming and ocean acidification is responsible for the extinction of three quarters of species on Earth on the past. For example, dinosaurs were pretty much extinct because of “The Deccan Traps”, an igneous province, one of the largest volcanic features on Earth, located on the west-central India, and the Siberian Traps have influenced the end-Permian extinction, in which more than 90% of life on Earth disappeared. Many patterns should be first understood to be able to forecast future climate change scenarios. We can however explain that the modern ongoing carbon dioxide emissions are similar to those that led to the end-Triassic mass extinction. The importance of understanding Earth’s deep water past is predicated on predicting how it will respond to future climate change. The mass extinction and high-stress conditions were explained by the intense Deccan volcanism leading to rapid global warming and cooling, with enhanced weathering, continental runoff, and ocean acidification, resulting in a carbonate crisis in the marine environment. The chronic explosive volcanic activity generated unstable benthic habitat colonized by only a few species. The increase in atmospheric CO2 concentrations lead to decreased pH and carbonate availability in the ocean, known as Ocean Acidification, and the ability of marine invertebrates to tolerate acidity are the ‘windows into the future’ to study. Cores with ashes and tephra in Papua New Guinea (PNG) during Expedition 363 sampled by the IODP show that total foraminiferal diversity was low when volcanic activity was in place detected by the presence of tephra and volcanic ashes. Foraminiferal density and diversity in PNG were high and similar to those observed on the Great Barrier Reef or other sites, however diversity decreases, and show inverse correlation by benthic foraminifera to high presence of ashes and tephra in the past. However, ecological studies from shallow reef environments observed increased foraminiferal dominance of opportunists when corals became rare from chronic or acute anthropogenic influences, for example with sewage and oil spills. Agglutinate taxa that do not rely on calcification will replace calcifying species, and we call it a fauna replacement by invasive species. Density and diversity of agglutinated taxa is also in decline, but are less marked than calcifying taxa in an environment where pH is low. Dissolution of foraminifera seen in marine sediment under elevated pCO2 unravels other direct ecological impacts. Impacts such as dissolution and loss of biogenesis of carbonate by other organisms that are under near-future pCO2 conditions, which will reach a problematic real-time scenario. None of the previous extinctions were as severe as the ecological or even taxonomic extinction in shallow carbonate areas which we are predicting. Because of the rate of increasing pCO2, and unfortunately, we expect that the increase in the temperature in the Holocene and the tendency until 2100 will take us to the warmest Pliocene climate with the unfortunate consequences of living in a warmer than optimum world. The variability based on the frequency and intensity of some events are one of the warmest our world has ever seen, reflecting changes in temperature derived from data from deep sea sediment core samples, and of course shells of benthic and planktonic Forams and other organisms like pollen act as proxies in drilled marine sediment cores reflecting historic climate. A unique fauna of foraminiferal species from these highly opposed environments created by differences in temperature in the past are recorded paleo cycles, of which responds to the amount of ice in the world, due to their high sensitivity to the environmental changes in the modern and past sediments. Here we show that tephra and ashes of IODP Hole U1485A (Exp. 363 WPWP) record a periodicity of explosive volcanism within the last 0.8 Myr. Possible triggering mechanisms for these mass flow deposits include earthquakes and associated tsunamis and shelf/slope sediment instabilities during times of rapid deposition such as can occur during river flood events. Over longer timescales, it is also possible that sea level played a role in the storage and release of sediment from the PNG shelf (although the shelf itself is very narrow) and from the paleo-valley of the Sepik River, which is a relatively large area presently few meters above sea level. Changes in diversity shows balance of alternating deep (cold) and shallow (warm) benthic foraminifera fauna along time in the past. The “at least” five decreases in diversity peaks in the past show that the response of the benthic community to adverse climate is a change in their ecological pattern. These changes can take a whole community and an entire ecosystem to extinctions, and we have already seen five extinctions along Earth’s history. And if history teaches us anything, it is how to react to and prepare for crisis rather than repeat mistakes. Research suggests we are fast approaching disastrous effects of this sixth Anthropocene extinction. However, we can successfully surmount the challenges of biodiversity loss and climate change and dramatically alter the trajectory if we can pinpoint and remediate problems within a near future. With our planet “in crisis”, evidence demonstrates widespread ecological collapse and biodiversity loss. We know that as average temperatures rise and the frequency of extremely warm years increases, the impacts of habitat loss and fragmentation become even more increasingly apparent. We are with without a doubt entering a sixth mass extinction event because of the rapid decline in biodiversity. The majority of these species inhabit environmentally delicate tropical and subtropical areas susceptible to human impacts. This refers to a situation where the extinction of one species affects other species that rely on it for survival, thereby also placing them at a ‘domino effect’ risk of extinction as part of a destructive chain reaction. Stop cutting and burn forests, stop global trade of wild species, study and protect, preserve, and conserve our planet’s biodiversity.

Continue reading ‘Chapter: Volcanic past cycles indicators: paleoclimatology and extinctions using benthic and planktonic forams community dynamics’

Chapter: ecological modeling and conservation on the coasts of Mexico

Mexico harbors several types of coastal ecosystems both in the Atlantic (Gulf of Mexico and Caribbean) and in the Pacific (tropical and subtropical) on which the regional and national socio-economic development depends. They have been studied through several modeling approaches for management, conservation, and necessary ecological studies. In this chapter, we review and synthesize the most recent and relevant studies conducted, with particular emphasis on coral reefs. In the Caribbean, coral reefs are likely the most rapidly changing ecosystems with a net decline in the cover of reef-building corals accompanied by rapid increases of fleshy macroalgae over the last decades. Remaining coral communities are changing toward weedy coral species that are unlikely to support reef growth and thus provide important services to other species and humans. Since 2015 the Mexican Caribbean coast experienced a massive influx of drifting Sargassum spp. that accumulated on the shores, resulting in a build-up of decaying beach-cast material and near-shore murky brown waters (Sargassum-brown-tides), drastically modifying near-shore waters conditions by reducing light, oxygen (hypoxia or anoxia), and pH. The Gulf of Mexico’s coastal ecosystems have also been under significant threats because of human activities, such as gas and oil extraction, pollution, and fishing. Despite numerous studies conducted in the Pacific, biodiversity knowledge is still incomplete, highly biased toward specific habitats, and often narrow in taxonomic and spatial scope. Concurrently, ecological processes that drive biodiversity have been scarcely disentangled. In spite of sub-optimal conditions for coral calcification (lower alkalinity, upwelling, ENSO, high nutrients concentration) some coral reefs thrive in the Pacific. Calcification rate is disrupted with ENSO events (20–50% drop), but it is not correlated to historical changes in sea surface temperature and it might decrease between 15 and 22% due to ocean acidification.

Continue reading ‘Chapter: ecological modeling and conservation on the coasts of Mexico’

Futureproofing the green-lipped mussel aquaculture industry against ocean acidification

Two mitigation strategies – waste shell and aeration – were tested in field experiments to see how effective they are at mitigating acidification around mussel farms. This report outlines the results and recommendations from this research. 


Primary results:

  • The inner Firth of Thames currently experiences the lowest seasonal pH of the sites monitored, with a daily minimum of 7.84 (7.79–7.96) in autumn, with short-term (15-minute) pH minima as low as 7.2. Time-series data in the inner and outer Firth of Thames, and also on a mussel farm in the western Firth, show episodic declines in carbonate saturation to the critical carbonate saturation state ΩAR = 1.0 at which solid aragonite (the form of carbonate in mussel shells) will start to dissolve. Consequently, mussels in the Firth of Thames experience episodic corrosive conditions.
  • The mean pH in the Marlborough Sounds region is projected to decrease by 0.15–0.4 by 2100 depending on future emission scenario. The corresponding decline of 0.5–1.25 in the saturation state of aragonite (ΩAR), results in the critical threshold of ΩAR =1 being reached by 2100 under the worst-case scenario. These projections are based only on future CO2 emission scenarios and do not consider other coastal sources of acidity in coastal waters which may also alter in the future.

Continue reading ‘Futureproofing the green-lipped mussel aquaculture industry against ocean acidification’

Benefits and gaps in area-based management tools for the ocean Sustainable Development Goal

Sustainable Development Goal (SDG) 14 provides a vision for the world’s oceans; however, the management interventions that are needed to achieve SDG 14 remain less clear. We assessed the potential contributions of seven key area-based management tools (such as fisheries closures) to SDG 14 targets. We conducted a rapid systematic review of 177 studies and an expert opinion survey to identify evidence of the ecological, social and economic outcomes from each type of tool. We used these data to assess the level of confidence in the outcomes delivered by each tool and qualitatively scored how each tool contributes to each target. We demonstrate that a combination of tools with diverse objectives and management approaches will be necessary to achieve all of the SDG 14 targets. We highlight that some tools, including fully and partially protected areas and locally managed marine areas, may make stronger contributions to SDG 14 compared with other tools. We identified gaps in the suitability of these tools to some targets, particularly targets related to pollution and acidification, as well as evidence gaps for social and economic outcomes. Our findings provide operational guidance to support progress toward SDG 14.

Continue reading ‘Benefits and gaps in area-based management tools for the ocean Sustainable Development Goal’

Chapter 2: The impact of climate change on oceans: physical, chemical and biological responses

The rising concentrations of carbon dioxide and other greenhouse gases have caused observed physical, chemical and biological changes in the oceans, with further changes projected over coming decades. The impact of climate change on the oceans are profound, with rapid warming in ocean hotspots combined with extreme events such as marine heatwaves changing the distribution and abundance of a wide range of marine species. Further, ocean acidification, sea level rise, and deoxygenation may have important consequences for the marine ecosystems and the ecosystem services derived from the ocean. These observed and future ocean changes are irreversible on the timescale of many centuries. As a result, management of marine resources, for both extractive (for example, fishing) and non-extractive (for example, marine tourism) will need to account for the effects of climate change. For example, changes in abundance of marine species will impact harvesting levels and ecosystem structure, while changes in species’ distribution will challenge place-based management and agreements between nations. Adaptation to some of these changes will be possible; however, without substantial reduction in greenhouse gas emissions the oceans will change and not provide the same support for human activities as currently enjoyed. The changing nature of the ocean, and the impact it may have on ecosystems and communities, represents a huge challenge to future community interactions at local, national and international scales. It also raises the possibility of active intervention in the climate system to minimize the impacts of climate change which will introduce a complex set of issues to be considered before implementing any intervention.

Continue reading ‘Chapter 2: The impact of climate change on oceans: physical, chemical and biological responses’

Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,416,877 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book

Archives