August | 2016 | Ocean acidification

Archive for August, 2016

Maui Economic Development Board’s Ke Alahele Education Fund supports STEM studies

Published 31 August 2016 Media coverage Leave a Comment

Maui Economic Development Board‘s Ke Alahele Education Fund Benefit Dinner and Auction grossed $331,800 to advance STEM education in Maui County. The event, held Aug. 20 at the Fairmont Kea Lani, celebrated the Fund’s 10th year with 550 attendees including U.S. Senators Mazie Hirono and Brian Schatz, Lieutenant Governor Shan Tsutsui and Mayor Alan Arakawa.

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The second place award went to Evelyn Haase for developing a pH sensor using a Raspberry Pi to monitor ocean acidification. Haase, a sophomore at Molokai High, invented a pH sensor that can measure accurate data detecting the tiniest changes to the ocean pH due to environmental fluctuations. Not only does it improve accuracy, but is offers a huge cost savings compared to the current systems available to marine scientists. Estimates are that her device is 1/42 of the price (which is about $200 to compared to $11,000 for today’s technology costs) and requires half the maintenance of the current system. Haase will receive $2,000 to further her scientific research and educational pursuits and Molokai High School will receive $3,300 for improvements to their STEMworks lab.

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UCSC receives nearly $1 million federal grant

Published 31 August 2016 Media coverage Leave a Comment

SALINAS, Calif. –

The University of California Santa Cruz will be getting nearly $1 million to study and predict the effects of ocean acidification. The $921,157 grant from the National Science Foundation was announced Tuesday by Representative Sam Farr (D-Carmel).

Ocean acidification occurs when carbon dioxide dissolves in seawater, leading to the water becoming more acidic. According to a release from Rep. Farr, acidity levels in the oceans and Great Lakes could rise to 125 percent of historic levels by the end of the century.

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Internship opportunity: Effect of ocean acidification on the small RNA expression of a coral

Published 31 August 2016 Jobs Leave a Comment

Internship description

Small RNAs (e.g. small interfering RNA, microRNA, Piwi-interacting RNA) are essential in the correct functioning of many biological processes of metazoans. To investigate the effect of ocean acidification on the small RNA profile of corals, we extracted and sequenced the small RNA fraction of a coral that was subjected to four different pCO₂ levels under controlled conditions. This project will involve the use of bioinformatics tools (and possibly even self-written ones!) to analyse the changes in expression of small RNAs, and identify biologically interesting small RNAs for further downstream verification.

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Beneath the waves, climate change puts marine life on the move

Published 31 August 2016 Media coverage Leave a Comment

Connecticut’s traditional fishing catch is heading north

There was a hefty irony to the announcement by Connecticut’s two U.S. senators earlier this summer that they were joining the sponsorship for a National Lobster Day next month.

The iconic symbol of the state’s fishing industry for years, Long Island Sound was once flush with lobster, traps and people who made their livings from them.

But no more.

Connecticut’s lobster landings topped 3.7 million pounds a year, worth $12 million, in the late 1990s, but by 2014 had diminished to about 127,000 pounds worth a little more than $600,000.

Instead of the picture of fishing success, lobster has become the face of climate change in New England: a sentinel of warming water, ocean acidification and other man-made impacts that have sent them and dozens of other marine animals scurrying in search of a more hospitable environment.

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Nuclear science for SDGs: Life Below Water (video)

Published 31 August 2016 Media coverage Leave a Comment

Science and technology are crucial for development. Nuclear science plays a significant role in the achievement of many of the Sustainable Development Goals (SDGs), especially in the fields of health, hunger, energy and the environment.

Oceans absorb around a quarter of all CO2 emissions. Nuclear techniques are used to study this process and its effects on sea life.

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Ocean acidification: linking science to management solutions using the Great Barrier Reef as a case study

Published 31 August 2016 Science Leave a Comment
Tags: biological response, corals, mitigation, review, socio-economy, South Pacific

Highlights

Ocean acidification knowledge is reviewed alongside management needs/priorities.
A framework is developed to link acidification research to management options.
The framework helps identify options to support coral reef ecosystem resilience.

Abstract

Coral reefs are one of the most vulnerable ecosystems to ocean acidification. While our understanding of the potential impacts of ocean acidification on coral reef ecosystems is growing, gaps remain that limit our ability to translate scientific knowledge into management action. To guide solution-based research, we review the current knowledge of ocean acidification impacts on coral reefs alongside management needs and priorities. We use the world’s largest continuous reef system, Australia’s Great Barrier Reef (GBR), as a case study. We integrate scientific knowledge gained from a variety of approaches (e.g., laboratory studies, field observations, and ecosystem modelling) and scales (e.g., cell, organism, ecosystem) that underpin a systems-level understanding of how ocean acidification is likely to impact the GBR and associated goods and services. We then discuss local and regional management options that may be effective to help mitigate the effects of ocean acidification on the GBR, with likely application to other coral reef systems. We develop a research framework for linking solution-based ocean acidification research to practical management options. The framework assists in identifying effective and cost-efficient options for supporting ecosystem resilience. The framework enables on-the-ground OA management to be the focus, while not losing sight of CO₂ mitigation as the ultimate solution.

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A year in the life of a central California kelp forest: physical and biological insights into biogeochemical variability

Published 31 August 2016 Science Leave a Comment
Tags: algae, biogeochemistry, biological response, chemistry, field, North Pacific

Kelp forests are among the world’s most productive marine ecosystems, yet little is known about their biogeochemistry. This study presents a fourteen-month time series (July 2013–August 2014) of surface and benthic dissolved inorganic carbon and total alkalinity measurements, along with accompanying hydrographic measurements, from six locations within a central California kelp forest. We present ranges and patterns of variability in carbonate chemistry, including pH (7.70–8.33), pCO₂ (172–952 µatm), and the aragonite saturation state, Ω_Ar (0.94–3.91). Surface-to-bottom gradients in CO₂ system chemistry were as large as the spatial gradients throughout the bottom of the kelp forest. Dissolved inorganic carbon variability was the main driver of the observed CO₂ system variability. The majority of spatial variability in the kelp forest can be explained by advection of cold, dense high CO₂ waters into the bottom of the kelp forest, with deeper sites experiencing high CO₂ conditions more frequently. Despite the strong imprint of advection on the biogeochemical variability of the kelp forest, surface waters were undersaturated with CO₂ in the spring through fall, indicative of the strong role of photosynthesis on biogeochemical variability. We emphasize the importance of spatially distributed measurements for developing a process-based understanding of kelp forest ecosystem function in a changing climate.

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Interactive effects of temperature and pCO2 on sponges: from the cradle to the grave

Published 30 August 2016 Science Leave a Comment
Tags: biological response, laboratory, morphology, mortality, multiple factors, otherprocess, photosynthesis, Porifera, reproduction, respiration, temperature

As atmospheric CO₂ concentrations rise, associated ocean warming (OW) and ocean acidification (OA) are predicted to cause declines in reef-building corals globally, shifting reefs from coral-dominated systems to those dominated by less sensitive species. Sponges are important structural and functional components of coral reef ecosystems, but despite increasing field based evidence that sponges may be ‘winners’ in response to environmental degradation, our understanding of how they respond to the combined effects of OW and OA is limited. To determine the tolerance of adult sponges to climate change, four abundant Great Barrier Reef species were experimentally exposed to OW and OA levels predicted for 2100, under two CO₂ Representative Concentration Pathways (RCPs). The impact of OW and OA on early life history stages was also assessed for one of these species to provide a more holistic view of species impacts. All species were generally unaffected by conditions predicted under RCP6.0, although environmental conditions projected under RCP8.5 caused significant adverse effects; with elevated temperature decreasing the survival of all species, increasing levels of tissue necrosis and bleaching, elevating respiration rates and decreasing photosynthetic rates. OA alone had little adverse effect, even under RCP8.5 concentrations. Importantly, the interactive effect of OW and OA varied between species with different nutritional modes, with elevated pCO₂ exacerbating temperature stress in heterotrophic species but mitigating temperature stress in phototrophic species. This antagonistic interaction was reflected by reduced mortality, necrosis and bleaching of phototrophic species in the highest OW/OA treatment. Survival and settlement success of C. foliascens larvae were unaffected by experimental treatments, and juvenile sponges exhibited greater tolerance to OW than their adult counterparts. With elevated pCO₂ providing phototrophic species with protection from elevated temperature, across different life-stages, climate change may ultimately drive a shift in the composition of sponge assemblages towards a dominance of phototrophic species.

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Proxy-based reconstruction of surface water acidification and carbonate saturation of the Levant Sea during the Anthropocene

Published 30 August 2016 Science Leave a Comment
Tags: chemistry, Mediterranean, paleo

Highlights

The effect over ocean acidification by the damming of the Nile in the Southeast Mediterranean was examined.
Reduced variability of salinity/alkalinity and pH follows the damming.
Post-dam acidification rates comparable to other marginal seas.
Increased alkalinity maintaining aragonite super-saturated.

Abstract

Ocean Acidification (OA) in marginal seas and shelf environments is a multifaceted phenomenon, most notably due to watershed export in the form of riverine influx. In this study, we examined the effect of decadal changes in alkalinity driven by fresh water influx from the Nile River before and after its damming, as well as the effect of this change on OA of the South-East Mediterranean (SE-Med) shelf. Two independent data sets were used to calculate the change in pH and aragonite saturation (Ω_ar) from 1948 to 2002: observational salinity data from which total alkalinity (A_T) was calculated and a δ¹³C record of the endemic Dendropoma reefs from which dissolved inorganic carbon (DIC) was estimated. Our calculations indicate the development of a localized low pH/low Ω_ar zone along the SE-Med shelf, associated to the Nile plumes. Following the damming of the Nile, a distinct acidification trend is observed. We infer an acidification rate of −0.0022 ± 0.0002 yr⁻¹ in the SE-Med following the damming; this rate exceeds those of the open-oceans but is comparable to other marginal seas. This trend is significantly correlated with the increase in atmospheric CO₂ since the 1960s, supporting the notion of a more substantial atmospheric impact from that period onward. However, despite evident acidification, the modern level of high alkalinity helped to buffer the system and maintained high levels of pH and aragonite saturation all year long.

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Effects of co-varying diel-cycling hypoxia and pH on growth in the juvenile eastern oyster, Crassostrea virginica

Published 30 August 2016 Science Leave a Comment
Tags: adaptation, biological response, growth, laboratory, mollusks, morphology, mortality, multiple factors, North Atlantic, otherprocess, oxygen

Shallow water provides important habitat for many species, but also exposes these organisms to daily fluctuations in dissolved oxygen (DO) and pH caused by cycles in the balance between photosynthesis and respiration that can contribute to repeated, brief periods of hypoxia and low pH (caused by elevated pCO2). The amplitude of these cycles, and the severity and duration of hypoxia and hypercapnia that result, can be increased by eutrophication, and are predicted to worsen with climate change. We conducted laboratory experiments to test the effects of both diel-cycling and constant low DO and pH (elevated pCO2) on growth of the juvenile eastern oyster (Crassostrea virginica), an economically and ecologically important estuarine species. Severe diel-cycling hypoxia (to 0.5 mg O2 L-1) reduced shell growth in juvenile oysters, as did constant hypoxia (1.2 and 2.0 mg O2 L-1), although effects varied among experiments, oyster ages, and exposure durations. Diel-cycling pH reduced growth only in experiments in which calcite saturation state cycled to ≤0.10 and only during the initial weeks of these experiments. In other cases, cycling pH sometimes led to increased growth rates. Comparisons of treatment effects across multiple weeks of exposure, and during a longer post-experiment field deployment, indicated that juvenile oysters can acclimate to, and in some cases compensate for initial reductions in growth. As a result, some ecosystem services dependent on juvenile oyster growth rates may be preserved even under severe cycling hypoxia and pH.

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