scholarly journals Limacina helicina shell dissolution as an indicator of declining habitat suitability owing to ocean acidification in the California Current Ecosystem

2014 ◽  
Vol 281 (1785) ◽  
pp. 20140123 ◽  
Author(s):  
N. Bednaršek ◽  
R. A. Feely ◽  
J. C. P. Reum ◽  
B. Peterson ◽  
J. Menkel ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Natural Environment ◽  
Habitat Suitability ◽  
California Current ◽  
Strong Positive Correlation ◽  
Near Shore ◽  
Biological Impacts ◽  
Biological Sampling ◽  
Physical And Chemical ◽  
Chemical Water

Few studies to date have demonstrated widespread biological impacts of ocean acidification (OA) under conditions currently found in the natural environment. From a combined survey of physical and chemical water properties and biological sampling along the Washington–Oregon–California coast in August 2011, we show that large portions of the shelf waters are corrosive to pteropods in the natural environment. We show a strong positive correlation between the proportion of pteropod individuals with severe shell dissolution damage and the percentage of undersaturated water in the top 100 m with respect to aragonite. We found 53% of onshore individuals and 24% of offshore individuals on average to have severe dissolution damage. Relative to pre-industrial CO 2 concentrations, the extent of undersaturated waters in the top 100 m of the water column has increased over sixfold along the California Current Ecosystem (CCE). We estimate that the incidence of severe pteropod shell dissolution owing to anthropogenic OA has doubled in near shore habitats since pre-industrial conditions across this region and is on track to triple by 2050. These results demonstrate that habitat suitability for pteropods in the coastal CCE is declining. The observed impacts represent a baseline for future observations towards understanding broader scale OA effects.

scholarly journals Microhabitat selection and distribution of functional feeding groups of mayfly larvae (Ephemeroptera) in lotic karst habitats

2018 ◽  
pp. 17 ◽  
Author(s):  
Marina Vilenica ◽  
Andreja Brigić ◽  
Michel Sartori ◽  
Zlatko Mihaljević
Keyword(s):  
Water Current ◽  
Functional Feeding Groups ◽  
Feeding Strategies ◽  
Microhabitat Selection ◽  
Dinaric Karst ◽  
Feeding Groups ◽  
Microhabitat Preferences ◽  
One Year ◽  
Physical And Chemical ◽  
Chemical Water

Research examining mayfly ecology in karst streams and rivers has increased in recent years, though microhabitat preferences remain poorly characterized. We examined mayfly assemblage taxonomy, functional feeding groups and microhabitat preferences in two contrasting lotic Dinaric karst catchments, one pristine and one anthropogenically impacted. At monthly intervals over a one-year period, all major microhabitats (i.e. dominated by boulders, cobbles, sand, silt, mosses, or angiosperms) were sampled at sites spanning springs, upper, middle and lower river reaches, and tufa barriers. In both catchments, mayfly species richness was comparable among microhabitats, while mayfly abundance was highest on mosses and lowest on silt. NMDS ordination did not group assemblages according to microhabitat type, which may reflect the greater influence of physical and chemical water properties. In both catchments and all microhabitats, mayfly assemblages were dominated by grazers/scrapers at upstream sites and by detritivores at downstream sites. Active filter feeders were more abundant in microhabitats with silt substrates and lower current velocities. This study demonstrated that certain mayfly species strongly preferred a specific microhabitat type, reflecting their water current preferences and feeding strategies, while other species shifted between microhabitats, likely in search of food resources and shelter. The results emphasize the importance of habitat heterogeneity in supporting diverse communities in karst rivers.

scholarly journals Should I stay or should I go? Modelling year-round habitat suitability and drivers of residency for fin whales in the California Current

2017 ◽  
Vol 23 (10) ◽  
pp. 1204-1215 ◽  
Author(s):  
Kylie L. Scales ◽  
Gregory S. Schorr ◽  
Elliott L. Hazen ◽  
Steven J. Bograd ◽  
Peter I. Miller ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
California Current ◽  
Fin Whales

scholarly journals Persistent spatial structuring of coastal ocean acidification in the California Current System

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
F. Chan ◽  
J. A. Barth ◽  
C. A. Blanchette ◽  
R. H. Byrne ◽  
F. Chavez ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Current System ◽  
California Current ◽  
Coastal Ocean ◽  
California Current System ◽  
Spatial Structuring

scholarly journals Laju Pertumbuhan Rumput Laut Gracilaria sp Melalui Budidaya IMTA (Integrated Multi Trophic Aquaculture) di Pantai Geger, Nusa Dua, Kabupaten Badung, Bali

2017 ◽  
Vol 4 (2) ◽  
pp. 191
Author(s):  
Kadek Yudiastuti ◽  
I Gusti Bagus Sila Dharma ◽  
Ni Luh Putu Ria Puspitha
Keyword(s):  
Water Quality ◽  
Design Method ◽  
Salt Water ◽  
Mesh Size ◽  
General Characteristic ◽  
Quality Parameters ◽  
Seaweed Cultivation ◽  
Randomized Design ◽  
Physical And Chemical ◽  
Chemical Water

Gracilaria sp is red alga which belong to class rhodophyceae. It can grow in shallow salt water with a general characteristic is having a cylindrical and branched thallus form. Seaweed cultivation can be performed through IMTA (Integrated Multi Trophic Aquaculture) method. The basic principle of cultivation through the IMTA method is utilizing service of the low thropic level species in marine ecosystems, such as shells and seaweed.  This method is believed to be able to overcome the environmental problems caused by cultivation activities, such as feces and uneaten feed. This research was perfomed 45 days, from February 25 to April 11, 2017. It was held at Geger Beach, Nusa Dua, Badung Regency, Bali, using a complete randomized design method that consist of three treatments and three repetition for each treatment. Treatment control (T1) consisted of 10 bunches of seaweed 100 grams without the abalone, treatement 2 (T2) consisted of 10 bunches of seaweed 100 grams and 20 abalones and treatement 3 (T3) consisted of 10 bunches of seaweed 100 grams and 40 abalones. The result showed that specific growth rate in Gracilaria sp.  was highest in treatment T1, compared to treatment T2 and T3. This was caused by the cage construction of abalone amd the present of small mesh size net to cover the seaweed  planting, which made the growth was not optimal.  However, the use of a nets system in seaweed cultivation could minimize the loss of thallus. It was proved by the survival rate of seaweed in first, second and third, that is averagely high, ranging from 90% to 100%. Physical and chemical water quality parameters are also measured, and It showed that the water quality was suitable for the cultivation of both, seaweed and abalone.

scholarly journals Analisa Kualitas Air Fisika dan Kimia di Danau Pampait (Physical and Chemical Water Quality Analysis in Lake Pampait)

2020 ◽  
Vol 7 (1) ◽  
pp. 75-87
Author(s):  
Ummi Suraya ◽  
Lilia Lilia
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Aquatic Organisms ◽  
Quality Analysis ◽  
Middle Section ◽  
Water Quality Analysis ◽  
Average Temperature ◽  
Physical And Chemical ◽  
Chemical Water ◽  
Quality Measurements

This study aims to determine the water condition of Lake Pampait, KamelohBaru Village, Sebangau District, Palangka Raya City, measured from physical and chemical water quality as a measure of the condition of the water quality in Lake Pampait. The study was conducted for approximately 2 (two) months, namely from June to July 2018. Sampling was carried out in 3 (three) stations, namely inlet (station I), middle section (station II) and outlets (station III). The physical and chemical water quality measurements are carried out directly, namely temperature, brightness, depth, pH (Degrees of Acidity) and DO (Dissolved Oxygen) while indirectly or analyzed in the laboratory are PO4 (Phosphate), NO3 (Nitrate) and NH3 (Nitrate) Ammonia). The results of research on physical and chemical water quality is an average temperature of 23.7 oC. Brightness 28.75 cm, Depth 4.25 m, Degree of Acidity (pH) with an average of 6.03, and Dissolved Oxygen (DO) 2.93 mg/L, Phosphate (PO4), Nitrate (NO3), and Ammonia (NH3) ) 0.932 mg/L, it can be concluded that Lake Pampait can be said to be still not polluted and is still considered good for the life of fish and other aquatic organisms.

scholarly journals Nitrogen enrichment offsets direct negative effects of ocean acidification on a reef-building crustose coralline alga

2018 ◽  
Vol 14 (7) ◽  
pp. 20180371 ◽  
Author(s):  
Maggie D. Johnson ◽  
Robert C. Carpenter
Keyword(s):  
Ocean Acidification ◽  
Nutrient Enrichment ◽  
Multiple Stressors ◽  
Crustose Coralline Alga ◽  
Nitrogen Enrichment ◽  
Coralline Alga ◽  
Ambient Conditions ◽  
Negative Effects ◽  
Near Shore ◽  
Near Future

Ocean acidification (OA) and nutrient enrichment threaten the persistence of near shore ecosystems, yet little is known about their combined effects on marine organisms. Here, we show that a threefold increase in nitrogen concentrations, simulating enrichment due to coastal eutrophication or consumer excretions, offset the direct negative effects of near-future OA on calcification and photophysiology of the reef-building crustose coralline alga, Porolithon onkodes . Projected near-future pCO 2 levels (approx. 850 µatm) decreased calcification by 30% relative to ambient conditions. Conversely, nitrogen enrichment (nitrate + nitrite and ammonium) increased calcification by 90–130% in ambient and high pCO 2 treatments, respectively. pCO 2 and nitrogen enrichment interactively affected instantaneous photophysiology, with highest relative electron transport rates under high pCO 2 and high nitrogen. Nitrogen enrichment alone increased concentrations of the photosynthetic pigments chlorophyll a , phycocyanin and phycoerythrin by approximately 80–450%, regardless of pCO 2 . These results demonstrate that nutrient enrichment can mediate direct organismal responses to OA. In natural systems, however, such direct benefits may be counteracted by simultaneous increases in negative indirect effects, such as heightened competition. Experiments exploring the effects of multiple stressors are increasingly becoming important for improving our ability to understand the ramifications of local and global change stressors in near shore ecosystems.

Water quality in two catchment areas: a case study of Crocodile (West) and Berg Catchment areas

2014 ◽  
Vol 9 (4) ◽  
pp. 526-533
Author(s):  
S. A. Akinseye ◽  
J. T. Harmse
Keyword(s):  
Water Quality ◽  
Catchment Area ◽  
Pearson Correlation ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Western Cape ◽  
Catchment Areas ◽  
Domestic Use ◽  
Physical And Chemical ◽  
Chemical Water

This study focuses on the different physical and chemical water quality parameters of two catchment areas centring on the extent of water pollution in the two basins. Data containing physical and chemical water quality parameters for the Crocodile (West) Catchment area (Gauteng) and the Berg Catchment area (Western Cape) at reconnaissance level of detail were collected from the Department of Water Affairs (DWA) over a period of 5 years, 2007–2011. The relevant data were screened and sorted using the SPSS Software Version 2.0. The data were subjected to ANOVA statistics to search for significant variations in the water quality parameters of concern across the study period in each of the catchment area. The physical and chemical analyses were carried out to determine whether the water quality falls within the total water quality range as prescribed by DWA and WHO for domestic use. Pearson correlation analyses were used to determine the relationship between physical and chemical water quality parameters and the rainfall data over the study period.

scholarly journals The Impacts of Ocean Acidification on Marine Ecosystems and Reliant Human Communities

2020 ◽  
Vol 45 (1) ◽  
pp. 83-112 ◽  
Author(s):  
Scott C. Doney ◽  
D. Shallin Busch ◽  
Sarah R. Cooley ◽  
Kristy J. Kroeker
Keyword(s):  
Climate Change ◽  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Information Needs ◽  
Field Studies ◽  
Future Climate Change ◽  
Future Research ◽  
Shoreline Protection ◽  
Biological Impacts ◽  
Estuarine Coastal

Rising atmospheric carbon dioxide (CO2) levels, from fossil fuel combustion and deforestation, along with agriculture and land-use practices are causing wholesale increases in seawater CO2 and inorganic carbon levels; reductions in pH; and alterations in acid-base chemistry of estuarine, coastal, and surface open-ocean waters. On the basis of laboratory experiments and field studies of naturally elevated CO2 marine environments, widespread biological impacts of human-driven ocean acidification have been posited, ranging from changes in organism physiology and population dynamics to altered communities and ecosystems. Acidification, in conjunction with other climate change–related environmental stresses, particularly under future climate change and further elevated atmospheric CO2 levels, potentially puts at risk many of the valuable ecosystem services that the ocean provides to society, such as fisheries, aquaculture, and shoreline protection. Thisreview emphasizes both current scientific understanding and knowledge gaps, highlighting directions for future research and recognizing the information needs of policymakers and stakeholders.

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