This document summarizes research on the impact of climate change on primary production in the Arctic Ocean. It finds that Arctic primary production has increased in recent decades due to sea ice loss and longer growing seasons for phytoplankton. Under-ice phytoplankton blooms have also been observed that are much larger than open-water blooms and account for most Arctic primary production. These under-ice blooms are supported by enhanced light transmission through thinner first-year sea ice and melt ponds.
I designed a restoration and conservation plan to improve the island habitat and native special at the Cedar Creek/Lake Muhlenberg region of Allentown, PA. My research proposal was part of an interdisciplinary Sustainability Studies course where each student selected a real environmental issue facing the City of Allentown in which the Parks and Recreation Department desired to improve. My proposal was actually picked up, funded by, and put into action by various partners who contributed their expertise to the project, such as the Edge of the Woods Nursery in Allentown, a nonprofit organization Friends of the Allentown Parks, and the Lehigh Valley Chapter of the National Audubon Society
I designed a restoration and conservation plan to improve the island habitat and native special at the Cedar Creek/Lake Muhlenberg region of Allentown, PA. My research proposal was part of an interdisciplinary Sustainability Studies course where each student selected a real environmental issue facing the City of Allentown in which the Parks and Recreation Department desired to improve. My proposal was actually picked up, funded by, and put into action by various partners who contributed their expertise to the project, such as the Edge of the Woods Nursery in Allentown, a nonprofit organization Friends of the Allentown Parks, and the Lehigh Valley Chapter of the National Audubon Society
Global Climate Change Effects on the Mid-ContinentMichelle Mullin
A Stable Isotopic Record for the Badlands National Park was obtained across the Eocene-Oligocene Transition (Greenhouse to Icehouse global climate change). The isotopic record indicates changes in temperature and aridity and allows for direct comparision of a local continental climate response to a global climate change event. Effect on regional biota are also described. This presentation was given at the GSA North-Central/South-Central Combined Meeting 2010.
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment.
Impact of climate change in atmosphere of oceanAshish sahu
How does climate change effect the ocean?
5 ways that climate change affects the ocean
Higher temperatures are bad for fish — and for us.
Polar ice is melting.
Rising sea levels represent a slow, seemingly unstoppable threat.
Warming oceans alter currents.
Climate change is affecting the chemistry of seawater.
Influencing the distribution of productivity in the ocean.
Ocean productivity
What does ocean productivity need?
What does ocean productivity
need?
Major Players in ocean productivity
Global Climate Change Effects on the Mid-ContinentMichelle Mullin
A Stable Isotopic Record for the Badlands National Park was obtained across the Eocene-Oligocene Transition (Greenhouse to Icehouse global climate change). The isotopic record indicates changes in temperature and aridity and allows for direct comparision of a local continental climate response to a global climate change event. Effect on regional biota are also described. This presentation was given at the GSA North-Central/South-Central Combined Meeting 2010.
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment.
Impact of climate change in atmosphere of oceanAshish sahu
How does climate change effect the ocean?
5 ways that climate change affects the ocean
Higher temperatures are bad for fish — and for us.
Polar ice is melting.
Rising sea levels represent a slow, seemingly unstoppable threat.
Warming oceans alter currents.
Climate change is affecting the chemistry of seawater.
Influencing the distribution of productivity in the ocean.
Ocean productivity
What does ocean productivity need?
What does ocean productivity
need?
Major Players in ocean productivity
Presentation on status of Oceanic Blue Carbon science and knowledge gaps. Presented at the Global Ocean Commission's High Seas Symposium, 12 November 2015.
The presentation analyses the causative factors, phenomenon and effects of global warming and tries to find answers to this perplexing problem facing mankind
This is a small presentation on ocean acidification.It is a compilation of all materials(including present information) I collected related to it, any new information beside this or concerning it please comment.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
1. Impact of Climate Change on Marine
Primary Production in the Arctic
Malvi Golwala
29/11/2017
2. Introduction
• Primary production or net primary production (NPP) provides an
estimate of the organic material available to fuel the ocean’s food
webs.
• Changing climate due to global warming has many side effects in the
oceans as it does in the environment.
• Phytoplankton/Primary production is a link in carbon cycling between
living and inorganic stocks.
• Everyday, hundred million tons of carbon as CO2 is fixed into organic material
in the ocean by phytoplankton which is then transferred to marine ecosystems
by sinking and grazing.
2
3. Introduction
• Phytoplankton grow in well-illuminated upper ocean.
• The basic requirements for phytoplankton growth are nutrients like nitrogen,
phosphorus, silicon and iron
• From nutrient rich deep waters that are upwelled and mixed with upper ocean waters with
an exception in iron that it receives from mineral continental dust as well.
• Satellite ocean colour sensors over the past decade have recorded a
huge change in NPP from 1,930Tg C yr-1 to 190Tg C yr-1.
• Temperature change in the upper ocean brings a change in stratification which
influences nutrient availability for phytoplankton.
2
7. What’s going on in the Arctic?
• An yearly average increase of 27.5TgCyr-1 since 2003 and 35TgCyr-1
between 2006 and 2007 was observed in the Arctic.
• 30%: loss of sea ice and decreased minimum sea ice extent; which is due to
increasing temperature.
• 70%: longer phytoplankton growing season.
• Continuity in these trends would bring a 3-fold increase in in
productivity above 1998-2002 level
• Potentially altering marine ecosystem structure and the degree of pelagic-
benthic coupling.
1
10. Why is NPP increasing in the Arctic?
• Due to increasing temperatures, sea ice in Arctic is melting, due to
which:
• Sunlight is more available than before
• Increased upwelling of nutrients due to wind influence on surface waters
• More water-to-environment interaction to absorb nutrients
• All of these factors positively influence the growth of phytoplankton
and hence then increase in NPP.
11. Arctic models
• While studying nutrient availability for NPP, a lot of controversies
took place between these models.
• Some overestimated surface nitrate due to incapability of reproducing vertical
mixing dynamics.
• Nitrate could have been overestimated because of insufficient nutrient uptake
by phytoplankton which depends on both temperature and irradiance
• both of which are changing due to climate change.
• There was also an understanding that NPP would reduce in the Arctic
in the future due to low surface nutrients because of regular enhanced
freshening from ice melting.
3
12. Arctic models
• Some models that overestimated nitrate and the length of euphotic
zone, NPP should increase.
• There could also be a possibility that simulated NPP was low not due
to limiting factors but because of very little biomass which could have
been because of:
• Excessive loss of carbon from or in the upper water column
• Physiological response of phytoplankton to light showed that
subsurface plankton were acclimated to lower irradiance.
• Photo-acclimation, photosynthetic efficiency and max. chlorophyll.
3, 4
13. Plankton Blooms under Arctic Sea Ice
• Observations made on ICESCAPE cruise reported massive phytoplankton
blooms 0.8-1.3m beneath first year thick ice on Chukchi sea.
• ~4-fold greater than in open water; extended for >100 km into the ice pack.
• Biomass was greatest (>1000mgCm−3) near the ice/seawater interface and
was associated with nutrient depletion to depths of 20 to 30 m.
• indicative of phytoplankton, rather than ice algal, growth.
• Species composition of the bloom was distinct from that in the overlying ice
and was dominated by healthy pelagic diatoms.
• genera Chaetoceros, Thalassiosira, and Fragilariopsis.
5
15. Plankton Blooms under Arctic Sea Ice
• Phytoplankton biomass in open waters was lower than beneath the ice
and lowest at depths of 20-50m because of nutrient depletion near the
surface.
• The high oxygen (480mmoll−1) and low dissolved inorganic carbon
(2020mmoll −1) relative to the low phytoplankton concentrations
(~150mgCm−3) in these nutrient-depleted waters suggest that they had
recently supported high rates of phytoplankton growth.
5
16. Plankton Blooms under Arctic Sea Ice
• The light required by the under-ice bloom had to penetrate the fully
consolidated ice pack to reach the upper ocean.
• The fraction of first-year ice, is much thinner (0.5 to 1.8 m) than the
historically dominant multi-year ice pack (2 to 4 m), especially by a
high surface melt pond fraction (25 to 50%).
• Optical measurements showed that the ice beneath these melt ponds
transmitted 4-fold more incident light (47 to 59%) than adjacent snow
free ice (13 to 18%).
5
19. Plankton Blooms under Arctic Sea Ice
• Similar blooms were reported in the Barents Sea, Beaufort Sea, and
Canadian Arctic Archipelago, suggesting that under-ice blooms are
widespread.
• Thus, current rates of annual NPP on Arctic continental shelves, based
only on open water measurements, may be drastic underestimates,
being 10-fold too low in our study area.
• This solves the controversies by previous model that suggested low
NPP; which was due to lack of nutrients as they were being used by
blooms under ice.
5
20. Summary
Fig. 16: Changes in annual NPP between 1998-2012 Fig. 17: Map showing percentage change in annual
NPP between 1998-2012
7
21.
22. References
1. Arrigo, K., Dijken, G., Pabi, S. Impact of a shrinking Arctic ice cover on marine primary
production. Geophysical Research Letters. 35 (2008).
2. Behrenfeld, M., O’Malley, R., Siegel, D., McClain, C., Sarmiento, J., et al. Climate-driven
trends in contemporary ocean productivity. Nature. 444, 752-755 (2006).
3. Lee, Y., Matrai, P., et al. Net primary productivity estimates and environmental variables in the
Arctic Ocean: An assessment of coupled physical-biogeochemical models. Journal of
Geophysical Research: Oceans. 121, 8635-8669 (2016).
4. Palmer, Molly., Dijken, G., Mitchell, B., et al. Light and nutrient control of photosynthesis in
natural phytoplankton populations from the Chukchi and Beaufort seas, Arctic Ocean.
Limnology Oceanography. 58, 2185-2205 (2013).
5. Arrigo, K., Perovich, D., Pickart, R., et al. Massive Phytoplankton Blooms Under Arctic Sea
Ice. Science. 336, 1408 (2012).
6. Arrigo, K., Perovich, D., Pickart, R., et al. Phytoplankton blooms beneath the sea ice in the
Chukchi sea. Elsevier. 105, 1-16 (2014).
7. Arrigo, K., Dijken, G. Continued increases in Arctic Ocean primary production. Elsevier. 136,
60-70 (2015).
23. Arctic models
• A research which used 21
regional and global
biogeochemical models
assessed NPP, Zeu
(euphotic layer depth),
sea ice concentration,
nitrate concentration and
mixed layer depths.
3
Fig. 10: Log transformed distribution of in situ iNPP down to
100m
25. Summary
• Early in the season, wintertime nutrient replenishment and regeneration increases
nutrient concentrations throughout the water column, with low light preventing net
photosynthesis. As solar elevation increases throughout the spring, the presence of
extensive sea ice results in little to no light penetration to the surface ocean, and
phytoplankton do not grow
• Once the snow has melted and light beneath the 100% sea ice cover exceeds the
compensation irradiance for phytoplankton net growth, the spring bloom develops
under the sea ice. Melt pond formation enhances light penetration through the ice,
accelerating the time to reach the light threshold necessary for photosynthesis.
This is aided by shade-adaptation by phytoplankton: our data show that low light
availability initially limits P* m, but nutrients are high so phytoplankton can
synthesize additional Chl a, allowing them to absorb more of the available light.
This large investment in light-harvesting machinery increases the photosynthetic
efficiency, growth rate, and accumulation of phytoplankton biomass under the ice.
Nutrients begin to be depleted from the surface waters under the ice pack
4
26. Summary
• As the season progresses, UI phytoplankton utilize the enhanced light (both
from increased solar intensity in the summer as well as thinner sea ice) to
extend deeper in the water column, depleting nutrients at increasingly
greater depths. Our data show that phytoplankton may grow to depths of up
to 30 m under the ice as they move deeper to exploit nutrients, and also that
an SCM may also begin to develop once nutrients are exhausted in the
surface layers. The highest rates of P* M are associated with depths where
NO3 is still available and light is sufficient for photosynthesis. The
phytoplankton blooming under the ice are photo-acclimated to the low-light
conditions and maintain comparable levels of P* m, a*, a¯*, and Wm
between the surface and the SCM. Importantly, the phytoplankton
community growing near the surface has high light availability, whereas the
community growing in the subsurface has high nutrient availability
4
27. Summary
• Finally, the ice melts and retreats, stratifying the water column and isolating
the nutrient-poor surface waters from nutrient rich waters below. As
described in Arrigo et al. (in press), it may be that in areas where there was
significant phytoplankton production under the ice, no bloom develops in
surface waters of the MIZ because of depleted nutrients, and the SCM in the
MIZ and OW zone could be considered a remnant under-ice bloom. Our
photo-physiological data are consistent with this idea, because it shows that
phytoplankton that had been growing in the low-light UI environment are
already acclimated to the low-light conditions of the OW SCM: the OW
subsurface communities have higher growth rates, Chl a :POC ratios, Wm,
and a*, and lower a¯* than those in the OW surface. The final phase of this
new paradigm described in Arrigo et al. (in press) is that as the OW SCM
becomes progressively deeper throughout the season, shade-acclimated
phytoplankton continue to grow well at depths where both light and
nutrients are available
4
Editor's Notes
8. Anna Hickman: How will climate change impact marine primary production?
Phytoplankton populations and primary production (PP) are expected to change as a result of global warming. What do global numerical models predict will be the key changes, and why? Is the evidence from numerical models consistent with satellite-derived and in situ observations? Focus on one or more key mechanisms considered to be important for long-term variability in phytoplankton populations and/or primary production and discuss whether or not the evidence from numerical models, satellite-derived observations and insitu measurements are consistent or at odds with one another. You could consider regional or global scales, or both. What are the main gaps in our understanding and what could be done to improve our ability to predict what will happen next?
Doney, S. C. (2006). Oceanography: Plankton in a warmer world. Nature, 444(7120), 695–696. doi:10.1038/444695a
Edwards, M. (2001). Long-term and regional variability of phytoplankton biomass in the Northeast Atlantic (1960–1995). Ices Journal of Marine Science, 58(1), 39–49. doi:10.1006/jmsc.2000.0987
Krause, J. W., Lomas, M. W., & Nelson, D. M. (2009). Biogenic silica at the Bermuda Atlantic Time-series Study site in the Sargasso Sea: Temporal changes and their inferred controls based on a 15-year record. Global Biogeochemical Cycles, 23(3), GB3004. doi:10.1029/2008GB003236
Saba, V. S., Friedrichs, M. A. M., Carr, M.-E., Antoine, D., Armstrong, R. A., Asanuma, I., et al. (2010). Challenges of modeling depth-integrated marine primary productivity over multiple decades: A case study at BATS and HOT. Global Biogeochemical Cycles, 24(3), GB3020. doi:10.1029/2009GB003655
Steinacher, M., Joos, F., Froelicher, T. L., Bopp, L., Cadule, P., Cocco, V., et al. (2010). Projected 21st century decrease in marine productivity: a multi-model analysis. Biogeosciences, 7(3), 979–1005.
Ref. 7
teragrams of carbon a year
Ref. 7
The climate–plankton link is found primarily in the tropics and mid latitudes, where there is limited vertical mixing because the water column is stabilized by thermal stratification (that is, when light, warm waters overlie dense, cold waters). In these areas, the typically low levels of surface nutrients limit phytoplankton growth. Climate warming further inhibits mixing, reducing the upward nutrient supply and lowering productivity (Fig. 1a). At higher latitudes, phytoplankton are often light-limited because intense vertical mixing carries them hundreds of metres down into darkness where sunlight does not penetrate. In these regions, future warming and a greater influx of fresh water, mostly from increased precipitation and melting sea-ice, will contribute to reduced mixing that may actually increase productivity5 (Fig. 1b). In the same simulations, the geographical boundaries that separate specific marine ecosystems (the ocean equivalents of forests, grasslands and so on) migrate towards the poles, and productivity increases at high latitudes because of surface warming, enhanced freshwater input and reduced deep mixing.
Ref. 7
Due to global warming, arctic sea ice has reduced a 23% below the previous low
Ref. 6
Fig. 2: Bathymetry of Arctic Fig. 3: Minimum sea ice extent of 2006
Fig. 4: minimum sea ice extent of 2007
Fig. 5: difference in the minimum sea ice extent between 2006 and 2007
Ref. 6
1. Satellite derived sea ice, sea surface temperature and chlorophyll to a primary production algorithm.
Pelagic-benthic coupling, refers to the relationships between pelagic (water column) and benthic (sediment column) environments in aquatic systems.
Ref. 6
Annual primary production in
2006
(b) 2007
Ref. 6
One of the predictions is that: Given that surface nutrients in the Arctic are generally low, it is possible that future increases in production resulting from decreased sea ice extent and a longer phytoplankton growing season will slow as surface nutrient inventories are exhausted. This could reduce primary productivity in waters downstream of the Arctic, such as in the western north Atlantic.
The change in:(c) annual primary production (warm colored areas were more productive in 2007)
(d) length of the phytoplankton growing season between 2006 and 2007 was calculated for each pixel by subtracting the value in 2007 from that in 2006
Ref. 6
Ref. 8
But, the results did not show the same indicating that those were not the limiting factors of growth.
Ref. 8, 9
Depth-integrated phytoplankton biomass beneath the ice was extremely high
ICESCAPE: Impacts of Climate on EcoSystems and Chemistry of the Arctic Pacific Environment
Ref. 10
Fig. 1. Under-ice phytoplankton bloom observed during ICESCAPE 2011.
Particulate organic carbon (POC)
POC
Sea ice concentrations and station numbers are shown above (A) and (B); black dots represent sampling depths; blacklines denote potential density.Ref. 10
2. Thus, the ice-free portions of both transects likely harbored remnant under-ice blooms that had developed near the surface weeks earlier, when the region was ice-covered.
Ref. 10
2. Although the under-ice light field was less intense than in ice-free waters, it was sufficient to support the blooms of under-ice phytoplankton, which grew twice as fast at low light as their open ocean counterparts as they were acclimated to lower irradiance.
Ref. 10
Melt ponds and bare ice in the Chukchi Sea
(B) Schematic showing light transmission through bare ice and melt ponds. Bare ice consists of a thin granular surface scattering layer that gives ice its white appearance and a thick congelation ice layer that consists of columnar ice containing numerous brine inclusions. Sea ice beneath melt ponds has no surface scattering layer and the congelation ice is generally thinner. The albedo of bare ice (70%) and melt ponds (20%) includes specular reflection at the air–ice interface and scattering of light back out of the ice interior. Light not backscattered or absorbed within the congelation ice layer is transmitted to the upper water column. Because light transmitted through the ice spreads in all directions, light levels below bare ice and melt ponds converge within 10 m of the ice interface.
Ref. 11
Depth-integrated chlorophyll a (diamonds) and particulate organic carbon (squares) along (A) Transect1 and (B) Transect2. Gray are as denote samples collected within the under ice phytoplankton bloom.
Ref. 11
Ref. 10
Changes in annual NPP (Tg C yr1) in the Arctic Ocean between 1998 and timing of advance in the fall is consistent with increased ocean 2012 using the algorithm of Arrigo and Van Dijken (2011).(b) Maps showing (a) the rate of change in annual NPP (% yr1) each year from 1998 to 2012
Ref. 12
Ref. 8
Fig. 1. Under-ice phytoplankton bloom observed during ICESCAPE 2011.
Particulate organic carbon (POC) and (C) nitrate from transect 1
POC and (D) nitrate from transect 2
Sea ice concentrations and station numbers are shown above (A) and (B); black dots represent sampling depths; blacklines denote potential density.Ref. 10