Subtropical ocean gyres, the areas being suggested for Ocean Iron Fertilization (OIF) in this article and in particular their convergence zones, are ideal for the large scale mariculture operations which use nutricline waters. OIF and large scale mariculture, such as OMEGA<http://blog.marinexplore.com/nasa-omega-project-the-ocean-as-a-platform-for-biofuel/>style projects, have significant technical and strategic differences. Yet, there may be a symbioses available between them.
It is important to keep in mind that the biomass produced through OIF has significant global commercial value, as well as significant GE importance beyond the biomass (carbon) being simply sequestered into the ocean floor ooze. On the commercial side, the induced algal biomass can feed a wide variety of commercially important organisms such as copepods, krill and bivalves. Copepod, rotifers and kril, in turn, would allow for the cultivation of higher organisms such as tuna/salmon. Further, the gyres' convergence zone(s) are the calmest oceanic waters on the planet and offer a *sunny lake like working environment throughout the year*. This combination of predictable working conditions, abundant nutrient availability and ample solar radiation makes the gyres' convergence zone(s) prime areas for mariculture operations of vast size. *The commercial potential of the biomass should not be devalued nor should the biomass be routinely sent to the floor. The potential revenue generation from the biomass would support (1) major scientific research efforts into Earth System Sciences, (2) globally needed food, biofuel, organic fertilizer etc. And, (3) provide globally needed jobs and taxes. Routinely sending this nutrient to the floor would be a colossal waste. Yet, the combination of OIF and OMEGA like operations may offer an adjustable means for seasonal and or emergancy CO2 mitigation. * * * * * * * * * First, It is important to keep in mind that the main reason the Sargasso Sea exists (in the North Atlantic Gyre) is the nutrient feed coming up from the GoMex via the Gulf Stream. It may be reasonable to speculate that if mariculture operations of large scale were to be established and maintained in the worlds' gyre convergence zones, large 'wild' Sargasso forests may take root (so to speak) in those areas as a response to the presence of the OMEGA operations SRM effect on the surrounding environment. The physical shading effect, thus surface water temperature reduction, provided by the OMEGA installations will cause an upward drift of the nutricline in the area of the installation(s). This will, in turn, possibly make that nutrient more easily available to surface organisms such as macroalgae. Mineral needs and total CO2 transfer will need to be monitored to insure maximum control and efficiency. Second, The operation of large scale mariculture operations within the gyres, along with the potential 'wild' macroalgal growth within and around such installations, would establish a baseline CO2 usage which can be large enough to offset global anthroprogenic CO2 emissions. If and when there is a need to go beyond the base line operation, such as the emergence of a tipping point, OIF could be temporarily employed to help draw down the needed atmospheric CO2. Thus, between the two methods, variable and on demand CO2 reduction rates would be possible. The following paper describes the importance of the nutricline to pCO2 reduction and a potential nutrient availibility decline due to increased thermal stratification: The role of nutricline depth in regulating the ocean carbon cycle<http://www.pnas.org/content/105/51/20344.short> *"Carbon uptake by marine phytoplankton, and its export as organic matter to the ocean interior (i.e., the “biological pump”), lowers the partial pressure of carbon dioxide (pCO2) in the upper ocean and facilitates the diffusive drawdown of atmospheric CO2. Conversely, precipitation of calcium carbonate by marine planktonic calcifiers such as coccolithophorids increases pCO2 and promotes its outgassing (i.e., the “alkalinity pump”). Over the past ≈100 million years, these two carbon fluxes have been modulated by the relative abundance of diatoms and coccolithophores, resulting in biological feedback on atmospheric CO2and Earth's climate; yet, the processes determining the relative distribution of these two phytoplankton taxa remain poorly understood. We analyzed phytoplankton community composition in the Atlantic Ocean and show that the distribution of diatoms and coccolithophorids is correlated with the nutricline depth, a proxy of nutrient supply to the upper mixed layer of the ocean. Using this analysis in conjunction with a coupled atmosphere–ocean intermediate complexity model, we predict a dramatic reduction in the nutrient supply to the euphotic layer in the coming century as a result of increased thermal stratification. Our findings indicate that, by altering phytoplankton community composition, this causal relationship may lead to a decreased efficiency of the biological pump in sequestering atmospheric CO2, implying a positive feedback in the climate system. These results provide a mechanistic basis for understanding the connection between upper ocean dynamics, the calcium carbonate-to-organic C production ratio and atmospheric pCO2 variations on time scales ranging from seasonal cycles to geological transitions.".* * * * * * * A combined OMEGA/OIF installation, within the gyre convergence zone, should be able to routinely and flexibly control the nutricline depth within their areas of operation. This would counter, to some degree and only within the OMEGA/OIF fields of operation, "*a dramatic reduction in the nutrient supply to the euphotic layer in the coming century as a result of increased thermal stratification.".* With this, a reliable and flexible means of GE can be established while providing globally important commercial commodities and opportunities and avoid increased thermal stratification within critical oceanic zones. The degree of speculation within this proposal is probably modest compared with many other GE concepts. It is important to note that this proposal is the only one which can offer the full combination of: (1) a means to be self funded; (2) a means to meet seasonal and* or emergency* environmental (GE) needs; (3) a means to addresses the rapidly expanding global demand for basic commodities such as food, biofuel, organic fertilizer and fresh water; The authors, Hardman-Mountford NJ, et al., state: *"Our results highlight the requirement for a fuller consideration of marine ecosystem interactions and feedbacks, beyond simply the stimulation of surface blooms, in the evaluation of putative geo-engineering approaches.". **I highly agree*. Best, Michael On Friday, November 1, 2013 9:28:17 AM UTC-7, andrewjlockley wrote: > > http://planetearth.nerc.ac.uk/news/story.aspx?id=1544&cookieConsent=A > > Link above is plain English. Abstract below > > Impacts of light shading and nutrient enrichment geo-engineering > approaches on the productivity of a stratified, oligotrophic ocean > ecosystem. > > Authors > > Hardman-Mountford NJ, et al. Show all > > Journal > > J R Soc Interface. 2013 Oct 16;10(89):20130701. doi: > 10.1098/rsif.2013.0701. Print 2013. > > Affiliation > > Plymouth Marine Laboratory, , Prospect Place, Plymouth PL1 3DH, UK. > > Abstract > > Geo-engineering proposals to mitigate global warming have focused either > on methods of carbon dioxide removal, particularly nutrient fertilization > of plant growth, or on cooling the Earth's surface by reducing incoming > solar radiation (shading). Marine phytoplankton contribute half the Earth's > biological carbon fixation and carbon export in the ocean is modulated by > the actions of microbes and grazing communities in recycling nutrients. > Both nutrients and light are essential for photosynthesis, so understanding > the relative influence of both these geo-engineering approaches on ocean > ecosystem production and processes is critical to the evaluation of their > effectiveness. In this paper, we investigate the relationship between light > and nutrient availability on productivity in a stratified, oligotrophic > subtropical ocean ecosystem using a one-dimensional water column model > coupled to a multi-plankton ecosystem model, with the goal of elucidating > potential impacts of these geo-engineering approaches on ecosystem > production. We find that solar shading approaches can redistribute > productivity in the water column but do not change total production. > Macronutrient enrichment is able to enhance the export of carbon, although > heterotrophic recycling reduces the efficiency of carbon export > substantially over time. Our results highlight the requirement for a fuller > consideration of marine ecosystem interactions and feedbacks, beyond simply > the stimulation of surface blooms, in the evaluation of putative > geo-engineering approaches. > > PMID > > 24132201 [PubMed - in process] > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
