2014 ndi 6ws fitzmier, Lundberg, Abelkop deep ocean neg privatization cp
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eutrophication turnAlgae cultivation leads to eutrophication of water systems – kills seagrasses that are key to maintain marine lifeNRC 12 (National Research Council, “Sustainable Development of Algal Biofuels in the United States”, Committee on the Sustainable Development of Algal Biofuels, 2012, http://www.laboratoryequipment.com/sites/laboratoryequipment.com/files/legacyimages/101412_report.pdf) Large-scale algae cultivation requires the provision of large quantities of nutrients, especially nitrogen and phosphorus, to ensure high yield (see section Nutrients in Chapter 4). Even where nitrogen and phosphorus are not in oversupply, the total nutrient concentrations in algal biomass will be high. Although accidental release of cultivation water into surface water and soil is unlikely, such an event could lead to eutrophication of downstream freshwater and marine ecosystems, depending on the proximity of algal ponds to surface and grormdwater sources. Eutrophication occurs when a body of water receives high concentrations of inorganic nutrients, particularly nitrogen and phosphorus, stimulating algal growth and resulting in excessive algal biomass. As the algae die off and decompose, high levels of organic matter and the decomposition processes deplete oxygen in the water and result in anoxic conditions (Smith, 2003; Breitburg et al., 2009; Rabalais et al., 2009; Smith and Schindler, 2009). In some cases, eutrophication-induced changes could be difficult or impossible to reverse if altemative stable states can occur in the affected ecosystem (Scheffer et al., 2001; Carpenter, 2005). Eutrophication effects have been well studied, and they depend on the nutrient loadings to the receiving waters and the volume and residence time of water of these systems (Smith et al., 1999; Smith, 2003). High nutrient loading could lead to anoxia in the deep cool portion of lakes or in hypoxia in the receiving water bodies. Potential biotic effects of eutrophication include changes in algal density and in the structure and biomass of the broader ecological community (Scheffer et al., 1997; Reynolds et al., 2002; Smayda and Reynolds, 2003). Fish yield is affected by phytoplanktonl biomass and by the nutrient ratios in the edibility of phytoplankton (Oglesby, 1977; Bachmann et al., 1996). Nutrient levels play a key role in determining the productivity and structure of the primary producing community in estuaries and coastal marine waters (Deegan et al., 2002; Smith, 2006) and by extension, the productivity and structure of higher trophic levels. Nutrient- enriched shallow marine systems tend to have a reduced seagrass community (Burkholder et al., 1992; Hauxwell et al., 2003) because elevated nitrogen concentrations and loadings adversely affect seagrass (Efroymson et al., 2007 and references cited therein). In high-nitrate environments, seagrasses can be shaded by epiphytic algae and macroalgae (Drake et al., 2003) or sometimes by phytoplankton blooms (Nixon et al., 2001). Seagrasses affect the entire estuarine food web because they stabilize sediments; serve as habitats and temporary nurseries for fish and shellfish; are sources of food for fish, waterfowl, benthic invertebrates, or manatees and provide refuges from predation. Eutrophication and other nutrient-related effects could be a concem for cultivation of microalgae or macroalgae in large suspended offshore enclosures (for example, Honkanen and Helminen, 2000). [note to self: seagrass impact card? regular ecosystems impact card?] toxins turnAlgae cultivation leads to water contamination – dangerous to human health and turns pollutionNRC 12 (National Research Council, “Sustainable Development of Algal Biofuels in the United States”, Committee on the Sustainable Development of Algal Biofuels, 2012, http://www.laboratoryequipment.com/sites/laboratoryequipment.com/files/legacyimages/101412_report.pdf) Some compounds present in algal ponds or photobioreactors could be toxic to humans or other organisms depending on exposure levels. Herbicides often are added to open systems to prevent growth of macrophytes and for selective control of algae (NALMS, 2004), but their application likely would be regulated as in the case of agriculture. If wastewater or oil well- produced water (Shpiner et al., 2009) is used as a water source for algae cultivation, heavy metals could be present. Wastewater could include industrial effluent (Chirmasamy et al., 2010) and municipal wastewater that has undergone various levels of treatment (Wang et al., 2010). The composition and amount of toxicants vary by the type of wastewater. Produced water (water contained in oil and gas reservoirs that is produced in conjunction with the fossil fuel) may contain high levels of organic compounds, oil and grease, boron, and ammonia (NH3) (Drewes et al., 2009). Many algal species including cyanobacteria, diatoms, and chlorophytes can bioconcentrate heavy metals (Watras and Bloom, 1992; Vymazal, 1995; Mathews and Fisher, 2008). Mercury could be introduced into feedstock production waters if unscrubbed flue gas from coal-fired power plants is used as a carbon dioxide (CO2) source (0'Dowd et al., 2006). Therefore, potential risks from using each type of produced water need to be identified so that adequate containment and mitigation measures can be implemented in cultivation and processing. Waterbome toxicants (toxic substances made or introduced into the environment anthropogenically, not including algal toxins) potentially pose risk to humans or other animals if exposures occur. Occupational exposures could be significant, especially during the harvesting phase. Thus, monitoring of toxic compounds in the culture media is important. Potential toxicity exposure to animals through drinking is discussed in the section on terrestrial biodiversity. The release of culture waters to natural environments could pose other risks to animal consumers. Toxic concentrations and doses for various chemicals are available in the Environmental Protection Agency (EPA) Integrated Risk Information System database for humans (EPA, 2012) in Suter and Tsao (1996) for aquatic biota, in Sample et al. (1996) for terrestrial wildlife, and in other government and independent compilations. Cultivation of algae in wastewater may require special handling and means of containment. Monitoring for the presence of toxicants or pathogens might be necessary to ensure the quality of the culture water. 1
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