Complications Ocean fertilization

1 complications

1.1 outright opposition
1.2 efficiency
1.3 side effects

1.3.1 algal blooms
1.3.2 impact on fisheries
1.3.3 ecosystem disruption
1.3.4 cloud formation

complications

while manipulation of land ecosystem in support of agriculture benefit of humans has long been accepted (despite side effects), directly enhancing ocean productivity has not. among reasons are:

outright opposition

according lisa speer of natural resources defense council, “there limited amount of money, of time, have deal problem....the worst possible thing climate change technologies invest in doesn’t work , has big impacts don’t anticipate.”

in 2009  aaron strong, sallie chisholm, charles miller , john cullen opined in nature ...fertilizing oceans iron stimulate phytoplankton blooms, absorb carbon dioxide atmosphere , export carbon deep sea — should abandoned.

efficiency

algal cell chemical composition 106 carbon: 16 nitrogen: 1 phosphorus: 0.0001 iron atoms. in other words, each atom of iron captures 1,060,000 atoms of carbon, while 1 nitrogen atom captures 6. experimental iron fertilisation in hnlc regions has been supplied excess iron cannot utilized before scavenged. organic material produced less if ratio of nutrients above achieved. fraction of available nitrogen (because of iron scavenging) drawn down. in culture bottle studies of oligotrophic water, adding nitrogen , phosphorus can draw down considerably more nitrogen per dosing. export production small percentage of new primary production , in case of iron fertilization, iron scavenging means regenerative production small. macronutrient fertilisation, regenerative production expected large , supportive of larger total export. other losses can reduce efficiency.

side effects
algal blooms

toxic algal blooms common phenomena in coastal areas. fertilization trigger such blooms. chronic fertilization risk creation of dead zones, such 1 @ mouth of missouri river.

impact on fisheries

adding urea ocean can cause phytoplankton blooms serve food source zooplankton , in turn feed fish. may increase fish catches. however, if cyanobacteria , dinoflagellates dominate phytoplankton assemblages considered poor quality food fish increase in fish quantity may not large. evidence links iron fertilization volcanic eruptions increased fisheries production. other nutrients metabolized along added nutrient(s), reducing presence in fertilized waters.

krill populations have declined dramatically since whaling began. sperm whales transport iron deep ocean surface during prey consumption , defecation. sperm whales have been shown increase levels of primary production , carbon export deep ocean depositing iron-rich faeces surface waters of southern ocean. faeces causes phytoplankton grow , take carbon. phytoplankton nourish krill. reducing abundance of sperm whales in southern ocean, whaling resulted in 2 million tonnes of carbon remaining in atmosphere each year.

ecosystem disruption

many locations, such tubbataha reef in sulu sea, support high marine biodiversity. nitrogen or other nutrient loading in coral reef areas can lead community shifts towards algal overgrowth of corals , ecosystem disruption, implying fertilization must restricted areas in vulnerable populations not put @ risk.

as phytoplankton descend water column, decay, consuming oxygen , producing greenhouse gases methane , nitrous oxide. plankton-rich surface waters warm surface layer, affecting circulation patterns.

cloud formation

many phytoplankton species release dimethyl sulfide, escapes atmosphere forms sulfate aerosols , encourages cloud formation, reduce warming. however, substantial increases in dms reduce global rainfall, according global climate model simulations, while halving temperature increases of 2100.