Editing SeaWiFS (section)

==Applications==
[[File:CO2 pump hg.svg|thumbnail|Biological pump, air-sea cycling and sequestering of CO<sub>2</sub>]]
Estimating the amount of global or regional chlorophyll, and therefore phytoplankton, has large implications for climate change and fisheries production. Phytoplankton play a huge role in the uptake of the world's carbon dioxide, a primary contributor to [[climate change]]. A percentage of these phytoplankton sink to ocean floor, effectively taking carbon dioxide out of the atmosphere and sequestering it in the deep ocean for at least a thousand years. Therefore, the degree of [[primary production]] from the ocean could play a large role in slowing climate change. Or, if primary production slows, climate change could be accelerated. Some have proposed [[Iron Fertilization|fertilizing the ocean with iron]] in order to promote phytoplankton blooms and remove carbon dioxide from the atmosphere. Whether these experiments are undertaken or not, estimating chlorophyll concentrations in the world's oceans and their role in the ocean's [[biological pump]] could play a key role in our ability to foresee and adapt to climate change.

Phytoplankton is a key component in the base of the oceanic [[food chain]] and oceanographers have hypothesized a link between oceanic chlorophyll and fisheries production for some time.<ref>{{cite journal|last=Ryther|first=J. H.|title=Photosynthesis and Fish Production in the Sea|journal=Science|date=3 October 1969|volume=166|issue=3901|pages=72–76|doi=10.1126/science.166.3901.72|pmid=5817762|bibcode = 1969Sci...166...72R |s2cid=30964270}}</ref> The degree to which phytoplankton relates to marine fish production depends on the number of trophic links in the food chain, and how efficient each link is. Estimates of the number of trophic links  and trophic efficiencies from phytoplankton to commercial fisheries have been widely debated, though they have been little substantiated.<ref>{{cite journal|last=Pauly|first=Daniel|title=One hundred million tonnes of fish, and fisheries research|journal=Fisheries Research|date=1 January 1996|volume=25|issue=1|pages=25–38|doi=10.1016/0165-7836(95)00436-X}}</ref>  More recent research suggests that positive relationships between {{not a typo|chlorophyll a}} and fisheries production can be modeled<ref>{{cite journal|last=Drexler|first=Michael|author2=Ainsworth, Cameron H. |author3=Davies, Andrew |title=Generalized Additive Models Used to Predict Species Abundance in the Gulf of Mexico: An Ecosystem Modeling Tool|journal=PLOS ONE|date=14 May 2013|volume=8|issue=5|pages=e64458|doi=10.1371/journal.pone.0064458|pmid=23691223|pmc=3653855|bibcode=2013PLoSO...864458D|doi-access=free}}</ref>  and can be very highly correlated when examined on the proper scale. For example, Ware and Thomson (2005) found an r<sup>2</sup> of 0.87 between resident fish yield (metric tons km-2) and mean annual {{not a typo|chlorophyll a}} concentrations (mg m-3).<ref>{{cite journal|last=Ware|first=D. M.|title=Bottom-Up Ecosystem Trophic Dynamics Determine Fish Production in the Northeast Pacific|journal=Science|date=27 May 2005|volume=308|issue=5726|pages=1280–1284|doi=10.1126/science.1109049|bibcode = 2005Sci...308.1280W|pmid=15845876|s2cid=9695575}}</ref> Others have found the Pacific's Transition Zone Chlorophyll Front (chlorophyll density of 0.2&nbsp;mg m-3) to be defining feature in loggerhead turtle distribution.<ref>{{cite journal|last=Polovina|first=Jeffrey J|author2=Howell, Evan |author3=Kobayashi, Donald R |author4= Seki, Michael P |title=The transition zone chlorophyll front, a dynamic global feature defining migration and forage habitat for marine resources|journal=Progress in Oceanography|date=1 January 2001|volume=49|issue=1–4|pages=469–483|doi=10.1016/S0079-6611(01)00036-2|bibcode = 2001PrOce..49..469P }}</ref>