TITLE:
Appropriate Location and Deployment Method for Successful Iron Fertilization
AUTHORS:
Tai-Jin Kim
KEYWORDS:
Appropriate Location, Deployment Method, Iron Fertilization, Volcanic Sulfur Compounds, Humpback Whale
JOURNAL NAME:
Open Journal of Marine Science,
Vol.10 No.3,
June
17,
2020
ABSTRACT: “High
nutrient, low chlorophyll (HNLC)” regions were created by locking iron into
sedimentary iron sulfides with hydrogen sulfide available from volcanic
eruptions in surrounding oceans. Appropriate locations and deployment methods
for the iron fertilization were far from volcanoes, earthquakes and boundaries
of tectonic plates to reduce the chance of iron-locking by volcanic sulfur
compounds. The appropriate locations for the large-scale iron fertilization are
proposed as Shag Rocks in South Georgia and the Bransfield Strait in Drake
Passage in the Southern Ocean due to their high momentum flux causing efficient
iron deployment. The iron (Fe) replete compounds, consisting of natural clay,
volcanic ash, agar, N2-fixing mucilaginous cyanobacteria, carbon
black, biodegradable plastic foamed polylactic acid, fine wood chip, and
iron-reducing marine bacterium, are deployed in the ocean to stay within a
surface depth of 100 m for phytoplankton digestion. The deployment method of Fe-replete
composite with a duration of at least several years for the successful iron
fertilization, is configured to be on the streamline of the Antarctic
Circumpolar Current (ACC). This will result in high momentum flux for its
efficient dispersion on the ocean surface where diatom, copepods, krill and
humpback whale stay together (~100 m).
Humpback whales are proposed as a biomarker for the successful iron
fertilization in large-scale since humpback whales feed on krill, which in turn
feed on cockpods and diatoms. The successful large-scale iron fertilization may
be indicated by the return of the humpback whales if they could not be found
for a long period before the iron fertilization. On-line monitoring for the
successful iron fertilization focuses on the simultaneous changes of the
following two groups; the increase concentration group (chlorophyll, O2,
Dissolved Oxygen (DO), Di Methyl Sulfide (DMS)) and the decrease concentration
group (nitrate, phosphate, silicate, CO2, Dissolved CO2 (DCO2)). The monitoring of chlorophyll-a, nitrate phosphate, and silicate concentrations after deploying
the Fe-replete complex is carried out throughout the day and night for the
accurate measurement of algal blooms.