Marine Ecosystems Research Department - jamstec japan agency ...

JAMSTEC 2002 Annual Report
Marine Ecosystems Research Department
Cooperative Research
Research on effective utilization of thermal energy
using deep sea water and hot springs water
Period: FY-FY
In Hokkaido we are building deep seawater intake
facilities at Kumaishi, Rausu and Iwanai-cho. Deep
seawater is characterized by its low temperature
throughout the year, and cold districts such as those
in Hokkaido require massive amounts of energy to
control water temperature for aquaculture. So we can
look at utilizing the abundance of hot springs water in
these regions as a means of saving energy. The aim of
this research is to expand the usage of deep seawater
by using the thermal energy of hot springs.
This year is the final year of the project, and we
comprehensively examined the effective utilization of
thermal energy from all data obtained to date. In fiscal
and we surveyed the sea area off
Kumaishi to determine the distribution of water temperature,
salinity and inorganic nutrients, and confirmed
seawater characteristics peculiar to the Sea of
Japan. We compared this with past survey results, and
found that the low temperature and eutrophicated
properties of deep seawater at depths below m are
stable throughout the year. Continuous measurement
of the temperature of hot springs water in Kumaishi
showed that it was around ˚C (Fig.). Considering
the temperature of deep seawater off Kumaishi is ˚C
at a depth of m, we examined the potential energy
saving benefits in controlling the temperature of
, tons of deep seawater a day expected to be used
in Kumaishi. We discovered that under current forecasts
for Kumaishi, a potential energy savings of %
can be achieved by using hot springs water to adjust
deep seawater to ˚C for use in abalone aquaculture
tanks. And our research findings are to be used in
water temperature control for abalone aquaculture in
Kumaishi. We also examined the potential for temperature
differential power generation, and confirmed
that this could supply % of the power needed to run
the water intake pumps assuming ammonia and
Temperature (˚C)
70
60
Hot springs water
50
40
30
Surface seawater
20
10
0
2001.1.9 0:00 2001.2.28 0:00 2001.4.19 0:00 2001.6.8 0:00 2001.7.28 0:00 2001.9.16 0:00 2001.11.5 0:00
Date
Fig.18 Fluctuations in hot springs and surface seawater temperatures
in Kumaishi.
Flourinert as working fluids.
In fiscal the Geological Survey of Hokkaido,
our cooperative research partner, conducted acoustic
surveys of the submarine topography, geology, and
bottom deposits in the Kumaishi submarine valley,
Iwanai Bay, and off Rausu. These surveys confirmed
the existence of a muddy layer at the bottom of the
submarine valley, highlighting the importance of
surveys of seafloor boundary layers when laying seawater
intakes.
Research on long-term rearing of mid-water animals
Period: FY-FY
Gelatinous zooplankton that are too fragile to keep
in aquaria over the long-term, are very abundant in the
midwater zone. At present, the physiology, ecology
and the life history of midwater animals are poorly
understood. In this program, we will develop longterm
rearing techniques and contribute to the elucidation
of the functional role of midwater ecosystems acting
on the ocean ecosystem. The present research project
collaborates with the Monterey Bay Aquarium
Research Institute (MBARI), under a memorandum
of understanding (MOU). This includes the sharing
of ROV payload protocols and data comparisons
between the midwater ecosystems studied by both
parties.
In fiscal we consolidated our research results
up to fiscal . We continued rearing the eight
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