probability of forming squid fishing areas. We believe
the results appropriately indicate squid locations,
since powerful lights on vessel attract squid. This study
has also provided quantitative evidence that variations
in the spatial pattern of fishing vessel lights in the Sea
of Japan can be linked to squid migration ecology.
However, effective classification is difficult unless
environment variables are taken into account. These
environmental variables should provide details on fishing
area formation to help define ecologically meaningful
associations. Future research should incorporate
data on environmental variables in order to better understand
the ecological structures and functions of
each class area. Another prerequisite for understanding
the potential role of an area is an understanding of
the early life stages of the squid and the relationships
between squid movements and typical oceanic
features.
Continual monitoring of Todarodes pacificus stocks
in the Sea of Japan will be required to assess management
efficiency and estimate the TAC. Targeting the
entire area around Japan will not accurately determine
the total catch. Fishing regions having the greatest
impact on the TAC must be determined. Thus, our
classification of 7 distinct areas can aid in squid catch
management by providing useful information on the
spatial and temporal formations of squid fishing areas.
This study presents an innovative methodological
approach to ocean ecological research and fisheries
oceanographic research.