A Snapshot of the Tropical Tuna Purse Seine Large-Scale Fishing ...

capacity to store fish. Two such measures are commonly used in the literature: Fish
carrying capacity (FCC) and fish hold volume (FHV). Here we conceptualize current
capacity in very general terms without distinguishing between different types of current
capacity such as that being actually realized ("active" capacity) or that which is "latent".
We included data for vessels that are currently authorized to fish, whether they fish or
not.
2.1 Sources of information
Each of the five tRFMOs (CCSBT, IATTC, ICCAT, IOTC and WCPFC) is required to
maintain one or more records (registers) of vessels authorized to fish in their
convention areas. In some cases these records are specific to vessels fishing for a
particular species and in other cases they are general lists of vessels authorized to fish
any species managed by that Commission.
There are several known problems with these lists, including:
- Individual vessels may be authorized in two or more RFMO areas at the same
time; being authorized to fish is not the same as actively fishing.
- The information entered in the lists is, for the most part, reported by
government agencies of the RFMO members. To the degree that not all agencies
have the same ability to monitor and manage their vessels, the information on
the lists is of highly variable quality. Furthermore, different countries may use
different definitions of vessel attributes such as length and tonnage.
- Even though each of the RFMO lists has several mandatory fields, much of the
information is incomplete or absent.
- The RFMO lists are not necessarily updated in real time. The frequency of
updates is not synchronized with the frequency with which vessels change flags,
names, etc.
For the above reasons, it must be borne in mind that the RFMO records are not 100%
accurate at any given point in time. Nevertheless, these lists are improving as the RFMOs
exercise greater scrutiny over them, and they are currently the best source of
information available for tuna fishing fleets at the global level.
The primary sources of information used in this paper were the RFMO vessel records
downloaded from their respective Web sites on December 16, 2011. Other sources of
information were consulted in order to verify duplicate entries, fill in missing data, or
reconcile contradictory information for a given vessel:
- The Consolidated List of Authorized Vessels (CLAV) that is put together several
times each year by the five tRFMO Secretariats. Putting together this consolidated
list involves merging the five lists and using computer algorithms to identify
entries that are likely duplicates. The CLAV is hosted at http://tunaorg.org/GlobalTVR.htm.
The version created on October 10, 2011 was used.
- The Forum Fisheries Agency (FFA) list of vessels "in good standing". Certain
vessels operating in the western Pacific Ocean are not required to be on the
WCPFC record if they do not fish on the high seas or in more than one EEZ. The
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