Chapter V — International 
Columbia, Canada. Although the review was held be- 
fore results of the 1990 monitoring programs had been 
released, it remains one of the most comprehensive 
examinations of the effects of driftnet fisheries done 
to date. Representatives from Australia, Canada, 
Japan, Korea, Taiwan, and the United States partici- 
pated in the meeting. Members of the Marine Mam- 
mal Commission’s Committee of Scientific Advisors 
were among the U.S. participants. 
During the review, Japanese participants presented 
estimates of the 1990 catch and bycatch for the entire 
Japanese squid driftnet fleet. For that fleet alone in 
1990, the estimates included 106 million neon flying 
squid, 34 million pomfret, 2.8 million skipjack tuna, 
799,000 albacore tuna, 141,000 salmon, 701,000 blue 
sharks, 4,700 billfish, 234,000 sooty and dark shear- 
waters, 9,000 Laysan albatross, 9,000 northern right 
whale dolphins, 5,000 northern fur seals, 4,000 
Pacific white-sided dolphins, and 300 leatherback sea 
turtles. The meeting participants also concluded that 
the number of northern right whale dolphins had 
declined significantly because of the take in driftnets 
and that Pacific white-sided dolphins could experience 
serious declines if driftnet fishing continued unabated. 
The limited information available at the time of the 
review precluded a more complete assessment of catch 
levels and effects on target and non-target species. 
Although a great deal of new information has been 
gathered since then, it has yet to be examined compre- 
hensively. Even assuming large-scale high seas 
driftnet fishing ceases at the beginning of 1993, a 
thorough assessment and synthesis of the data remain 
an urgent need. Among other things, such a review 
is needed to better understand how these fisheries may 
have affected particular stocks and functional relation- 
ships among components of the North Pacific marine 
ecosystem, and to gain insight regarding the manage- 
ment of catch and bycatch in future high seas fishing. 
In anticipation of these needs, the Marine Mammal 
Commission has taken several preliminary steps. 
Late in 1991 the Commission contracted for a 
study to determine the possible second-order effects of 
driftnet fisheries in the North Pacific Ocean. The 
purpose of the study is to review and assess how 
large-scale driftnet fisheries have affected the eco- 
logical structure and productivity of the North Pacific 
131 
Ocean environment and to identify steps that should 
be taken prior to and during the development of new 
high seas fisheries. At the end of 1992, the prelimi- 
nary results of the study were under review. A final 
report is expected to be available in 1993. 
In addition, during the course of preparing advice 
to the National Marine Fisheries Service on the 
driftnet monitoring programs with Japan, Taiwan, and 
the Republic of Korea, the Marine Mammal Commis- 
sion became concerned about the statistical tools being 
used to determine the level of observer effort. 
Therefore, in June 1991, the Marine Mammal Com- 
mission and the National Marine Fisheries Service 
entered into an agreement to allow a member of the 
Commission’s Committee of Scientific Advisors 
access to the observer data collected during individual 
driftnet operations. Under the agreements with each 
nation, these data were not to be included in the sum- 
mary reports and were to remain confidential. 
In examining the data, it became apparent that the 
bycatch of certain marine mammals as well as other 
species were not evenly distributed among net retriev- 
al operations. Instead, most of the catch of certain 
species was taken in a comparatively few sets. The 
methods used to summarize and report the bycatch do 
not reflect this highly aggregated catch distribution. 
Also, the methods used to determine observer levels 
have not taken catch aggregation into account. As a 
result, the numbers of observers in high seas driftnet 
fisheries and perhaps other fisheries with highly 
aggregated bycatch may be too low to allow incidental 
catch rate estimates with the desired level of accuracy. 
By letter of 8 June 1992 the Commission advised 
the National Marine Fisheries Service of these find- 
ings and their potential implication for designing 
observer programs in general. In doing so, the 
Commission recommended that the Service conduct an 
in-depth investigation of the unsummarized observer 
data for the 1990 and 1991 driftnet fishing seasons, 
focusing on the levels of bycatch aggregation for 
different species and on determining the most appro- 
priate statistical tools for characterizing the bycatch. 
The Commission recommended that the Service con- 
duct a review focusing on the nature of the observer 
data and the statistical methods used to determine the 
level of observer effort for other observer programs. 
