The Hawaii-based Longline Logbook Summary Report
October-December 2007
This report summarizes data on fish catch and fishing effort of Hawaii-based longline vessels during the fourth quarter of 2007 (Q4-2007), based on the date gear was hauled, as reported to the National Marine Fisheries Service in Federal logbooks of daily fishing activity submitted by vessel operators. The report covers longline operations for fishing trips completed in the fourth quarter of 2007 and most, but not all, Q4-2007 data from trips that began late in the fourth quarter and continued into the first quarter of 2008. Therefore, the Q4-2007 summary statistics reported here are preliminary. When data for all fourth quarter longline operations are available, tables and graphs of summary statistics included in these Web pages will be updated
In Q4-2007, the shallow-set fishery targeting swordfish continued to operate under annual limits on allowed interactions with loggerhead and leatherback sea turtles and the total number of shallow sets. Similarly, the deep-set tuna fishery operated under an annual quota of 500 metric tons for U.S. longline catches of bigeye tuna east of 150o W longitude. The quota established under Resolution C-06-02 of the Inter-American Tropical Tuna Commission as a measure to conserve bigeye tuna in the eastern Pacific Ocean. None of the limits had been reached by the end of the fourth quarter.
During Q4-2007, 124 vessels were active in the Hawaii-based fleet, 4 more than in the Q4-2006 (Table 1, Fig. 1). They made 474 longline trips (13 more than in Q4-2006), including 466 deep-set gear to target tuna (5 more than in Q4-2006) and 8 using shallow-set gear to target swordfish (there were no shallow-set operations in Q4-2006; Fig. 2). A record 12.2 million hooks were deployed in Q4-2007, 1.3 million more than in Q4-2006 (Fig. 3). They fished mainly in the Exclusive Economic Zone (EEZ) of the Main Hawaiian Islands (MHI) (53% of total hooks set) followed by waters outside the U.S. EEZ (38%) and waters within the EEZ of the Northwestern Hawaiian Islands (NWHI) (9%).
In Q4-2007, the Hawaii longline fleet caught a record 61,511 bigeye tuna (Fig. 4); 50% were caught in the MHI EEZ, 39% outside the U.S. EEZ, and 11% in the NWHI EEZ. The bigeye tuna catch-per-unit-of-effort (CPUE) on tuna-targeted trips was 5.1 fish per 1000 hooks; exceeding last year's CPUE of 4.4 (Fig. 5). The albacore catch and CPUE on tuna-targeted trips in Q4-2007 were 4,278 fish and 0.33 fish per 1000 hooks, respectively (Figs. 6-7). The yellowfin tuna catch (14,489 fish) in Q4-2004 established a fourth quarter record and the yellowfin CPUE (1.2 fish per 1000 hooks) was higher than average for the quarter (Figs. 8-9).
The Q4-2007 swordfish catch was 1,790 fish, substantially higher than in Q4-2006 (Fig. 10). The bigger swordfish catch is attributed mostly to the 73 shallow sets made in Q4-2007, which had a much higher catch rate of swordfish than the deep sets. No shallow sets were permitted in Q4-2006 because the swordfish fleet had reached its limit on loggerhead interactions in the first quarter. In Q4-2007, swordfish CPUE on shallow-set swordfish-targeted trips was 14.5 fish per 1000 hooks (Fig. 11).
The Q4-2007 striped marlin catch (1,348 fish) and CPUE on tuna-targeted trips (0.11 fish per 1000 hooks) were lower than in Q4-2006 by 85% and 86%, respectively (Figs. 12-13). Similarly, the Q4-2007 blue marlin catch (922 fish) and CPUE on tuna-targeted trips (0.08 fish per 1000 hooks) were lower than in Q4-2006 by 41% and 43% (Figs. 14-15).
The fleet caught 26,936 sharks in Q4-2007, of which 593 (2% )were kept. Blue shark comprised 92% of the total shark catch (24,698 fish) (Fig. 16). Blue shark CPUE on shallow-set swordfish-targeted trips was 19.7 fish per 1000 hooks (Fig. 17).
In Q4-2007, the Hawaii longline catch of other key pelagic species included 26,931 mahimahi (Fig. 18) with a CPUE of 2.2 fish per 1000 hooks on tuna-targeted trips (Fig. 19); 3,280 moonfish (Fig. 20) with a CPUE of 0.27 fish per 1000 hooks on tuna-targeted trips (Fig. 21); 10,085 pomfret (Fig. 22) with a CPUE of 0.8 fish per 1000 hooks on tuna-targeted trips (Fig. 23); and 3,125 wahoo (Fig. 24) with a CPUE of 0.26 fish per 1000 hooks on tuna-targeted trips (Fig. 25). A high percentage of the catch of these species was kept.
The summary statistics in Table 1 are based on logbook records from all fishing areas combined and all types of longline trips—those targeting swordfish and those aimed at catching tuna. Hence, the CPUE figures in Table 1 differ from those reported above, which were calculated using data exclusively from tuna-targeted trips or swordfish-targeted trips, depending on the species of interest.
In addition to longline statistics for all fishing areas combined, Q4-2007 summary catch and effort were compiled by several geographical sub-areas including: the MHI EEZ; the NWHI EEZ; the EEZ of the Pacific Remote Islands Areas (PRIA, consisting of the U.S. possessions Wake Island, Jarvis Island, Howland Island, Baker Island, Kingman Reef, Palmyra Atoll, and Johnston Atoll), the combined EEZ of MHI, NWHI and PRIA; and waters outside the U.S. EEZ. These statistics are presented in Tables 2-6. Q4-2007 summary statistics for the entire fishing area are also presented for each distinct trip type: shallow-set swordfish-targeted trips (Table 7) and deep-set tuna-targeted trips (Table 8).
Preliminary annual summary fishery statistics for 2007 are also presented in this report (Tables 9-16). In addition, graphs of annual Hawaii longline fishing effort and catch by species for the years 1991-2007 are presented in Figs. A1-A7.
During 2007, 129 vessels were active in the Hawaii-based longline fleet, 2 more than in 2006 (Table 9, Fig. A1). Fleet size has remained relatively constant for the past four years. During 2007, longline fishers made 1,515 longline trips, 123 more than in 2006, including 1,426 trips using deep-set gear to target tuna (up 91 trips from 2006) and 89 using shallow-set gear to target swordfish (up 32 trips) (Tables 15-16, Fig. A2). In 2007, a record 40.2 million hooks were deployed, 5.0 million more than in 2006 (Fig. A3). The number of hooks set has increased steadily since 1994. A growing proportion of hooks are being set outside the U.S. EEZ (59% of total hooks set in 2007; Table 14).
In 2007, the Hawaii longline fleet caught a record 159,389 bigeye tuna (Table 9, Fig. A4). The trend of bigeye tuna catches remains upward (Fig. A4). In contrast, albacore catches have been declining following a peak in 1997, recording a record low of 10,844 in 2007. The catch of yellowfin tuna in 2007 was 26,280 fish. Yellowfin catches have remained steady for the past several years.
The 2007 swordfish catch was 24,271 fish, 47% higher than in 2006 (Table 10, Fig. A5). The larger swordfish catch is attributed to the longer swordfish season in 2007; in 2006, swordfish operations were halted in March when shallow-set limit on loggerhead interactions was reached during the first quarter. The 2007 striped marlin catch was 8,203 fish, a decline of 61% from 2006 catch; it has varied considerably over the 17-year period of logbook records, but without a discernable trend. Similarly, the 2007 blue marlin catch of 3,290 fish was down 34% from its 2006 level.
The fleet caught 75,725 sharks in 2007, of which 3% were kept (Table 9). Blue shark comprised 86% of the total shark catch (65,509 fish). Catches of blue shark, mako shark, and thresher shark have trended higher from the late 1990s (Fig. A6). In 2007, the Hawaii longline catch of other key pelagic species included a record 82,870 mahimahi, 39,639 pomfret, 27,201 oilfish, 14,371 moonfish, and 12,555 wahoo (Table 9) Catches of these important species also have increased gradually from lower levels observed in the late 1990s (Fig. A7).
In addition to tables and graphs referenced in the narrative above, this Web site has an archive of quarterly and annual summary tables of fish catch and fishing effort from 1991 to the present. The statistics in these online graphs and archived tables are updated periodically as new records are added to the database and corrections are made.