Annual Report on Seabird Interactions and Mitigation Efforts 

in the Hawaii Longline Fishery for 2007 

ADMINISTRATIVE REPORT 

U.S. DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric Administration 

National Marine Fisheries Service 

Pacific Islands Regional Office 

Honolulu, Hawaii 

June 2008 
PACIFIC ISLANDS REGIONAL OFFICE 

This report is used to ensure the dissemination of preliminary results, interim reports and 

special studies. The material is not ready for formal publication. Abstracting, citing or 

reproduction of this information is not allowed. Contact the Pacific Islands Regional 

Office of the National Marine Fisheries Service if additional information is required. 

Cover photo: Short-tailed albatross (Phoebastria albatrus), Laysan albatrosses 

(Phoebastria immutablis), and black-footed albatrosses (Phoebastria nigripes), Midway 

Atoll. Photo courtesy U.S. Fish and Wildlife Service. 

2 
Annual Report on Seabird Interactions and Mitigation Efforts 

in the Hawaii Longline Fishery for 2007 

Prepared by 

Lewis Van Fossen 

Sustainable Fisheries Division 

National Marine Fisheries Service 

Pacific Islands Regional Office 

1601 Kapiolani Blvd. Suite 1110 

Honolulu, HI 96814 

(808) 944-2200 

June 2008 

3 
 

 

 

 

 

 

 

 

Table of Contents 

1.0 Introduction 9 

2.0 Description and Status: Short-tailed Albatross 10 

3.0 Description and Status of Proxy Species 11 

4.0 Description of the Hawaii Pelagic Longline Fishery 14 

5.0 Seabird Deterrence Measures 19 

6.0 Observer Coverage in 1994-2007 26 

7.0 Protected Species Workshops in 2007 28 

8.0 Seabird Interactions 30 

9.0 Summary 38 

10.0 Literature Cited 40 

11.0 Acknowledgements 44 

12.0 Appendices 45 

Appendix 1: Pelagic Management Unit Species and Common Catch 

Species 45 

Appendix 2: Interaction estimates with incidentally caught sea turtles, 

seabirds, and marine mammals in the Hawaii longline 

 deep-set fishery. 48 
 

 

 

 

 

 

List of Tables 

1) Table 1. Characteristics of the Shallow-set (swordfish-targeting) and 

Deep-set (tuna-targeting) Components of the Hawaii Longline Fishery 14 

2) Table 2. Hawaii Longline Fishery effort data, 2000–2007 17 

3) Table 3. Summary of current seabird regulations for the Hawaii longline 

fleet, effective as of January 18, 2006 21 

4) Table 4. Hawaii Longline Observer Data Collection Requirements from 

1994-Present 27 

5) Table 5. Types of Interactions between Albatrosses and Hawaii Longline 

Vessels in 2007 33 

6) Table 6. Release Condition for Albatrosses Captured Incidentally to 

Fishing Operation in the Hawaii Longline Fishery in 2007 34 

7) Table 7. Probable Time of Capture for Observed Albatross Interactions 

in the Hawaii Longline Fishery in 2007 35 

8) Table 8. Interaction estimates with incidentally caught albatrosses and 

corresponding 95% confidence intervals (C.I.) for the Hawaii Deep-set 

Longline Fishery in 2007 36 

9) Table 9. Short-tailed Albatross Sightings in 2007 38 

5 
 

 

 

 

 

 

 

List of Figures 

Figure 1. Short-tailed albatross nesting pairs on Torishima Island, 

Japan, 1976-2007 11 

Figure 5. Generalized depiction of shallow-set (swordfish) and deep-set 

Figure 8. Catch per unit effort (CPUE) in the Hawaii longline fishery in 

Figure 9. Hooks set per year in the deep-set and shallow-set fisheries 

Figure 14. Observer coverage on deep-setting vessels north of 23° N latitude, 

Figure 15. Protected Species Workshop certifications for Hawaii, Guam, and 

Figure 16. Total estimated albatrosses incidentally taken by Hawaii longline 

Figure 17. Total observed black-footed and Laysan albatross interactions in the 

Figure 2. Number of Albatross Breeding Pairs at Laysan Island 1992-2008 12 

Figure 3. Number of Black-footed Albatross Breeding Pairs at Midway Atoll 13 

Figure 4. Number of Active Nests at Midway Atoll 1992-2008 13 

(tuna) gear types 15 

Figure 6. Observed fishing effort in the shallow-set fishery, 1994-2007 16 

Figure 7. Observed fishing effort in the deep-set fishery, 1994-2007 16 

fish per 1000 hooks from 1999-2007 18 

2000-2007 in millions of hooks 18 

Figure 10. Depictions of side-setting and stern setting 22 

Figure 11. Bird curtain specifications and preferred design 23 

Figure 12. Preparing swordfish head for strategic offal discard 25 

Figure 13. Observer coverage on deep-setting vessels, 2000-2007 28 

2000-2007 28 

American Samoa longline fishermen, 2000-2007 29 

vessels 2000-2007 30 

Hawaii pelagic longline fishery in 2007 32 

6 
 

List of Figures (Cont.) 

Figure 18. Types of Interactions between Albatrosses and Hawaii longline 

vessels in 2007 33 

Figure 19. Release condition for albatrosses captured incidentally to fishing 

operations in the Hawaii longline fishery in 2007 34 

Figure 20. Time of capture for observed albatross interactions in the Hawaii 

longline fishery in 2007 35 

Figure 21. Estimated fleet-wide incidental interactions with black-footed and 

Laysan albatrosses in the Hawaii longline fishery during, 1999-2007 37 

Figure 22. Short-tailed albatross sightings by NMFS observers, 2007 38 

7 
List of Acronyms 

BiOp Biological Opinion 

BFAL Black-footed Albatross 

CI Confidence Interval 

CMC Center for Marine Conservation 

CPUE Catch Per Unit Effort 

EEZ Exclusive Economic Zone 

ESA Endangered Species Act 

FR Federal Register 

FMP Fishery Management Plan 

HLA Hawaii Longline Association 

LAAL Laysan Albatross 

NMFS National Marine Fisheries Service 

NOAA National Oceanic and Atmospheric Administration 

NWHI Northwestern Hawaiian Islands 

OLE Office for Law Enforcement 

PIFSC Pacific Islands Fisheries Science Center 

PIRO Pacific Islands Regional Office 

PMUS Pelagic Management Unit Species 

PRIA Pacific Remote Islands Area 

SFD Sustainable Fisheries Division 

STAL Short-tailed Albatross 

USFWS U.S. Fish and Wildlife Service 

WPFMC Western Pacific Fishery Management Council 

8 
 

 

Annual Report on Seabird Interactions and Mitigation Efforts in the Hawaii 

Longline Fishery for 2007 

1.0 Introduction 

In the western Pacific, the National Oceanic and Atmospheric Administration (NOAA) National 

Marine Fisheries Service (NMFS), through its Pacific Islands Regional Office (PIRO), is 

responsible for managing, protecting, and conserving living marine fishery resources in Federal 

waters of the U.S. Pacific islands areas.1

 PIRO accomplishes this aim through the 

implementation of regulations and policies designed to sustain healthy marine resources, prevent 

overfishing, rehabilitate depleted stocks, and promote the recovery of protected species. The 

NMFS Pacific Islands Fisheries Science Center (PIFSC) conducts fisheries research and provides 

scientific information and expertise on Pacific insular and pelagic marine resources and protected 

species. The Western Pacific Fishery Management Council (WPFMC) is responsible for 

developing domestic fishery policies and management plans for the region. The PIRO, PIFSC, 

WPFMC, and the U.S. Fish and Wildlife Service (USFWS) work cooperatively to prevent and 

mitigate the bycatch of protected resources, including seabirds, by U.S. domestic fisheries 

governed under fishery management plans.2 

Seabird mitigation measures, authorized under the Magnuson-Stevens Fishery Conservation and 

Management Act (Magnuson-Stevens Act), are prescribed in fishery management plans 

governing fisheries operating in the U.S. Exclusive Economic Zone (EEZ) and international 

waters of the western Pacific region. To assess possible impacts of the Hawaii pelagic longline 

fishery on the endangered short-tailed albatross (Phoebastria albatrus) population NMFS 

consulted with USFWS under Section 7 of the Endangered Species Act (ESA). A “Biological 

Opinion on the effects of the Hawaiian Longline Fishery on the short-tailed albatross” (BiOp) 

was issued by USFWS on November 28, 2000 [FWS 1-2-1999-F-02; USFWS 2000], and 

subsequently revised November 18, 2002 [FWS 1-2-1999-F-02R; USFWS 2002]. The 2002 

revision examined the effects of the deep-set fishery on the short-tailed albatross after a 

suspension of the shallow-set fishery was ordered by the U.S. Court in Center for Marine 

Conservation (CMC) v. NMFS on April 1, 2001. USFWS issued a supplement to the BiOp in 

October 2004 entitled “Biological Opinion on the Effects of the reopened shallow-set sector of 

the Hawaii Longline Fishery on the short-tailed albatross (Phoebastria albatrus)” [FWS 1-2-

1999-F-02.2: USFWS 2004]. Prior to its suspension, the shallow-set sector of the Hawaii 

longline fishery accounted for the majority of seabird mortalities, so the October 2004 BiOp 

evaluated only the effects of the April 2004 reopening of the shallow-set longline fishery on the 

short-tailed albatross. From 2004-2007, no short-tailed albatross interactions were reported in 

1

 American Samoa, Guam, Hawaii, Northern Mariana Islands, and the U.S. Pacific remote islands areas (PRIA), 

consisting of Howland Island, Baker Island, Jarvis Island, Johnston Atoll, Midway Atoll, Kingman Reef, Palmyra 

Atoll, and Wake Island. 

2

 Fishery management plans, if approved by the Secretary of Commerce, are implemented by regulations by NMFS 

at 50 CFR 665. Five fishery management plans governing western Pacific fisheries including pelagics, 

bottomfish/seamount groundfish, crustaceans, precious corals, and coral reef ecosystems. 

9 
 

the Hawaii shallow-set longline fishery which is required to have 100% observer coverage.3 The 

BiOp issued on November 18, 2002, on the deep-set sector remains in effect. 

The three BiOps (USFWS 2000, 2002, 2004) require NMFS to report annually any observed 

interactions and sightings of short-tailed albatrosses with the Hawaii longline fishery, and any 

observed and estimated total number of interactions with Laysan (P. immutabilis) and blackfooted (P. nigripes) albatross by set type.4

 Because observed interactions between short-tailed 

albatrosses and Hawaii pelagic longline vessels are non-existent and are thought to be very rare, 

surrogate species are used to predict expected interaction rates. Black-footed and Laysan 

albatrosses are used as surrogate species to assess the effects of fishery interactions and the 

efficacy of mitigation measures on the short-tailed albatross population due to their relatedness, 

similar habitats, and likely similar foraging strategies. In addition, NMFS must report on the 

status of observer coverage, provide assessments of the effectiveness of required seabird 

deterrents including a review of the observer data from vessels choosing to side-set, and 

summarize the results of the Federally-mandated Protected Species Workshops conducted by 

NMFS. This report includes the reporting requirements under the Terms and Conditions of each 

BiOp for the Hawaii longline fishery operating during 2007. 

2.0 Description and Status: Short-tailed Albatross 

The short-tailed albatross (STAL) is the largest of the northern hemisphere albatross species (33-

37 inches as compared with body lengths of 31-32 in for Laysan and 27-29 in for black-footed 

albatrosses, USFWS 2005). They are long-lived and reach breeding age around six years old 

(USFWS 2004). Their plumage varies in color as they mature. Shortly after fledging (leaving 

the nest), STALs develop a distinctive large pink bill with a gray tip and thin black line at its 

base which they have for the rest of their lives. The STAL’s feet are pinkish. When STALs are 

one year old, their plumage may resemble a BFAL, but may be distinguished from BFALs 

primarily by their pink bills (the BFAL has a black beak). As the STAL matures, its stomach, 

and back become white in color. It is the only albatross in the North Pacific with a white back. 

The color on the upper surface of the wings is variable being proximally white and distally 

brown. A fully mature STAL has a golden head. 

STALs once ranged throughout most of the North Pacific Ocean and Bering Sea, with known 

nesting colonies on western Pacific islands near Japan and Taiwan (Hasegawa 1979). During the 

early 20th century, the species was nearly extirpated due to overharvest for feathers and oil. 

Between 1880 and 1903 5 million STALs were harvested on Torishima alone (USFWS 2004). 

The species began to recover during the 1950s. Likely due to habitat management and habitat 

protection, the population is growing annually (Figure 1). Today, the only known currentlyactive breeding colonies of STALs are on Torishima south of Honshu Island, Japan, (30° 29’ N 

140° 18’ E) and Minami-kojima in the Senkaku Islands just north of Taiwan (25° 43’ N 123° 

33’ E) (USFWS 2004). It is estimated that 80-85% of the known breeding STAL use a single 

3

 The shallow-set sector of the Hawaii longline fishery reopened with a final rule on April 2, 2004 (69 FR 17329). 4

 NMFS described tuna (deep-set) and/or swordfish (shallow-set) type. 

10 
colony at Tsudame-zaki, on Torishima, an active volcanic island (Suryan et al. 2007). The 

current worldwide STAL population is estimated to be approximately 2,000 individuals, with 

382 nesting pairs observed on Torishima Island during the 2007-2008 breeding season 

(Hasagawa 2007b). 

STAL Nesting Pairs on Torishima 

0 

100 

200 

300 

400 

500 

1976 

1978 

1980 

1982 

1984 

1986 

1988 

1990 

1992 

1994 

1996 

1998 

2000 

2002 

2004 

2006 

Year 

Nesting Pairs 

Figure 1. Short-tailed albatross nesting pairs on Torishima Island, Japan, 1976-2007. 

(Sources: Sievert 2007, Hasegawa 2006, 2007a, 2007b) 

In recent developments, Japanese wildlife managers began a translocation project to establish a 

new breeding colony on Muko-shima Island on February 19, 2008. Muko-shima is two hundred 

miles south of Torishima in the Bonin Archipelago (Kim 2008, Suryan 2008). In the 

Northwestern Hawaiian Islands, mating behavior was witnessed between two short-tailed 

albatrosses at Midway Atoll in January 2008. No offspring were produced (USFWS 2008). 

3.0 Description and Status of Proxy Species 

Laysan Albatross 

The Laysan albatross (LAAL) is one of the most abundant albatross in the world (BirdLife 

International 2004). They are characterized by a white head, neck and under parts. There is dark 

plumage surrounding the eyes. Dorsally, the wings and back are dark brown. Ventrally, the 

wings are variably white and brown differing between individuals. The tail is dark brown. 

Because variables such as population structure, mortality, and individual breeding frequency are 

not fully understood, a total world population estimate cannot be determined for LAAL. Instead, 

an estimate of total numbers of nesting pairs has been used to track LAAL populations. The 

worldwide breeding population of LAAL is estimated at 590,000 pairs in 2005 (Naughton 2007) 

and 99% of the world’s LAAL breed in the Northwestern Hawaiian Islands (NWHI). Other 

breeding sites are in Japan and Mexico. 

11 
Black-footed Albatross 

BFALs have black legs and black bills with a prominent ring of white at plumage at the base. 

Overall, the plumage is dark brownish gray. Birds older than two years have white plumage 

surrounding the vent. The world breeding population of BFAL was estimated to be 61,700 pairs 

in 2005 (Naughton 2007) and according to USFWS, approximately, 97% of BFALs breed in the 

NWHI (72 FR 57278). A smaller population of approximately 2000 breeding pairs nests in the 

Bonin Islands south of Japan. Walsh and Edwards (2005) have demonstrated that the Japanese 

sub-population is reproductively isolated from NWHI BFALs. 

Population Status of Proxy Species 

Assessing albatross populations is a daunting task. Because juvenile animals and not all birds 

return to the breeding colonies every year, direct counts of populations cannot be made. Instead, 

the number of breeding pairs, or number of active nests, is one measure used to assess the health 

of albatross populations. This proxy measurement can be used to assess long-term trends in 

populations. Environmental factors such as foraging success may influence how many 

albatrosses return to a colony to breed. During the 2007-08 breeding season, the usual nest 

counts for LAALs and BFALs could not completed due to exigent circumstances at French 

Frigate Shoals. The figures below illustrate trends in breeding pair numbers at Laysan Island and 

Midway Atoll from 1992-2008. 

Figure 2. Number of Albatross Breeding Pairs at Laysan Island 1992-2008 

(Source: USFWS 2008) 

12 
Figure 3. Number of Black-footed Albatross Breeding Pairs at Midway Atoll 

(Source: USFWS 2008) 

Figure 4. Number of Active Nests at Midway Atoll 1992-2008 

(Source: USFWS 2008) 

13 
 

 

4.0 Description of the Hawaii Pelagic Longline Fishery 

Background 

Historically, the Hawaii-based longline fishery has had the greatest number of seabird 

interactions of any U.S. managed fishery in the tropical Pacific (NMFS 2001). The fishery 

began around 1917 employing techniques similar to those of Japan. Early Hawaii-based 

longliners used tarred braided rope and flagged marker buoys. A relatively small number of 

vessels continued targeting tuna using this gear until the late 1980s. At that time, the fleet 

expanded from 37 vessels in 1987 to 138 vessels in 1991 with the influx of longliners from the 

East Coast and Gulf of Mexico targeting swordfish with monofilament mainlines and radio 

buoys (NMFS 2007). 

Today, the Hawaii longline fishery is comprised of two components: deep-set, targeting tuna, 

and shallow-set, targeting swordfish. While the deep-set fishery generally targets bigeye tuna 

(Thunnus obesus), the shallow-set fishery targets swordfish (Xiphias gladius). In addition to 

tunas and swordfish, a variety of other pelagic fish species are caught in both segments of the 

fishery. Some of these species are kept and considered catch, while others are discarded and 

considered bycatch5. Lists of Pelagic Management Unit Species that are specifically managed 

under the Pelagics FMP and other commonly encountered fish species can be found in 

Appendix 1. 

The general characteristics of the two gear types are provided in Table 1 and Figure 5, 

illustrating the differences and similarities between them. 

Table 1. Characteristics of the shallow-set (swordfish-targeting) and deep-set (tunatargeting) components of the Hawaii longline fishery. 

Characteristics Swordfish-targeting Tuna-targeting 

Set depth Shallow (~ 40 m) 

18/0 circle hook 

(maximum 10° offset) 

Fusiform Fish 

Deep (~100-300 m) 

3.6-3.8 mm tuna hooks or 

14/0-16/0 circle hooks 

Saury 

Hook type 

Bait 

Lightsticks used? Yes No 

Set deployment/retrieval Night/Morning Morning/Night 

No. hooks between floats 4 - 6 15 - 30 

Approx. no. hooks per set 800 2,000 to 3,000 

5

 For the purpose of this report bycatch is defined as discards plus unseen mortality due to fishing operations. This 

includes incidental interactions with seabirds. 

14 
Figure 5. Generalized depiction of shallow-set (swordfish) and deep-set (tuna) gear types 

(Source: PIFSC) 

As seen in Figure 5, deep-set gear is intended to reach depths where bigeye tuna concentrations 

are highest. Matsumoto et al. (2007) have demonstrated through archival tagging studies that 

bigeye tuna tend to congregate at depths reached by the lower half of mainline in the deep-set 

fishery. The set configuration is achieved by use of a line shooter. The line shooter deploys the 

line faster than the vessel is moving forward, thus forming deep sags in the line. In contrast, 

shallow-set gear is usually deployed by simply allowing the mainline to spool off of the mainline 

reel as the vessel is underway. No line shooter is used. Additionally, fewer hooks are deployed 

between floats. This results in the line being set relatively shallow in the water column where 

swordfish tend to congregate. There are differences between the two segments of the fishery 

(Figures 6 and 7). 

15 
Figure 6. Observed fishing effort in the shallow-set fishery, 1994-2007. 

(Source: PIRO) 

Figure 7. Observed fishing effort in the deep-set fishery, 1994-2007. 

(Source: PIRO) 

16 
 

 

The majority of the fishing effort in the shallow-set component of the fishery has occurred to the 

north of the Hawaiian Archipelago, while the majority of deep-set effort has been distributed to 

the south of the islands. 

Effort, as measured by number of vessels or number of trips, has been relatively stable from 

2000 to 2007 for the combined fishery (both shallow- and deep-sets) (Table 2). The number of 

sets made and total number of hooks deployed for this combined fishery have increased during 

the 2000 to 2007 period. Even at its highest effort, the shallow-set fishery has always deployed 

far fewer hooks per year than the deep-set fishery. CPUEs for the major species – tunas, billfish, 

and sharks - decreased by about 50% from 1999-2005, but have remained relatively steady for 

the last three years (Figure 8). 

Table 2. Hawaii longline fishery effort data, 2000–2007 

(Sources: NMFS 2008, PIFSCS, WPFMC) 

Year #Vessels #Trips #Sets #Hooks 

(Total) 

#Hooks 

(Deep-set) 

#Hooks6 

(Shallow-set) 

2000 125 1,135 12,930 20,282,826 17,192826 3,090,000 

2001 101 1,075 12,169 22,327,897 21,837897 490,000 

2002 102 1,193 14,225 27,018,673 27,018,673 0 

2003 110 1,215 14,560 29,297,813 29,297,813 0 

2004 125 1,338 15,976 31,967,874 31,891,124 76,750 

2005 124 1,533 18,083 34,895,229 33,566,423 1,328,806 

2006 127 1437 17,247 35,192,344 34,486,898 705,446 

2007 129 1515 19,379 40,197,926 38,825,977 1,371,949 

6

 Hooked deployed in the shallow-set fishery for 2000 and 2001 include hooks reported deployed for swordfish and 

mixed species targeted trips. Mixed targeted trips were generally reported for smaller shallow-set vessels that would 

often target swordfish at the beginning of fishing trips and target tuna or marlins towards the end. Source: WPFMC. 

17 
 - -

CPUE in Hawaii Longline Fishery 

0 

2 

4 

6 

8 

10 

1999 2000 2001 2002 2003 2004 2005 2006 2007 

Year 

Fish per 1000 Hooks

Tuna 

Sharks 

Billfish 

Other PMUS* 

Figure 8. Catch per unit effort (CPUE) in the Hawaii longline fishery in fish per 1000 hooks 

 from 1999-2007 (Source PIFSC) 

Hooks Set per Year in the Deep set and Shallow set Fisheries 

2000-2007 

29.3 

27.0 

21.8 

17.2 

31.9 33.6 34.5 

38.8 

3.1 

0.5 0.0 0.0 0.1 1.3 0.7 1.4 

0.0 

5.0 

10.0 

15.0 

20.0 

25.0 

30.0 

35.0 

40.0 

45.0 

2000 2001 2002 2003 2004 2005 2006 2007 

Deep-set Hooks 

(milions) 

Shallow-set Hooks 

(Millions) 

Figure 9. Hooks set per year in the deep-set and shallow-set fisheries 2000-2007 

 in millions of hooks. (Sources: PIFSC, WPFMC) 

On June 12, 2001, NMFS issued an emergency rule that closed the shallow-set fishery and 

implemented the Terms and Conditions of the November 28, 2000 Short-tailed Albatross BiOp 

issued by USFWS (66 FR 31563). Some traditional swordfish vessels switched to targeting 

tunas further widening the disparity of the numbers of hooks deployed between the two fisheries. 

It is interesting to note that even with the reopening of the shallow-set fishery in 2004, the 

number of hooks deployed per year in the deep-set continues to increase (Figure 9). Over twice 

as many hooks were deployed in the deep-set fishery in 2006 and 2007 as were in 2000. 

18 
 

Conversely, the number of hooks deployed in the shallow-set fishery in 2007 and 2007 is less 

than half of the number deployed in 2000. 

In April 2004, the shallow-set fishery was reopened under a suite of new management measures 

that required new gear configurations and specialized turtle dehooking equipment were put in 

place to reduce incidental captures of sea turtles and increase their post-hooking survival (69 FR 

17329, May 19, 2004). 

Requirements for the shallow-set fishery (69 FR 17354, April 2, 2004) include: 

• 100% observer coverage 

• a maximum of 2,120 sets are permitted annually 

• 18/0 circle hooks with 10 degree offset 

• Mackerel-type bait 

• Sea turtle handling measures including dehooking equipment; and 

• Annual attendance at mandatory Protected Species Workshops for vessel operators and 

owners 

• Interaction Limits for Loggerhead sea turtles (n=17) and Leatherback sea turtles (n=16) 

The seabird deterrents for both segments of the Hawaii longline fishery will be discussed 

separately in the next section. 

Summary of 2007 Fishery Effort 

In 2007, there were 129 active Hawaii longline vessels that made 1,515 trips in 2007 (Table 2). 

The trips targeted tunas (bigeye (Thunnus obesus), albacore (Thunnus alalunga), and yellowfin 

(Thunnus albacares)) and swordfish (Xiphias gladius). A total of 1426 tuna trips and 89 

swordfish trips were made7. There were 8146 sets made at or above 23° N latitude. Of these, 

6614 were deep sets and 1532 were shallow sets (PIFSC, unpubl.). Of 40,197,926 total hooks 

fished, the deep-set fishery deployed a reported 38,825,977 hooks in 17,809 sets and the shallowset fishery deployed a reported 1,371,949 hooks on 1570 sets (PIFSC, unpubl.). 

5.0 Seabird Mitigation Measures 

Background 

The emergency rule (66 FR 31563, June 12, 2001) that closed the shallow-set fishery also 

implemented non-discretionary terms and conditions of the BiOp issued by the USFWS on 

November 28, 2000 (USFWS 2000). A final rule (67 FR 34408, May 14, 2002) subsequently 

implemented the requirements contained in the emergency rule. The required suite of seabird 

mitigation techniques were as follows: when making deep sets north of 23° N., vessels must 

employ a line-setting machine with at least 45 g weights attached within 1 m of each hook, use 

thawed blue-dyed bait and strategic offal discards during the setting and hauling of longline gear. 

7

 The shallow-set fishery was closed on March 20, 2006 after reaching the interaction limit for loggerhead sea turtles 

(17) on March 17, 2006. There is an interaction limit in this fishery of 16 leatherback turtles that has never been 

reached. 

19 
These measures were revised (70 FR 75075, December 19, 2005), to satisfy the terms and 

conditions of the 2004 BiOp. These current seabird mitigation requirements for Hawaii-based 

longline fishermen are listed in Table 6. 

Description of Mitigation Measures 

Vessel operators have the option of either using side-setting (as it’s defined under the 

regulations) or an alternate suite of mitigation methods. A variety of seabird deterrence methods 

for longline fisheries have been tested and found to reduce interaction rates as well as mortality 

of seabirds (e.g., Brothers 1995; Brothers et al. 1999; McNamara et al. 1999; Gilman et al., 2003, 

2005, and 2007). When employed effectively, seabird avoidance measures have the potential to 

nearly eliminate seabird interactions. To resolve the problem of seabird mortality in these 

fisheries, there is a need to identify deterrent methods that not only have the capacity to 

minimize seabird interactions, but are also practical and convenient to use by fishermen (Gilman 

et al. 2005). 

The following seabird deterrent methods are explained in more detail: 

• side-setting. 

• strategic offal discarding; 

• thawed blue-dyed bait; 

• weighted branch lines; and 

• night setting 

20 
 

 

 

 

 

 

 

 

 

 

 

Table 3. Summary of current seabird regulations for the Hawaii longline fleet, effective as 

of January 18, 2006. 

(Source: NMFS PIRO) 

X = Required Measure Side-Setting Stern- Setting 

Shallow 

Set 

Deep Set 

>23°N 

Deep Set 

<23°N 

Shallow 

Set 

Deep Set 

>23°N 

Deep Set 

<23°N 

Weights (minimum 45 g) 

attached within 1 m of the 

hook 

X X X 

Set from port or starboard 

side X X 

Setting station at least 1 m 

forward of stern corner X X 

Line shooter at least 1 m 

forward of stern corner (if 

used) 

X X 

Deploy gear so that hooks do 

not resurface X X 

Use bird curtain X X 

Use blue-dyed bait (thawed) X X 

Maintain at least 2 (1 lb) 

containers of blue dye on 

board the vessel 

X X 

Use line shooter X 

Employ strategic offal 

discards X X 

Begin set 1 hr after 

sunset/complete before dawn X 

Follow seabird handling 

procedures X X X X X X 

Side-setting 

Side-setting involves deploying the gear from the side of the vessel, as compared to the 

conventional approach of setting from the stern (Figure 10). The effect is that baited hooks are 

deployed closer to the side of the vessel’s hull where seabirds are unable or unwilling to pursue 

them. With proper weighting, baited hooks deployed in this manner will sink to a depth where a 

North Pacific albatross species could not reach them. Additionally, deploying a bird curtain 

inhibits the ability of seabirds to land along the side of the vessel where baits are accessible; an 

ancillary benefit of this technique is reduced bait loss for fishermen. 

21 
Figure 10. Depictions of side-setting and stern setting 

(Source: Gilman et al. 2003) 

Side-setting regulatory requirements are as follows: 

1) Deploy the mainline as far forward on the vessel as practicable including mounting line 

shooters (if used) at least 1 m forward from the stern corner of the vessel; 

2) Set the mainline and branch lines from the port or starboard side of the vessel; 

3) Attach weights (45 g minimum) to branchline within one meter of the hook; 

4) When seabirds are present, the longline gear must be deployed so that baited hooks 

remain submerged and do not rise to the sea surface; and 

5) A bird curtain must be deployed, that consists of the following three components (See 

Figure 11): 

a) a pole that is fixed to the side of the vessel aft of the line shooter and that is at least 3 

m long; 

b) at least three main streamers that are attached at regular intervals to the upper 2 m of 

the pole and each of which has a minimum diameter of 20 mm; and 

c) branch streamers attached to each main streamer at the end opposite from the pole, 

each of which is long enough to drag on the sea surface in the absence of wind, and 

each of which has a minimum diameter of 10 mm. 

If the above conditions are not met by a vessel, it is not considered to be side-setting by NMFS. 

22 
Figure 11. Bird curtain specifications and preferred design 

(Source: Gilman et al. 2003) 

Sea trials indicate that side-setting is the most effective of any single seabird mitigation method 

in reducing albatross mortality in the Hawaii longline fishery. Side-setting produced the lowest 

seabird interaction rates when compared to underwater setting chutes and blue-dyed bait in both 

deep-set and shallow-set fisheries (Gilman 2007). In 2005, observers did not record any seabird 

interactions on vessels employing side-setting. Out of 124 active Hawaii longline vessels, 44 

converted their vessels to side-setting by December 2005. In 2006, 35 vessels were configured 

for side-setting. In 2007, 25 deep-setting vessels with observers used the technique when fishing 

above 23° N latitude. This represented 47.9% of all observed effort above that latitude for 2007 

(PIRO unpub.). No shallow-setting vessels were observed using the technique in 2007. Some 

vessels that were outfitted for side-setting never used the measure and some vessels have 

reverted to stern-setting (Brothers and Gilman 2007). It is not known at this time how many 

vessels have reverted back to stern setting, but a survey of vessels is planned for the summer of 

2008. Again, because of its effectiveness and the high likelihood of compliance, even in the 

absence of observers, it is the preferred seabird mitigation technique by NMFS for deep-set 

vessels. NMFS strongly encourages its use. 

Vessel operators targeting swordfish are unlikely to switch to side-setting due to their 

unwillingness to place weights within one meter of the hook. Therefore, these vessels even if 

they set their gear from the side would not conform to the definition of side-setting under current 

regulations. While weights (≥45 g) are normally placed on shallow-set branchlines, they are 

usually situated far from the hook in the middle of the branchline. Safety considerations are 

usually cited by fishermen as the reason for placing weights in the middle of branchlines rather 

than closer to the hook. Experiments testing weight placement and weights designed to address 

23 
safety concerns are being conducted and the results of these experiments will be detailed in next 

year’s report (see section on Weighted Branch Lines). 

In 2007, there was some confusion regarding the use of bird curtains during fishing operations 

north of 23° N. Some fishermen understood that the bird curtain did not need to be used if 

seabirds were not present. Outreach efforts were undertaken to advise fishermen that regulations 

require the use of a bird curtain at all times when side-setting. Failure to deploy the bird curtain 

when fishing above 23° N Latitude is considered a violation of Federal regulations (50 CFR 

665.35). 

Strategic Offal Discards 

Strategically discharging offal is a technique developed by fishermen to mitigate interactions 

with albatrosses attempting to steal baits from branchlines before they could be retrieved. 

Fishermen would throw swordfish heads and livers over the side of the vessel to distract 

albatrosses away from the baited hooks. It was noted by some NMFS observers in the mid1990s that strategically discharging offal seemed to reduce incidental hookings and 

entanglements with albatrosses. 

Strategic offal discards have been proven to be effective in reducing interactions with seabirds – 

if employed properly. Strategic offal discards reduced gear contacts with seabirds in the Hawaii 

longline shallow-set fishery by 51% and seabird interactions by 88% (McNamara et al 1999). 

However, over time, this practice is believed to attract birds to the vicinity of the vessel, 

increasing bird abundance, searching intensity, and interaction (Brothers et al. 1999) by 

reinforcing the association that birds make with specific longline vessels being a source of food. 

Brothers (1996) hypothesizes that seabirds learn to recognize by smell specific vessels that 

provide a source of food, implying that vessels that consistently discard offal and fish bycatch 

will attract more seabirds than vessels that do not discard offal and fish waste. NOAA Fisheries 

will continue to monitor the effectiveness of strategic offal discards and other mitigation 

measures. 

Strategically discharging offal to reduce seabird interactions requires vessel operators to: 

1) Retain sufficient quantities of spent bait and fish offal with hooks removed for use as 

strategic offal discards during fishing operations; 

2) Retain swordfish heads and prepare them by removing the bill, cutting them lengthwise between the eyes, and freezing them (See Figure12); 

3) Retain swordfish livers and freeze them; and 

4) Discharge all spent bait and fish parts on the opposite side of the vessel during gear 

deployment and retrieval, if seabirds are present. 

24 
 

 

 

Figure 12. Preparing swordfish head for strategic offal discard (Source: PIRO) 

Traditionally in this longline fishery, only swordfish were gilled and gutted at sea. However, in 

December 2004, the Food and Drug Administration (FDA) regulations required all fish be gilled 

and gutted at sea. Results from an analysis of Hawaii longline fishery observer data indicate that 

only 18% of tuna-targeting sets employed strategic offal discards (Gilman 2004). This 

percentage increased to approximately 50%8

 in 2005, partially due to the new FDA regulations. 

Thawed Blue-dyed Bait 

Dying bait to a specific blue color is a means to reduce the visibility of baits by reducing their 

contrast with the sea surface. The bait is thawed in order to increase sink rates. 

Almost all bait used in the Hawaii longline fisheries consists of fusiform fish. Using squid for 

bait is prohibited in the shallow-set fishery to reduce sea turtle interactions. While squid may 

still be used in the deep-set fishery, the cost is prohibitive. Several concerns have been noted by 

fishermen regarding the required bait treatments of thawing and dyeing and bait type: 1) blue dye 

is absorbed less readily by fish than by squid, 2) baits must be thoroughly thawed in order to 

ensure maximum dye absorption, 3) it is difficult to achieve the NMFS-required color intensity 

due to scale loss by fish baits, 4) thawing the bait results in its lower retention because thawed 

bait falls off the hook more easily than partially frozen bait, 5) thawed blue-dyed bait results in 

slower hook setting rates because of the time spent thawing and dying the bait blue during the 

setting of longline gear, 6) dye can be messy, dyeing the hands and clothes of the crew and the 

deck of the vessel. While fishermen must (and do) comply with blue dyed bait requirements and 

the benefits have been experimentally proven, they do not favor the technique. Gilman et al. 

(2007) suggest most of the practicality and convenience problems could be addressed if pre-bluedyed bait were commercially available. 

8

 This percentage is an estimated value, as observer data was recorded differently beginning in June of 2005 when 

the regulation for “strategic offal discards” changed to be recorded only when seabirds are present (NMFS 2006). 

25 
 

Weighted Branch Lines 

Weights placed close to the hook on branch lines are intended to quickly sink baited hooks, 

before foraging seabirds can take the baits and subsequently become hooked or entangled in 

longline gear. Hawaii longline vessels use 45 g, 60 g, and/or 80 g weights within 1 m of the 

hook to quickly sink their branchlines to desired target depths. A recent study comparing the 

effective sink rates of 45 g (1.2 m/s) and 60 g (1.3 m/s) weighted branch lines concluded the 

difference in sink rates to be negligible (Brothers and Gilman 2005). Thus, 45 g weights are the 

current minimum weight requirement for deep-setting vessels fishing north of 23° N and for 

side-setting vessels, wherever they fish. 

As noted previously, some fishermen in the shallow-set fishery are concerned that placing 

weights close to the hook may be dangerous if branchlines break while setting gear. Because 

using weights to increase sink rates has been proven effective in reducing seabird incidental 

interactions, NOAA Fisheries is funding a study to evaluate the use of “safe-leads” to address 

safety concerns. Safe-leads are designed to release from branchlines if they break while under 

tension. 

Night Setting 

The use of night setting as a seabird mitigation measure requires that fishermen must set their 

gear no earlier than one hour after local sunset, and completing the set no later than sunrise, 

using only the minimum number of lights necessary to conform to navigation rules and best 

safety practices. It is based on the premise that seabirds cannot see baited hooks in the dark and 

thus do not attack them. The effectiveness of this measure may potentially be affected by moon 

phase and cloud cover, vessel lighting, and the use of light sticks to illuminate baits making them 

more conspicuous9. Night-setting has been identified as an effective seabird mitigation measure, 

reducing seabird interactions by 73% (McNamara et al 1999) and even by as much as 98% 

(Boggs 2001). In the past, shallow-set vessels were able to set before sunset and correspondingly 

high sea bird interaction rates occurred. Interaction rates have remained low in the shallow-set 

fishery with the inception of this mitigation requirement. 

Because the time at sunset changes with longitude and Hawaii-based longline vessels operate 

over a wide geographical area, NMFS observers aid fishermen to determine when it is legal for 

them to begin dear deployment. NMFS observers are trained to use issued Global Positioning 

System units to determine the exact time of sunset for their vessel’s longitude. This has proven to 

be very helpful, especially on cloudy evenings. 

6.0 Observer Coverage from 1994-2007 

Background 

The two major sources of information regarding albatross interactions with the Hawaii longline 

fishery are mandatory logbooks and observer data collection programs, both administered by 

NMFS. The longline logbook program requires longline vessel operators to complete and submit 

9

 Lightsticks are used to make baits more conspicuous to swordfish feeding at night. 

26 
 

 

 

 

to NMFS a daily log sheet containing detailed catch and effort information about each set, 

including interactions with protected species (50 CFR 665.14). 

NMFS observers have been deployed aboard Hawaii longline vessels since 1994 to document 

protected species interactions, collect fishery-related information, and perform other biological 

work as requested by PIRO. The terms and conditions of the 2004 Pelagics BiOp (NMFS 2004) 

required 100% observer coverage on shallow-setting vessels, whereas the 2005 BiOp on the 

deep-set fishery (NMFS 2005a) directs NMFS to maintain an annual level of at least 20% 

observer coverage on deep-setting vessels. 

Table 4 provides a brief history of seabird data collection requirements for the Hawaii Longline 

Observer Program under program protocols and the terms and conditions of applicable biological 

opinions. 

Table 4. Hawaii longline observer data collection requirements from 1994-Present 

Time Period Authorities Observer Data Collection Requirements 

1994-2001 Observer Program Protocols 

(NMFS 1999) 

1) Record all STAL interactions with fishing 

gear 

2001-2002 November 2000 STAL BiOp 

(USFWS 2000) 

1) Record all interactions with fishing gear 

2) Record all STAL sightings 

3) Return all dead STAL specimens to port 

2002-2004 November 2001 Revision to 1) Record all STAL interactions with fishing 

November 2000 STAL BiOp gear 

(USFWS 2002) 2) Record all STAL sightings 

3) Record sightings and behavior of albatrosses 

during the set and haulback of the mainline 

4) Record seabird sightings in the vicinity of the 

longline gear during setting and haulback 

operations 

5) Return all dead STAL specimens to port 

2004-Present 1) November 2002 Revision to 

November 2000 STAL BiOp 

(USFWS 2002) 

2) October 2004 STAL BiOp 

on Shallow-set Fishery 

(USFWS 2004) 

1) Record all STAL interactions with fishing 

gear 

2) Record all STAL sightings 

3) Record sightings and behavior of albatrosses 

during the set and haulback of the mainline 

4) Record seabird sightings in the vicinity of the 

longline gear during setting and haulback 

operations 

5) Conduct two (2) five-minute scan counts for 

seabird abundance on shallow-sets during the 

first hour of setting operations as daylight 

permits and every two hours during haulback 

operations 

6) Return all dead STAL specimens to port 

Observer Coverage in 2007 

In 2007, NMFS maintained an observer coverage rate of 20.1% for the deep-set fishery 

(Figure13). As per the Terms and Conditions of the 2002 BiOp, NMFS maintained a 16.2% 

27 
annual observer coverage rate on deep-set vessels fishing above 23° N. latitude observing 1069 

out of 6614 sets (Figure 14). All shallow-sets above 23° N. latitude were observed in 2007. 

Average % Observer Coverage, 2000-2007 

Deep-set 

10.4% 

22.5% 24.6% 22.2% 24.6% 26.1% 

21.2% 20.1% 

0.0% 

5.0% 

10.0% 

15.0% 

20.0% 

25.0% 

30.0% 

2000 2001 2002 2003 2004 2005 2006 2007 

Year 

Percent 

Figure 13. Observer coverage on deep-setting vessels, 2000-2007. 

(Source: PIRO) 

Deep-set Observer Coverage > 23 Degrees 

N. Latitude 2000-2007 

7.6% 

18.8% 20.8% 

24.3% 

20.1% 

32.1% 

17.7% 16.2% 

2000 2001 2002 2003 2004 2005 2006 2007 

Year 

Percent 

Figure 14. Observer coverage on deep-setting vessels north of 23° N latitude, 

2000-2007(Source: PIRO) 

7.0 Protected Species Workshops in 2007 

The Protected Species Workshops have been conducted by PIRO, Sustainable Fisheries Division 

(PIRO SFD) annually since 2000. Workshops are mandatory for all operators and owners of 

28 
vessels permitted for use with a limited entry permit issued by PIRO (50 CFR 665.21). 

Participants receive a certification card upon completion of the workshop, and the card must be 

carried on board the vessel during fishing operations. PIRO SFD collaborates with USFWS, 

PIFSC, and NMFS Office for Law Enforcement (OLE), and the PIRO Observer Program and 

PIRO’s Protected Resources Division in the development of content material for the workshops. 

This collaborative approach has resulted in informative and successful Protected Species 

Workshops. 

The workshops present information on seabird, sea turtle, and marine mammal identification and 

life history, mitigation techniques, current regulations, and any updates on current research 

pertinent to the fishery. Participants receive workbooks containing current regulations, copies of 

presentations, and information placards. Written materials and video presentations are provided 

in English, Vietnamese, and Korean, which are the predominant languages of captains of Hawaii 

longline vessels. In recent years, crews have been recruited from various parts of Micronesia, 

the Philippines, and Indonesia to work on Hawaii longline vessels. The majority of materials 

have been translated into Tagalog to accommodate crews from the Philippines. The introduction 

of Indonesian workers is fairly recent, and outreach materials have not yet been prepared for this 

group. Additionally, all outreach materials have been translated into Samoan for use in the 

American Samoa-based longline fishery. 

In 2007, NMFS presented the Protected Species Workshops to 346 longline vessel operators and 

owners in Hawaii, American Samoa, and Guam (Figure 15). 

Protected Species Workshop Attendance 

101 113 

180 

225 

199 

229 

251 

0 0 

86 88 79 93 

0 0 0 0 0 0 0 2 

139 158 158

0 

50 

100 

150 

200 

250 

300 

2000 2001 2002 2003 2004 2005 2006 2007 

Year 

Number of Participants

Hawaii 

American Samoa

 Guam 

Figure 15. Protected Species Workshop certifications for Hawaii, Guam, and American Samoa 

longline fishermen, 2000-2007 (Source: PIRO) 

PIRO SFD began beta testing an interactive version of the workshops in 2007. Twenty-five 

fishermen participated in the tests and provided valuable feedback. The on-line course was wellreceived in regard to content and ease of use. Additionally, the system was successfully tested 

from sites on the mainland U.S., Guam, Hawaii, and on board fishing vessels. Currently, 

guidelines to use the interactive course are in the last stages of review. The interactive course is 

29 
expected to become an integral part of the Protected Species Workshop program before the end 

of 2008. An option for the more traditional classroom-style workshop will continue to be 

available. 

8.0 Seabird Interactions 

Background 

Since 2001, the estimated number of seabirds incidentally taken in Hawaii pelagic longline 

fisheries has dramatically decreased (Figure 16). 

Total Albatross Interactions 2000-2007 

(LAAL and BFAL) 

194 88 173 26 

257 116 510 

2433 

0 

500 

1000 

1500 

2000 

2500 

3000 

2000 2001 2002 2003 2004 2005 2006 2007 

Year 

Number of

Interactions 

Figure 16 Total estimated albatrosses (LAAL and BFAL) incidentally taken by Hawaii longline 

vessels 2000-2007 (Source PIRO) 

In 2000, an estimated 2,433 seabirds were captured. In 2001, an estimated 510 seabirds were 

incidentally taken in Hawaii longline fisheries. This reduction can be primarily attributed to the 

curtailment and eventual closure of the shallow-set fishery in 2001 due to sea turtle interactions. 

The swordfish fishery remained completely closed throughout 2002 and 2003. During this 

period, the deep-set fishery had an estimated 373 incidental interactions with seabirds (116 in 

2002 and 257 in 2003). 

In April 2004, the swordfish fishery re-opened under a new management program that limited 

effort in the fishery to a maximum of 2180 sets annually (69 FR 17330). During 2004, 26 

albatrosses were estimated to have been captured in the shallow-set and deep-set components 

combined. It should be noted that the shallow-set component was only open from October 

through December in 2004. In 2005, NMFS estimated that 194 seabirds were captured by the 

entire fishery. Even with the shallow-set fishery open for the entire year, the fishery did not 

experience the high interaction rates that occurred in prior years (e.g. 2000). While the shallowset fishery was curtailed in 2006 because it reached the loggerhead sea turtle interaction limit, 

30 
both the total numbers of birds taken (as would be expected) and the seabird interaction rate 

(0.015 seabirds per 1000 hooks) remained low compared to years prior to the shallow-set closure. 

A key factor contributing to the decrease in estimates of seabird interactions over the years is the 

implementation of seabird deterrence measures. In June 2001, a suite of seabird measures 

became mandatory in the Hawaii longline fishery with the implementation of an emergency rule 

(66 FR 31561). The final rule for this suite of seabird deterrence techniques was published in 

May 2002 (67 FR 34408). Since then, the number of seabirds incidentally taken in the Hawaii 

longline fishery has remained low. The seabird interactions have remained low under more 

recent mitigation measures implemented on January 18, 2006 (70 FR 75075). 

Efforts were made to analyze observer data to determine the effectiveness of three treatments: 1) 

side setting with plain baits; 2) stern setting with plain baits; and 3) stern setting with blue-dyed 

baits using observer data from the deep-set fishery (Gilman 2006). The results were 

inconclusive due to the small number of albatross interactions (n=6). Because albatross 

interactions in the deep-set fishery are such rare events the sample size of 323 sets was not 

adequate to make any solid conclusions. An analysis with a larger sample size determined that 

the current regulations reduced the observed rate of incidental seabird interactions in the deepset fishery by about 83% (Gilman and Kobayashi 2007). The only treatment that showed a 

significant difference in efficacy above side-setting for stern setting vessels was when heavier (> 

60 g) weights were used with thawed blue-dyed baits. 

Spatial and temporal placement of fishing operations and the localized seabird abundance around 

vessels likely influence interaction rates and thus the efficacy of seabird mitigation measures. 

The NMFS observer program records relative seabird abundance during fishing operations. 

Including relative seabird abundance into analyses will improve the understanding of the relative 

success of seabird mitigation measures and enable the calculation of more precise interaction 

rates. For instance, it is possible that observed reductions in seabird interaction rates result from 

fewer albatrosses in the vicinity of observed fishing vessels due changes in fishing patterns. 

However, it was found that there were no discernable spatial differences in fishing effort since 

the reopening of the swordfish fishery in 2004 compared to historic fishing effort for either the 

deep-set fishery or the shallow-set fishery (Figs. 6 and 7) (NMFS 2006). Therefore, if albatross 

abundances in the vicinity of Hawaii longline vessels have also not changed, then differences in 

seabird interaction rates must be a result of something besides differences in spatial-temporal 

patterns of fishing effort and seabird abundance proximal to fishing operations. 

NMFS’s efforts to gather ship-board estimates of relative seabird abundance are continuing. 

These observations will likely prove valuable when combined with on-going tracking studies of 

all three species of North Pacific albatrosses. Even with no changes in temporal-spatial effort 

over time and seabird abundance, it is difficult to gauge the effectiveness of mitigation measures 

in Hawaii longline fisheries - especially, in the shallow-set fishery. Regulations designed to 

protect sea turtles in the shallow set fishery (large circle hooks, mackerel-type bait, sea turtle 

interaction limits) likely provided an ancillary benefit to reduce seabird interactions. For instance, 

the shallow-set fishery was closed in March 2006 because the interaction limit on loggerheads 

31 
was reached. Obviously, the closure meant that fewer incidental interactions with seabirds 

occurred that year. 

Seabird Interactions 2007 

Incidental interactions with seabirds are usually recorded during the haulback of longline gear, 

but on rare occasions they may be recorded by observers during the setting of gear. Section 9 of 

the ESA and Federal regulations pursuant to section 4(d) of the ESA prohibit the take of 

endangered and threatened species without special exemption. Take is defined as to “harass, 

harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to attempt to engage in any 

such conduct.” An incidental take of one STAL is allowed per year for the shallow-set fishery 

under the 2004 BiOp (USFWS 2004) and 15 over a seven year period for the deep-set fishery 

(USFWS 2002). 

Observed Interactions 

There were no observed interactions with STALs in either the deep-set or shallow-set 

components of the Hawaii longline fishery during 2007. However, NMFS observers recorded 

interactions with 18 BFAL and 7 LAAL in the deep-set fishery with a 20.1 % observer coverage 

rate for trips returning in 2007 (0.003 seabirds per 1,000 hooks). Interactions with 8 BFAL and 

40 LAAL were observed in the shallow-set component of the fishery in 2007 with a 100% 

observer coverage rate (0.035 seabirds per 1,000 hooks) (Figure 17). While the observed 

interaction rate for the deep-set component remained roughly the same, the interaction rate for 

the shallow-set component roughly doubled from 2006 to 2007. Only albatrosses were observed 

taken incidentally to fishing operations in 2007. 

Observed Interaction Statistics 

Observed BFAL and LAAL Albatross Interactions in the 

Hawaii Longline Fishery 2007 

8 

18 

7 

40 

0 

10 

20 

30 

40 

50 

Tuna Sets Swordfish Sets 

Set Type 

Number of

Interactions

BFAL: 

LAAL 

Figure 17. Total observed black-footed and Laysan albatross interactions in the Hawaii pelagic 

longline fishery in 2007 (Source: PIRO) 

32 
Albatross Interaction Types in the Hawaii 

Longline Fishery 2007 

10 

20 

30 

40 

50 

60 

umber of Interactions

Hooking 

Entanglement 

Hooked and Entangled 

0 N

Deep-set Shallow-set Combined 

Figure 18. Types of observed interactions between albatrosses and Hawaii longline vessels in 

2007 (Source: PIRO) 

Table 5. Types of Interactions between Albatrosses and Hawaii Longline Vessels in 2007 

Deep-set (25 Total) Shallow-set (48 

Total) 

Combined (73 Total) 

Hooking 22 (88%) 34 (71%) 56 (77%) 

Entanglement 3 (12%) 11 (23%) 14 (19%) 

Hooked and Entangled 0 (0%) 3 (6%) 3 (4%) 

The types of interactions in 2007 occurred in roughly the same proportions in the deep-set and 

shallows-set fishery with hookings accounting for the majority of observed interactions. A 

smaller proportion of albatrosses were entangled. There were three (3) albatrosses observed 

hooked and entangled in the shallow-set component. No seabirds were observed hooked and 

entangled in the deep-set component (Figure 18 and Table 5). 

33 
Release Condition for Albatrosses in the Hawaii 

Longline Fishery in 2007 

0 

10 

20 

30 

40 

50 

Deep-set Shallow-set Combined 

Number of Interactions

Alive 

Injured 

Dead 

Figure 19. Release condition for albatrosses captured incidentally to fishing operations in the 

Hawaii longline fishery in 2007 (Source PIRO) 

Deep-set (25 Total) Shallow-set (48 Total) Combined (73 Total) 

Alive 0 (0%) 0 (0%) 0 (0%) 

Injured 0 (0%) 40 (83%) 40 (55%) 

Dead 25 (100%) 8 (17%) 33 (45%) 

Table 6. Release condition for albatrosses captured incidentally to fishing operations in the Hawaii longline 

fishery in 2007 (Source PIRO) 

In 2007, all albatrosses that were observed captured in the deep-set component were dead when 

recovered. In contrast, the majority (83%) of albatrosses observed captured in the shallow-set 

component were released injured. The remaining incidental interactions in the shallow-set 

fishery resulted in mortalities. No albatrosses were observed released alive (Figure 19 and Table 

6). According to observer program staff, seabirds are seldom given an “Alive” release code. 

This could only happen if a seabird were to become lightly entangled and free itself without the 

aid of the observer (pers. comm. Jeremy Willson, April 2007). There is a strong correlation 

between the release condition and the phase of fishing operations in which seabirds are captured. 

If seabirds are caught during gear deployment, they are unlikely to survive gear interactions. In 

contrast, the majority of seabirds caught during gear retrieval are usually released injured. 

Based on 2007 observer data, it can be determined whether an albatross was captured during gear 

deployment and the soak period or gear retrieval. Data were analyzed and most probable time of 

capture was determined. No albatrosses were observed captured in the deep-set component 

during the gear retrieval phase of fishing operations (Figure 20 and Table 7). The observer 

narratives are consistent with the interpretation that all captures occurred during gear deployment 

in the deep-set component of the fishery. In contrast, the majority (83%) of interactions in the 

shallow-set component were directly observed occurring during the gear retrieval operations 

(haul). Most interactions that occurred during the haul happened when albatrosses were 

34 
attempting to steal baits from branchlines that were being retrieved. The rest of the interactions 

(17%) appear to have occurred during gear deployment or when the gear was soaking. 

Time of Capture for Albatrosses in Hawaii Longline 

Fishery in 2007 

0 

10 

20 

30 

40 

50 

Deep-set Shallow-set Combined 

Number of Interactions

Set/Soak 

Haul 

Figure 20. Time of capture for observed albatross interactions in the Hawaii longline 

fishery in 2007 (Source PIRO) 

Deep-set Shallow-set Combined 

Set/Soak 25 (100%) 8 (17%) 33 (45%) 

Haul 0 (0%) 40 (83%) 40 (55%) 

Table 7. Probable time of capture for observed albatross interactions in the 

 Hawaii longline fishery in 2007 (Source PIRO) 

All of the albatrosses in both components of the fishery that were determined to have been 

caught during gear deployment/soak were also recovered dead. 

Estimated Interactions 

Interaction estimates are calculated for the deep-set fishery in which ≥20% observer coverage is 

maintained annually (NMFS 2005a). In the shallow-set fishery, 100% observer coverage is 

required; therefore, all observed interactions are assumed to equal total interactions. 

Because of fluctuations in the deep-set fleet’s activity levels and observer availability, coverage 

levels vary throughout the year. These fluctuations make it impractical to sample trips so that 

each trip has an equal chance of being sampled (simple random sample). Furthermore, it is 

inappropriate to estimate the total number of incidental interactions by simply raising the average 

observed catch rate by the total amount of effort as this estimator assumes a simple random 

sample. 

The Horvitz-Thompson estimator methodology used for the deep-set fishery is an unbiased 

estimator based on the sampling design (McCracken 2006). The sampling design uses a 

35 
systematic sample as the primary sample and a daily random sample as a secondary sample. The 

systematic component uses a random number generator to select trips based on the order in 

which they are called in. This systematic schedule is usually designed to provide a 15% sampling 

rate. The daily sample selects trips randomly from vessel notifications at the end of a business 

day when observers are available. This hybrid approach to sampling is necessary to address the 

needs of fishing vessels to be able to fish, the ability of the NMFS Observer Program to place 

observers on vessels as observer availability varies, and the need to maintain a minimum 20% 

annual observer coverage rate for deep-set vessels. For instance, right after an observer training 

class there may be more than an adequate number of observers available to cover 20% of deepset trips. Sampling can easily follow the systematic schedule. Often during these periods the 

coverage rate is above 20% and vessels have a greater chance of being sampled. Conversely, if 

there are other demands on observers, like when trying to cover 100% of shallow-set trips, 

NMFS cannot simply prevent deep-set vessels from fishing. This leads to periods of low 

observer coverage and lower probabilities that a particular vessel will be sampled. The HorvitzThompson estimator used by McCracken accounts for the interplay between observer availability 

and fleet activity which, in turn, influences the probability of whether a trip is sampled, or not. 

While point estimates derived through the Horvitz-Thompson estimator are considered reliable, 

periods of low observer coverage (i.e., small sample size) lead to wider confidence intervals. 

Because seabird interactions are relatively rare events, confidence intervals were computed using 

accepted methods for estimating confidence intervals for rare events (Poissant variants). 

Confidence intervals for the yearly total were not computed because it is unreasonable to assume 

the interaction rates are constant throughout the year (McCracken 2006). 

Table 8. Interaction estimates with incidentally caught albatrosses and corresponding 95% 

confidence intervals (C.I.) for the Hawaii deep-set longline fishery in 2007. 

(Source: PIFSC) 

Quarter 1 

Point 

Estimate, C.I. 

Quarter 2 

Point 

Estimate, C.I. 

Quarter 3 

Point 

Estimate, C.I. 

Quarter 4 

Point 

Estimate, C.I. 

Annual 

Total 

Species 

Black-footed 

Albatross 

Laysan 

Albatross 

33, [4,98] 

30, [3,98] 

25, [5,62] 

5, [1,27] 

7, [1,30] 

0, [0,23] 

12, [4,28] 

9, [0,10] 

77 

44 

In 2007, the Hawaii deep-set longline fishery was estimated to have incidentally interacted with 

77 BFAL and 44 LAAL. The estimated interaction rates for 2007 in the deep-set fishery by 

species are 0.002 BFAL per 1000 hooks and 0.001 LAAL per 1000 hooks. The overall deep-set 

fishery interaction rate was 0.003 albatrosses per 1000 hooks. 

In 2007, there were an estimated 85 total interactions with BFAL and 88 total interactions with 

LAAL (173 total). Total estimates for the entire fishery were determined by combining the 

36 
estimated interactions (e.g. point estimates) with the total number observed in the shallow-set 

(swordfish) fishery (Figure 17). Fleet-wide seabird interactions for both components of the 

Hawaii longline fishery (estimated deep-set plus observed shallow-set) from 2000 through 2007 

are depicted in Figure 21. It should be taken into account that the shallow-set fishery closed in 

April 2001, and re-opened in October 2004. 

Estimated Albatross Interactions Hawaii Longline 

Fleet 2000-2007 

51 146 258 

1339 

89 73 85 65 16 111 

252 

1094 

88 15 105 10 

0 

200 

400 

600 

800 

1000 

1200 

1400 

1600 

2000 2001 2002 2003 2004 2005 2006 2007 

Year 

Number of Interactions

BFAL 

LAAL 

Figure 21. Estimated fleet-wide incidental interactions with black-footed and Laysan albatrosses 

in the Hawaii longline fishery during, 1999-2007 (Source: PIRO) 

Relatively more BFALs are taken compared to their population size (recall that the BFAL 

nesting pair population is about one tenth that of LAALs) than are LAALs since they are taken in 

about even total numbers. This trend seems to be consistent over the years (Figure 21). 

Fernandez et. al. (2001) note that this species is commonly seen following ships, and the results 

of a satellite telemetry study by Hyrenbach et. al. (2002) suggests that BFALs may selectively 

forage during the breeding season in the same areas that are fished by Hawaii-based longline 

vessels. Both studies show that during the early breeding period (January and February) both 

species may make short foraging trips to areas that are often fished by Hawaii-based longline 

vessels close to the NWHI. The Hyrenbach study also demonstrates a preference by LAALs for 

boreal and sub-arctic waters away from pelagic longline fishing grounds later in the breeding 

season (March and April). The differences in behavior and preferred foraging areas during the 

breeding season between the two species may have some influence on why BFALs are caught in 

disproportionate numbers relative to their population. Research into the feeding behaviors, 

monitoring of albatross abundance and interactions on fishing grounds, and telemetry studies 

should continue in order to help clarify why BFALs are taken more often in pelagic longline 

fishing operations relative to their population size. 

37 
Short-tailed Albatross Sightings in 2007 

There were four short-tailed albatross sightings in 2007 by NMFS observers aboard Hawaiibased longliners (Table 9). All details of the sightings were provided to USFWS. 

Figure 22. Short-tailed albatross sightings by NMFS observers, 2007 (Source: PIRO) 

Table 9. Short-tailed albatross sightings in 2007 

Date Trip Type Comments 

January 4, 2007 Shallow-set No gear contact. Bird sighted resting on the water. 

January 14, 2007 Shallow-set No gear contact. 

January 14, 2007 Shallow-set No gear contact. (Same trip and day). 

December 11, 

2007 

Deep-set No gear contact. Bird sighted resting on the water 20 – 30 m 

from vessel. 

9.0 Summary 

In 2007, total observer coverage averaged 25.6% (20.1% for deep-setting vessels and 100% for 

shallow-setting vessels; 4,964 of 19,385 total sets) based on trips arriving in 2007. Additionally, 

NMFS observers monitored 31.9% of all longline sets north of 23° N and 16.2% of deep-sets 

north of 23° N that were hauled in 2007 (NMFS unpubl. 2008). 

38 
 

Of 40,197,926 total hooks fished, the deep-set fishery deployed about 39 million hooks in 17,809 

sets, and the shallow-set fishery deployed a reported a little more than1.3 hooks in 1,570 sets 

(NMFS 2008). 

No interaction was observed or reported with a STAL in the Hawaii longline fishery, either by 

deep-setting or shallow-setting vessels. However, there were four sightings of STALs by NMFS 

observers aboard Hawaii-based longline vessels. In 2007, the shallow-set fishery was observed 

to interact with 8 BFALs and 40 LAALs, an interaction rate of 0.035 albatross per 1000 hooks. It 

was estimated that there were 77 BFAL and 44 LAAL interactions in the deep-set fishery in 

2007. Overall, the deep-set fishery had an estimated interaction rate of 0.003 albatrosses per 

1000 hooks. Since 2004, the estimated number of albatrosses taken incidentally to fishing 

operations by Hawaii pelagic longline fisheries has been reduced by 92-99% compared to the 

2000 estimates. No other species besides albatrosses were reported caught incidentally to fishing 

operations in the Hawaii-based longline fishery in 2007. 

39 
10.0 Literature Cited 

BirdLife International. 2004. Tracking ocean wanderers: the global distribution of albatrosses 

and petrels. Results from the Global Procellariiform Tracking Workshop, 1-5 

Septemeber, 2003, Gordon’s Bay, South Africa. Cambridge, UK: BirdLife International. 

Boggs, C.H. 2001. Deterring albatrosses from contacting baits during swordfish longline sets. 

Proceedings of the Symposium on Seabird Bycatch: Trends, Roadblocks and Solutions. 

Pacific Seabird Group, University of Alaska Sea Grant Program. AK-SG-01-01. 

Brothers, N. 1995. Catching fish not birds: A guide to improving your longline fishing 

efficiency. Australian Longline Version. Hobart, Australia: Australia Parks and 

Wildlife Service. 70 pp. 

_____. 1996. Longline fishing dollars and sense: Catching fish not birds using 

bottom set or mid-water set longlines. Tasmanian Parks and Wildlife Service, Hobart. 

Brothers, N. and Gilman E. 2007. Side Setting Technical Assistance Program for the Hawaii 

Pelagic Longline Fleet: Phase 4. Prepared for the National Marine Fisheries Service, 

Pacific Islands Regional Office. Honolulu, Hawaii. 

Brothers, N. and Gilman E. 2005. Technical assistance for Hawaii pelagic longline vessels to 

change deck design and fishing practices to side-set. Prepared for the Hawaii Longline 

Association and U.S. NOAA Fisheries Pacific Islands Fisheries Science Center. 20 

October 2005, p12. 

Brothers, N.P., Cooper, J., and Lokkeborg, S. 1999. The incidental catch of seabirds by longline 

fisheries: Worldwide review and technical guidelines for mitigation. FAO Fisheries 

Circular No. 937. Food and agriculture Organization of the United Nations: Rome. 100p. 

Clemens, A. 2006. Annual Report on Seabird Interactions and Mitigation Efforts in the Hawaii 

Longline Fishery for 2005. AR-PIRO-05-06. National Marine Fisheries Service. 

Honolulu. pp. 35. 

Fernandez, P., Anderson D.J., Sievert, P.R., Huyvaert, K. P. 2001. Foraging destinations of 

three low latitude albatross (Phoebastria) species. J. Zool., London. 254, 391-404. 

Flint, Beth. 2007. Hawaiian Islands National Wildlife Refuge and Midway Atoll National 

Wildlife Refuge – Annual Nest Counts through Hatch Year 2007. USFWS, Pacific 

Remote Islands National Wildlife Refuge Complex, 20pp. 

Gilman, E. 2006. Comparison of Seabird Capture Rates for Hawaii-based Longline Tuna 

Vessels Side v. Stern Setting Based on an Analysis of Observer Data. Blue Ocean 

Institute. Honolulu, Hawaii. 16 pp. 

40 
 

 

 

Gilman, E. 2004. Assessment of data collection protocols by the Hawaii pelagic 

longline onboard Observer program to assess effectiveness of strategies to reduce seabird 

bycatch and comparison of seabird bycatch rates for the Hawaii pelagic longline tuna 

vessels side-setting, stern-setting, and using blue-dyed bait, and stern-setting with no 

seabird avoidance methods for the period 15 August 2003-26 October 2004. Prep. for the 

Western Pacific Regional Fishery Management Council. Honolulu. 

Gilman E., Brothers N., Kobayashi D. 2007. Comparison of the efficacy of three seabird 

bycatch avoidance methods in Hawaii pelagic longline fisheries. Fisheries Science; 73: 

208-210. 

Gilman, E., Brothers, N., Kobayashi, D. 2005. Principles and approaches to abate seabird 

bycatch in longline fisheries. Fish and Fisheries 6(1): 35-49. 

Gilman, E., Boggs, C., and Brothers, N. 2003. Performance assessment of an underwater setting 

chute to mitigate seabird bycatch in the Hawaii pelagic longline tuna fishery. Ocean and 

Coastal Management 46(11-12): 985-1010. 

Gilman, E, and Kobayashi D. 2007. Reducing Seabird Bycatch in the Hawaii Longline Tuna 

Fishery. Report. NMFS Pacific Islands Regional Office. Honolulu. pp. 13. 

Hasegawa, H. 1979. Status of the STAL of Torishima and in the Senkaku Retto in 1978/79. 

Pacific Seabird Group Bull. 6(1): 806-814. 

_____. 2006. “My 91st visit to Torishima.” E-mail to Greg Balogh (USFWS). January 16, 

2006. 

_____. 2007a. “Short-tailed Albatrosses on Torishima in 2006-07.” E-mail to Thorn Smith 

(Alaska Longliners Association). January 13, 2007. 

_____. 2007b. “Re: Report of Hasegawa’s latest survey on Torishima.” E-mail to Greg Balogh 

(USFWS). December 18, 2007. 

Hyrenbach, D.K., Fernandez, P., Anderson, D. J. 2002. Oceanographic habitats of two 

sympatric North Pacific albatrosses during the breeding season. Marine Ecology 

Progress Series. Vol. 233:283-301. 

Kim, Chanki. 2008. Short-tailed Albatross of Japan. E-mail to Lewis Van Fossen (NMFS). 

February 18, 2008. 

Matsumoto T., Y. Semba, H. Okamoto, S. Kondo, J. Sakaki, I. Ohta, M. Okuhara, M. Mizoguchi. 

2007. Behavior of bigeye tuna based on archival tagging in the southwestern part of 

Japan. Abstract. Second International Symposium on Tagging and Tracking Marine Fish 

with Electronic Devices, October 8-11, 2007. Donostia-San Sebastian, Spain. 

41 
McCracken, Marti L. 2006. Estimating Bycatch for Hawaii-based Deep-set Pelagic Longline 

Fishery (Tuna). pp.6. Pacific Islands Fisheries Science Center, NMFS, NOAA, Honolulu, 

HI. 

McNamara, B., Torre, L., and Morgan, K.H. 1999. Final report: Hawaii longline seabird 

mortality mitigation project. Report prepared by Garcia and Associates for the Western 

Pacific Fishery Management Council. 93 pp + appendixes. 

National Marine Fisheries Service. 1999. Biological Assessment: Effects of the Hawaii domestic 

longline fishery on the STAL around the Hawaiian Islands. Pacific Islands Area Office, 

National Marine Fisheries Service, February 1999. 40p. 

_____. 2001. Final Environmental Statement: Fishery Management Plan for Pelagic Fisheries of 

the Western Pacific Region. March 30, 2001. 

_____. 2004. Biological Opinion on the Western Pacific Pelagics FMP. NMFS Pacific Islands 

Regional Office, February 23, 2004. 252pp. 

_____. 2005. Biological Opinion on the Hawaii-based pelagic, deep-set longline fishery. NMFS 

Pacific Islands Regional Office, October 4, 2005. 187pp. 

_____. NMFS 2006. Annual report on seabird interactions and mitigation efforts in the Hawaiibased longline fishery for 2005. Pacific Islands Regional Office. Administrative Report 

AR-PIR-05-06, 33 pp. 

_____. NMFS 2008. The Hawaii-based Longline Logbook Summary Report October-December 

2007. Pacific Islands Fishery Science Center, March 5, 2008. Data Report DR-08-002. 

pp. 37. 

Naughton MB, MD Romano, TS Zimmerman. 2007. A conservation action plan for blackfooted albatross (Phoebastria nigripes) and Laysan albatross (P. immutabilis), Ver. 1.0. 

Sievert P., 2007. “Re: Historic Population of STAL.” E-mail to Lewis Van Fossen (NMFS). 

April 17, 2007. 

Suryan, R.M. 2008. “STAL maps and update.” E-mail to multiple persons. April 11, 2008. 

Suryan R.M., Dietrich K.S., Melvin E.F., Balogh G.R., Sato F., Ozaki K., 2007. Migratory 

routes of short-tailed albatrosses: Use of exclusive economic zones of North Pacific Rim 

countries and spatial overlap with commercial fisheries in Alaska. Biological 

Conservation. 137 (2007) 450-460. 

U.S. Fish and Wildlife Service (USFWS). 2000. BiOp of the U.S. Fish and Wildlife Service for 

the effects of the Hawaii Domestic Longline Fleet on the STAL (Phoebastria albatrus), 

November 2000. Honolulu, HI. 96 pp. FWS 1-2-1999-F-02. 

_____. 2002. Revised BiOp of the U.S. Fish and Wildlife Service for the effects of the Hawaii 

Domestic Longline Fleet on the STAL (Phoebastria albatrus), November 2002. 

Honolulu, HI. 30 pp. FWS 1-2-1999-F-02R. 

42 
 

_____. 2004. BiOp on the Effects of the Reopened Shallow-Set Sector of the Hawaii Longline 

Fishery on the STAL (Phoebastria albatrus), October 2004. Honolulu, HI. 129 pp. FWS 

1-2-1999-F-02.2. 

_____. 2005. Short-tailed Albatross Draft Recovery Plan. Anchorage, AK, 62 pp. 

http://ecos.fws.gov/docs/recovery_plans/2005/051027.pdf 

Walsh, H.E., and Edwards S.V., 2005. Conservation genetics and Pacific fisheries bycatch: 

Mitochondrial differentiation and population assignment in black-footed albatrosses 

(Phoebastria nigripes). Conservation Genetics 6:289-295. 

43 
11.0 Acknowledgements 

Dr. Marti McCracken of the Pacific Islands Fisheries Science Center provided the 2006 

interaction estimates for protected species incidentally caught in the Hawaii longline fishery. 

Eric Gilman of the Blue Ocean Institute provided input on the effectiveness of seabird deterrence 

measures. Lesley Jantz of the Pacific Islands Region Hawaii Longline Observer Program 

provided the Hawaii longline effort plots and general data requests. Jeremy Willson and Eric 

Forney were essential in gathering data for the report. Dr. Beth Flint of the U.S. Fish and 

Wildlife Service provided the current status of albatross populations. Dr. Scott Schaffer and Dr. 

Robert Suryan provided guidance and papers on understanding albatross movements. Kim 

Rivera, National Seabird Coordinator, NOAA Fisheries, and Brett Wiedoff (SFD) for reviewing 

the document prior to distribution. 

44 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12.0 Appendices 

Appendix 1. Pelagic Management Unit Species and Common Catch Species 

Table 1. Pelagic Management Unit Species (Source: WPFMC) 

Common name Scientific name 

Mahimahi (dolphinfish) Coryphaena spp. 

Indo-Pacific blue marlin Makaira mazara 

Black marlin M. indica 

Striped marlin Tetrapturus audax 

Shortbill spearfish T. angustirostris 

Swordfish Xiphias gladius 

Sailfish Istiophorus platypterus 

Pelagic thresher shark Alapias pelagicus 

Bigeye thresher shark Alopias 

Common thresher shark Alopias vulpinus 

Silky shark Carcharhinus falciformis 

Oceanic whitetip shark Carcharhinus longimanus 

Blue shark Prionace glauca 

Shortfin mako shark Isurus oxyrinchus 

Longfin mako shark Isurus paucus 

Salmon shark Lamna ditropis 

Albacore Thunnus alalunga 

Bigeye tuna T. obesus 

Yellowfin tuna T. albacore 

Northern bluefin tuna T. thynnus 

Skipjack tuna Katsuwonus pelamis 

Kawakawa Euthynnus affinis 

Wahoo Acanthocybium solandri 

Moonfish Lampris spp. 

Oilfish family Gempylidae 

Pomfret family Bramidae 

Other tuna relatives Auxis spp., Scomber spp.; Allothunus spp. 

45 
 

 

 

 

 

 

Table 2. Common Fish Species Encountered in the Hawaii-based Pelagic Longline Fishery 

(Source: PIFSC) 

Black Mackerel Scombrolabrax heterolepis 

Bony Fishes, Unidentified Osteichthys 

Crestfish Lophotus lacepede 

Dolphinfish Coryphaena hippurus 

Dolphinfish, Pompano Coryphaena equiselis 

Driftfish Cubiceps 

Escolar, Oilfish Ruvettus pretiosus 

Escolar, Roudi Promethichthys prometheus 

Escolar, Smith's Lepidocybium flavobrunneum 

Great Barracuda Sphyraena barracuda 

Jack, Cottonmouth (Unidentified) Uraspis spp. 

Jack, Rainbow Runner Elagatis bipinnulatus 

Jack, Yellowtail Seriola lalandi 

King-of-Salmon Trachipterus altivelis 

Lancetfish, Longnose Alepisaurus ferox 

Louvar Luvarus imperialis 

Mackerel, Pacific (Chub) Scomber japonicus 

Manta, Atlantic Manta birostris 

Manta-Mobula (Unidentified) Mobulidae 

Marlin, Black Makaira indica 

Marlin, Indo-Pacific Blue Makaira mazara 

Marlin, Striped Tetrapturus audax 

Mola, Common (Ocean Sunfish) Mola mola 

Mola, Sharptail Masturus lanceolatus 

Mola, Slender Ranzania laevis 

Oarfish Regalecus glesne 

Omosudid (Hammerjaw) Omosudis lowei 

Opah Lampris guttatus 

Pelagic Puffer Lagocephalus lagocephalus 

Pelagic Stingray Dasyatis violacea 

Pomfret, Brilliant Eumegistus illustris 

Pomfret, Knifetail Taractes rubescens 

Pomfret, Rough Taractes asper 

Pomfret, Sickle Taractichthys steindachneri 

Pomfrets, Unidentified Bramidae 

Ray (Other) Rajiformes 

Ray (Unidentified) Rajiformes 

Razorback Scabbardfish Assurger anzac 

Rough Triggerfish Canthidermis maculata 

Sailfish Istiophorus platypterus 

46 
 

 

 

 

 

 

 

 

 

 

 

 

 

Scalloped Hammerhead Shark Sphyrna lewini 

Scalloped Ribbonfish Zu cristatus 

Shark (Other) 

Shark, Bigeye Thresher Alopias superciliosus 

Shark, Bignose Carcharhinus altimus 

Shark, Blacktip Carcharhinus limbatus 

Shark, Blue Prionace glauca 

Shark, Cookie Cutter Isistius brasiliensis 

Shark, Crocodile Pseudocarcharias kamoharai 

Shark, Galapagos Carcharhinus galapagensis 

Shark, Grey Reef Carcharhinus amblyrhynchos 

Shark, Longfin Mako Isurus paucus 

Shark, Oceanic Whitetip Carcharhinus longimanus 

Shark, Pelagic Thresher Alopias pelagicus 

Shark, Salmon Lamna ditropis 

Shark, Sandbar Carcharhinus plumbeus 

Shark, Shortfin Mako Isurus oxyrinchus 

Shark, Silky Carcharhinus falciformis 

Shark, Smooth Hammerhead Sphyrna zygaena 

Shark, Thresher Alopias vulpinus 

Shark, Tiger Galeocerdo cuvieri 

Shark, Unidentified Chondrichthyes 

Shark, Velvet Dogfish Scymnodon squamulosus 

Shark, White Carcharodon carcharias 

Sharks, Hammerhead Sphyrna 

Sharks, Thresher (Unidentified) Alopiidae 

Shortbill Spearfish Tetrapturus angustirostris 

Snake Mackerel Gempylus serpens 

Swordfish Xiphias gladius 

Tapertail Ribbonfish Trachipterus fukuzakii 

Triggerfish, Unidentified Balistidae 

Tuna, Albacore Thunnus alalunga 

Tuna Bigeye Thunnus obesus 

Tuna, Kawakawa Euthynnus affinis 

Tuna, Pacific Bluefin Thunnus orientalis 

Tuna, Pacific Bonito Sarda chiliensis 

Tuna, Skipjack Katsuwonus pelamis 

Tuna, Yellowfin Thunnus albacares 

Wahoo Acanthocybium solandri 

47 
Appendix 2: Interaction estimates with incidentally caught sea turtles, seabirds, and 

marine mammals in the Hawaii longline deep-set fishery. 

48 
Estimation of Incidental Interactions with Sea Turtles and Seabirds 

in the 2007 Hawaii Longline Deep Set Fishery 

Marti L. McCracken 

Pacific Islands Fisheries Science Center 

National Marine Fisheries Service 

This report provides estimates of the number of incidental interactions with protected 

species by the Hawaii longline deep set fishery in the year 2007 (Table 1). Within this report, an 

incidental interaction means an event during a longline fishing operation in which a protected 

animal is hooked or entangled by the fishing gear. An incidental interaction estimate refers to the 

estimated total number of incidental interactions for all longline deep set fishing trips landing in 

the specified time period. A longline deep set fishing trip is defined as any commercial fishing 

trip by a vessel with a Hawaii longline permit that departs or returns at a Hawaii port, excluding 

those trips using a certificate for swordfish fishing. 

The interaction estimates are based on a random sample of longline trips on which 

scientific observers are deployed. In 2007, observed trips were selected using two sampling 

schemes to accommodate fluctuating coverage levels and utilize observers efficiently. Coverage 

levels vary throughout the year because of fluctuation in the fleet’s activity level, demands of 

100% coverage in the Hawaii longline shallow set fishery for swordfish, and an influx of 

observers after completion of NMFS observer training. Because observers are not paid while 

waiting to be deployed, they must be assigned with minimal delay when available. The 

alternative of paying them while they are waiting to be deployed would increase the cost of the 

observer program. The two sampling schemes attempt to reach a balance between obtaining a 

probability sample and being cost effective. A probability sample implies that all trips have a 

probability of being sampled and the sampling probabilities are known. These sampling 

probabilities form the basis of design-based estimators. An unbiased design-based estimator has 

the merit that it is unbiased regardless of the characteristics of the population being surveyed. 

The primary scheme was a systematic sample. Before departing on a fishing trip, 

longline vessels were required to call the NOAA Fisheries Pacific Islands Regional Office 

(PIRO) observer program contractor at least 72 hours prior to their intended departure date. To 

enable sample selection, the PIRO contractor numbered calls sequentially in the order in which 

they were received. Herein, this assigned number is referred to as the call number. Prior to the 

beginning of a quarter, a systematic sample of call numbers was drawn by PIFSC and supplied to 

the contractor. The trips associated with these selected call numbers were designated to be 

sampled. Although every reasonable effort was made to sample selected trips, there were some 

selected trips that departed without an observer. In this situation, the PIRO contractor recorded 

that the trip was not sampled along with a short explanation of why it was not sampled. If a trip 

was selected but the vessel did not leave within a reasonable amount of time, usually the 

observer was reassigned to a different vessel trip. When the selected vessel was ready to depart a 

different observer was assigned to it. 

49 
The systematic sample requires having an observer available to be deployed whenever a 

selected trip is ready to depart. To achieve this requirement under full targeted coverage 

throughout the year requires increasing the current number of observers on contract and paying 

them when they are not deployed on a vessel. These requirements frequently cannot be met 

under the current level of funding; therefore, the quarterly sample selected under the systematic 

design was usually slightly smaller than the targeted coverage, typically 5% less. When this 

occurred, the additional trips needed to reach the full targeted level were selected using a 

secondary sampling scheme. This secondary scheme was used when all trips selected by the 

systematic sample were already covered and an observer was ready to be deployed. In this 

instance, a trip was randomly selected with equal probability from the calls received that day that 

had not already been selected. If more than one observer needed to be assigned, the appropriate 

number of trips was sampled with equal probability from this pool of call-ins. The coverage 

obtained by this secondary sampling scheme was flexible and dependent on the need to deploy 

observers. The additional samples drawn under the secondary sampling scheme depart from 

traditional probability samples because the days when additional samples were drawn were not 

randomly selected but determined by the need to deploy observers. 

Because the systematic sample was selected quarterly, point estimates of incidental 

interactions were computed on a quarterly basis and then summed to estimate the year’s total 

interactions. All observed incidental interactions on a trip were assigned to the quarter when the 

vessel returned to port after completing the trip. Some quarterly estimates of interactions 

therefore involve interactions that occurred during an earlier quarter. Accordingly, these 

estimates are not the best source of information on seasonality of interactions. 

The contractor’s sampling records were used to approximate sampling probabilities. The 

sampling probabilities during the periods when additional (secondary) samples were drawn were 

computed by enumerating the number of call-ins during consecutive periods of comparable 

coverage. It was then assumed that the additional trips were selected with equal probability from 

those trips that had not been selected as part of the systematic sample. When coverage was 

below that of the anticipated systematic sample, the sampling probabilities were computed by 

enumerating all call-ins during this period and assuming that the trips sampled were selected 

with equal probability. 

Because the coverage level changed with the fluctuations in observer availability and 

fishing activity, the observed trips were not selected with equal probability. Therefore, the 

Horvitz-Thompson estimator was used to estimate total interactions, as it takes into account 

unequal sampling probabilities. The incidental interaction records used to compute the HorvitzThompson estimator were those available in the Longline Observer Database System on 2 April 

2008. 

Confidence intervals for the quarterly incidental interactions were estimated using the 

approximated sampling probabilities and assuming that the number of incidental interactions per 

trip for a given species was an independent Poisson variate with a constant mean value. The 

50 
 

 

 

 

 

 

 

 

assumption that the average rate of incidental interactions was constant throughout a quarter is 

questionable but necessary to compute confidence intervals. Confidence intervals for the yearly 

total were not computed, as it seems unreasonable to assume that incidental interaction rates 

were constant throughout the entire year. A quarter’s confidence interval does not incorporate 

information beyond the quarter’s data. Therefore, for some species the upper bound of the 

confidence interval may seem high given historical records. For example, there has not been an 

observed incidental interaction with a short-tailed albatross during the history of the observer 

program and based on this information it seems highly improbable that the incidental interaction 

levels would be as high as the upper bounds of the confidence intervals for this species. 

Table 1. Point estimates of the number of incidental interactions by species and corresponding 

95% confidence intervals (C.I.) for the Hawaii deep set longline fishery in 2007. All protected 

species of sea turtles and seabirds with an observed interaction are listed as well as species that 

most commonly interact with the fishery or are of special concern because of their endangered 

species status. 

Quarter Annual 

Total 

Number of Incidental Interactions 

Species Point 

Estimate C.I. 

Point 

Estimate C.I. 

Point 

Estimate C.I. 

Point 

Estimate C.I. 

Point 

Estimate 

Turtles 

Loggerhead 0 [0,38] 0 [0,17] 7 [1,30] 0 [0,10] 7 

Leatherback 0 [0,38] 2 [1,22] 0 [0,23] 2 [1,12] 4 

Olive Ridley 0 [0,38] 11 [2,38] 0 [0,23] 15 [5,32] 26 

Green 0 [0,38] 0 [0,17] 0 [0,23] 0 [0,10] 0 

Albatrosses 

BlackFooted 

33 [4,98] 25 [5,62] 7 [1,30] 12 [4,28] 77 

Laysan 30 [3,93] 5 [1,27] 0 [0,23] 9 [3,23] 44 

Short-tailed 0 [0,38] 0 [0,17] 0 [0,23] 0 [0,10] 0 

51 
 52