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Hawaii Deep-set Longline Fishery

Current Classification on the 2017 LOF

Category I
Estimated Number of Participants^ 139
Target Species tuna
Applicable Take Reduction Plans False Killer Whale Take Reduction Plan
Observer Coverage* This fishery has been observed since 1994.  Initially, observer coverage was less than 5%, increased to 10% in 2000, and exceeded 20% in 2001 and 2002.  Observer coverage was 22.2% in 2003; 24.6% in 2004; 26.1% in 2005; 21.2% in 2006; and 20.1% in 2007
Marine Mammal Species/Stocks Killed or Injured Bottlenose dolphin, HI Pelagic;
False killer whale, MHI insular1;
False killer whale, HI pelagic1;
False killer whale, NWHI;
Pygmy killer whale, HI;
Risso’s dolphin, HI;
Short-finned pilot whale, HI;
Sperm Whale, HI;
Striped dolphin, HI.

^ Number of participants estimates are based on state and federal fisheries permit data.  The estimated number of participants is expressed in terms of the number of active participants in the fishery, when possible.  If this information is not available, the estimated number of vessels or persons licensed for a particular fishery is provided.  If no recent information is available on the number of participants, then the number from the most recent LOF is used.  NMFS acknowledges that, in some cases, these estimations may be inflating actual effort.  

*Observer coverage levels include the latest information reported in the most current final Stock Assessment Report (SAR)

1 Indicates the stock or species is driving the classification of the fishery 

Note: Current classification based on final LOF, no proposed changes are reflected in this table.


Basis for Current Classification

The total annual mortality and serious injury of false killer whales (HI pelagic stock) in this fishery exceeds 50% of the stock's Potential Biological Removal (PBR) level.   


This fishery operates inside and outside the US EZZ, primarily around the main Hawaiian Islands and Northwestern Hawaiian Islands, with some trips to the EEZs around the U.S. Pacific Remote Island Areas. Vessels vary their fishing grounds depending on their target species. Most of the deep-set fishing occurs north and south of the Hawaiian Islands, according to fishing conditions. This fishery operates year-round, although vessel activity increases during the fall and is greatest during the winter and spring months.  

Gear Description

This fishery uses longline gear.  Deep-set longline gear typically consists of a continuous mainline set below the surface and supported in the water column horizontally by floats with branch lines attached at intervals on the mainline.  Mainline is 3.2-4.0mm diameter monofilament and stored on large hydraulic reels. In addition, radio buoys are also used to keep track of the mainline as it drifts at sea.  A line shooter is used on deep-sets to deploy the mainline faster than the speed of the vessel, thus allowing the longline gear to sink to its target depth (target depth for bigeye tuna is approximately 400 m).  The mainline is typically 25 to 45 nmi long.  A minimum of 15, but typically 25 to 30, weighted branch lines (gangions) are clipped to the mainline at regular intervals between the floats. All float lines must be at least 20 m in length. Each branch line terminates with a single baited hook.  The branch lines are typically 11 to 15 m (25 to 50 ft) long. Sanma (saury) or sardines are used for bait.  The use of light sticks (or any light emitting device) is prohibited.  Unlike the shallow-set fishery, the deep-set does not have regulations regarding the time of day that the gear may be set.  However, it is common for fishermen to set their gear in the morning and haul in the afternoon/night, mainly to maximize their target catch rates.


This fishery is a Federal limited access program and is managed by the Western Pacific Fishery Management Council under the Fishery Ecosystem Plan for Pelagic Fisheries of the Western Pacific Region, and is subject to Federal regulation. Measures that are currently applicable to the fishery include, but are not limited to, limited access (permit requirement), vessel and gear marking, vessel length restrictions, Federal catch and effort logbooks, large longline restricted areas around the Hawaiian Archipelago, vessel monitoring system (VMS), annual protected species workshops, and the possession and use of sea turtle and seabird mitigation gear and safe handling techniques.  The vessel operator must notify NMFS prior to departure whether the vessel is undertaking a deep-set or shallow-set trip.  Once the trip type is set, it cannot be changed during the trip.  Vessel operators must take a NMFS contracted observer if requested by NMFS – target observer coverage is 20% of trips.  If any marine mammal interaction (hooking or entanglement) resulting in injury or mortality occurs, the vessel operator must complete and mail a pre-addressed, postage paid form to NMFS within 48 hours of the end of the trip. Additional information on all applicable regulations for the deep-set longline fishery is available at  This fishery is subject to the FKWTRT.  NMFS is currently implementing the Take Reduction Plan and, potentially, associated regulations.


Historical Information

Original Category (Year added to the LOF) III (1996)
Original Number of Participants 140
Basis for Original Classification Observer data indicated that interactions occur with various marine mammal stocks (for example, there was an interaction with a humpback whale in 1991); however, estimates of PBR levels and annual mortality and serious injury for many stocks were not available.
Past Names HI Deep-set (tuna target) Longline/Set Line (until 2015);
HI swordfish, tuna, billfish, mahi mahi, wahoo, oceanic sharks longline/set line (until 2009)
Species/stocks with historically documented as killed or injured (but not currently on list) Blainville's beaked whale, HI;
Bryde's whale, HI;
Humpback whale, Central North Pacific;
Hawaiian monk seal, MHI;
Spinner dolphin, HI


Timeline of Changes

  • Removed Pantropical spotted dolphin (HI).
  • Added pygmy killer whale (HI).
  • Estimated number of participants updated from 135 to 139.
  • Added false killer whale (NWHI).
  • Removed false killer whale (Palmyra Atoll).
  • Estimated number of participants updated from 129 to 135.
  • Removed humpback whale (CNP).
  • Changed name from HI Deep-set (tuna target) Longline/Set Line to HI Deep-set Longline.
  • Added sperm whale (HI).  
  • Changed false killer whale (HI insular) to (MHI insular) and removed “1”.
  • Removed Blainville’s beaked whale.  
  • Estimated number of participants updated from 124 to 129.
  • Estimated number of participants reduced from 127 to 124.
  • Added false killer whale (HI stock).
  • Added false killer whale (HI Insular stock).   
  • Added false killer whale (Palmyra Atoll stock).  
  • Changed stock name of bottlenose dolphins “HI” to “HI Pelagic.”
  • Changed stock name of Pantropical spotted dolphins from "unknown" to "HI."
  • Changed stock name of bottlenose dolphin from "HI" to "HI Pelagic".
  • Estimated number of participants reduced from 129 to 127.
  • False killer whale stock name changed from "HI" to “HI pelagic".
  • Added Pantropical spotted dolphin (stock unknown).
  • Removed spinner dolphin (HI).
  • Listed as a separate Category I fishery on the LOF.  Listed by splitting the Category I “HI swordfish, tuna, billfish, mahi mahi, wahoo, oceanic sharks longline/set line” fishery into this Category I deep-set (tuna target) fishery and the Category II shallow-set (swordfish target) fishery.
  • Retained the species/stocks on the list of those incidentally killed/injured in the “HI swordfish, tuna, billfish, mahi mahi, wahoo, oceanic sharks longline/set line” fishery that were documented as taken in the deep-set (tuna target) fishery.
  • Retained the superscript “1” after false killer whales (HI stock).
Changes on the LOF for the “HI swordfish, tuna, billfish, mahi mahi, wahoo, oceanic sharks longline/set line”
  • Added Bryde's whale (HI) and striped dolphin (HI).
  • Added Blaineville's beaked whale (HI) and Pantropical spotted dolphin (HI).
  • Elevated to Category I based on the level of incidental mortality and serious injury and revised PBR levels of false killer whale (HI). Also, NMFS had information of serious injury and mortality of interactions with all other stocks listed under this fishery. As a result of the a 2002 NMFS survey of cetacean abundance in waters where the HI longline fishery operated (throughout the HI EEZ in conjunction with 1993-98 aerial survey data conducted within 25 nmi of the main HI Islands), and the 2002 SARs using data from observer coverage, false killer whales were determined to be a strategic stock.  The previous PBR for false killer whales was set with 1993-1998 data that did not cover the entire range of the species.  Based on extrapolations of available data, the total annual mortality and serious injury of false killer whales (HI) was 4.4 animals/year, which exceeded 50% of PBR (PBR= 1.2).  The continued take of false killer whales and other cetaceans, including endangered humpback (Pacific Islands Observer Program annual reports list one humpback whale released injured from deep-set gear in both 2002 and 2004) and sperm whales, warranted elevation to a Category I.  Observer coverage would be high from then on as a result of an ESA B.O. requiring 100% coverage in the shallow-set component of the fishery and 20% coverage in the deep-set component.
  • NMFS proposed to elevate the fishery to Category II based on 1) observer data indicating that interactions with marine mammal stocks was not a rare occurrence, 2) the diversity of species documented as incidentally killed or seriously injured in this fishery, and 3) by analogy with other longline fisheries in the U.S. that use similar gear and target similar species, which are Category I or II.  NMFS did not elevate the fishery at that time because: 1) there were plans to conduct new abundance surveys in 2002 for all marine mammals inhabiting HI waters; 2) changes in the operation of the fishery were predicted as a result of a Biological Opinion (B.O.) under the Endangered Species Act (ESA) on the proposed FMP for Pelagic fisheries in the Western Pacific Region, which provided several Reasonable and Prudent Alternatives to address adverse effects on endangered sea turtles; and 3) the B.O. included terms to continue the observer program  at 20% coverage annually.  These 3 factors would increase data and knowledge about the level of mortality and serious injury of marine mammals.  NMFS indicated that reclassification may be warranted in a future LOF.
  • Added sperm whale (HI) and false killer whale (HI).
  • Deleted monk seal (HI).
  • Humpback whale (Central North Pacific) retained even though the last observed interaction was in 1991. NMFS scientists determine the most appropriate date to use on a case-by-case basis.  This data was peer reviewed by the Pacific Scientific Review Group.
  • Observer coverage was expanded and NMFS began developing expanded take estimates for consideration of reclassification of this fishery in a future LOF.
  • Added spinner dolphin (HI) and short-finned pilot whale (HI).


Updated January 15, 2017