NOAA Technical Memorandum NMFS-PIFSC-9

March 2007

The Hawaiian Monk Seal 

in the Northwestern Hawaiian Islands, 2003 

Compiled and Edited by 

Thea C. Johanos 

and 

 Jason D. Baker 

Pacific Islands Fisheries Science Center 

National Marine Fisheries Service 

National Oceanic and Atmospheric Administration 

U.S. Department of Commerce
About this document

The mission of the National Oceanic and Atmospheric Administration (NOAA) is to 

understand and predict changes in the Earth=s environment and to conserve and manage 

coastal and oceanic marine resources and habitats to help meet our Nation=s economic, 

social, and environmental needs. As a branch of NOAA, the National Marine Fisheries 

Service (NMFS) conducts or sponsors research and monitoring programs to improve the 

scientific basis for conservation and management decisions. NMFS strives to make 

information about the purpose, methods, and results of its scientific studies widely available. 

NMFS= Pacific Islands Fisheries Science Center (PIFSC) uses the NOAA Technical 

Memorandum NMFS series to achieve timely dissemination of scientific and technical 

information that is of high quality but inappropriate for publication in the formal peerreviewed literature. The contents are of broad scope, including technical workshop 

proceedings, large data compilations, status reports and reviews, lengthy scientific or 

statistical monographs, and more. NOAA Technical Memoranda published by the PIFSC, 

although informal, are subjected to extensive review and editing and reflect sound 

professional work. Accordingly, they may be referenced in the formal scientific and 

technical literature. 

A NOAA Technical Memorandum NMFS issued by the PIFSC may be cited using the 

following format: 

Author. Date. Title. U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFSPIFSC-XX, xx p. 

__________________________ 

For further information direct inquiries to

Chief, Scientific Information Services 

Pacific Islands Fisheries Science Center 

National Marine Fisheries Service 

National Oceanic and Atmospheric Administration 

U.S. Department of Commerce 

2570 Dole Street 

Honolulu, Hawaii 96822-2396 

Phone: 808-983-5386 

Fax: 808-983-2902 

___________________________________________________________ 

Cover photo by Suzanne Canja, PIFSC, of a Hawaiian monk seal at French Frigate Shoals in 

2003. 
Pacific Islands Fisheries Science Center 

National Marine Fisheries Service 

National Oceanic and Atmospheric Administration 

U.S. Department of Commerce

The Hawaiian Monk Seal 

in the Northwestern Hawaiian Islands, 2003 

Compiled and Edited by 

Thea C. Johanos and Jason D. Baker 

Protected Species Division 

Pacific Islands Fisheries Science Center 

2570 Dole Street 

Honolulu, Hawaii 96822-2396 

NOAA Technical Memorandum NMFS-PIFSC-9

March 2007

iii

EXECUTIVE SUMMARY

During 2003, field studies of the endangered Hawaiian monk seal (Monachus

schauinslandi) were conducted at all of its main reproductive sites in the Northwestern

Hawaiian Islands. These studies provide information necessary to identify and mitigate

factors impeding the species recovery by evaluating (1) the status and trends of monk seal

subpopulations, (2) natural history traits such as survival, reproduction, growth, behavior,

and feeding habits, and (3) the success of various activities designed to facilitate

population growth. 

Results of these studies are best described on a site-by-site basis, and the

information presented in this document is organized accordingly. Site-specific data

pooled for all sites, however, provide useful indices of the status and trends of the species

as a whole, including the total number of pups at all main reproductive sites, the total of

the site-specific mean beach counts, and the size composition of the seals observed during

the counts (Fig. 1).

Since 1983, the number of pups born at the main reproductive sites has been

highly variable. In 2003, 176 pups were counted at these sites, 52 of which were born at

French Frigate Shoals (FFS). Although a record number of pups were born at Midway

Atoll, pupping at FFS was at its lowest level since monitoring began in the early 1980s. 

Mean beach counts, excluding pups, from the main reproductive sites totaled 331.1 seals. 

Counts remained essentially unchanged from 1993 to 2000, but declined in 2001–2003

(Fig. 1b). 

From the mid-1980s to the mid-1990s, adults and pups made up a growing portion

of the animals counted while juveniles and subadults declined (Fig. 1c), and in 2003, the

composition of the counts again was dominated by adults and pups. This composition

bodes poorly for reproduction in the near future because older adult females are not being

replaced by sufficient numbers of maturing young females. High mortality of immature

seals appears to have led to the shift in composition, particularly at FFS.

In 2003, the following activities were conducted by the Marine Mammal Research

Program (Pacific Islands Fisheries Science Center, National Marine Fisheries Service)

and cooperating scientists to enhance recovery of the species: (1) disentangling 11 seals

and removal of debris capable of entangling seals; (2) guiding a seal stranded behind a

deteriorating sea wall at FFS to the water’s edge; (3) translocating 23 weaned pups

between islets within FFS to decrease their risk of shark predation; (4) removing two

Galapagos sharks after they exhibited predatory behavior toward monk seal pups at FFS;

(5) cutting the umbilical cords to remove placentas from two newborn pups at risk of

drowning or attracting sharks at FFS; (6) performing six human-assisted mother-pup

exchanges (resulting in reuniting 4 pups with their mothers) at FFS, Laysan, and Lisianski

Islands, and reuniting two separated mom-pup pairs at Laysan Island; (7) interrupting five
iv

incidents of aggressive males mounting weaned pups at FFS, Laysan, Lisianski, and Kure

Atoll; (8) monitoring beaches on Midway Atoll for disturbance and mitigating human

impacts through education; and (9) rehabilitating a prematurely weaned pup at Midway

Atoll.

This document describes these and other field studies conducted during 2003, and

provides complete, standardized, and timely summaries of the research activities and

findings at each study site. The availability of such information is essential for ongoing

efforts to stop the decline of this species and enhance its recovery.
v

(A)

(B)

(C)

Figure 1.-- Demographic trends of the Hawaiian monk seal, based on the main

reproductive sites. (A) Number of pups born (minimum). (B) Total of mean beach

counts, excluding pups, with 1 standard deviation. (C) Percentage of counts comprised of

adults, subadults, juveniles, and pups.

vii

CONTENTS

Page

CHAPTER 1. GENERAL INTRODUCTION ................................. 1

MATERIALS AND METHODS ..................................... 4

Censuses and Patrols ........................................ 4

Reproduction .............................................. 5

Factors Affecting Survival .................................... 5

Individual Identification ...................................... 6

Measurements of Seals ...................................... 8

Collection of Samples ....................................... 8

CHAPTER 2. THE HAWAIIAN MONK SEAL ON

FRENCH FRIGATE SHOALS, 2003 ....................................... 9

RESEARCH .................................................... 11

Censuses and Patrols ....................................... 11

Individual Identification ..................................... 12

Collection of Samples ...................................... 12

Special Studies ............................................ 12

Galapagos Shark Observations, Deterrence and Culling at

Trig, Round, and Little Gin Islets . . . . . . . . . . . . . . . . . 12

Translocation of Weaned Pups . . . . . . . . . . . . . . . . . . . . . . . . . 14

East Island Video Cameras ............................ 15

East Island Adult Male Aggression Observations . . . . . . . . . . . 15

Tagging of Galapagos Sharks .......................... 16

Foraging Ecology and Habitat Studies . . . . . . . . . . . . . . . . . . . . 16

Tern Island Seal Monitoring for Sea Wall

 Reconstruction Project ......................... 16

Noteworthy Events ......................................... 17

Human Intervention .................................. 17

RESULTS ..................................................... 17

Subpopulation Minimum Abundance and Composition . . . . . . . . . . . . 17

Reproduction ............................................. 17

Interatoll Movement ........................................ 18

Factors Affecting Survival ................................... 18

ACKNOWLEDGMENTS ......................................... 19

TABLES....................................................... 21

CHAPTER 3. THE HAWAIIAN MONK SEAL ON

LAYSAN ISLAND, 2003 ............................................... 31

RESEARCH .................................................... 33

Censuses and Patrols ....................................... 33

Individual Identification ..................................... 33
(CONTENTS, continued)

Page

viii

Collection of Samples ...................................... 34

Noteworthy Events ......................................... 34

Human Intervention .................................. 34

RESULTS ..................................................... 35

Subpopulation Minimum Abundance and Composition . . . . . . . . . . . . 35

Reproduction ............................................. 35

Interatoll Movement ........................................ 36

Factors Affecting Survival ................................... 36

ACKNOWLEDGMENTS ......................................... 36

TABLES....................................................... 37

CHAPTER 4. THE HAWAIIAN MONK SEAL ON 

LISIANSKI ISLAND, 2003 ............................................... 47

RESEARCH .................................................... 49

Censuses and Patrols ....................................... 49

Individual Identification ..................................... 49

Collection of Samples ...................................... 50

Special Studies ............................................ 50

Male Aggression Towards Weaned Pups . . . . . . . . . . . . . . . . . 50

Noteworthy Events ......................................... 50

Human Intervention .................................. 50

RESULTS ..................................................... 51

Subpopulation Minimum Abundance and Composition . . . . . . . . . . . . 51

Reproduction ............................................. 51

Interatoll Movement ........................................ 51

Factors Affecting Survival ................................... 51

ACKNOWLEDGMENTS ......................................... 52

TABLES....................................................... 53

CHAPTER 5. THE HAWAIIAN MONK SEAL ON

PEARL AND HERMES REEF, 2003 ...................................... 63

RESEARCH .................................................... 65

Censuses and Patrols ....................................... 65

Individual Identification ..................................... 65

Collection of Samples ...................................... 65

Special Studies ............................................ 66

Emergent Reef Surveys ............................... 66

RESULTS ..................................................... 66

Subpopulation Minimum Abundance and Composition . . . . . . . . . . . . 66

Reproduction ............................................. 66
(CONTENTS, continued)

Page

ix

Interatoll Movement ........................................ 66

Factors Affecting Survival ................................... 67

ACKNOWLEDGMENTS ......................................... 67

TABLES....................................................... 69

CHAPTER 6. THE HAWAIIAN MONK SEAL ON

MIDWAY ATOLL, 2003 ............................................... 79

RESEARCH .................................................... 81

Censuses and Patrols ....................................... 81

Individual Identification ..................................... 81

Collection of Samples ....................................... 82

Special Studies ............................................ 82

Emergent Reef Surveys ............................... 82

Noteworthy Events ......................................... 82

Beach Monitoring and Public Education . . . . . . . . . . . . . . . . . . 82

Prematurely Weaned Pup Rehabilitation Project . . . . . . . . . . . . 82

RESULTS ..................................................... 83

Subpopulation Minimum Abundance and Composition . . . . . . . . . . . . 83

Reproduction ............................................. 83

Interatoll Movement ........................................ 83

Factors Affecting Survival ................................... 83

ACKNOWLEDGMENTS ......................................... 84

TABLES....................................................... 85

CHAPTER 7. THE HAWAIIAN MONK SEAL ON

KURE ATOLL, 2003 ................................................... 93

RESEARCH .................................................... 95

Censuses and Patrols ....................................... 95

Individual Identification ..................................... 95

Collection of Samples ...................................... 96

Noteworthy Events ......................................... 96

Human Intervention .................................. 96

RESULTS ..................................................... 96

Subpopulation Minimum Abundance and Composition . . . . . . . . . . . . 96

Reproduction ............................................. 96

Interatoll Movement ........................................ 97

Factors Affecting Survival ................................... 97

ACKNOWLEDGMENTS ......................................... 97

TABLES....................................................... 99
(CONTENTS, continued)

Page

x

CHAPTER 8. THE HAWAIIAN MONK SEAL ON

NIHOA ISLAND, 2003 ................................................. 109

RESEARCH .................................................... 111

Censuses and Patrols ....................................... 111

Individual Identification ..................................... 111

Collection of Samples ...................................... 111

RESULTS ..................................................... 111

Subpopulation Minimum Abundance and Composition . . . . . . . . . . . . 111

Reproduction ............................................. 112

Interatoll Movement ........................................ 112

Factors Affecting Survival ................................... 112

ACKNOWLEDGMENTS ............................................... 112

REFERENCES ....................................................... 113

APPENDIXES

Appendix A.--Reports summarizing annual field research on the Hawaiian

monk seal by the National Marine Fisheries Service and

collaborating scientists ............................... A-1

Appendix B.--Hawaiian monk seal census form and 2003 census form

directions .......................................... B-1
CHAPTER 1. GENERAL INTRODUCTION

3

The endangered Hawaiian monk seal’s (Monachus schauinslandi) current core

range is in the Northwestern Hawaiian Islands (NWHI, Fig. 1.1). The National Marine

Fisheries Service (NMFS) is the lead agency responsible for the recovery of the Hawaiian

monk seal. Each year the NMFS Pacific Islands Fisheries Science Center, Marine

Mammal Research Program conducts studies at the main breeding sites to provide

information necessary to evaluate (1) the status and trends of the monk seal

subpopulations; (2) natural history traits such as survival, reproduction, growth, behavior,

and feeding habits; and (3) the success of various activities designed to facilitate

population growth.

The Marine Mammal Research Program began research on Hawaiian monk seals

at most major reproductive sites in the NWHI during 1980 (Lisianski Island), 1981

(Laysan Island and Kure Atoll), 1982 (French Frigate Shoals (FFS) and Pearl and Hermes

Reef), and 1983 (Midway Atoll). Nearly every year thereafter, field camps were

established for periods of several days to 9 months to monitor and enhance the recovery

of this species. Limited population monitoring has also been conducted at Nihoa and

Necker Islands, where subpopulations appear to be limited to a small number of animals

by availability of haulout area. Reports summarizing past NMFS research are listed in

Appendix A.

In 2003, Hawaiian monk seal research activities included (1) conducting beach

counts (censuses); (2) tagging weaned pups and other seals for permanent identification

and retagging animals to maintain identification; (3) identifying other seals by previously

applied tags and by natural or applied markings; (4) monitoring reproduction, survival,

injuries, entanglements, interatoll movements, disappearances, and deaths; (5) performing

necropsies; (6) collecting scat and spew samples for food habits analysis; (7) collecting

skin punches and shed molt samples for a DNA tissue bank; (8) collecting samples of

placentas found with or from aborted fetuses or with deceased perinatal pups for

histological and bacteriological examination; (9) disentangling seals; and (10) removing

debris capable of entangling seals from beaches. Location-specific objectives and

summaries of data collected during the 2003 field season are described in the following

chapters. Much of the information presented in this memorandum is incorporated into

larger data sets for additional analysis and publication elsewhere. Research was

conducted under the authority of the following permits: Special Use Permits

12520-03006, 02521-03011, and 02521-03021, and Marine Mammal Permits 848-1335

and 848-1695.
4

MATERIALS AND METHODS

Censuses and Patrols

The primary means of data collection were censuses and patrols. Censuses

consisted of timed, standardized beach counts during which an entire island or atoll was

surveyed for seals. Although data were collected on all seals, those that were in the

water, captive, or dead were excluded from the beach count totals. Identified individuals

were counted only once if they were resighted during the survey. The resulting counts did

not reflect total population size but provided an index of population size for comparison

among years and locations. Data collected on each seal observed during censuses

included size class (ranging from pup, juvenile, subadult, and adult size as described in

Stone, 1984 and Appendix B); sex; location on the island; beach position (indicating

whether the seal was in the water or on land); body condition (a subjective estimate; e.g.,

fat, medium, or thin); identification information (permanent or temporary identification

numbers and tag numbers); molting status (an estimate of the percentage completed); and

disturbance index (the extent that the observer disturbed the seal). Further data were

collected if any of the following events occurred: (1) factors affecting survival (e.g.,

entanglements, mobbings, or shark injuries), (2) animal handling, (3) photography, and

(4) documentation of tag condition (e.g., good or broken). In addition, behavioral data

(seal associations and interactions) were collected on Laysan and Lisianski Islands. A

sample census form and guidelines for its completion are included in Appendix B. 

Censuses were conducted once at Nihoa Island and every 4 to 10 days at all other

locations, starting at 1300 Hawaii Standard Time when possible, using census methods

and criteria outlined in Johanos et al. (1987). Atoll-wide counts for locations with more

than a single island (French Frigate Shoals, Pearl and Hermes Reef, Midway Atoll, and

Kure Atoll) were completed within a 2-day period. The perimeter of each study area was

divided into sectors to facilitate the analysis of data and detection of demographic trends

in different geographic areas. Census methods specific to each location are detailed in the

following chapters.

Patrols consisted of untimed surveys of an entire island perimeter on foot. 

Information collected during patrols was similar to that collected during censuses. 

Because patrols were not timed, observers concentrated on documenting adult and

subadult behavior, identifying and marking individuals, and collecting scat and spew

samples. Island-specific standardized patrols were conducted at some locations and are

described in the following chapters. 

During all observation periods (i.e., censuses, patrols, and incidental sightings),

observers attempted to minimize seal disturbance by walking above the beach crest and

using vegetation as a visual barrier. On census days, activities that threatened to disturb

the animals and bias the count were not conducted until after the count was completed. 

Additionally, the following were recorded whenever observed: (1) births, pup exchanges,
5

and weanings; (2) mating activities, adult male aggression, and post-mobbing

aggregations (defined below); (3) entanglements in marine debris; (4) injuries; and (5)

deaths.

Reproduction

Parturient females were identified when possible, and birth and weaning

information was recorded. Because parturient females will nurse pups other than their

own (Boness, 1990; Boness et al., 1998), efforts were made to identify pups and

document changes in nursing relationships from birth to weaning. A pup exchange

occurred when the pups of two lactating females were switched or one nursing female

suckled multiple pups. Typically, such exchanges occur during an aggressive interaction

between the two females. On other occasions, a mother and pup become separated, and

one or both seals then actively seek and obtain another nursing relationship (Boness,

1990).

The average nursing period was calculated for some or all pups at each location. 

The average lactation period of parturient females was also calculated for seals at FFS

because higher population density and frequent pup exchanges (Boness, 1990; Boness et

al., 1998) made it difficult to track individual pups and determine their nursing period. 

Nursing or lactation periods were defined as the number of days from birth until the end

of the last nursing relationship. Temporary breaks (e.g., if a mother and pup became

separated and one or both seals subsequently obtained another nursing relationship) were

not subtracted from the total. When the exact birth or weaning date was not known but

occurred within a range of 4 days or less, then the midpoint of that range was used as the

start or end date for calculation of average nursing or lactation period. Nursing or

lactation data were not used if the birth or weaning range exceeded 4 days or if the pup

died or disappeared before weaning. Prior to 2002, nursing or lactation periods of less

than 20 days were also excluded from calculations.

Factors Affecting Survival

The origins of a wide range of injuries were distinguished based on characteristic

wound patterns described in Hiruki et al. (1993). Injuries were documented if they were

related to attacks by large sharks, mounting attempts by male Hawaiian monk seals, or

entanglement in marine debris or if they were considered severe enough to possibly affect

survival. Injuries were considered severe, and were summarized if they consisted of (1)

the total combined area of all abscesses or abscess-like raised areas was > 8 cm diameter

circle area (approximately 50 cm ); (2) an amputation of a minimum of half a flipper 2

(either foreflipper or hindflipper); (3) the total combined exposed area of all punctures or

gaping wounds was > 8 cm diameter circle area; or (4) densely spaced (overlapping)
6

scratches, abrasions, or lacerations covering an area equivalent to half the dorsum, or

evidence of extensive underlying tissue damage (e.g., an uneven or darkened surface of

the injured area, leaching fluids), or impaired seal movement. Major healed injuries that

had been incurred since the previous season were documented but not included in

summaries.

A seal was listed as dead if its death or carcass was observed. Deaths summarized

here include carcasses found at the beginning of the field season if the seal had clearly

died during the calendar year. A seal was listed as probably dead if it sustained severe

injuries or was emaciated (with skeletal structure clearly evident) and subsequently

disappeared. In addition, one of the following conditions must have been satisfied to

place a seal in the "probably dead" category: (1) the seal was lethargic, had difficulty

moving, or floated listlessly in the water, and disappeared more than a week before the

end of data collection for the field season, or (2) the seal was in deteriorating condition

(loss of weight, enlargement of abscesses, sloughing of skin) and disappeared a minimum

of 10 surveys or 1 month before the end of data collection for the field season (whichever

was longer). Nursing pups were listed as probably dead if they disappeared within 3

weeks of birth. Losses of apparently healthy older nursing pups (over 3 weeks of age)

and newly weaned pups (within 2 weeks post-weaning) were listed as disappeared,

suspected dead, if the pups were last seen a minimum of 10 surveys or 1 month before the

end of data collection.

Multiple male aggression (or “mobbing”) and other mating-related male

aggression were observed and recorded. By definition, multiple male aggression occurred

when more than one male attempted to mate with a single seal, usually an adult female or

immature seal of either sex, causing injury or death of that seal (e.g., Alcorn, 1984). 

Single male aggression was defined as any incident where an adult or subadult male

repeatedly bit the dorsum, attempted to mount, and tried to prevent the escape of another

seal. These incidents were summarized in this report if they simultaneously involved

more than one male aggressor, resulted in a minimum of one puncture or gaping wound

(missing skin or extending into the blubber layer) or > 15 scratches to the dorsum or

flanks or if intervention was required to prevent drowning. Post-aggression aggregations

were also summarized: these were groups of males congregated on the beach, attending a

seal with new mounting injuries as described above.

Individual Identification

During censuses and patrols, individual seals were identified with tags, applied

bleach marks, scars, or natural markings. After weaning, pups were tagged on each hind
 Reference to trade names does not imply endorsement by the National Marine Fisheries Service,

1

NOAA.

7

flipper with a colored plastic Temple Tag, uniquely coded to indicate island or atoll

®1

subpopulation, year of birth, and individual identification number (Gilmartin et al., 1986). 

In addition, a passive integrated transponder (PIT) tag was implanted subcutaneously in

the posterior dorsum of most weaned pups (see Lombard et al., 1994, for detailed tagging

procedures).

Colored plastic Temple Tags have been applied to nearly all weaned pups since

1981 at Kure Atoll; since 1982 at Lisianski Island; since 1983 at Laysan Island and Pearl

and Hermes Reef; since 1984 at French Frigate Shoals; and since 1995 at Midway Atoll. 

Pups at Midway Atoll, Necker and Nihoa Islands, and the main Hawaiian Islands have

been tagged opportunistically since 1983. Since 1991, PIT tags have also been implanted

subcutaneously in the ankle (1991) or the posterior dorsum (all subsequent years) of most

weaned pups. 

In 2003, untagged immature and adult seals were opportunistically tagged with

Temple Tags uniquely coded to indicate that their ages and birth locations were unknown.

These seals also received PIT tags. Seals with lost or broken tags were retagged to

maintain their identities.

Seals were bleach-marked for individual identification (Stone, 1984), using the

solution described in Johanos et al. (1987), and applied bleach marks were photographed

and sketched onto scar cards. Molting seals were re-marked with bleach to maintain their

identities until the next molt. Some nursing pups were also bleach-marked prior to the

post-natal molt to facilitate identification during the nursing period.

 Digital photographs of scars and natural markings were added to individual

identification folders throughout the field season to maintain a current description of the

identifying marks of each seal.

Minimum subpopulation abundance and size-sex composition are presented. 

These statistics included all individuals observed alive at the location during the interval

from March through August and all known parturient females and pups born anytime

during the year. 

The movement of seals among island or atoll subpopulations within and between

years complicates the estimation of minimum subpopulation size and composition. This

is particularly true at Midway Atoll, where a number of the observed seals were tagged at

other locations (primarily Kure Atoll and Pearl and Hermes Reef). Therefore,

standardized rules for assigning each seal identified to just one subpopulation are applied

as follows. If a seal was observed at more than one location during March-August, it was
8

included exclusively in the subpopulation where it was sighted nearest to May 15, unless

it pupped or molted at another location. A parturient female was always exclusively

included in the subpopulation where she pupped, and a non-parturient seal was

exclusively included in the subpopulation where it molted. Pups were always exclusively

included in the subpopulation where they were born.

Measurements of Seals

Pups were measured to provide information on condition. Measurements were

taken as soon after weaning as possible, and measurements taken within 2 weeks after

weaning were included in the summaries. Measurements included straight dorsal length

(Winchell, 1990) and axillary girth (American Society of Mammalogists, 1967). Some

older animals captured for retagging, foraging ecology, health, or disease studies were

also measured.

Collection of Samples

Samples were collected for a DNA tissue bank, pathology analysis, investigation

of food habits, and documentation of marine debris. Tissue punches for DNA were

collected during tagging efforts for all newly tagged or retagged seals and during

necropsies on seals that had recently died. Samples of placentas found with or from

aborted fetuses or deceased perinatal pups were also collected. 

For each dead seal recovered, an external examination was made, photographs

were taken, and external measurements and observations were recorded. For a recent

death, an internal examination was made, and samples of tissue, organs, parasites, and

stomach contents were collected. Detailed descriptions of necropsy procedures and

sample collection methods are in Winchell (1990).

Scat and spew samples were collected opportunistically for analysis of food habits

(Goodman-Lowe, 1998). These samples were collected from seals of known size and sex

class when possible. 

Nets, lines, ropes, and other debris capable of entangling seals and turtles were

removed from beaches. From 1982 to 1998, potentially entangling marine debris was

incinerated on site at all locations, and debris incineration continued at Kure Atoll

through 2001. More recently, marine debris was removed by ship. 
CHAPTER 2. THE HAWAIIAN MONK SEAL ON

FRENCH FRIGATE SHOALS, 2003

Suzanne M. Canja, Brenda L. Becker, Aaron Dietrich, Shawn C. Farry, Jennifer L.

Palmer, Dan F. Luers, and Misty E. Niemeyer

11

The largest subpopulation of Hawaiian monk seals is located at French Frigate

Shoals (FFS, lat. 23°45' N, long. 166°10' W), ca. 830 km northwest of Oahu in the

Northwestern Hawaiian Islands. This atoll is part of the Hawaiian Islands National

Wildlife Refuge (Fig. 1.1) and consists of nine permanent islets (Disappearing, East, Gin,

Little Gin, La Perouse Pinnacles, Round, Shark, Tern, and Trig), three semipermanent

islets (Bare, Mullet, and Whaleskate), and several transient sand spits (Fig. 2.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research on Hawaiian

monk seals at FFS in 1982. In 2003, research was conducted by NMFS from

April 22 to September 9. Incidental observations were recorded by U.S. Fish and

Wildlife Service (USFWS) personnel during the rest of the year. The perimeters of the

five larger islets (East, Gin, Little Gin, Tern, and Trig) were divided into sectors using

artificial or natural landmarks. Research activities specific to this subpopulation in 2003

included (1) monitoring and removal of Galapagos sharks preying on monk seal pups at

Trig and Round Islands; (2) translocating newly weaned pups to reduce their risk of shark

attack; (3) retagging or newly tagging seals; (4) observing adult male aggression at East

Island; (5) tagging Galapagos sharks to determine movement patterns within the atoll; (6)

collecting organisms for a Hawaiian monk seal prey fatty acid analysis; (7) assessing seal

foraging using archival movement recorders imbedded in simulated “rocks”; and (8)

conducting videographic surveys of benthic habitat.

Censuses and Patrols

Atoll-wide censuses (n = 10) were conducted every 6 d, on average, from May 27

to July 27. Each atoll census required 2 d to complete. Disappearing, Round, Bare, and

Mullet islets were surveyed either on foot or by boat; while the remaining islets (East,

Gin, Little Gin, Shark, Tern, Whaleskate, and Trig) were censused on foot by 1–4 people. 

Bare Island was rarely above water during the season and Mullet was completely

submerged by August 13. Whaleskate Island was present the entire season and larger than

Round Island. 

Individual islet censuses and patrols were scheduled to ensure the entire atoll was

monitored at least once each week during May 27–August 25. However, surveys at all

islands, except Disappearing and Shark, commenced May 13. Surveys were more

frequent at islets where most pups were born and nearby sites, and sites of high shark

activity: Trig was monitored daily, Round approximately every 1–2 d; East, Gin, Little

Gin, Mullet, Tern, and Whaleskate islets were monitored on average every 2–4 d; and
12

Bare, Disappearing, and Shark averaged every 6–8 d. Survey frequency at Round Island

was greater than in previous years because Galapagos sharks were observed patrolling the

nearshore waters and one nursing pup sustained a serious shark bite. Also, because of

high levels of shark predation of pups at Trig Island in previous years, daily surveys

began April 22 and increased to twice daily May 25–September 2. Seals were surveyed at

the beginning and end of each day of shark observations at Trig. Surveys at Little Gin

Island increased to every 1–2 d from July 24 to August 4 because of an unusual increase

in large shark sightings there.

Individual Identification

A total of 291 individuals (239 excluding pups) were identified by existing or

applied tags, bleach marks, scars, or natural markings. Bleach marks were applied to 70

seals, including 23 nursing pups. Thirty-seven weaned pups were tagged with Temple

Tags; 34 of which also received a passive integrated transponder (PIT) tag. Two of these

pups were tagged by USFWS personnel post-field season, and two weaned pups were not

tagged because of their compromised conditions (one sustained a severe injury to both

hindflippers and the other was likely blind). Additionally, four male seals were retagged

(three adults, one subadult) and one adult male was newly tagged with Temple and PIT

tags.

Collection of Samples

Twenty-nine scat and one spew samples were collected. Fifty skin punches were

collected. Necropsies were performed on nine of 11 carcasses (includes four fetuses and

a mummified carcass believed to have died prior to 2003). Shed molt samples from two

seals, and ten fresh placentas were also collected. A total of 307 fish and invertebrates

representing 48 species were collected for fatty acid analysis. Potentially entangling

marine debris was collected and stored in a secure location on Tern Island pending

removal. In addition, three items that had entangled seals were also collected.

Special Studies

Galapagos Shark Observations, Deterrence and Culling at Trig, Round, and Little

Gin Islets

Trig Island--From April 22 through September 8, Trig Island was monitored daily

 to document the presence of Galapagos sharks and their predatory behavior towards

monk seal pups. Observations were conducted on 125 days (excluding nine

weather/logistical days) between 0600 and 2015 for a total of 929.5 hours
13

(avg. 7.4 hr/day). To observe during early morning and late afternoon hours, the Trig

observation team spent 16 non-consecutive nights on the island. Two Galapagos sharks

which exhibited predatory behavior towards monk seal pups were lethally removed. 

Samples were collected and morphometrics taken from both of these animals. Three pups

disappeared and are suspected dead (two nursing and one near weaning), and minor shark

injuries were inflicted to two other pups (one nursing and another near weaning). 

Detailed results of the shark studies conducted on Trig Island and at other locations

within FFS will be presented elsewhere.

Round Island--On May 30, a large Galapagos shark was seen in the shallow

waters next to Round Island where three nursing pairs were present. Daily observations

were conducted from May 30 to June 4 (excluding June 3) to monitor shark activity. 

Observations ranged from 0.2 to 2.8 h and occurred between 1250 and 1625 for a total of

5.25 h. Sharks were seen May 30—one Galapagos shark; May 31—two sharks (species

unknown); June 1—one Galapagos shark; June 2—no sharks; and June 4— four

Galapagos sharks. On June 4, one nursing pup was discovered with a fresh, severe shark

injury, resulting in loss of one entire hindflipper and half of the other. At the time of this

sighting, four Galapagos sharks were seen simultaneously, actively patrolling the area and

two direct aggressive approaches to a nursing pair in the water by 1–2 sharks were

witnessed. The adult female successfully fended off the sharks and then immediately

exited the water with her pup. To more closely monitor seal/shark interactions, Round

Island surveys were increased to every 1–2 d from May 27 to August 13. 

Boat-based observations were conducted from June 5 to June 13, between 0700

and 1745 for a total of 41.5 h (range 1.5-10 hrs/day) over 8 of the 9 days. Round Island

shark observations were only conducted when Galapagos shark activity was seen or

suspected, e.g., Galapagos sharks seen patrolling or a pup injury, death, or disappearance

was attributed to shark predation. No sharks were removed here; however, two

unsuccessful attempts were conducted on June 5. One nursing pup disappeared and

probably died, and another pup was seriously compromised because of its limited

mobility as a result of the complete loss of one and the partial loss of the other hindflipper

from a shark attack. 

Little Gin Island--Because of shark activity observed near Little Gin on July 22,

incidental observations were conducted on 18 days between July 22 and September 2. 

These observations were conducted from a boat anchored off the southwest side of the

island, just outside the reef break at the entrance of a bay. Observations ranged from 0.2

to 1.9 h and occurred between 1000 and 1650 for a total of 21.5 h. Large sharks (both

Galapagos and tiger sharks) were seen on 9 days from July 22 to July 29 (no observations

July 23) and August 7 and August 25 when one to four large sharks were seen during

observations. 
14

The majority of observed shark activity occurred along a shallow reef northwest

of the bay opening, approximately 33 m from the island, where a strong odor of

undetermined origin was detected during July 22–August 2. Tiger sharks were seen on 6

days during this period, with a maximum of three tiger sharks seen in 1 day. On one

occasion, a tiger shark patrolled the shoreline, passing within a few feet of a nursing pair

on the beach. One very large (4.0–4.3 m) tiger shark was uniquely identifiable and

observed on 2 successive days. Galapagos sharks were seen on 4 days (July 22, 24, 26,

and August 25) with a maximum of two sharks seen in a day. Galapagos shark sightings

were brief and usually occurred near the previously mentioned reef area. The exception

was on August 25, when a probable Galapagos shark cruised along the shoreline 30

minutes after a dead, shark bitten pup had been recovered by researchers from the wave

wash. A Galapagos shark was also seen near the boat within an hour after the carcass was

recovered.

Seals, primarily weaned pups, were observed in the water simultaneously with

sharks on 4 days. No sharks were seen to approach seals. The only observed shark injury 

at Little Gin resulted in the death of a nursing pup (the carcass mentioned above). In

addition, an apparently healthy 29–35-day-old pup disappeared near weaning between

August 14–18 and is suspected dead. Two weaned pups that had been translocated to

Little Gin from Trig Island also disappeared, both within a week after translocation; one

was translocated on June 22 and was last seen June 29, the other was translocated on July

19 and was last seen July 21. Notable shark activity was first observed on July 22.

Translocation of Weaned Pups

To improve weaned pup survival, newly weaned pups were translocated from areas

of high shark predation risk to islets with lower evidence of shark activity. The majority

of these pups were moved on the day of weaning. Because of weather or logistical

constraints, three pups (2 Trig, 1 Whaleskate) were translocated within 2 days of weaning.

This included an unusual observation where both the mother and pup disappeared near the

time of weaning from Trig and then 2 days later the pup reappeared alone and weaned. 

Two pups were temporarily held in a pen on Trig to prevent them from venturing into the

water before they could be translocated. 

Little Gin was the primary release site, because there were no nursing pairs present

(until mid-July) with which the weaned pups might interact. By July 19, twelve newly

weaned pups had been translocated to Little Gin and two had disappeared within a week of

translocation. Because of the shark activity and the pup disappearances noted above, all

newly weaned pups from Trig and Round Islands were taken to Tern Island after July 23. 

All 23 newly weaned pups from Trig (18), Round (4) and Whaleskate (1) islets

were translocated, with two nursing pups remaining on Trig at the end of the season. 
15

Twelve were taken to Little Gin (from Trig-10, Round-1, Whaleskate-1), one pup to Gin

(from Trig), and 10 pups to Tern (from Trig-7, Round-3). One Trig Island pup was

translocated twice; initially from Tern to Trig Island when it was 13 days old. This

nursing pup swam from Trig to Tern Island and was held in a cage overnight until it could

be returned to its birth mother on Trig the next day. This pup was translocated again, this

time from Trig back to Tern, after it weaned.

East Island Video Cameras

As part of the turtle nesting and basking behavior studies directed by George

Balazs (NMFS PIFSC), two remote video cameras were mounted at 13.7 m and 19.8 m

above ground, to the pole located near the center of East island. These solar powered,

pan-tilt zoom cameras with digital photo and video capabilities were remotely controlled

from the Tern Island field station 7 miles away. Thirty-nine preset locations were

programmed to photograph the entire island perimeter daily at 2-h intervals from 0600 to

2000. Researchers were free to use the Turtle Cam to monitor other wildlife when the

programmed photos were not being taken. This proved especially valuable in monitoring

monk seals, noted below. 

East Island Adult Male Aggression Observations

On July 16, two incidents of adult male monk seal aggression towards two

weaned pups were observed on East Island within an hour. One incident was halted by

researcher intervention. Following these events, observation effort was substantially

increased at East Island to determine the persistence and extent of this behavior and the

effects on the weaned pups. Daily incidental observations began July 19 through

September 7, with three exceptions: July 22 and August 1 and August 21. The majority of

these observations were conducted via the Turtle Cam from the Tern Island field station,

allowing researchers to remotely scan the entire island and to video document pertinent

events. In all, 48 days of observations were conducted, including both standard on-island

surveys (13) and Turtle Cam video surveys (45). Both types of surveys were performed

on 10 days. Observations were conducted between 0632 and 2011 and ranged from 4

min to 8.5 h for a total of 58.1 h (47.3 h using the remote video cameras).

The adult male (identifiable by tags and a large applied dorsal bleach mark) that

had been observed harassing pups on July 16, was present on 11 of the 48 survey days. 

He was typically observed either sleeping on the beach or cruising in the water near shore.

He was observed with weaned pups on four occasions (excluding the initial observation

on July 16); two times sleeping near a pup (ranging 1–6 m away), once investigating a

pup hauled out on the beach and then leaving, and once attempting to mount a pup in the

water. This last incident, occurring on August 16, was aggressive and at times included
16

holding the pup underwater. Although not constant harassment, the interaction lasted 8

minutes and ended when the adult male left the area and hauled out alone to sleep for a

few hours before leaving the islet for the evening. Only minor injuries were inflicted to

the pups during the July 16 mounting attempts. One of the weaned pups mounted on July

16 had been sighted 4 days previously with two slightly raised areas on its dorsum

(approximately 10–15 cm diameter). That injury was believed to be seal inflicted, but did

not appear to change in size during the field season, nor did the pup appear compromised.

Tagging of Galapagos Sharks

From August 1 to August 15, a team was deployed to capture, measure, and tag

Galapagos sharks to investigate their movements and site fidelity within FFS. This was

the fourth and final year of a study initiated in 2000 and was conducted in collaboration

with California State University Long Beach, Hawaii Institute of Marine Biology, and the

NMFS Narragansett Laboratory. Fishing efforts were primarily focused near Trig and

Round Islands where known Galapagos sightings have occurred, with some effort also

near East, Shark, Tern, and Whaleskate Islets. No Galapagos sharks were captured. Five

gray reef and two whitetip sharks were captured and two of the gray reef sharks were

tagged with conventional ID tags. In addition, 10 previously installed acoustic monitoring

stations were serviced and downloaded twice during the field season.

Foraging Ecology and Habitat Studies

In October 2003, NMFS PISFC Ecosystems and Oceanography Division

personnel continued efforts to provide reference material for fatty acid analysis of monk

seal prey items. Sand trawls were conducted on the deep terrace on the north side of the

atoll and shallow reef fish and invertebrates were collected by divers within the atoll

using pole spears. Mixed gas divers also recovered archival movement recorders

imbedded in simulated “rocks,” which had been redeployed the previous year on the 70-m

north slope of the atoll to monitor year-round seal foraging activity. Videographic

surveys were also conducted to map benthic habitat types.

Tern Island Seal Monitoring for Seawall Reconstruction Project

To monitor the potential effects on haulout patterns of monk seals prior to and

during the Tern Island seawall reconstruction project scheduled to begin in 2004, USFWS

personnel conducted weekly “rapid assessment” seal censuses from mid-September

through the end of the year. These baseline data were given to NMFS for analysis of the

effects of this construction project.
17

Noteworthy Events

Human Intervention

In January, USFWS personnel assisted a molting adult male who had strayed to

the far northwest corner of Tern Island above the seawall. To help guide the seal back to

the water, a ramp was made and the seal was coaxed safely over the seawall uninjured

into the water. During the field season, researchers halted aggressive male mounting of a

weaned pup on East Island (mentioned above), and cut the umbilical cords (and collected

placentas) of two newborn Trig Island pups because the attached placentas restricted 

movement and placed the pups in danger of drowning or attracting sharks. In one case,

the attached placenta was in the wavewash attracting a Galapagos and gray reef sharks

(the Galapagos shark was lethally removed during this incident). 

Four human-assisted pup exchanges (all on Trig Island) occurred when

researchers intervened to improve the survival of a nursing pup. Researchers also

attempted to foster two small weaned pups to adult females who had lost their pups 2–6

days earlier; although neither attempt was successful. 

RESULTS

Subpopulation Minimum Abundance and Composition

The mean (± SD) of 10 atoll censuses was 102.3 seals (± 13.6) including pups,

and 79.5 seals (± 8.6) excluding pups (Table 2.1). The total number of seals identified as

part of the spring-summer subpopulation was 290 individuals, 238 excluding pups (Table

2.2). This number is a subset of the total identified in the calendar year, and is an

unknown proportion of the total subpopulation as many of the older, untagged seals

couldn’t be uniquely identified. The numbers of tagged known-age seals born at FFS

during the period from 1984 to 2002 and resighted at any location in 2003 are

summarized in Table 2.3.

Reproduction

At least 52 pups were born at FFS in 2003: 39 pups successfully weaned

(including 2 nursing at the end of the NMFS field season), 7 died or probably died prior

to weaning; 3 pups older than 21 days suspiciously disappeared prior to weaning; and the

weaning status is unknown for 3 pups (2 disappeared at/near weaning and 1 pup was still

nursing at the end of the NMFS season) (Table 2.4a). The following were birth locations

for these pups: 23 born at Trig, 9 at East, 6 Gin, 5 Round, 4 Tern, 2 Little Gin, 1 Shark, 1

Whaleskate, and 1 born at an unknown location (weaned prior to the field season). The
18

birth at Shark Island was the first documented since 1998, and the birth at Whaleskate

Island was the first known since 1999. Since 1996, the presence of Whaleskate Island has

been intermittent. Nursing periods and measurements of weaned pups are summarized in

Table 2.4b. Seven births and six weanings were observed, all on Trig Island. Thirty-five

pup exchanges were documented between 23 adult females; 19 of these events were

observed and 4 of these involved human assistance to improve survival. A minimum of

21 pups were fostered by mothers other than their own (15 Trig, 4 Round, 1 Gin, 1 East). 

In addition to pups listed in Table 2.4a, four fetuses were found during February and

March. 

Interatoll Movement

Interatoll movement was documented for three seals that completed a total of five

movements between FFS and Laysan Island (Tables 2.5a and b).

Factors Affecting Survival

Attacks by large sharks, mounting attempts by male Hawaiian monk seals,

entanglement in marine debris, emaciation, and unknown factors led to 24 life-threatening

conditions, which resulted in the confirmed deaths of 6 seals and the probable deaths of 5

seals (including 4 nursing pups less than 3 weeks old) (Table 2.6). In addition to the

incidents presented in Table 2.6, seven pups disappeared and are suspected dead (two

newly weaned, two near weaning, and three nursing pups older than 3 weeks old). 

Of 52 pups born at FFS this year, 2 pups (both nursing) were seriously bitten by

sharks: one died (at Little Gin) and the other (at Round Island) had most of its

hindflippers amputated. Galapagos sharks were observed at the time both of these injuries

were discovered. The pup with the amputated hindflippers was translocated to Tern upon

its successful weaning, and remarkably made a round-trip transit from Tern to Trig Island

9 weeks post-weaning. This seal was seen through the end of December though its longterm survival was likely compromised by limited mobility. Three additional pups (two

weaned male and one nursing female) received very minor shark injuries, not serious

enough to include in Table 2.6. Two of these injuries occurred on Trig; one to a male pup

near weaning and the other to a female nursing pup. Both pups were immediately

translocated and the injuries healed. One weaned pup, born at Trig and translocated to

Little Gin in June, was seen back at Trig Island mid-August with a healed minor shark

bite to its left posterior. 

Shark attack was the likely cause for the disappearances of 11 other pups; this

includes the probable deaths of the four nursing pups, and the suspected deaths of the
19

seven other pups mentioned earlier. Three pup disappearances occurred each at Trig and

Little Gin (including two translocated weaned pups at Little Gin) two at East, two at Gin,

and one on Round Island. Shark attack was the suspected cause for all these

disappearances, as the pups appeared healthy and normal. There were typically multiple

sightings of Galapagos sharks patrolling Trig, Round, and Little Gin Islets near the time

of the disappearances. In seven of nine cases involving nursing pups, the parturient

female was present and actively searching for her missing pup, confirming that the pups

had not been weaned. The two weaned female pups, both translocated from Trig to Little

Gin, disappeared within 1 week post-weaning. It is highly unusual for apparently healthy

weaned pups in good condition to not be seen consistently for at least the first month after

weaning. Shark activity was observed the day after the second pup was last sighted.

Three seals were observed entangled in marine debris; a subadult male and a

female weaned pup both on Tern, and a parturient female on Trig. USFWS personnel

observed the entangled subadult seal on Tern Island in January (prior to the NMFS field

camp) and were able to cut the net free from its neck. The parturient female was only

briefly entangled when she investigated a net in the water and was able to free herself

after violently thrashing around. Fortunately her pup was not involved in the incident. A

weaned pup was discovered on Tern Island (at the US Coast Guard dump site) with a

rubber gasket loosely fit around its neck; however, the pup had freed itself by the time

observers returned intending to free it.

 

Also in addition to incidents presented in Table 2.6, four fetuses were found by

USFWS staff during February and March, the desiccated carcass of an immature seal

believed to have died prior to 2003 was found in May, and two seals were observed with 

healed shark injuries inflicted since the previous season (an adult female and yearling

female, with severe and minor healed injuries, respectively). Also of note, a nursing pup

had an unusual eye condition with possible vision impairment. Though this pup

successfully weaned, it was not tagged to avoid any risk of injuring the seal’s eyes. This

seal was last observed October 21. Another unusual case involved a 2-year-old male

who did not undergo an annual molt. The seal was unmolted in July 2002 when

instrumented with a CRITTERCAM as a yearling. The instrument mount was still attached

to his shoulder area in 2003 confirming he had not molted in 2002. At the beginning of

the 2003 season this animal was thin, and though his body condition did improve, he did

not molt during the field season.

ACKNOWLEDGMENTS

We gratefully acknowledge the support of the USFWS, Hawaiian Islands National

Wildlife Refuge staff and volunteers. Special thanks to Dominique Horvarth for her

logistical support. USFWS Tern Island staff conducted invaluable seal monitoring and

assistance. This includes Chris Eggleston, Alex Wegmann, Carrie Blemker, Jonathan
20

Sprague, Rachael Seabury, Melissa Roth, and Jennifer Tietjen. Steve Barclay also

provided a significant amount of support and logistical assistance, particularly with the

preparation for the seawall project. We also thank NMFS personnel Charles Littnan and

John Peschon for seal observations and field assistance. George Balazs graciously shared

his Turtle Cam equipment to allow remote monitoring of seals on East Island. We thank

the captains, officers, and crew of the NOAA ship Oscar Elton Sette, M/V American

Islander, F/V Ocean Fury, and US Coast Guard Cutter Kukui, and the pilots of Pearl

Pacific Enterprises for logistical assistance.
TABLES

for French Frigate Shoals

23

Table 2.1.--Summary statistics for atoll censuses (n = 10) of Hawaiian monk seals at

 French Frigate Shoals from May 27 to July 27, 2003.

Size/Sex Mean number of individuals Standard deviation

Adults 58.7 8.7

Male 18.9 4.4

Female 37.5 6.4

Unknown 2.3 1.3

Subadults 8.2 3.0

Male 4.3 2.1

Female 3.4 1.3

Unknown 0.5 1.3

Juveniles 12.2 1.9

Male 4.3 1.3

Female 7.1 2.0

Unknown 0.8 0.9

Pups 22.8 6.9

Male 6.9 2.2

Female 14.1 3.9

Unknown 1.8 1.3

Non-pup total 79.5 8.6 a

Grand total 102.3 13.6 a

Total includes some seals which were not placed in any size class. a
24

Table 2.2.--Composition of the Hawaiian monk seal subpopulation at French Frigate

 Shoals during the spring and summer of 2003. These numbers are an

 unknown portion of the entire subpopulation. Includes all known parturient

 females and pups born during the calendar year. 

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 69 100 0 169 0.7:1

Subadults 14 12 0 26 1.2:1

Juveniles 17 26 0 43 0.6:1

Pups 20 29 3 52 0.7:1 a a a

Non-pup Total 100 138 0 238 0.7:1

Grand Total 120 167 3 290 0.7:1

Includes one male and one female perinatal dead pup; neither was seen alive.

a
25

Table 2.3.--Summary of tagged known-age seals born at French Frigate Shoals and

 resighted at any location in 2003.

Cohort year

Age

(years) Sex

Number originally

tagged

Number resighted

 in 2003

1984 19 Male

Female

49

43

6

a

9

a

1985 18 Male

Female

48

38

3

 a

8

a

1986 17 Male

Female

52

48

6

a

16a

1987 16 Male

Female

55

51

5

5

1988 15 Male

Female

52

62

4

 

5

1989 14 Male

Female

51

50

5

5

a

1990 13 Male

Female

38

41

1

6

a

1991 12 Male

Female

24

44

1

4

a

1992 11 Male

Female

36

55

2

9

a

1993 10 Male

Female

40

39

3

2

1994 9 Male

Female

47

48

1

7

a

1995 8 Male

Female

29

26

 2

11a

1996 7 Male

Female

39

30

3

 

3

1997 6 Male

Female

32

19

1

0

1998 5 Male

Female

49

39

4

4
Cohort year

Age

(years) Sex

Number originally

tagged

Number resighted

 in 2003

26

1999 4 Male

Female

30

30

7

4

2000 3 Male

Female

27

30

2

4

2001 2 Male

Female

21

19

4

5

2002 1 Male

Female

25

28

13

21

Cohort survivors include seals removed from French Frigate Shoals for rehabilitation or direct a

translocation. These seals were either released at Kure or Midway Atoll (n = 15) or taken into permanent

captivity (n = 12).
27

Table 2.4a.--Summary of Hawaiian monk seals born at French Frigate Shoals in 2003.

 Event

Number of pups

Male Female Unknown Total

Born 20 29 3 52

Died/probably died

 prior to weaning

3 2 2 7

Disappeared, suspected dead

 prior to weaning

2 1 0 3

Weaning status unknown 1 1 1 3

a b a

Weaned 14 25 0 39

Tagged 12 25 0 37 c c

 Pup disappeared at or near weaning. a

 Pup was nursing on Trig Island at the end of the NMFS field camp and was not seen b

 during USFWS autumn seal tagging efforts.

Two male weaned pups were not tagged due to their compromised conditions (one likely c 

 blind, one sustained hindflipper amputations.

Table 2.4b.--Summary of nursing periods and measurements of weaned pups at French

 Frigate Shoals in 2003. Nursing periods were calculated where birth

 and weaning dates were both known or occurred within a range of 4 days or 

 less. All measurements were taken within 2 weeks after weaning. 

Nursing period 

(d)

Axillary girth

(cm)

Straight dorsal length

(cm)

Mean 37.0 102.6 123.6

St. Dev. 3.4 10.3 6.6

n 28 35 35
28

Table 2.5a.--Documented movement of Hawaiian monk seals to French Frigate Shoals

 from other locations in 2003, summarized by movements between two

 locations. One seal made more than one documented trip.

Original location Number of trips, size, and sex class

Laysan Island 3 adult female

Table 2.5b.--Documented movement of Hawaiian monk seals from French Frigate Shoals

 to other locations in 2003, summarized by movements between two

 locations. No seals made more than one documented trip.

Destination Number of trips, size, and sex class

Laysan Island 2 adult female
29

Table 2.6.--Factors affecting Hawaiian monk seal survival at French Frigate Shoals in

 2003. 

Outcome

Size Sex Total Injured Died Probably

Attack by Large Shark

Adult Male

Female

2

4

b

2

a

4

0

0

0

0

Juvenile Male 1 1 0 0

Nursing pup Male 

Female

1

1

1

c

0

0

1

d

0

0

Mounting

Weaned pup Female 1 0 0 0

e

Entanglement

Adult Female 1

f 0 0 0

Subadult Male 1 0 0 0

g 

Weaned pup Female 1 0 0 0

f 

Emaciated

Adult Male 2 0 1 1

Juvenile Female 1 0 1 0

h

Unknown

Adult Female 1 1 0 0

i

Juvenile Female 1 0 1 0

j

Nursing pup Male

Female

Unknown

3

1

2

0

0

0

1

k

1

k

0

2

l

0

 

2

l

One seal was in poor condition and seen only once during the season, on May 25. a

USFWS personnel documented one injury in January, prior to field season, and one injury after the field b

season in October. The female with the January injury aborted a fetus three weeks later; it is unknown if this

is related to the injury.

Shark bitten nursing pup at Round Island, entire left hindflipper and most of the right hindflipper c

amputated.

Found dead at Little Gin Island, torso only. d
30

This incident, disrupted by observers, and two harassments (of a male and female weaned pup) were e

witnessed on East Island, all involving the same adult male aggressor (ID number Y1AO). No injuries, or

very minor injuries, were observed following these incidents.

Seals freed themselves uninjured after brief entanglement; nursing mom with a net/line and a weaned pup f

with a rubber ring.

Released uninjured by USFWS personnel prior to field season. g

Found dead on Little Gin by USFWS personnel 2 days prior to start of field season. h

Open gash on top of head. Received injury prior to field season, reported by USFWS personnel. i

Found dead on East island by USFWS personnel prior to field season. j 

One neonate pup death, not seen alive. k

Shark inferred mortality. l
CHAPTER 3. THE HAWAIIAN MONK SEAL ON

LAYSAN ISLAND, 2003

Karen J. Holman, Catherine Gunther-Murphy, 

Jennifer L. Palmer, and Laura J. Boren

33

Laysan Island (lat. 25°42' N, long. 171°44' W) is located ca. 1,300 km northwest

of Oahu in the Northwestern Hawaiian Islands (Fig. 1.1). This island lies within the

Hawaiian Islands National Wildlife Refuge and is one of the six primary haulout and

pupping locations of the Hawaiian monk seal (Fig. 3.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research on Hawaiian

monk seals at Laysan Island in 1981. In 2003, research was conducted by NMFS during

March 7–July 20, and incidental observations were recorded by U.S. Fish and Wildlife

Service (USFWS) personnel during the remainder of the year. The perimeter of the

island (ca. 11 km) was divided into 20 sectors using artificial or natural landmarks (Fig.

3.1). Research objectives specific to this subpopulation in 2003 included (1) assessment

of maternity and pup exchanges; and (2) documentation of male behavior, including

aggression.

 

Censuses and Patrols

Censuses and patrols were scheduled to ensure that the entire island perimeter was

monitored at least once daily during March 10–July 20. Censuses (n = 28) were

conducted by two observers every fourth day from March 25 to July 15, beginning at

1300 Hawaii Standard Time and continuing for 2.2 to 4.4 h.

Standardized behavior patrols were conducted on non-census days from March 27

to July 9 to assess activity patterns of adults and large subadults and document male

aggression. During these patrols (n = 23), attention was directed out to sea as much as

possible since multiple male aggression has been observed most frequently in the water. 

Full-island standardized incidental surveys (n = 66) were conducted on non-census and

non-behavior patrol days to record female and pup pairs, factors affecting survival,

weaned pups, and molting animals. Additional partial island surveys were conducted as

needed.

Individual Identification

A total of 277 individuals (244 excluding pups) were identified by existing or

applied tags, bleach marks, scars, or natural markings. Bleach marks were applied to 180

seals, including 29 nursing pups. All pups weaned by the end of the field season (n = 26)
34

were tagged with Temple Tags and most (n = 25) received passive integrated transponder

(PIT) tags. A total of six yearlings were newly tagged and received PIT tags. In addition,

one 2-year-old seal and two weaned pups were retagged with temple tags to replace

broken or lost tags.

Collection of Samples

One hundred-six scat and two spew samples were collected. Skin punches were

collected from 26 weaned pups, 6 yearlings, and a 2-year-old seal. In addition, one tissue

sample was collected from an adult female with a severed lobe of the left hind flipper.

Shed molt samples were collected from 36 individuals. Fresh placentas were collected

from three births. Necropsies were performed, and tissue samples collected, from four

recently dead seals. Skulls were collected from two of these seals. One seal torso was

found washed up, consisting mainly of rotted blubber and skeletal remains. A tissue

sample and vertebrae were collected. Potentially entangling marine debris was collected

from beaches and stored in a secure location pending removal. One piece of fine rope was

removed and collected from an entangled seal.

Noteworthy Events

Human Intervention

Human intervention promoted the survival of nursing and weaned pups in

potentially life-threatening situations, including one premature weaning, two mother-pup

separations, and two incidents of male aggression. 

In the case of premature weaning, a female pup was involved in a pup switch on

the day of her birth and began nursing an adult female that had already completed 25 days

of nursing. When the pup was prematurely weaned from her foster mother after only 24

days of nursing, she was returned to her birth mother in a human-assisted pup exchange.

The prematurely weaned pup was returned to her birth mother, displacing a female pup in

excellent condition after having completed a 41-day nursing period. Subsequently, the

pup returned to her mother nursed an additional 10 days.

In the first mother-pup separation, a 3-day-old male pup was observed alone and

vocalizing at the shoreline, approximately 200 m away and out of line of sight from his

sleeping mother. The pup was successfully reintroduced to his birth mother, completed a

full nursing period, and subsequently weaned. A second male pup was abandoned by his

mother on the day of his birth: first for a period of at least 4.5 h and secondly, for

approximately 12 h. In the first instance, the mother, attended by an adult male, returned

to her pup independently and no human intervention was necessary. During her second
35

departure, however, the pup was monitored by researchers overnight and repeatedly

coaxed from the shallow water. The mother was sighted the following day approximately

300 m away and researchers successfully reintroduced the pair, resulting in a full nursing

period without interruption.

Following weaning, however, this latter pup was observed repeatedly interacting

with an adult male and two incidents of targeted, sustained male aggression were

disrupted by researchers. During these incidents the adult male was mildly biting the

weaned pup’s posterior and forcing the weaned pup underwater for prolonged periods of

time (> 2 minutes). Researchers repeatedly deterred the adult male in two separate

incidents through arm-waving and shouting. Although the male repeatedly returned to the

weaned pup after initial interventions, the weaned pup and adult male were not observed

in association again for the remainder of the season (44 days) after the last human

intervention. 

RESULTS

Subpopulation Minimum Abundance and Composition

The mean (± SD) of 28 censuses was 88.4 seals (± 14.0) including pups, and 73.7

seals (± 12.9) excluding pups (Table 3.1). The total spring-summer minimum

subpopulation was 272 individuals, 239 excluding pups (Table 3.2). This number is a

subset of the total identified in the calendar year. The overall adult sex ratio was at 0.8:1

(65 males: 78 females). The numbers of tagged known-age seals born at Laysan Island

during the period from 1983 to 2002, and resighted at any location in 2003, are

summarized in Table 3.3. 

Reproduction

At least 33 pups were born at Laysan Island in 2003: 29 were successfully

weaned, 3 died/probably died prior to weaning, and weaning status of 1 pup was

unknown because it disappeared at/near weaning (Table 3.4a). Three pups were still

nursing at the end of the NMFS field season (all of which subsequently weaned) and one

pup (of unknown weaning status) was born afterwards. Nursing periods and

measurements of weaned pups are summarized in Table 3.4b. The birth rate measured as

the number of pups born divided by the number of adult-sized females in the

subpopulation x 100 was 42.3% ((33/78) x 100). A minimum of 21 pup exchanges

occurred between 12 nursing females; four of these incidents were observed. One birth

was observed, and a fostering led to an unusually long nursing duration of 76 days when a

pup who initially weaned at 35 days began nursing an adult female whose pup had

recently disappeared.
36

Interatoll Movement

Interatoll movement was documented for 18 seals that completed a total of 30

movements between Laysan Island and either French Frigate Shoals or Lisianski Island

(Tables 3.5a and b).

Factors Affecting Survival

Attacks by large sharks, mounting attempts by male Hawaiian monk seals,

entanglement in marine debris, and other/unknown factors led to 15 life-threatening

conditions, which resulted in the confirmed deaths of 5 animals and the probable deaths

of 1 adult female and 1 nursing pup (Table 3.6). Incidents of prolonged adult male

aggression towards a weaned pup were observed and ceased after human intervention.

Three adult females sustained male mounting injuries, leading to one confirmed death

and one probable death. One seal was entangled around the neck with fine rope and

released by observers. One male juvenile was found dead along a rocky shoreline. The

seal was slightly thin, although not emaciated, and cause of death unknown. Two nursing

pups (a male and female) died of unknown causes, and a seal torso was found washed up

in a severely degraded condition. The torso consisted mainly of rotted blubber with one

fore-flipper still attached. Judging from the size of the foreflipper, researchers suspect the

carcass to be that of a juvenile or subadult. In addition to the cases summarized in Table

3.6, a pup disappeared near weaning at 19–36 days old and is suspected dead. It was first

sighted on July 28 after the end of the NMFS field season and was last seen with its

mother on August 15. The pup was missing by August 26 and was not resighted on nine

additional USFWS surveys through October 24. Two seals were observed with healed

wounds from between-season shark bites, and five yearlings (2 males and 3 females) were

observed with unusual pelage conditions.

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian

Islands National Wildlife Refuge staff and thank the captain and crew members of The

American Islander and the NOAA ship, The Oscar Elton Sette. Special thanks are

extended to Brenda Becker for assisting with establishing the field camp and general

orientation to the island and sharing her wealth of local knowledge with the field team. 

Special thanks are also extended to Jason Baker for his encouragement, and to the

USFWS crew on Laysan including Kevin Payne, Matt Toomey, Melissa Roth, Chris

Depkin, John Kellam, Stefan Kropidlowski, Greg McClelland, and Natalie and Tom

Wilkie for their support and data collection. 
TABLES

for Laysan Island

39

Table 3.1.--Summary statistics for censuses (n = 28) of Hawaiian monk seals at Laysan

 Island from March 25 to July 15, 2003.

Size/Sex Mean number of individuals Standard deviation

Adults 45.5 8.5

Male 19.8 5.9

Female 23.6 4.3

Unknown 2.1 2.2

Subadults 14.3 4.5

Male 6.7 2.0

Female 7.1 3.3

Unknown 0.5 0.6

Juveniles 13.9 4.5

Male 8.4 3.6

Female 5.4 1.8

Unknown 0.1 0.4

Pups 14.6 6.3

Male 4.4 2.9

Female 8.8 3.8

Unknown 1.5 1.5

Non-pup total 73.7 12.9

Grand total 88.4 14.0
40

Table 3.2.--Composition of the Hawaiian monk seal subpopulation at Laysan Island

 during the spring and summer of 2003. Includes all known parturient females

 and pups born during the calendar year. 

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 65 78 0 143 0.8:1

Subadults 20 25 0 45 0.8:1

Juveniles 27 24 0 51 1.1:1

Pups 12 19 2 33 0.6:1

Non-pup total 112 127 0 239 0.9:1 

Grand total 124 146 2 272 0.8:1
41

Table 3.3.--Summary of tagged known-age seals born at Laysan Island and resighted at any

location in 2003.

Cohort year

Age

(years) Sex

Number

originally tagged

Number

resighted 

in 2003

1983 20 Male

Female

10

10

1

6

1984 19 Male

Female

16

13

2

4

1985 18 Male

Female

16

14

1

3

1986 17 Male

Female

15

17

0

2

1987 16 Male

Female

13

15

3

3

1988 15 Male

Female

23

17

5

2

1989 14 Male

Female

16

13

2

1

1990 13 Male

Female

7

9

2

2

1991 12 Male

Female

18

13

7

3

1992 11 Male

Female

18

14

2

3

1993 10 Male

Female

23

14

4

4

1994 9 Male

Female

18

29

7

7

1995 8 Male

Female

16

21

7

8

1996 7 Male

Female

23

21

7

10
Cohort year

Age

(years) Sex

Number

originally tagged

Number

resighted 

in 2003

42

1997 6 Male

Female

19

16

5

7

1998 5 Male

Female

Unknown

24

20

1

12

9

0

1999 4 Male

Female

20

 34

8

18

2000 3 Male

Female

14

20

2

2

2001 2 Male

Female 

16

17 

8

10

2002 1 Male

Female

21

16

19

14
43

Table 3.4a.--Summary of Hawaiian monk seals born at Laysan Island in 2003.

Event

Number of pups

Male Female Unknown Total

Born 12 19 2 33a,b

Died/Probably died prior to weaning 1 1 1 3

Weaning status unknown 0 0 1 1

a

Weaned 11 18 0 29b

Tagged 10 18 0 28

A pup suspiciously disappeared at 19–36 days old. 

a

Three pups, still nursing after the NMFS field season, subsequently weaned and were b

 bleached by USFWS personnel. Two of these pups (both females) were tagged in 2004 whereas the third pup (a

male) was not.

Table 3.4b.--Summary of nursing periods and measurements of weaned pups at Laysan Island in

2003. Nursing periods were calculated where both birth and weaning date ranges

were < 4 d. All measurements were taken within 2 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal length

(cm)

Mean 37.4 101.5 123.9 a

Standard deviation 9.1 8.9 5.0

n 26 26 26

Includes one pup who was initially weaned at 35 days and then began nursing an adult female with a recently a

disappeared pup before weaning a second time at 76 days (including a 6-day break between the two nursing periods).
44

Table 3.5a.–Documented movement of Hawaiian monk seals to Laysan Island from other

locations in 2003, summarized by movements between two locations. One seal

made more than one documented trip.

Original location Number of trips, size, and sex class

French Frigate Shoals 2 adult female

Lisianski Island 2 adult male

8 adult female

Table 3.5b.–Documented movement of Hawaiian monk seals from Laysan Island to other

locations in 2003, summarized by movements between two locations. Two seals

made more than one documented trip.

Destination Number of trips, size, and sex class

French Frigate Shoals 3 adult female

Lisianski Island 3 adult male

10 adult female

 2 subadult female
45

Table 3.6.--Factors affecting Hawaiian monk seal survival at Laysan Island in 2003.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Male

Female

1

1

1

1

0

0

0

0

Juvenile Male

Female

1

1

1

1

0

0

0

0

Mounting by Males

Adult Female 3 1 1 1

 ab

Weaned pup Male 1 0 0 0

c

Entanglement

Subadult Male 1 0 0 0

d 

Other/Unknown

Adult Male 1 1 0 0

Juvenile Male 1 0 1 0

e

Nursing pup Male

Female

Unknown

1

1

1

0

0

0

1

f

1

g

0

0

0

1

h

Immature Unknown 1 0 1 0

i

Seal found dead underwater with a severe mounting injury.

a

Seal sustained severe mounting injuries. She was lethargic and remained in the same location until she disappeared b 

48 days before the NMFS field camp ended.

Escalating incidents of sustained targeted male aggression were observed between the same adult male and pup c 

from 6/03 to 6/08. Aggressive interactions ceased following human interventions on 6/07 and 6/08.

Seal was found with a thin grey rope embedded around it’s neck, and was released by researchers. The seal d 

sustained a minor injury.

Juvenile found dead along rocky shoreline, cause of death unknown. Seal slightly thin but not emaciated. e 

Pup found dead underwater, cause of death unknown. f 

Pup found dead on beach, cause of death unknown. g 

 A pup disappeared and probably died at 9-10 days old, and it’s mother was observed patrolling shores and h

vocalizing for her lost pup. 

A severely degraded torso washed up on beach, consisting of blubber with the left front flipper still attached. No i 

organs remained. The size of the foreflipper was consistent with a juvenile or subadult seal.

CHAPTER 4. THE HAWAIIAN MONK SEAL ON 

LISIANSKI ISLAND, 2003

Maia N. Yannacone, Shawn C. Farry, Stori C. Oates, and Tracy A. Wurth

49

Lisianski Island (lat. 26°02' N, long. 174°00' W) is one of the primary haulout and

pupping locations of the Hawaiian monk seal. The island is located ca. 1,760 km

northwest of Oahu (Fig. 1.1) and is situated in Neva Shoal, a shallow reef bank within the

Hawaiian Islands National Wildlife Refuge (Fig. 4.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research on Hawaiian

monk seals at Lisianski Island in 1980. In 2003 research was conducted by NMFS during

March 10–July 16. The perimeter of the island was divided into 20 sectors using artificial

or natural landmarks (Fig. 4.1). Research activities specific to this subpopulation in 2003

included (1) assessment of maternity and pup exchanges; and (2) documentation of adult

male behavior and aggression, including focal observations in areas frequented by

weaned pups.

Censuses and Patrols

Censuses and patrols were scheduled to ensure that the entire island was

monitored at least once daily during March 10–July 13. Censuses (n = 25) were

conducted by two observers every fourth day from April 2 to July 9, beginning at 1300

Hawaii Standard Time and continuing from 1.2 to 2.4 h. 

Standardized behavior patrols were conducted on non-census days to assess

activity patterns of adults and large subadults and document male aggression. During

these patrols (n = 21), attention was directed out to sea as much as possible since multiple

male aggression has been observed most frequently in the water. Full-island

standardized incidental surveys (n = 79) were conducted on non-census and nonbehavior

patrol days from March 10 to July 13 to record female and pup pairs, factors affecting

survival, weaned pups, and molting animals. Additional partial island surveys were

conducted as needed.

Individual Identification

A total of 184 individuals (156 excluding pups) were identified by existing or

applied tags, bleach marks, scars, or natural markings. All weaned pups (n = 26) were

tagged with Temple tags and passive integrated transponder (PIT) tags. 
50

Collection of Samples

Ninety-nine scat samples were collected. Skin punches were collected from 26

seals during tagging and from three dead pups (2 nursing and 1 weaned) during

necropsies. Necropsies were performed and tissue samples were collected from two male

nursing pups and one female weaned pup. Skeletal samples were collected from all three

seals. One dead yearling was found at the beginning of the season and was partially

decomposed; tags were removed from this individual. Two placentas were collected. 

Thirty-six shed molt samples were collected from 36 individuals, and one eel cone was

removed from a male weaned pup’s muzzle and also collected. Potentially entangling

marine debris was collected from beaches and stored in a secure location pending

removal.

Special Studies

Male Aggression Towards Weaned Pups

Focal observations of sectors frequented by weaned pups were conducted

intermittently from May 15 to June 20, with researchers noting any aggressive male

behavior and intervening as needed when life-threatening situations arose. Three

incidents of targeted, sustained male aggression were observed. A female-weaned pup

was found dead in the surf zone with an adult biting her back, assuming a copulatory

posture, and holding her head underwater. On two separate occasions, male-weaned pups

were similarly harassed, bitten on the dorsum and held underwater; both incidents were

disrupted by researchers. One pup developed multiple abscesses and the other only

sustained superficial lacerations. All three incidents involved different male aggressors. 

Noteworthy Events

Human Intervention

Two of the single, male aggression incidents noted above were disrupted by

researchers. One successful human-assisted pup switch was initiated by researchers

reuniting two mothers with their birth pups. Previous pup exchanges had resulted in one

pup in a nursing association with a foster mother, while the pup’s birth mother (and the

foster mother’s pup) remained alone. The nursing female pup was removed from her

foster mother and was moved approximately 10 meters to her birth mom who was alone

and searching for her. The other male pup, who was found without a female a few meters

from his birth mother, was then able to reunite with his birth mother once she was alone.
Submersible pilot and operations director, onboard RV Ka’imikai-o-Kanaloa.

2

51

RESULTS

Subpopulation Minimum Abundance and Composition

The mean (± SD) of 25 censuses was 67.3 seals (± 8.3) including pups, and 51.8

seals (± 7.1) excluding pups (Table 4.1). The minimum spring-summer subpopulation

was 177 individuals, 149 excluding pups (Table 4.2). This number is a subset of the total

identified during the calendar year. The overall adult sex ratio was at 1.2:1 (60 males:49

females). The numbers of tagged known-age seals born at Lisianski Island during the

period from 1982 to 2002, and resighted at any location in 2003, are summarized in 

Table 4.3.

Reproduction

A minimum of 28 pups were born at Lisianski Island in 2003: 26 were

successfully weaned and 2 died prior to weaning (Table 4.4a). Nursing periods and

measurements of weaned pups are summarized in Table 4.4b. The birth rate, measured as

the number of pups born divided by the number of adult-sized females in the

subpopulation x 100 was 57.1% ((28/49) x 100). A minimum of 29 pup exchanges

occurred among 15 nursing females. One human-assisted pup exchange reunited two

birth mothers with their pups.

Interatoll Movement

Interatoll movement was documented for 17 seals that completed a total of 27

movements between Lisianski Island and either Laysan Island, Kure Atoll, or Maro Reef. 

An adult male from Lisianski Island (ID number GT24), videotaped at Maro Reef by

researchers on board a deep-sea submersible on October 5 at 536 m depth, was identified

by his bleach number (Terry Kerby, personal communication ) (Tables 4.5a and b). 2

Another seal, observed on the same dive at 483 m depth, remains unidentified and is not

included in the total.

Factors Affecting Survival

Attacks by large sharks, mounting attempts by male Hawaiian monk seals,

entanglement in marine debris, emaciation, and other/unknown factors led to 13 lifethreatening conditions, which resulted in the confirmed deaths of 4 animals and the

probable deaths of 3 others (Table 4.6). Two entangled seals were successfully freed, one
52

male weaned pup with an eel cone on its muzzle and one female juvenile with net around

her neck. The second seal was partially released by researchers and completely freed

herself after escape from restraint. Adult male harassment of two male weaned pups

resulted in one of those weaned pups developing multiple abscesses on his dorsum

presumably from seal bites. One female weaned pup was found dead in the water with an

adult male who was biting her and assuming a copulatory posture. Cause of death was

probable drowning; no signs of trauma other than superficial lacerations and a missing nail

on the right foreflipper were noted. One newborn male pup was found dead in the surf

zone with his mom approximately 5 meters away being attended by an adult male. A small

hematoma was found on the skull; however, cause of death is unknown.

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian

Islands National Wildlife Refuge staff. We thank the captain, officers, and crew of the

NOAA ship Oscar Elton Sette and M/V American Islander for logistical assistance. 
TABLES

for Lisianski Island

55

Table 4.1.--Summary statistics for censuses (n = 25) of Hawaiian monk seals at Lisianski

 Island from April 2 to July 9, 2003.

Size/Sex Mean number of individuals Standard deviation

Adults 40.0 5.9

Male 19.0 3.8

Female 18.8 3.5

Unknown 2.2 1.7

Subadults 6.4 2.8

Male 3.7 2.3

Female 2.6 1.2

Unknown 0.1 0.4

Juveniles 5.4 2.6

Male 3.1 1.6

Female 2.2 1.3

Unknown 0.1 0.3

Pups 15.5 4.1

Male 7.6 2.0

Female 7.8 2.4

Unknown 0.1 0.3

Non-pup total 51.8 7.1

Grand total 67.3 8.3
56

Table 4.2.--Composition of the Hawaiian monk seal subpopulation at Lisianski Island

 during the spring and summer of 2003. Includes all known parturient females

 and all pups born during the calendar year.

Number of seals

Size Male Female Total

Sex ratio

male:female

Adults 60 49 109 1.2:1

Subadults 13 9 22 1.4:1

Juveniles 9 9 18 1.0:1

Pups 14 14 28 1.0:1

Non-pup total 82 67 149 1.2:1

Grand total 96 81 177 1.2:1
57

Table 4.3.--Summary of tagged known-age seals born at Lisianski Island and resighted at

 any location in 2003.

Cohort year

Age

(years) Sex

Number

originally tagged

Number

resighted in 2003

1982 21 Male

Female

7

6

2

0

1983 20 Male

Female

6

18

1

7

1984 19 Male

Female

10

5

4

1

1985 18 Male

Female

5

9

1

1

1986 17 Male

Female

11

9

5

2

1987 16 Male

Female

12

6

1

1

1988 15 Male

Female

10

8

5

6

1989 14 Male

Female

--

--

--

--

1990 13 Male

Female

8

9

3

3

1991 12 Male

Female

9

6

4

2

1992 11 Male

Female

13

8

6

4

1993 10 Male

Female

4

9

2

2

1994 9 Male

Female

 4

5

1

0

1995 8 Male

Female

 7

10

2

2

1996 7 Male

Female

 9

13

2

1
Cohort year

Age

(years) Sex

Number

originally tagged

Number

resighted in 2003

58

1997 6 Male

Female

 10

9

4

3

1998 5 Male

Female

 10

11

3

4

1999 4 Male

Female

 16

11

3

2

2000 3 Male

Female

 9

9

1

2

2001 2 Male

Female

5

9

1

1

2002 1 Male 

Female

12

11

7

7
59

Table 4.4a.--Summary of Hawaiian monk seals born at Lisianski Island in 2003.

Event

Number of pups

Male Female Unknown Total

Born 14 14 0 28

Died prior to weaning 2 0 0 2

Weaned 12 14 0 26

Tagged 12 14 0 26

Table 4.4b.--Summary of nursing periods and measurements of weaned pups at Lisianski

 Island in 2003. Nursing periods were calculated where both birth and

 weaning date ranges were < 4 days. All measurements were taken within 2

 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal

length (cm)

Mean 35.1 101.7 119.3

Standard

deviation

3.5 11.4 7.4

n 25 25 26
60

Table 4.5a.--Documented movement of Hawaiian monk seals to Lisianski Island from

 other locations in 2003, summarized by movements between two locations. 

 One seal made more than one documented trip.

Original location Number of trips, size, and sex class

Laysan Island 3 adult male

10 adult female

 2 subadult female

Kure Atoll 1 juvenile male

Table 4.5b.--Documented movement of Hawaiian monk seals from Lisianski Island to

 other locations in 2003, summarized by movements between two locations. 

 One seal made more than one documented trip.

Destination Number of trips, size, and sex class

Laysan Island 2 adult male

8 adult female

Maro Reef 1 adult male
61

Table 4.6.--Factors affecting Hawaiian monk seal survival at Lisianski Island in 2003.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Female 1 0 0 1

 a

Subadult Male 1 1 0 0

Juvenile Female 1 1 0 0

Mounting by Male

Weaned pup Male

Female

2

b

1

1

0

0

1

c

0

0

Entanglement

Juvenile Female 1 0 0 0

d

Weaned pup Male 1 0 0 0

e

Emaciation

Juvenile Male

Female

1 

1 

0

0

0

0

1

1

Other/Unknown

Juvenile Male 1 0 1 0

Nursing pup Male 2 0 2 0

 Seal was in medium/thin condition when last sighted prior to attack. a

 Two observed incidents of single adult male aggression were interrupted by researchers. 

b

 One pups developed abscesses whereas the other only sustained superficial lacerations. 

 A dead pup was observed being mounted repeatedly by a single adult male. c

 Seal released by researchers. d

 Seal partially released by researchers freed herself completely after escape from restraint. e

CHAPTER 5. THE HAWAIIAN MONK SEAL ON

PEARL AND HERMES REEF, 2003

Chad H.Yoshinaga, Maire K. Cahoon, and Jason D. Baker 

65

Pearl and Hermes Reef (lat. 27°55' N, long. 175°45' W) is one of the primary

haulout and pupping locations of the Hawaiian monk seal. This atoll is located ca. 

1,900 km northwest of Oahu in the Northwestern Hawaiian Islands and is part of the

Hawaiian Islands National Wildlife Refuge (Fig. 1.1). Pearl and Hermes is composed of

four vegetated and three nonvegetated sand islets enclosed in a barrier reef (Fig. 5.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research on Hawaiian

monk seals at Pearl and Hermes Reef in 1982. In 2003, research was conducted by

NMFS on March 9, and during May 20–August 3. The perimeters of the four larger

vegetated islets were divided into sectors using natural landmarks. Research activity

specific to this subpopulation in 2003 included using kayaks to conduct opportunistic

surveys of the north-northeast emergent reef to identify seals resting on the reef.

Censuses and Patrols

Atoll censuses (n = 6) were conducted every 10 days, on average, from May 31 to

July 18. All islets were censused on foot by one or two persons. In addition, incidental

surveys were conducted opportunistically to resight seals tagged in previous years and to

identify and bleach-mark all animals in the subpopulation. 

Individual Identification

A total of 211 individuals (181 excluding pups) were identified by existing or

applied tags, scars, or natural markings. Twenty-four weaned pups were tagged with

Temple Tags and passive integrated transponder (PIT) tags.

Collection of Samples

Twenty-nine scat and three spew samples were collected. Skin punches were

collected from 18 seals during tagging. One complete adult female skeletal sample was

collected in addition to two pup skulls. Additional samples were collected

opportunistically, including 100 bird ticks and 3 placenta samples. Potentially entangling

marine debris was collected from beaches and stored in a secure location pending

removal.
66

Special Studies

Emergent Reef Surveys

Three surveys of the north-northeast emergent reef were conducted June 7–July

29, and the total number of seals counted on each survey ranged from 4 to 9. In all, nine

seals were identified resting on the reef (2 weaned pups, 2 juveniles, 2 subadults, and 3

adults), and two individuals were identified resting on the reef more than once. 

Although all nine seals were also observed elsewhere during standard surveys of the atoll,

two male seals (a weaned pup and a juvenile) were only identified once each at another

location (both at North Island).

RESULTS

Subpopulation Minimum Abundance and Composition

The mean (± SD) of 6 atoll censuses was 84.8 seals (± 15.5) including pups and

71.2 seals (± 13.5) excluding pups (Table 5.1). The total minimum spring-summer

subpopulation was 207 individuals, 177 excluding pups (Table 5.2). This number is a

subset of the total identified during the calendar year. The numbers of tagged known-age

seals born at Pearl and Hermes Reef during the period from 1983 to 2002 and resighted at

any location in 2003 are summarized in Table 5.3.

Reproduction

At least 30 pups were born at Pearl and Hermes Reef in 2003: 24 were

successfully weaned, 4 died prior to weaning, and two were still nursing at the end of the

research period (Table 5.4). The birth rate, measured as the number of pups born divided

by the number of adult-sized females identified in the subpopulation x 100, was 44.8%

((30/67) x 100). Nursing periods and measurements of weaned pups are summarized in

Table 5.4.

Interatoll Movement

Interatoll movement was documented for 10 seals that completed a total of 13

movements between Pearl and Hermes Reef and either Midway Atoll, or Kure Atoll

(Tables 5.5a and b). 
67

Factors Affecting Survival

Entanglement in marine debris and unknown factors led to seven life-threatening

conditions, which resulted in the confirmed deaths of five seals (Table 5.6). A dead adult

male was found on North Island, and four pups died, one each found on Southeast Island,

North Island, Little North Island, and Seal Kittery Island. Two male seals (an adult and

subadult) were disentangled from debris. In addition to the incidents presented in Table

5.6, the mummified carcass of an adult female, that died since the previous season, was

found on Southeast, and an adult male that probably drowned a pup in 2002 (ID number

BC25) was observed harassing a male weaned pup at Little North in 2003.

ACKNOWLEDGMENTS

We thank the captain, officers, and crew of the NOAA ship Oscar Elton Sette. 

We also acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian Islands

National Wildlife Refuge staff.

TABLES

for Pearl and Hermes Reef

71

Table 5.1.--Summary statistics for atoll censuses (n = 6) of the Hawaiian monk seal at

 Pearl and Hermes Reef from May 31 to July 18, 2003.

Size/Sex Mean number of individuals Standard deviation

Adults 54.0 9.3

Male 21.2 5.1

Female 24.5 4.6

Unknown 8.3 2.4

Subadults 11.2 3.7

Male 3.8 1.8

Female 7.2 2.2

Unknown 0.2 0.4

Juveniles 5.8 2.6

Male 3.7 2.1

Female 1.7 1.0

Unknown 0.5 0.5

Pups 13.7 3.8

Male 7.5 2.1

Female 5.7 1.9

Unknown 0.5 1.2

Non-pup total 71.2 13.5 a

Grand total 84.8 15.5 a

 Total includes some seals which were not placed in any size class. a
72

Table 5.2.--Composition of the Hawaiian monk seal subpopulation at Pearl and Hermes

 Reef during the spring and summer of 2003. These numbers are an unknown

 portion of the entire subpopulation. The table includes all known parturient

 females and pups born during the calendar year. 

Number of seals

Size Male Female Unknow

n

Total

Sex ratio

male:female

Adults 62 67 3 132 0.9:1

Subadults 12 16 1 29 0.8:1

Juveniles 10 6 0 16 1.7:1

Pups 14 10 6 30 1.4:1

Non-pup total 84 89 4 177 0.9:1

Grand total 98 99 10 207 1.0:1
73

Table 5.3.--Summary of tagged known-age seals born at Pearl and Hermes Reef and

 resighted at any location in 2003.

Cohort year

Age

(years) Sex

Number

originally

tagged

Number

resighted 

in 2003

1983 20 Male

Female

8

2

0

1

1984 19 Male

Female

5

8

1

2

1985 18 Male

Female

9

6

1

4

1986 17 Male

Female

Unknown

10

7

1

2

2

0

1987 16 Male

Female

14

7

4

2

1988 15 Male

Female

12

6

8

3

1989 14 Male

Female

8

6

2

1

1990 13 Male

Female

5

1

2

0

1991 12 Male

Female

10

11

7

4

1992 11 Male

Female

13

10

4

6

1993 10 Male

Female

14

7

3

3

1994 9 Male

Female

--

--

–

--

1995 8 Male

Female

15

12

7

5

1996 7 Male

Female

11

12

2

4
Cohort year

Age

(years) Sex

Number

originally

tagged

Number

resighted 

in 2003

74

1997 6 Male

Female

16

11

8

3

1998 5 Male

Female

 8

21

4

11

1999 4 Male

Female

11

15

4

4

2000 3 Male

Female

 12

 10

6

2

2001 2 Male

Female

16

 9

2

2

2002 1 Male

Female

16

6

4

2
75

Table 5.4a.--Summary of Hawaiian monk seals born at Pearl and Hermes Reef in 2003.

Event

Number of pups

Male Female Unknown Total

Born 14 10 6 30

Died prior to weaning 0 0 4 4

Weaning status unknown 0 0 2 2

 a

Weaned 14 10 0 24

Tagged 14 10 0 24

Two pups were still nursing at the end of the NMFS field camp. a 

Table 5.4b.--Summary of nursing periods and measurements of weaned pups at Pearl and

 Hermes Reef in 2003. All measurements were taken within 2 weeks after

 weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal length

(cm)

Mean 36.5 106.6 124.7

Standard

deviation

1 12.8 9.4

n 3 15 15
76

Table 5.5a.--Documented movement of Hawaiian monk seals to Pearl and Hermes Reef

 from other locations in 2003, summarized by movements between two

 locations. No seals made more than one documented trip.

Original location Number of trips, size, and sex class

Midway Atoll 1 adult male

3 adult female

Kure Atoll 2 adult male 

1 adult female

Table 5.5b.--Documented movement of Hawaiian monk seals from Pearl and Hermes

 Reef to other locations in 2003, summarized by movements between two

 locations. No seal made more than one documented trip.

Destination Number of trips, size, and sex class

Midway Atoll 4 adult female

Kure Atoll 1 adult male

1 adult female
77

Table 5.6.--Factors affecting Hawaiian monk seal survival at Pearl and Hermes Reef in

 2003.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

(none observed)

Mounting by Males

(none observed)

Entanglement

Adult Male 1 0 0 0

a 

Subadult Male 1 0 0 0

a 

Unknown

Adult Male 1 0 1 0

Nursing Pup Unknown 4 0 4 0

 

Seal released by observers. a

CHAPTER 6. THE HAWAIIAN MONK SEAL AT

MIDWAY ATOLL, 2003

Leona Laniawe and Misty Niemeyer

81

Midway Atoll (lat. 28°14' N, long. 177°22' W) is one of the primary haulout and

pupping locations of the endangered Hawaiian monk seal. This atoll is located ca. 2,100

km northwest of Oahu in the Northwestern Hawaiian Islands (Fig. 1.1) and comprises a

circular atoll approximately 9 km in diameter, enclosing a lagoon and three permanent

islets (Fig. 6.1). Eastern and Spit Islands are uninhabited. Sand Island was the site of a

U.S. Naval Air base from ca. 1939 until 1993. The U.S. Fish and Wildlife Service

(USFWS) maintained an overlay refuge (Midway Atoll National Wildlife Refuge) at the

site from 1988, until full authority was transferred to the USFWS in October 1996. 

RESEARCH

The National Marine Fisheries Service (NMFS) began limited monitoring of

Hawaiian monk seals at Midway Atoll in 1983. This effort was increased to year-round

monitoring during 1997–1999 by collaborating researchers from Oceanic Society (OS)

and Hawaii Wildlife Fund. In 2003, research was conducted by NMFS during May 24– 

July 18. Incidental observations were recorded by USFWS personnel during the rest of

the year. Perimeters of the three permanent islets were divided into sectors using

artificial or natural landmarks. Research activities specific to this subpopulation in 2003

included (1) emergent reef surveys to determine haulout patterns on these areas; (2) 

tissue and spew sampling for DNA, ciguatera survey, and foraging ecology studies; (3)

survey for and removal of marine debris from the north and east reef flats, emergent reef

areas, and along the shores of the atoll’s three islets; and (4) monitoring human impacts

on seals to quantify occurrence and potential effects on monk seal habitat usage. 

Censuses and Patrols

Atoll censuses (n = 8) were conducted every 7th day, on average, from May 24 to

July 7. All islets were censused on foot by one or two persons. Spit was occasionally

surveyed by boat on severe weather days. Patrols of Sand Island (n = 15), Eastern (n =

22), or Spit (n = 26) were conducted on non-atoll census days during January 30–July 17.

Individual Identification

A total of 69 individuals (54 excluding pups) were identified by existing or

applied tags, bleach marks, scars, or natural markings. Fifteen pups weaned at Midway

and fourteen were tagged with Temple tags and passive integrated transponder (PIT) tags. 

One weaned pup was not tagged, due to health issues. 
82

Collection of Samples

Skin punches were collected from 14 weaned pups during tagging. One spew,

several ticks, 3 pieces of entangling debris, and 10 shed molt samples were collected. 

One necropsy was performed by cooperating scientists after the field season. Swab,

blood, and fecal samples were collected from a prematurely weaned pup for health

assessment purposes. Potentially entangling marine debris was collected from beaches

and stored in a secure location pending removal. 

Special Studies

Emergent Reef Surveys

Patrols were conducted twice during the field season along the emergent reef

areas of the North Reef (n = 2), and East Reef (n = 2) on July 1 and July 8, 2003. Two

people using kayaks and a motorboat surveyed the reefs for seals and turtles. On both

occasions, the North and East emergent reef areas were surveyed within 1 day of atoll

counts to provide an estimate of atoll-wide beach/emergent reef counts.

Noteworthy Events

Beach Monitoring and Public Education

From January to July 2003, Sand Island beaches and trails were monitored for

approximately 10 h/week. Monk seal natural history was shared opportunistically with

visitors and residents. Other actions taken to mitigate disturbance to seals included the

posting of seal signs set approximately 50 yards away from the individual, informing

people that a seal was in the area.

Prematurely weaned Pup Rehabilitation Project

On June 10, an undersized prematurely weaned pup was observed and tagged on

Eastern Island. The female pup was later collected and rehabilitated from June 13 to July

16, 2003. On July 16, the pup was radio (VHF) tagged and released back on Eastern

Island. The pup was last seen, in good condition, on November 5, 2003 and has not been

seen since. 
83

RESULTS

Subpopulation Minimum Abundance and Composition

The mean (+ SD) of 8 atoll censuses was 25.9 seals (+ 5.6) including pups, and

16.9 seals (+ 4.1) excluding pups (Table 6.1). The minimum spring-summer

subpopulation was 63 seals, 48 excluding pups (Table 6.2). This number is a subset of

the total identified in the calendar year. The numbers of tagged known-age seals born at

Midway Atoll during the period from 1988 to 2002, and resighted at any location in 2003,

are summarized in Table 6.3.

Reproduction

A minimum of 15 pups were born at Midway Atoll in 2003, and all successfully

weaned (Table 6.4a). The birth rate, measured as the number of pups born divided by the

number of adult-sized females in the subpopulation x 100 was 62.5% ((15/24) x 100). A

minimum of one pup exchange occurred between nursing females, resulting in one

prematurely weaned female pup and one large male pup. Nursing periods and

measurements of weaned pups are summarized in Table 6.4b.

Interatoll Movement

Interatoll movement was documented for 19 seals that completed a total of 30

movements between Midway Atoll and either Pearl and Hermes Reef or Kure Atoll

(Tables 6.5a and b).

Factors Affecting Survival

Attacks by sharks, entanglement in marine debris, and other causes led to six lifethreatening conditions, which resulted in the confirmed death of one individual (Table

6.6). One weaned male pup exhibited an unusually bloated body condition and was not

observed on land post-weaning. In addition, green algae covered a large percentage of its

body and he exhibited signs of discomfort upon an observed attempt to haul out onto a

beach. This pup was later found dead and was necropsied. A defect was found in the

chest wall and findings suggested nutritional panniculitis caused by eating dead, rancid

fish, with bronchiopneumonia identified as the likely cause of death. Four seals were

entangled in marine debris: a juvenile male escaped unaided, and three others (an adult

female, a juvenile female, and a weaned female pup) were released by observers. In

addition, one female weaned pup sustained a large shark related wound to the left side of

her head. 
84

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service. Special

thanks are extended to John Klavitter, Refuge Biologist; Mike Johnson, Assistant Refuge

Manager; and Tim Bodeen, Refuge Manager. We also thank Dr. Robert Braun, Howard

Rhinehart, and Michelle Caudle for their efforts in the preweaned pup rehabilitation and

the officers and crew of the NOAA ship Oscar Elton Sette for logistical assistance. 
TABLES

for Midway Atoll

87

Table 6.1.--Summary statistics for atoll censuses (n = 8) of Hawaiian monk seals at 

 Midway Atoll from May 24 to July 7, 2003.

Size/Sex Mean number of individuals Standard deviation

Adults 10.4 3.6

Male 1.1 1.4

Female 8.4 3.2

Unknown 0.9 1.4

Subadults 4.3 0.9

Male 2.9 0.6

Female 1.1 0.6

Unknown 0.3 0.5

Juveniles 2.3 1.3

Male 0.4 0.5

Female 1.9 1.0

Unknown 0.0 0.0

Pups 9.0 2.4

Male 1.8 0.7

Female 3.5 1.4

Unknown 3.8 2.5

Non-pup total 16.9 4.1

Grand total 25.9 5.6
88

Table 6.2.--Composition of the Hawaiian monk seal subpopulation at Midway Atoll

 during the spring and summer of 2003. These numbers are an unknown

 portion of the entire subpopulation. Includes all known parturient females

 and pups born during the calendar year.

Number of seals

Size Male Female Total

Sex ratio

Male:Female

Adults 7 25 32 0.3:1

Subadults 8 3 11 2.7:1

Juveniles 1 4 5 0.2:1

Pups 6 9 15 0.7:1 a

Non-pup total 16 32 48 0.5:1

Grand total 22 41 63 0.5:1

Includes one untagged weaned pup, found dead in August 2003. a
89

Table 6.3.--Summary of tagged known-age seals born at Midway Atoll and resighted at

 any location in 2003.

Cohort year

Age

(years) Sex

Number

originally

tagged

Number

resighted 

in 2003

1988 15 Male

Female

0

1

NA

1

1989 14 Male

Female

0

0

NA

NA

1990 13 Male

Female

0

0

NA

NA

1991 12 Male

Female

1

1

0

1

1992 11 Male

Female

0

1

NA

1

1993 10 Male

Female

1

0

0

NA

1994 9 Male

Female

0

0

NA

NA

1995 8 Male

Female

Unknown

1

6

1

0

1

0

1996 7 Male

Female

1

4

0

0

1997 6 Male

Female

3

6

1

2

1998 5 Male

Female

8

2

3

2

1999 4 Male

Female

7

4

2

1

2000 3 Male

Female

5

9

1

0

2001 2 Male

Female

6

5

1

2

2002 1 Male

Female

7

4

1

3
90

Table 6.4a.--Summary of Hawaiian monk seals born at Midway Atoll in 2003.

Event

Number of pups

Male Female Total

Born 6 9 15 

Died prior to weaning 0 0 0

 

Weaned 6 9 15

Tagged 5 9 14 a a

One weaned male pup was not tagged, and later found dead. a

.

Table 6.4b.--Summary of nursing periods and measurements of weaned pups at Midway

 Atoll in 2003. Nursing periods were calculated where both birth and

 weaning date ranges were < 4 d. All measurements were taken within 2

 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal

length (cm)

Mean 36.0 114.6 130.6

Standard

deviation

-- 11.7 7.8

n 19 9
91

Table 6.5a.--Documented movement of Hawaiian monk seals to Midway Atoll from other

 locations in 2003, summarized by movements between two locations. Two

 seals made more than one documented trip.

Destination Number of trips, size, and sex class

Pearl and Hermes Reef 4 adult female

Kure Atoll 5 adult male

8 adult female

Table 6.5b.--Documented movement of Hawaiian monk seals from Midway Atoll to other

 locations in 2003, summarized by movements between two locations. No

 seals made more than one documented trip.

Destination Number of trips, size, and sex class

Pearl and Hermes Reef 1 adult male

3 adult female

Kure Atoll 4 adult male

5 adult female
92

Table 6.6.--Factors affecting Hawaiian monk seal survival at Midway Atoll in 2003.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Weaned Pup Female 1 1 0 0

Mounting by Males

(none observed)

Entanglement

Adult Female 1 1 0 0

a 

Juvenile Male

Female

1

b

1

a

0

0

0

0

0

0

Weaned pup Female 1 0 0 0

a 

Other

Weaned pup Male 1 0 1 0

c

 Seal released by researchers.

a

 Seal freed itself. b

 Prior to death, the pup exhibited an unusually bloated body condition and was not observed on land post- c

weaning.
CHAPTER 7. THE HAWAIIAN MONK SEAL AT

KURE ATOLL, 2003

Lizabeth S. Kashinsky and Robert D. Marshall

95

Kure Atoll (lat. 28°25' N, long. 178°10' W) is one of the primary haulout and pupping

locations of the Hawaiian monk seal. The atoll is located ca. 2,300 km northwest of Oahu in the

Northwestern Hawaiian Islands (Fig. 1.1) and is a seabird sanctuary of the State of Hawaii. The

atoll consists of a circular fringing reef approximately 9 km in diameter, the enclosed lagoon, one

permanent vegetated island (Green Island), two sand islets (Sand and Shark), and an ephemerally

emergent area known locally as Stark Reef (Fig. 7.1). From 1960 to 1992, Green Island was the

site of a U.S. Coast Guard (USCG) LORAN station, staffed by 20-30 USCG personnel. In July

1992, this station was closed and vacated by the USCG, leaving the atoll uninhabited. In 1993,

the USCG completed the removal of most of the infrastructure on Green Island. 

RESEARCH

National Marine Fisheries Service (NMFS) began research on the Hawaiian monk seal at

Kure Atoll in 1981. In 2003, research was conducted by NMFS during 

May 24–July 14, and additional incidental observations were recorded by State of Hawaii

personnel until September 23. The perimeter of Green Island was divided into eight sectors

using artificial or natural landmarks. 

Censuses and Patrols

Atoll censuses (n = 11) were conducted every twice weekly on average, from 

June 6 to July 14. All islets were censused on foot by one or two persons. Shark Islet and Stark

Reef were not emergent during the 2003 field season. Patrols were conducted on non-atoll

census days to identify seals and monitor locations used by parturient females. In total, 28 patrols

of Green Island and 1 patrol of Sand Islet were conducted. 

Individual Identification

A total of 103 individuals (85 excluding pups) was identified by existing or applied tags,

bleach marks, scars, or natural markings. All weaned pups (n = 18) were tagged with Temple

Tags, and passive integrated transponder (PIT) tags were applied. 
96

Collection of Samples

Twenty scat, three spew, and seven molt samples were collected. Skin punches were

collected from 18 seals during tagging. One satellite-linked dive recorder (SLDR) that was

applied to a seal in October–November 2001 was found on the beach and retrieved. Potentially

entangling marine debris was collected from beaches and stored in a secure location pending

removal. A large conglomerate of buried net remains within and near the Paradise Queen II

wheel house on the east shore of Green Island. An unstable section of the deck and hull remains

on the reef. 

Noteworthy Events

Human Intervention

An adult male was observed in the water mounting a newly weaned female pup for

several minutes. Human interference caused the adult male to back off, and the weaned pup

immediately hauled out on the beach. No significant injuries were noted on the pup.

RESULTS

Subpopulation Minimum Abundance and Composition

The mean (± SD) of 11 atoll censuses was 46.5 seals (± 4.3) including pups, and 37.3

seals (± 4.5) excluding pups (Table 7.1). The minimum spring-summer subpopulation was 93

individuals, 75 excluding pups (Table 7.2). This number is a subset of the total identified in the

calendar year. The numbers of tagged known-age seals born at Kure Atoll during the period

from 1981 to 2002, and resighted at any location in 2003, are summarized in Table 7.3.

Reproduction

At least 18 pups were born at Kure Atoll in 2003, and all successfully weaned (Table

7.4a). Nursing periods and measurements of weaned pups are summarized in Table 7.4b.) The

birth rate, measured as the number of pups born divided by the number of adult-sized females in

the subpopulation x 100 was 54.5% (18/33 x 100). Six of the seven identified parturient females

(85.7%) had either been temporarily maintained as pups in the Kure Atoll Head Start Project or

rehabilitated from FFS.
97

Interatoll Movement

Interatoll movement was documented for 16 seals that completed a total of 28

movements between Kure Atoll and either Lisianski Island, Pearl and Hermes, or Midway

Atolls (Table 7.5a and b).

Factors Affecting Survival

Attacks by large sharks, mounting attempts by male Hawaiian monk seals, and

entanglement in marine debris led to six life-threatening conditions (Table 7.6). No

deaths were recorded. One weaned pup and one adult female were disentangled by

observers. In addition, an adult female was observed twice with a plastic loop around her

neck, but was able to free herself both times. One female weaned pup was observed with

a wound likely resulting from a shark attack. Observers intervened in single male

aggression towards a weaned female pup. 

ACKNOWLEDGMENTS

We acknowledge the support of the State of Hawaii, Department of Land and

Natural Resources and Division of Forestry and Wildlife, especially Cynthia A.

Vanderlip. We also thank the captains and crew of the NOAA ship Oscar Elton Sette and

American Islander for logistical support and for transport to and from Kure Atoll.

TABLES

for Kure Atoll

101

Table 7.1.--Summary statistics for atoll censuses (n = 11) of Hawaiian monk seals at Kure

Atoll from June 6 to July 14, 2003.

Size/Sex Mean number of individuals Standard deviation

Adults 31.8 4.4

Male 9.4 2.7

Female 14.7 3.1

Unknown 7.7 3.0

Subadults 4.2 1.6

Male 2.3 1.5

Female 0.5 0.7

Unknown 1.4 1.7

Juveniles 1.2 0.9

Male 0.5 0.5

Female 0.4 0.5

Unknown 0.3 0.5

Pups 9.2 2.1

Male 4.3 1.0

Female 4.3 1.6

Unknown 0.6 1.3

Non-pup total 37.3 4.5 a

Grand total 46.5 4.3 a

 Total includes some seals which were not placed in any size class. a
102

Table 7.2.--Composition of the Hawaiian monk seal subpopulation at Kure Atoll during

 the spring and summer of 2003. Includes all known parturient females and

 pups born during the calendar year.

Number of seals

Size Male Female Total

Sex ratio

male:female

Adults 26 33 59 0.8:1

Subadults 7 3 10 2.3:1

Juveniles 3 3 6 1.0:1

Pups 8 10 18 0.8:1

Non-pup total 36 39 75 0.9:1

Grand total 44 49 93 0.9:1
103

Table 7.3.--Summary of tagged known-age seals born at Kure Atoll and resighted at any 

location in 2003.

Cohort year

Age

(years) Sex

Number

originally

tagged

Number

resighted

in 2003

1981 22 Male

Female

3

5

0

0

1982 21 Male

Female

1

3

0

1

1983 20 Male

Female

4

0

2

NA

1984 19 Male

Female

4

2

0

2 

1985 18 Male

Female

2

3

0

1

1986 17 Male

Female

1

0

0

NA

1987 16 Male

Female

1

3

0

3

a

1988 15 Male

Female

2

5

2

 2 

1989 14 Male

Female

5

4

1

 1 

1990 13 Male

Female

3

3

0

 2 

1991 12 Male

Female

7

6

4

3

a

1992 11 Male

Female

5

8

3

4

1993 10 Male

Female

9

4

5

2

1994 9 Male

Female

3

0

0

NA
Cohort year

Age

(years) Sex

Number

originally

tagged

Number

resighted

in 2003

104

1995 8 Male

Female

6

5

3

2

1996 7 Male

Female

10

6

3

0

1997 6 Male

Female

9

7

1

2

1998 5 Male

Female

17

6

5

3

1999 4 Male

Female

8

13

2

2

2000 3 Male

Female

5

8

1

0

2001 2 Male

Female

4

13

0

1

2002 1 Male

Female

11

7

3

1

Cohort survivors include seals removed from Kure Atoll for rehabilitation. These seals (n = 2) were a

released at Kure or Midway Atoll.
105

Table 7.4a.--Summary of Hawaiian monk seals born at Kure Atoll in 2003.

Event

Number of pups

Male Female Total

Born 8 10 18

Died prior to weaning 0 0 0

Weaned 8 10 18

Tagged 8 10 18

Table 7.4b.--Summary of nursing periods and measurements of weaned pups at Kure

 Atoll in 2003. Nursing periods were calculated where both birth and 

 weaning date ranges were < 4 d. All measurements were taken within 

 2 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal length

(cm)

Mean 32.0 110.6 126.2

Standard deviation -- 7.2 4.7

n 1 7 7
106

Table 7.5a.--Documented movement of Hawaiian monk seals to Kure Atoll from other

 locations in 2003, summarized by movements between two locations.

 No seals made more than one documented trip.

Original location Number of trips, size, and sex class

Pearl and Hermes Reef 1 adult male 

1 adult female

Midway Atoll 4 adult male 

5 adult female 

Table 7.5b.--Documented movement of Hawaiian monk seals from Kure Atoll to other

 locations in 2003, summarized by movements between two locations. Two

 seals made more than one documented trip.

Destination Number of trips, size, and sex class

Lisianski 1 juvenile male

Pearl and Hermes Reef 2 adult male 

1adult female

Midway Atoll 5 adult male 

8 adult female 
107

Table 7.6.--Factors affecting Hawaiian monk seal survival at Kure Atoll in 2003.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Weaned pup Female 1 1 0 0

Mounting by Males

Weaned pup Female 1 1 0 0

a

Entanglement

Adult Female 3 0 0 0

b

Weaned pup Male 1 0 0 0

c

An adult male was observed attempting to mount a newly weaned female pup for several minutes. a

Observers interrupted the event and noted that the pup sustained subdermal trauma and swelling.

One adult had a polyurethane line around neck, released by observers; one adult was observed twice with a b

plastic loop around neck, freed self both times.

Seal had a polyurethane line around neck, released by observers. c

CHAPTER 8. THE HAWAIIAN MONK SEAL ON

NIHOA ISLAND, 2003

Alexander S. Wegmann and Thea C. Johanos

111

Nihoa Island (lat. 23°04' N, long. 161°55' W) is located ca. 450 km northwest of

Oahu in the Northwestern Hawaiian Islands (Fig. 1.1) and lies within the Hawaiian

Islands National Wildlife Refuge. Although endangered Hawaiian monk seals use this

island, their numbers are limited by lack of haulout area.

RESEARCH

In 2003, a survey was conducted at Nihoa Island on September 11. The

perimeter of Nihoa Islands was divided into three sectors using natural landmarks (Fig.

8.1). In 2003, research objectives at Nihoa included assessment of pup production and

obtaining a seal census count.

Censuses and Patrols

A beach count was conducted on Nihoa Island by two observers on September 11,

beginning at approximately 1100 Hawaii Standard Time. 

Individual Identification

No seals were identified on Nihoa Island in 2003.

Collection of Samples

No samples were collected at Nihoa Island in 2003. 

RESULTS

Subpopulation Minimum Abundance and Composition

The census total for one count conducted on Nihoa Island was 27 seals (25

excluding pups). Because of limited effort, the composition of the spring-summer

subpopulation was not determined. 
112

Reproduction

At least two pups (of unknown sex) were born at Nihoa Island in 2003; one pup

was still nursing and the weaning status of the other pup was unknown.

Interatoll Movement

Interatoll movement was not documented for seals observed at Nihoa Island. 

Factors Affecting Survival

Factors affecting survival were not observed on Nihoa Island in 2003. 

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian

Island National Wildlife Refuge staff, and members of the Polynesian Voyaging Society. 

We also thank Russel Amimoto, of the Polynesian Voyaging Society, for his assistance

and observations on Nihoa Island.
REFERENCES

115

Alcorn, D. J.

1984. The Hawaiian monk seal on Laysan Island: 1982. U.S. Dep. Commer.,

NOAA Tech. Memo., NOAA-TM-NMFS-SWFC-42, 37 p.

American Society of Mammalogists, Committee on Marine Mammals.

1967. Standard Measurements of Seals. J. Mammal. 48:459–462.

Boness, D. J.

1990. Fostering behavior in Hawaiian monk seals: is there a reproductive cost? 

Behav. Ecol. Sociobiol. 27:113–122.

Boness, D. J., M. P. Craig, L. Honigman, and S. Austin.

1998. Fostering behavior and the effect of female density in Hawaiian monk

seals, Monachus schauinslandi. J. Mammal. 79(3):1060–1069.

Gilmartin, W. G. and T. Gerrodette.

1986. Hawaiian monk seal status and recovery potential at Kure Atoll. Honolulu

Lab., Southwest Fish. Cent., Natl. Mar. Fish. Serv., NOAA, Honolulu, HI

96822-2396, Southwest Fish. Cent. Admin. Rep. H-86-16, 26 p.

Goodman-Lowe, G. D.

1998. Diet of the Hawaiian monk seal (Monachus schauinslandi) from the 

Northwestern Hawaiian Islands during 1991 to 1994. Mar. Biol. 132:535-546.

Hiruki, L. M., Gilmartin, W. G., Becker, B. L., and Stirling, I.

1993. Wounding in Hawaiian monk seals (Monachus schauinslandi). Can. J.

Zool. 71:458–468.

Johanos, T. C., A. K. H. Kam, and R. G. Forsyth.

1987. The Hawaiian monk seal on Laysan Island: 1984. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-70, 38 p.

Lombard, K. B., B. L. Becker, M. P. Craig, G. C. Spencer, and K. Hague-Bechard.

1994. The Hawaiian monk seal on Laysan Island, 1990. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-206, 16 p.

Stone, H. S.

1984. Hawaiian monk seal population research, Lisianski Island, 1982. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-47, 33 p.
116

Winchell, J. 

1990. Field manual for phocid necropsies (specifically Monachus schauinslandi). 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-146,

55 p.
APPENDIXES

A-1

Appendix A.--Reports summarizing annual field research on the Hawaiian monk seal by

 the National Marine Fisheries Service and collaborating scientists.

All islands

Johanos, T. C., and J. D. Baker (Eds.).

2005. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 2002. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-PIFSC-5, 115

p.

Johanos, T. C., and J. D. Baker (Eds.).

2004. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 2001. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-PIFSC-1, 134

p.

Johanos, T. C., and J. D. Baker (Eds.).

2002. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 2000. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-340,

100 p.

Johanos, T. C., and J. D. Baker (Eds.).

2001. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1999. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-310,

130 p.

Johanos, T. C., and J. D. Baker (Eds.).

2000. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1998. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-292,

125 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1999. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1997. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-262,

131 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1999. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1996. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-259,

134 p.
Appendix A.--Continued.

A-2

Johanos, T. C., and T. J. Ragen (Eds.).

1997. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1995. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-241,

121 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1996. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1993. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-227,

141 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1996. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1994. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-229,

111 p.

Johanos, T. C., L. M. Hiruki, and T. J. Ragen (Eds.).

1995. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1992. 

U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-216,

128 p.

French Frigate Shoals

Craig, M. P., J. L. Megyesi, C. S. Hall, J. L. Glueck, L. P. Laniawe, E. A. Delaney, S. S.

Keefer, M. A. McDermond, M. S. Schulz, G. L. Nakai, B. L. Becker, L. M. Hiruki, and

R. J. Morrow.

1994. The Hawaiian monk seal at French Frigate Shoals, 1990-91. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-210, 70 p.

Craig, M. P., D. J. Alcorn, R. G. Forsyth, T. Gerrodette, M. A. Brown, B. K. Choy, L.

Dean, L. M. Dennlinger, L. E. Gill, S. S. Keefer, M. M. Lee, J. S. Lennox, C. R. Lorence,

G. L. Nakai, and K. R. Niethammer.

1992. The Hawaiian monk seal at French Frigate Shoals, 1988-89. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-178, 83 p.

Eliason, J. J., J. R. Henderson, and M. A. Webber.

1993. Hawaiian monk seal observations at French Frigate Shoals, 1985. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-187, 46 p.
Appendix A.--Continued.

A-3

Eliason, J. J., and J. R. Henderson.

1992. Hawaiian monk seal observations at French Frigate Shoals, 1984. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-177, 61 p.

Fairaizl, G. W.

1984. Intra-atoll resighting of the Hawaiian monk seal, Monachus schauinslandi,

at French Frigate Shoals, 1 January 1983-31 August 1983. Southwest Fish.

Cent. Honolulu Lab., Natl. Mar. Fish Serv., NOAA, Honolulu, HI

96822-2396. Southwest Fish. Cent. Admin. Rep. H-84-5C, 27 p.

Johnson, P. A., and B. W. Johnson.

1984. Hawaiian monk seal observations on French Frigate Shoals, 1980. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-50, 47 p.

Laysan Island

Alcorn, D.

1984. The Hawaiian monk seal on Laysan Island: 1982. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-42, 37 p.

Alcorn, D. J., and E. K. Buelna.

1989. The Hawaiian monk seal on Laysan Island, 1983. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-124, 46 p.

Alcorn, D. J., and R. L. Westlake.

1993. The Hawaiian monk seal on Laysan Island, 1986. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-191, 25 p.

Becker, B. L., P. A. Ching, L. M. Hiruki, and S. A. Zur.

1994. The Hawaiian monk seal on Laysan Island, 1987 and 1989. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-213, 20 p.

Becker, B. L., R. J. Morrow, and J. K. Leialoha.

1989. Censuses and interatoll movements of the Hawaiian monk seal on Laysan

Island, 1985. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TMNMFS-SWFC-135, 25 p.
Appendix A.--Continued.

A-4

Becker, B. L., K. E. O'Brien, K. B. Lombard, and L. P. Laniawe.

1995. The Hawaiian monk seal on Laysan Island, 1991. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-214, 16 p.

Johanos, T. C., and S. L. Austin.

1988. Hawaiian monk seal population structure, reproduction, and survival on

Laysan Island, 1985. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TMNMFS-SWFC-118, 38 p.

Johanos, T. C., B. L. Becker, M. A. Brown, B. K. Choy, L. M. Hiruki, R. E. Brainard, 

 and R. L. Westlake

1990. The Hawaiian monk seal on Laysan Island, 1988. U.S.Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-151, 24 p.

Johanos, T. C., A. K. H. Kam, and R. G. Forsyth.

1987. The Hawaiian monk seal on Laysan Island: 1984. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-70, 38 p.

Johnson, B. W., and P. A. Johnson.

1984. Observations of the Hawaiian monk seal on Laysan Island from 1977

through 1980. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TMNMFS-SWFC-49, 65 p.

Lombard, K. B., B. L. Becker, M. P. Craig, G. C. Spencer, and K. Hague-Bechard.

1994. The Hawaiian monk seal on Laysan Island, 1990. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-206, 16 p.

Lisianski Island

Alcorn, D. J., R. G. Forsyth, and R. L. Westlake.

1988. Hawaiian monk seal research on Lisianski Island, 1984 and 1985. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-120, 22 p. 

Johanos, T. C., and J. R. Henderson.

1986. Hawaiian monk seal reproduction and injuries on Lisianski Island, l982. 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-64, 7 p.
Appendix A.--Continued.

A-5

Johanos, T. C., and A. K. H. Kam.

1986. The Hawaiian monk seal on Lisianski Island: 1983. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-58, 37 p.

Johanos, T. C., and R. P. Withrow.

1988. Hawaiian monk seal and green turtle research on Lisianski Island, 1987. 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-121, 18

p.

Lee, M. M., L. K. Timme, R. Van Toorenburg, and B. L. Becker.

1993. The Hawaiian monk seal on Lisianski Island, 1988 and 1990. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-179, 33 p.

Stone, H. S.

1984. Hawaiian monk seal population research, Lisianski Island, 1982. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-47, 33 p. 

Westlake, R. L., and P. J. Siepmann.

1988. Hawaiian monk seal and green turtle research on Lisianski Island, 1986. 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-119, 18

p.

Pearl and Hermes Reef

Choy, B. K., and L. M. Hiruki.

1992. The Hawaiian monk seal and green turtle on Pearl and Hermes Reef, 1988. 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-175,

18 p. 

Finn, M. A., J. R. Henderson, B. L. Becker, and T. J. Ragen.

1993. The Hawaiian monk seal and green turtle at Pearl and Hermes Reef, 1990

and 1991. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFSSWFSC-182, 29 p.

Forsyth, R. G., D. J. Alcorn, T. Gerrodette, and W. G. Gilmartin.

1988. The Hawaiian monk seal and green turtle on Pearl and Hermes Reef, 1986. 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-107, 24

p.
Appendix A.--Continued.

A-6

Kure Atoll

Bowlby, C. E., P. Scoggins, R. Watson, and M. Reddy.

1991. The Hawaiian monk seal, Monachus schauinslandi, at Kure Atoll, 1982-

83. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC155, 28 p.

Gilmartin, W. G., R. J. Morrow, and A. M. Houtman.

1986. Hawaiian monk seal observations and captive maintenance project at Kure

Atoll, l981. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TMNMFS-SWFC-59, 9 p.

Henderson, J. R., and M. R. Finnegan

1990. Population monitoring of the Hawaiian monk seal, Monachus

schauinslandi, and captive maintenance project at Kure Atoll, 1988. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-150, 24 p.

Reddy, M. L.

1989. Population monitoring of the Hawaiian monk seal, Monachus

schauinslandi, and captive maintenance project for female pups at Kure Atoll,

1987. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TMNMFS-SWFC-123, 37 p.

Reddy, M. L., and C. A. Griffith.

1988. Hawaiian monk seal population monitoring, pup captive maintenance

program, and incidental observations of the green turtle at Kure Atoll, 1985. 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-101, 35

p.

Van Toorenburg, R. A., W. G. Gilmartin, and J. R. Henderson.

1993. Composition of the Hawaiian monk seal population at Kure Atoll, 1990. 

Pac. Sci. 47(3):211–214.

Nihoa and Necker Islands

Conant, S.

1985. Observations of Hawaiian monk seals on Necker Island, Northwestern

Hawaiian Islands. 'Elepaio. 6(2):11–12.
Appendix A.--Continued.

A-7

Finn, M. A. and M. A. Rice.

1994. Hawaiian monk seal observations at Necker Island, 1993. 'Elepaio. 

55(9):55–58.

Morrow, R. J., and E. K. Buelna.

1985. The Hawaiian monk seal and green turtle on Necker Island, 1983. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-55, 11 p.

Appendix B.--Hawaiian monk seal census form and 2003 census form directions.

(See following pages.)



B-3

 

2003

CENSUS FORM DIRECTIONS

(Unabridged - Laysan and Lisianski Islands)

This form is used to record all Hawaiian monk seal and green turtle sightings. Turtle sightings are recorded

only during census activities (not during patrols), unless noteworthy event occurs (turtle injured, tagged,

tumored, mating, etc.). On the census form, all data that can be recorded for seals can also be recorded for

turtles (although this data may not be required). At French Frigate Shoals, do not record a data line for

each turtle sighting; instead, write the total for each size/sex class at the bottom of the page.

All original data should be coded in pencil. Never erase data once you have left the recording site. Instead,

cross errors out with a single line so that the original information can still be read. Field editing is editing

before running the data entry and checking program. All field editing by the data collector should be in

blue, and field editing by others should be in red. As soon as you begin the entry and checking program, the

computer will assign the computer page number and display it on the screen. At this point, be sure to fill it

in on your census form. All editing after this point should be in orange. After completing the entry and

checking program, check off and initial the ENTERED box on the census form.

A separate data sheet should be filled out for each date, observer, data type, and island within an atoll. If no

seals are present, you should still fill out the information at the top of the census form and write "No seals"

in the data area (only enter the header information and a blank line # 1). If the island itself is not present,

indicate this by using 99 for the sector code, leaving the rest of the (first) line blank. To save paper, you

should use a census form with multiple headers if you only have a few seals to record (i.e., at some islands

within an atoll, or when recording incidental sightings before or after census or patrol). In essence, on a

census form with multiple headers, each header and its associated lines represents a separate data sheet. 

If two people conduct the census, they should have the same weather and the same begin and end time (i.e.,

both begin at the same time and place, and proceed in opposite directions until they meet on the other side

of the island or islet) and combine pages into one set. Patrols may be conducted by more than one observer,

but page sets are not combined, and header information may differ between page sets. Patrol observers

should attempt to start at roughly the same time. The sum of all observers' patrol activity for a day should

result in one complete island count.

Always record disturbance. You must be honest about this! Fill out a census form to document

disturbance if you disturb a seal when you are not otherwise collecting data. On a census or atoll count, it is

also assumed that condition and molt data will be taken. 

Do not make up additional codes. If the need for an additional code arises, contact Honolulu.
B-4

PAGE HEADER

DATA TYPE

C =Census: A complete, timed count on an island begun around 1300. Census is conducted as

quickly as possible (while gathering all information). Data collected on all seals and turtles. 

A = 

Atoll-wide census (must be completed within 2 consecutive days). Data collected on all seals and

turtles.

B = 

Behavior patrol: A complete, untimed count where size, sex, ID and disturbance are recorded.

Associations are assumed to be coded for all seals. In 2003 collect at Laysan and Lisianski Islands;

record spatial and pair associations, and paired male-male contests involving adult and S4 seals,

otherwise code behavior X (data not taken). Record turtles only if noteworthy observation.

P =

Patrol: A complete, untimed count where size, sex, ID and disturbance are recorded. Behavior data

is not taken. Record turtles only if noteworthy observation.

I =

Incidental observation. In this data type, null fields are interpreted as "data not recorded", so code

data explicitly. If numbered, this indicates a full island incidental with year-specific goals. At

Laysan and Lisianski Islands in 2003, these surveys will record mother-pup pairs, weaned pups,

molters, survival factors (including severe harassments and mobbings) and other noteworthy

observations. 

T =

Tag status entry (to record that a given tag is now inactive/not on a seal). Record tag status (found

or recovered) in notes columns. 

COMPUTER PAGE NO.

Leave this blank during data collection. It will be assigned and displayed on the screen when you

enter the data. At that time, be sure to fill in the computer page number on your census form, as this

number is needed for data retrieval.

PAGE Page number within a census or patrol. For example, if the census (or patrol) requires three

pages, then mark the first page as "page 1 of 3" and so on. If more than 1 person conducts the

census, then combine page numbers; person A has pages 1 and 2, while person B has pages 3

and 4 of a four-page census day. The maximum number of pages in a set is 9. Header

information (time begin/end, date, number, and weather) should be the same for all pages

within a set.

ISLAND Name of island and atoll, e.g., East, FFS. 

OBSERVER

Three initials. If no middle initial, use the first and last block. 

TIME BEGIN and END

On a 24-h clock, e.g., 6 p.m. = 1800, for the group of pages. Midway uses Midway time, all other

sites use Hawaii Standard time.

DATE The date that data are collected (in YYYYMMDD format).

NUMBER Censuses, Atoll counts, Behavior patrols, and Patrols must be numbered. Each data type will

have its own 3 digit number series, starting with 001. For data types other than A, have a

separate number series for each islet within an atoll.
B-5

Weather information (except temperature) should be a summary of the entire day up until the end of the

census or patrol, not merely an instantaneous observation. Temperatures taken in the morning are not

representative for the period of data collection.

TEMP. Temperature in degrees Celsius at beginning of census or patrol.

WIND Speed:0 = no wind, calm (<5 knots)

1 = light breeze (5-15 knots)

2 = strong wind (>15 knots)

Direction:NN,NE,EE,SE,SS,SW,WW,NW

Thus, 2 N N = strong wind from north 

CLOUD Cloud cover: 00 = no clouds

01-09 = 10 to 90% cover

10 = 100% cover

PREC. Precipitation: 0 = no precipitation or trace

1 = mist/drizzle

2 = rain

3 = intermittent rain

LINES

CONTINUE If the same seal sighting is recorded on several lines for any reason (e.g., additional tag or

association, behavior at a later time, change of beach position, or photos), put the original

line number you are continuing from here. Lines may be continued only within the same

page. Fill in the original line as completely as possible. During entry, the data in all fields

from TIME through MOLT must be copied from the original line if left blank on the

continuation line. Do not copy other fields after MOLT (see entry directions for more

information). Several lines can have the same continuation line number. 

Make a new original line (i.e. do not use continuation lines) for a seal each time that

you come abreast of it on census or patrol. This is important because beach position on

the original line determines if a seal is counted on census (if the seal is ashore it will be

counted). When recording paired male-male contests (at Laysan and Lisianski Islands in

2003), record contests as you see them ahead of you (within 30 m). When you come

abreast of the seal, record the beach position and time and make this your original line. All

previously recorded lines for this sighting will be reverse continuation lines.

TIME The time should be recorded for each seal sighting, on a 24-h clock

SECTOR Location on island (e.g., 1-20 on Laysan)

Special codes as follows:

00 = unknown sector (use also for areas without sectors, i.e. middle of the lagoon)

77 = pen

88 = offshore spit/emergent reef

99 = island not present

SIZE Size is estimated using a classification scheme from Stone (1984), using the following terminology. 

Note that seals are "sized" by length, girth, appearance, and reproductive status, not by age (except

pups):
B-6

Pup Seals born within the calendar year. Newborn pups are black, and weight ca. 11 to

15 kg. Pups molt to a silver-gray pelage near weaning. Weaning weight is ca. 50

to 80 kg.

Juvenile Short, slight seals from the length of a weaned pup (about 138 cm) to 20-30 cm

longer; includes yearlings, and other young seals up to 3 years. Distinguished

from pups by thinness and yellowish color.

Subadults Seals perceptibly longer than juveniles up to breeding size; less robust than

adults, generally with lighter pelage. Immature seals ca. 3 to 5 or 6 years old.

Adult Reproductively active or breeding size seals at least as long as known breeders. 

Mature or probably mature seals. Adult females often have extensive back scars

or wounds; adult males usually dark, including ventrum, and extensively scarred.

Code size as follows:

Pups of the year

P0 = Fetus (aborted, clearly pre-term pup)

P = Nursing pup

P1 = Nursing pup, wrinkles

P2 = Nursing pup, no wrinkles

P3 = Nursing pup, blimp, black

P4 = Nursing pup, molting

P5 = Nursing pup, molted

PW = Prematurely weaned/undersized weaned pup (weaned < 2 wks ago and < 90cm

girth). Code as PW at time of weaning, and then can code as W for remainder of

season.

W = Weaned pup 

Immatures

I = Immature

J = Juvenile

J1 = Juvenile I

J2 = Juvenile II

S = Subadult

S3 = Subadult III

S4 = Subadult IV

Adults

A = Adult

Unknowns

U = Seal of unknown size

Turtles

T = Turtle (lengths from anterior to posterior tip of carapace)

T1 = Turtle, juvenile (<65 cm straight carapace length)

T2 = Turtle, subadult (65 - 80 cm)

T3 = Turtle, adult (>80 cm)
B-7

Only code a seal’s sex as known if the ventral is seen, even if you "know" the sex because of the tag,

bleach, scars, or behavior. The only exception is that the mother in a mother/pup pair should be recorded

as a female. The sex of a turtle can only be distinguished externally if it is adult-sized.

SEX M =

Male

F =

Female

U =

Unknown

BEACH POS. Location of seal or turtle when observer comes abreast of animal (e.g., if seal is seen in the

water from a distance and yet is on the beach when the observer come abreast, the seal is

recorded as being on the beach). When recording paired male-male contests (at Laysan

and Lisianski Islands in 2003), record contests as you see them ahead of you (within 30 m). 

When you come abreast of the seal, record the beach position and time and make this your

original line. All previously recorded lines for this sighting will be reverse continuation

lines.

0 = animal floating or swimming in water (not included in census tally but may be

used for behavioral data or other analysis).

1 = on the beach (or regularly surveyed areas on the fringing reef for Midway Reef

Surveys)

9 = on an offshore rock/reef with no connections to the island. Separated from shore

by a deep channel or substantial distance, and not regularly surveyed (not

included in census tally). For Midway Reef Surveys, use beach position 9 for

the back side of the reef and other areas that are not regularly surveyed.

X = data not taken

CONDITION Condition is recorded for all seals (except nursing pups) on census or atoll count. Always

record the condition of the mom on her first sighting postpartum, and of the mom and pup

on their first sighting post-weaning, regardless of data type. Always note condition when

recording a survival factor. Unusual conditions should be further described in Notes.

Condition codes:

M = medium 

P = probably pregnant 

F = fat 

T = thin, includes emaciated (ribs visible, neck obvious, concave dorsal musculature)

X = data not taken

Codes F and T indicate extreme conditions, seals that are medium-fat, or medium-thin

should be coded as medium. Always code condition explicitly.
B-8

A seal is either identified or not during a sighting. If both the ID No. and Tag No. fields are empty, the

seal is unidentified. If either the ID No./Tag No. field is filled, the seal may be identified depending on

how the ? columns are filled. Questionable codes blank, 0, or 4 indicate the seal is identified with

certainty, whereas codes 1 or 5 indicate uncertainty. If a seal’s identity is confirmed by any method,

coding for the entire sighting (on the original line and all continuation lines) must ultimately show

certainty. For example, if the ID columns indicate the seal is identified with certainty but the Tag

columns indicate uncertainty, look up the correct tag number during data editing, enter it, and change

the Tag? code from uncertain (1 or 5) to certain (4)).

ID DATA These fields can be used to record either a temporary or permanent ID number. Although

the paper form only has one ID field, the database actually has two ID fields. Thus, you

can record both a temporary and a permanent ID number on a seal’s original line (to do

this on the form, split the ID field horizontally and write both numbers on a single line, or

expand the original line by sacrificing the subsequent line). Use continuation lines to

record two or more temporary numbers. If the seal is identified, it will not be counted twice

on census. To link two sightings of an unidentified seal during a survey (i.e. for a cruiser

moving ahead of you), assign it a temporary number in a series reserved for unidentified

seals, and code a 6 in the temp ? field.

T/P Indicate whether the number in the subsequent field is a temporary or permanent ID number.

T = temporary ID number (or bleach number)

P = permanent ID number

TEMPORARY ID NO. Record the temporary ID number (or bleach number) of seal if known; right

justified. This field may be used for any temporary number. Use separate

number series for bleach and various types of temporary numbers. If a number is

incompletely read, use dashes as place-holders within the number to indicate

missing digits (e.g., incompletely read bleach 152 may be coded -52, 1-2, or 15-). 

? column: 

0 = seal is definitely unmarked; can coexist with a non-bleach temporary number, or

with a bleach number if bleach hasn't taken yet or the number has molted off

1 = bleach is present but the recorded bleach number is questionable, and the seal is

not identifiable from other information

4 = partially read bleach number completed from other data

5 = incompletely read bleach number, there isn’t enough information to identify the

seal but the partial data are certain, the seal is not identifiable from other

information

6 = temporary number valid for this survey only (for unident. cruisers moving ahead of

you on census, etc.). Use a special number series so these numbers are not

confused with real temporary ID numbers. Numbers may be reused on the next

survey for different seals.

blank = number is certain and complete if present

PERMANENT ID NO. Record the 4 digit permanent ID number of seal if known (put both the

island-specific prefix and next digit in the first box provided).

? column: 

1 = ID number is questionable, and the seal is not identifiable from other information

blank= ID number is certain and complete if present. A Permanent ID is not visible, and is

always completed from other data. For certain ID numbers, always use ID? =

blank, not ID? =4.
B-9

TAG NO. The complete tag number if known; right justified. If a number is incompletely read, use

dashes as place-holders within the number to indicate missing digits. Put the alpha prefix of

the temple tag (combined with tag ? column code = 5) if you can determine the hole drilling

pattern, but can't decipher the number (e.g. A--RT5 for a right tan tag with a 1983 drill

pattern). Explain how you came up with the prefix, and draw the hole drill pattern in Notes.

Record all tag sightings explicitly (i.e., both left and right tag numbers) at least once during

your stay. During the first weeks of the field camp, note tag condition each time that a tag is

sighted. Once the majority of tags have been resighted, observers can carry a list of

tags/individuals that haven't been seen, and only note tag condition if these tags/individuals

are resighted. Also carry a list of broken or lost tags, and current tag conditions, so that you

will be aware, and can record, if a specific tag breaks or is lost, or a tag condition changes

during the field season. When a pup is tagged, record the animal handling event on the

census data sheet, and record detailed information (such as all tag numbers, all temporary

numbers, and the permanent number) on a Tagging/Handling card. If a seal is identified via

a tag, it is not necessary to determine and enter its ID number on the census form. The ID

number can be determined by computer later. 

L/R: Tag position 

L = tag on left flipper 

R = tag on right flipper

B = tags on both flippers (enter one tag number). This code can be used if the seal has

only 2 Temple tags (one on each flipper).

COL: Color code -see the Tag Sample Kit if unsure of the colors

Temple tags Other tag types

Y = yellow (FFS) M = metal, Monel 

T = tan/brown (Laysan) C = clear, PIT tag

G = green (Lisianski) 

B = blue (Pearl & Hermes)

K = silver/gray (Kure) 

R = red (Midway, Necker, Nihoa, Main Islands)

? column:

0 = seal is definitely not tagged on either flipper. To indicate that a seal has lost a tag,

code a known missing tag using tag? code 8. If the tag number is unknowable,

write the information in Notes.

1 = seal is tagged but the recorded tag data are questionable, and the seal is not

identifiable from other information

4 = partially read tag completed from other data

5 = incompletely read tag, there isn’t enough information to identify the seal but the

partial data are certain, the seal is not identifiable from other information

8 = a specific tag is lost/unreadable. Fill out tag position (L/R) and the tag condition

event with codes L or U. Complete the tag number and color from other data

before entry.

blank = tag information is certain if present. Partial data (either complete Tag #, position,

or color not filled) are OK and will be completed by computer if the seal is

identified by ID, Temporary #, or Tag #, and there is only one possible tag for that

flipper. The computer will only fill blank fields, so an incomplete Tag # must be

completed by hand (use a "4" in the tag ? column).
B-10

MOLT Percentage of old pelage lost, optional for pups. However, for

weaned pups, record the % molt at time of tagging. Record molt

as 100% for at least 1 month post-molt. Code the full percentage

(1 to 100%) in the single box provided.

blank = no molting evident

1 to 99 = 1 to 99% molted. The first signs of molt usually occur around the eyes,

nose, flippers, and scars. The first record of >10% of the old pelage

molted off is considered the first day of true molt.

100 = 100% molted, freshly molted, required for the first month after molt. 

Put all 3 digits of the 100 in the single box provided.

? column: 

0 = seal is definitely not molting

1 = seal is molting, but % molt estimate is questionable. May or may not include an

estimate in the molt column

"End of season" editing codes that override erroneous molt estimates:

2 = seal in molt

3 = seal pre-molt

4 = seal post-molt

DISTURB The degree to which the seal may have been disturbed by observer. Record disturbance

every time a seal is disturbed, regardless of your activity. The only exception is that you do

not need to record a disturbance for a seal that you are handling (i.e., tagging,

disentangling).

0 = no disturbance, or seal merely raised its head or looked at observer - If column

blank, 0 is assumed

1 = seal vocalized, gestured, or moved <2 body lengths

2 = seal alerted to observer and moved >2 body lengths

3 = seal alerted to observer and fled into water
B-11

ASSOCIATION DATA Behavior data is collected at Laysan and Lisianski Islands because adult male

aggression has been more commonly observed at these locations, resulting in

injury and death of adult female and immature seals. At Laysan, these data

were used to identify 37 males for removal in a successful management action

that reduced the adult sex ratio and increased female survival. Data are now

used to monitor the long term effects of sex ratio adjustment at Laysan, and

assess management options at Lisianski Island. 

Record spatial and pair associations involving adult and S4 seals at Laysan and

Lisianski Islands in 2003. Don't record associations that only involve S3 or

smaller sized seals or associations that involve turtles. If you wish to indicate

that a seal was alone, use the O (this code is alpha, not zero!) behavior code. If

you do not record association data on a census or behavior patrol at Laysan or

Lisianski Island for any reason, indicate this with an X for the behavior code. 

Always explicitly record whether the seal is unassociated or association

data is not recorded. Use continuation lines to record more than one

association. 

An association should either be all blank or have the O, Z, or X behavior only

(with no line number or distance), or have a line number, a distance, and some

behavior code (other than O or X) all present. 

All associations should be recorded in pairs, i.e., between animals on two

different lines. You should fill in the line numbers, distances, and behavior

codes for both animals involved in the each association. The association line

number should refer directly to the line where the corresponding behavior is

coded (i.e. if the corresponding code is on a continuation line, refer to that

particular line, not to the original line or a different continuation line). If two

seals are associated, the time recorded on their lines doesn’t need to match, but

should be within 30 minutes of each other. 

Active associations will not be recorded in 2003. However, if a paired male-male contest occurs

write a

brief summary in Notes and code the contest outcome (see the attached CONTEST

RULES).

Spatial associations

1) noted as observer comes abreast of the subject

2) individual seals 

- mother-pup pair (N): any distance

- Adult or S4 seals (L): distances <10 m away, record two nearest neighbors in a

straight line of sight. Seals can be on opposite sides of a log, etc. 

LINE NO. Identity of the other seal in the association. Put its line number here (note line number

refers to within same census page only).

DIST. Closest distance during behavior - both associated lines must have the same minimum

distance. 

0 = body contact

1 = <2 m

2 = 2-5 m

3 = >5 m (>5 m but <10 m in the case of L behavior code)
B-12

BEHAVIOR Up to four behaviors may be recorded for each association, but L, N, X, and O should not

appear together with other behaviors. If there is a paired male-male contest write a brief

summary in Notes. Focus on the major points, such as the seals involved, pairings before

and after the interaction, the contest winner/loser, and the most intense behaviors (joust,

bite, mount, chase, displace). 

1) individual seal 

a) spatial association

N =mother-pup pair (any distance), does not imply actual nursing behavior. This is

the only association recorded between mother-pup pairs, and the N code must

be on the original line for each pair member. If there is an unusual event (i.e.,

birth, weaning, or pup switch) write a brief summary in Notes and use the

appropriate Notes Code. 

L = association by location only (distance <10 m apart, for all except mother-pup

pairs)

 Z = cruising (OPTIONAL CODE). A/S4 only behavior (actual sex may be

unknown). Does not require a line number reference to another seal, but may

have one.

b) additional codes (Laysan and Lisianski 2003)

*L1 = pair assoc. A/S4 male actively defends an adult female or immature of either

sex (actual sex may be unknown), or establishes a pair relationship with a

female or immature after displacing another male. Code the L1 relationship

both before and after the contest if a displacement occurs.

*Q = loser (quitter) 

*W = winner

*Y = tie 

Note: codes Q, W, and Y are used for A/S4 male-male contests only, although the

actual

sexes may be unknown (in which case record as though they were known to

be males); see the attached CONTEST RULES. 

* requires a corresponding code on the line of the associated seal

Code Corresponding code

 N.....................N

L.....................L

L1....................L1

 Q.....................W

 W.....................Q

 Y.....................Y

2) nothing nearby

O = no behavior or association

3) no data

X = no association data recorded on Census or Atoll Count
B-13

NOTES--There is room to code 2 different notes. Always use the first column first. Code an H if you have

handwritten notes on the observation. Put handwritten notes on the bottom of the census form, labeled by

line number. If more than two note codes apply, use continuation lines. 

A = artwork (scars drawn) - attach drawing, labeled with date, island, observer, data type,

page number, and line number 

B = birth, 1st sighting postpartum (mom and pup)

G = seal is green with algae

H = handwritten notes

M = marked, indicate each time a seal is bleached (includes attempts to bleach)

W = weaning, 1st sighting post-weaning (pup or mom, whichever sighting confirms weaning or

end of nursing (i.e., mom alone after pup disappearance).

X = pup exchange, 1st sighting after exchange (mom and pup)

Y = disturbance is to "bystander" seal during non-survey activity such as tagging, bleaching,

instrumenting, disentangling, etc. This includes all animal handlings/"hands on" research,

even if the attempt was unsuccessful (i.e., removing dead pups, cutting umbilical cords, or

reuniting pups with their mothers).

FOR DATA TYPE "T" (TO RECORD THAT A GIVEN TAG IS NOW INACTIVE/NOT ON A

SEAL):

F = tag found 

R = tag recovered from seal in hand 

EVENT These columns are used to record a variety of data. The codes used will depend upon the type of

event that you wish to record. Left justify your coding:

TYPE CODES CONTENT

COLUM N

F = survival factor ONLY RECORD RESIGHT OF A SURVIVAL FACTOR AS AN

EVENT IF THERE ARE IMPORTANT CHANGES TO DOCUMENT,

SUCH AS A NEW WOUND, HEALING, DEATH, ETC.,

TRANSCRIBE NOTES TO SURVIVAL FACTOR FORM. For turtles,

use a different survival factor number series (i.e., begin at 500), fill out a

survival factor form (or use an alternate format if specified by mtrp), but

do not enter the data into the seal survival factor database.

1-3 Survival Factor number 

 4 Factor Type. If seal dead, always record factor

type "D" on ORIGINAL LINE. For mobbings/

harassments, always code a census entry with

factor type "M" for the victim at the beginning and

end of the incident. Otherwise, you only need to

record the most appropriate factor type if more

than one applies. 

D = death

W = wound (includes abscess/raised

area)

E = entanglement

V = very thin (emaciated)
B-14

I = illness/abnormal (includes eye

disease)

M = mobbing/harassment/post-mobbing 

 aggregation

O = other

 5 Participant type (for mobbings/ harassments/postmobbing aggreg. only)

 V = victim/subject

M = male aggressor

H = handling of wild seal HANDLINGS DO NOT NECESSARILY INVOLVE RESTRAINT OF THE

SEAL. FILL OUT BOTH A SEAL SIGHTING (WITH HANDLING EVENT)

AND A TAGGING/HANDLING CARD. For direct translocations, fill out two

seal sightings (one each at the time of capture and at the time of release) and fill

out a single tag/handling card with restraint time from capture until release into

the wild. In cases where the translocated seal is held in a pen before release into

the wild, fill out four seal sightings (one each at the time of initial capture,

“release” into pen, “capture” in pen, and release into wild) and fill out two

tag/handling cards, one at the time of initial capture (with restraint time until

“release” into the pen) and a second card at the time of “capture” in the pen

(with restraint time until release into the wild).

 1 Handling type

T = tagging (w/ restraint)

M = measuring (includes weighing)

A = all (both tagging and measuring)

R = remote tagging

D = disentangle (even if not restrained)

I = instrument application

B = bleeding

C = take from the wild into captivity (or

capture for translocation) 

F = free from captivity (or free after

translocation) into the wild

O = other (includes instrument removal

and “captures/releases” of seals within

a pen) 

TYPE CODES CONTENT

COLUM N

P = photo SEAL OR TURTLE PHOTOS ARE THE ONLY PHOTOS CODED ON

THE CENSUS FORM. OTHER PHOTOS SHOULD BE RECORDED

IN NOTES, AND TRANSFERRED TO THE PHOTO COMMENT

FORM. 

 1 Type of photo

S = slide

P = print

D = digital

2-5 Digital: Consecutive File Number, or
Film: columns 2-3 Roll number (pad with zeros) 

columns 4-5 Frame number (pad

with zeros)

 6 Side

L = left lateral or flipper

R = right lateral or flipper

D = dorsal side

V = ventral side

B = both (used for rear flippers only)

X = other, describe in hand-written

NOTES

 7 Part

H = head

A = anterior body (neck and shoulders)

M = midbody (behind fore-flippers and before

posterior)

P = posterior body (behind midbody and before rear

flippers)

F = foreflipper; write whether dorsal/ventral in

comments

R = rearflipper; write whether dorsal/ventral in

comments

O = overall view of a particular side

X = other, describe in comments

 8 Purpose

 I = identification

F = survival factor (link with survival

factor EVENT using continuation

lines)

X = other, describe in comments

TYPE CODES CONTENT

COLUM N

T = tag condition RECORD TAG CONDITION FOR BOTH SIDES OF EACH TAG AT LEAST 

ONCE DURING THE SEASON. If tag condition is recorded for an incompletely

read tag, complete the tag number (with appropriate tag? Code) prior to computer

entry.

1 Web 

 A-D = from inner (medial) to outer web.

E = ankle

P = posterior

U = unknown

B-15
B-16

2 Side of tag, the dorsal tag side is on the dorsal flipper surface unless the tag is

reversed. For Temple Tags, the dorsal side is the bigger side; for Metal (Monel)

tags, the dorsal side is the "male" side. For PIT tags, code the side as B (both). 

D = dorsal 

V = ventral 

B = both 

U = unknown

 3 Condition, code U (unreadable) if cannot use tag to

ID seal (i.e. if broken so number gone). Also code

U for a PIT tag if you completely scan for it with a

reliable reader but get no reading. If reader is

unreliable, put attempt in Notes and only code PIT

tag as unreadable after 3 separate attempts. 

Combine the L or U codes with the tag

questionable code of 8. You can combine the tag

questionable code of 8 with other condition codes

to describe why the tag is unreadable (i.e., worn or

broken). Unreadable tags can still be used as

partial information to help determine a seal’s

identity. Code more than one condition using

continuation lines.

 B = broken

F = faded color

G = good

L = tag lost 

N = no/partial resin

O = other 

P = pulling out

U = unreadable

V = tag side reversed 

W = no. worn /abraded 
B-17

CONTEST RULES

1. Male-male contest definition (must conform to at least one condition below):

a. Distance between adult males = 0

b. Either adult male vocalizes, chases, displaces or jousts with the other male

2. The contest outcome depends upon pair type (what size/sex seal the adult male is paired with) 

a. For contest rules, size S4 seals are considered to be adults (both sexes), seals size S3 or

smaller are considered to be immature 

b. Definition of (L1) pair type:

i. Pair type #1: adult male paired with (actively defending) an adult female

ii. Pair type #2: adult male paired with (actively defending) an immature seal of either

sex 

3. Contest outcomes (definition of winner or loser adult male):

Case Winner (W) Loser (Q) Tie (Y)

Paired Male vs.

Single Male:

i) The paired male wins if he is not

displaced

ii) The single male wins if he

displaces the original paired male

Unsuccessful single

male 

Displaced originally

paired male 

No Ties

No Ties

Male Paired with

Adult Female vs.

Male Paired with

Immature Seal:

 (#1 vs. #2)

i) The male paired with the adult

female wins if he is not displaced 

ii) The male paired with the immature

seal if he displaces the male

originally paired with the adult

female

Unsuccessful male

paired with immature

Displaced originally 

paired male

No Ties

No Ties

Paired Male vs.

Paired Male of

equal pair type:

(#1 vs. #1 or

#2 vs. #2)

Displaces the other seal Is displaced Tie if neither seal

is displaced

4. Generalizations:

a. Unequal pair types

i. There are no ties 

ii. The male with the higher pair type (1>2) always wins unless he is displaced

iii. A seal can win without being aware of the contest. For example, if the "winner" is

not aware that the other seal flees, but that seal fled in response to a vocalization,

then code the fleeing seal as the loser (Q) and the other seal as the winner (W))

b. Equal pair types

i. Males tie unless there is a clear winner/loser

ii. To win, a male must displace the other male 
B-18

HAWAIIAN MONK SEAL TEMPLE TAGS:

NUMBERING SCHEME AND HOLE DRILLING PATTERN FOR TAGS APPLIED TO WEANED

PUPS

Be sure to code the original tag color, not the color that a tag has faded to. See the Tag Sample Kit.

Original tag color: Faded tag may appear:

Temple Tags:

 Yellow...................................................White, Lt. Yellow

 Light Tan (A,T,K,L series @ Laysan).............Gray, Lt. Yellow, White

 Dark Tan/Brown (later series @ Laysan)..........Red

 Dark Forest Green.....................................Dark Blue, Navy

 Kelly Green (C, P, and Y cohorts)................. --

 Blue (light)...............................................--

 Red.......................................................Orange

 Gray (A,T,K,L,N,F,U,G series @ Kure).........Light Tan

 Silver Gray (600-900,0,Z and later @ Kure)......Metal
B-19

Availability of NOAA Technical Memorandum NMFS 

Copies of this and other documents in the NOAA Technical Memorandum NMFS series issued 

by the Pacific Islands Fisheries Science Center are available online at the PIFSC Web site 

http://www.pifsc.noaa.gov in PDF format. In addition, this series and a wide range of other 

NOAA documents are available in various formats from the National Technical Information 

Service, 5285 Port Royal Road, Springfield, VA 22161, U.S.A. [Tel: (703)-605-6000]; URL: 

http://www.ntis.gov. A fee may be charged. 

Recent issues of NOAA Technical Memorandum NMFS–PIFSC are listed below: 

NOAA-TM-NMFS-PIFSC-3 Modeling a very rare event to estimate sea turtle 

 bycatch: lessons learned. 

 M. L. MCCRACKEN 

 (November 2004) 

 4 Evaluation of time-area closures to reduce incidental 

 sea turtle take in the Hawaii-based longline fishery: 

 generalized additive model (GAM) development and 

 restrospective examination. 

 D. R. KOBAYASHI and J. J. POLOVINA 

 (March 2005) 

 5 The Hawaiian monk seal in the Northwestern 

 Hawaiian Islands, 2002. 

 T. C. JOHANOS and J. D. BAKER (comps. and eds.) 

 (July 2005) 

 6 A sociocultural assessment of Filipino crew members 

 working in the Hawaii-based longline fleet. 

 S. D. ALLEN and A. GOUGH 

 (October 2006) 

 7 Sea turtle and pelagic fish sensory biology: developing 

 techniques to reduce sea turtle bycatch in longline fisheries. 

 Y. SWIMMER and R. BRILL 

 (December 2006) 

 8 Hawaii longline fishermen’s experiences with the observer 

 program. 

 S. STEWART and A. GOUGH 

 (February 2007)