The Endangered Hawaiian Monk Seal

1
The Endangered Hawaiian Monk Seal

• Willon Ching
• Biology 172L Section 13
• TA - Tobias Koehler
• April 19, 2002

2
Overview

• General Information
• Reasons for Being Endangered
• Human Intervention
• Ongoing Research

3
General Information

• Physical Aspects
• Meals
• Habitat
• Location

4
General Information

• Physical Aspects

Lifespan approximately 25-30 years Size Males
grow to about 7 feet long Females grow to
about 7 to 8 feet long Weight Males weigh about
400 to 600 pounds Females weigh about
600 to 800 pounds (Depending on the
reproductive state) Coat Color Adults (brownish)
and juveniles (silvery gray)
5
General Information

• Meals

Consists of many
6
General Information

• Meals

The Menu
- Eel
- Lobsters
- Variety of Reef Fishes
- Small Sharks
- Octopus
7
General Information

• Habitat

• Shallow waters
• Sandpits and beaches
• Permanent islets

This picture is from the Universal Cetacean
Institute
8
General Information

• Location

Mostly found at the Northwestern Hawaiian
Islands aka
French Frigate Shoals (area
between islands of Kure to Nihoa)
Occasionally found at the Main Hawaiian Islands
9
General Information

• Location

10
Reasons for being endangered

• Poachers

• Mobbing

• Shortages in Food Supply

• Pollution

This picture is from the Pacific Whale Foundation
11
Reasons for being endangered

• Poachers

Huge problem in the 19th century during sealing
expeditions (Capt. N. C. Brooks slaughtered 1,500
seals in one voyage) Hawaiian monk seals were
killed for their skin and seal oil
However Preservation laws in 1957 helped the
Hawaiian monk seal population to rebound.
12
Reasons for being endangered

• Mobbing

Mobbing is when male monk seals accidentally
cause numerous injuries to female monk seals
while trying to compete with other males to mate
with the female monk seal
As a result Bite marks from mobbing causes a
trail of blood which attracts sharks As well as
parasites that could infect the injured site
13
Reasons for being endangered

• Shortages in Food Supply

Commercial lobster fishery directly competing
with monk seals for prey Sometimes octopuses
(also part of the monk seals diet) accidentally
caught in those traps
Therefore Monk seals must swim farther and deeper
from their home just to look for prey
14
Reasons for being endangered

• Shortages in Food Supply

15
Reasons for being endangered

• Pollution

Fish nets and drift nets kill many seals due to
entanglement
An endangered Hawaiian Monk seal finds a clear
spot on the beach on Gin Island (French Frigate
Shoals) amongst washed up drift nets.
This picture is from NOAA.
16
Human Intervention

• PIT tags (Passive Integrated Transponder) can be
  used to track the seals movements to determine
  paths in migration
• Beach counts are used to show statistics on
  trends in male to female ratio
• Video camera mounted seals can show types of food
  monks seals are eating
• Recovery programs to keep the seals safe

17
ongoing Research

• Determine how the Hawaiian monk seals survived
  and reproduce all these years with mobbing

• Find out what other physical as well as
  environmental factors are contributing to the
  endangerment of the species.

18
Any Questions?
Yes, I have one. When is lunch?