**Preassessment Data Report #11**

**Summary of Aerial, On-Water, and Beach Surveys of Marine Mammals in
the Vicinity of the Grounded *Selendang Ayu* on the Northwest Coast of
Unalaska Island, Alaska, December 2004 - January 2005**

![](media/image1.jpeg){width="4.604861111111111in" height="3.0in"}

Based on Reports from U. S. Fish and Wildlife Service and

National Oceanic and Atmospheric Administration Trustee Representatives

and International Wildlife Research Personnel

**February 2008**

Abstract

The freighter Selendang Ayu grounded on Unalaska Island, AK on 8
December 2004 and released an estimated 339,538 gallons of Intermediate
Fuel Oil (IFO) 380 and 14,680 gallons of marine diesel and miscellaneous
oils. The natural resource trustees initiated a Natural Resource Damage
Assessment (NRDA) to investigate impacts. This report summarizes
observations on marine mammals made by NOAA and USFWS representatives as
part of the Preassessment Phase of a NRDA. Observations made by
International Wildlife Research personnel are also discussed. The
observations confirm that a number of marine mammals were in the
vicinity of the spill-affected area around the time of the spill. Oil
was observed on some marine mammals, and six sea otters carcasses and
skeletons were collected.

Introduction

While traveling the Great Circle Route through the Aleutian Islands the
738-foot freighter *Selendang Ayu* reported on 7 Dec 2004 that it had
lost power. Attempts to tow the vessel were unsuccessful and it ran
aground on Unalaska Island 8 Dec 2004 and split in half shortly
thereafter. The wreck's position was 53º 38´ 04´´ N, 167º 07´ 30´´ W on
Spray Cape, approximately 25 nautical miles Southwest of Dutch Harbor (a
50 nautical mile transit by vessel). The initial volume of fuel onboard
was 446,280 gallons of intermediate fuel (IFO 380) and 31,573 gallons of
marine diesel oil. It is estimated that the total release to the
environment was 339,538 gallons of IFO 380 and 14,680 gallons of diesel
(Alaska Department of Environmental Conservation 2006).

In response to the incident natural resource Trustees initiated NRDA
Preassessment activities to investigate potential impacts of oil on
natural resources and services. The marine mammal NRDA Preassessment
Phase efforts were largely conducted in conjunction with response
efforts or with preassessment surveys for birds. Adverse weather
conditions made observations of marine mammals difficult and restricted
the surveys both temporally and spatially. Despite these limitations,
Trustees collected six sea otter carcasses of which two were determined
to have contacted oil, documented the exposure of some marine mammals to
*Selendang Ayu* oil, and documented the presence of other marine mammals
in the vicinity of oil and therefore at risk for potential exposure to
oil. Other observations of marine mammals were made by International
Wildlife Research personnel, who were in the field to identify sea
otters at risk and coordinate follow up actions.

Methods

Marine mammal observations were made on overflights, on the water, and
on shoreline surveys. Most of the overflights were undertaken primarily
for response or bird surveys, and were conducted in a manner best suited
for those purposes, rather than for observing marine mammals. Therefore
these observations were able to provide a minimum estimate of the
abundance of some marine mammal species in the area affected by the
spill, but likely missed other species that have been observed
previously in this area during the winter season. Other Trustee
observations were made from support vessels or skiffs, and on beaches
accessible from skiffs. These observations are reported in Table 1.

International Wildlife Research personnel conducted aerial and
skiff-based surveys, primarily focused on sea otters with the intent of
identifying otters at risk and coordinating appropriate response
actions. No sea otters were captured for cleaning, but observations on
Sea Otters and other marine mammals made during their survey reports are
included in Table 1.

Results and Discussion

Numerous sea otters, Steller sea lions, and harbor seals were seen
within the area affected by oil from the Selendang Ayu in December 2004
and January 2005 (Table 1). One whale spout was also seen, which was
thought to be from a minke whale, but the species could not be
determined. Some oiling was observed on harbor seals and sea otters. A
total of six dead sea otters were collected following the spill; two
carcasses and four skeletons. Necropsies were performed on the two otter
carcasses, and the results were consistent with death from exposure to
oil. The other four sea otters may or may not have been killed as a
result of exposure to *Selendang Ayu* oil and scavenged. Many
individuals of the three identified marine mammal species were seen in
the vicinity of oil, including swimming in sheen. Therefore, there is a
potential for an unknown number of individuals of these species to have
been injured by *Selendang Ayu* oil.

Other marine mammals that are known to occur in the Unalaska area in the
winter, but which were not observed during this survey include the
Northern fur seal (*Callorhinus ursinus*), Dalls porpoise (*Phocoenoides
dalli*) harbor porpoise (*Phocoena phocoena)*, killer whale (*Orcinus
orca*), Sperm whale *(Physeter macrocephalus),* Cuvier's beaked whale
*(Ziphius cavirostris),* Baird's beaked whale *(Berardius bairdii)*,
Stejneger's beaked whale (*Mesoplodon stejnegeri)*, gray whale
(*Eschrichtius robustus),* humpback whale (*Megaptera novaengliae*),
right whale (*Balaena glacialis),* minke whale *(Balaenoptera
acutorostrata), s*ei whale (*Balaenoptera borealis),* fin whale
(*Balaenoptera physalus),* and Blue whale (*Balaenoptera musculus)* (US
Department of Commerce, 1988). Adverse weather conditions, the large
area oiled, the high priority given to response activities over surveys
for marine mammals, and other factors (such as different flight speeds
and elevations being more effective for one marine mammal species over
other marine mammal species), however, so the lack of observations of
these species does not indicate that they were not present in the
vicinity at the time of the incident.

Table 1. Summary of marine mammal observations made following the
*Selendang Ayu* oil spill by Trustees and International Wildlife
Research personnel.

+-----------+-----------+-----------+----------+----------+-----------+
| DATE      | Org       | SURVEY    | LOCATION | PRIMARY  | OBS       |
|           | anization | TYPE      |          | PURPOSE  | ERVATIONS |
+===========+===========+===========+==========+==========+===========+
| 12/9/2004 | USFWS     | Fixed     | M        | Response | Sea       |
|           |           | wing      | akushin, |          | Otter,    |
|           |           | aircraft  | Skan,    |          | Steller   |
|           |           |           | Pum      |          | Sea Lion, |
|           |           |           | icestone |          | Harbor    |
|           |           |           | Bays     |          | Seal      |
+-----------+-----------+-----------+----------+----------+-----------+
| 12/13/04  | USFWS     | Boat      | Western  | Birds    | 5 Sea     |
|           |           |           | Skan Bay | and      | Otters,   |
|           |           |           |          | Marine   | one of    |
|           |           |           |          | Mammals  | which was |
|           |           |           |          |          | dead      |
+-----------+-----------+-----------+----------+----------+-----------+
| 12/14/04  | USFWS     | Boat      | Southern | Birds    | 2 Sea     |
|           |           |           | Skan Bay | and      | Otters,   |
|           |           |           |          | Marine   | Uni       |
|           |           |           |          | Mammals  | dentified |
|           |           |           |          |          | Whale     |
|           |           |           |          |          | (spout    |
|           |           |           |          |          | seen),    |
|           |           |           |          |          | and a     |
|           |           |           |          |          | Harbor    |
|           |           |           |          |          | Seal      |
+-----------+-----------+-----------+----------+----------+-----------+
| 12/15/04  | USFWS     | Beach/    | Northern | Birds    | 25 Harbor |
|           |           | Shoreline | Skan Bay | and      | Seals,    |
|           |           |           |          | Marine   | some      |
|           |           |           |          | Mammals  | appeared  |
|           |           |           |          |          | to be     |
|           |           |           |          |          | oiled     |
+-----------+-----------+-----------+----------+----------+-----------+
| 12/16/04  | USFWS     | Boat      | Northern | Birds    | 12 Harbor |
|           |           |           | Skan Bay | and      | Seals,    |
|           |           |           |          | Marine   | some      |
|           |           |           |          | Mammals  | appeared  |
|           |           |           |          |          | to be     |
|           |           |           |          |          | oiled, 2  |
|           |           |           |          |          | Sea       |
|           |           |           |          |          | Otters    |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/5/05    | NOAA      | Fixed     | Eider    | Birds    | 19 Sea    |
|           |           | wing      | Point to |          | Otters,   |
|           |           | aircraft  | Cape     |          | 112       |
|           |           |           | Tanak    |          | Steller   |
|           |           |           | and Sea  |          | Sea       |
|           |           |           | T        |          | Lions, 27 |
|           |           |           | ransects |          | Harbor    |
|           |           |           |          |          | Seals     |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/7/05    | NOAA      | Fixed     | Eider    | Birds    | 24 Sea    |
|           |           | wing      | Point to |          | Otters,   |
|           |           | aircraft  | Cape     |          | 265       |
|           |           |           | Tanak    |          | Steller   |
|           |           |           | and Sea  |          | Sea       |
|           |           |           | T        |          | Lions, 20 |
|           |           |           | ransects |          | Harbor    |
|           |           |           |          |          | Seals     |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/7/05    | Inte      | H         | Cus      | Sea      | 12 Sea    |
|           | rnational | elicopter | Point to | Otters   | Otters    |
|           | Wildlife  |           | Spray    |          |           |
|           | Research  |           | Cape     |          |           |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/8/05    | NOAA      | Fixed     | Eider    | Birds    | 1 Sea     |
|           |           | wing      | Point to |          | Otter,    |
|           |           | aircraft  | Cape     |          | 256       |
|           |           |           | Tanak    |          | Steller   |
|           |           |           | and Sea  |          | Sea       |
|           |           |           | T        |          | Lions, 82 |
|           |           |           | ransects |          | Harbor    |
|           |           |           |          |          | Seals     |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/10/05   | NOAA      | Fixed     | Unalask  | Birds    | 25 Sea    |
|           |           | wing      | South    |          | Otters,   |
|           |           | aircraft  | and West |          | 381       |
|           |           |           | Umnak    |          | Steller   |
|           |           |           |          |          | Sea       |
|           |           |           |          |          | Lions, 8  |
|           |           |           |          |          | Harbor    |
|           |           |           |          |          | Seals     |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/11/05   | Inte      | Boat      | Ande     | Sea      | 48 Sea    |
|           | rnational |           | rsonBay, | Otters   | Otters    |
|           | Wildlife  |           | Naginak  |          |           |
|           | Research  |           | Cove,    |          |           |
|           |           |           | and      |          |           |
|           |           |           | Udamak   |          |           |
|           |           |           | Cove     |          |           |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/12/05   | Inte      | Boat      | Cannery  | Sea      | No marine |
|           | rnational |           | Bay      | Otters   | mammals   |
|           | Wildlife  |           |          |          | observed  |
|           | Research  |           |          |          |           |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/13/05\* | Inte      | Boat      | Humpback | Sea      | 1 Harbor  |
|           | rnational |           | Bay and  | Otters   | Seal, 21  |
|           | Wildlife  |           | Peter    |          | Sea       |
|           | Research  |           | Island   |          | Otters    |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/14/05   | Inte      | Boat      | Peter    | Sea      | 10 Sea    |
|           | rnational |           | Island   | Otters   | Otters    |
|           | Wildlife  |           |          |          |           |
|           | Research  |           |          |          |           |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/15/05   | Inte      | Boat      | Cof      | Sea      | 7 Sea     |
|           | rnational |           | Point to | Otters   | Otters,   |
|           | Wildlife  |           | Spray    |          | "many"    |
|           | Research  |           | Cape     |          | Harbor    |
|           |           |           |          |          | Seals,    |
|           |           |           |          |          | one       |
|           |           |           |          |          | oiled,    |
|           |           |           |          |          |           |
|           |           |           |          |          | "several" |
|           |           |           |          |          | Steller\  |
|           |           |           |          |          | Sea Lions |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/16/05   | Inte      | Boat      | Pum      | Sea      | 11 Sea    |
|           | rnational |           | icestone | Otters   | Otters,   |
|           | Wildlife  |           | Bay      |          |           |
|           | Research  |           |          |          | "many"    |
|           |           |           |          |          | Harbor    |
|           |           |           |          |          | Seals,    |
|           |           |           |          |          | "many"    |
|           |           |           |          |          | Steller   |
|           |           |           |          |          | Sea Lions |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/17/05   | Inte      | Boat      | Kashega  | Sea      | 39 Sea    |
|           | rnational |           | Bay      | Otters   | Otters,   |
|           | Wildlife  |           |          |          |           |
|           | Research  |           |          |          | Harbor    |
|           |           |           |          |          | Seals and |
|           |           |           |          |          | Steller   |
|           |           |           |          |          | Sea Lions |
|           |           |           |          |          | (not      |
|           |           |           |          |          | further   |
|           |           |           |          |          | d         |
|           |           |           |          |          | escribed) |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/18/05   | USFWS     | Fixed     | Eider    | Birds    | 86 Sea    |
|           |           | wing      | Point to |          | Otters,   |
|           |           | aircraft  | Cape     |          | 132       |
|           |           |           | Tanak    |          | Steller   |
|           |           |           | and Sea  |          | Sea       |
|           |           |           | T        |          | Lions, 68 |
|           |           |           | ransects |          | Harbor    |
|           |           |           |          |          | Seals     |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/18/05   | Inte      | H         | Dutch    | Sea      | 5 Sea     |
|           | rnational | elicopter | Harbor   | Otters   | Otters    |
|           | Wildlife  |           | to       |          |           |
|           | Research  |           | Anderson |          |           |
|           |           |           | Bay      |          |           |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/18/05   | Inte      | Beach/    | Northern | Sea      | 1 Harbor  |
|           | rnational | Shoreline | Anderson | Otters   | Seal      |
|           | Wildlife  |           | Bay      |          |           |
|           | Research  |           |          |          |           |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/19/05   | USFWS     | Fixed     | Eider    | Birds    | 69 Sea    |
|           |           | wing      | Point to |          | Otters,   |
|           |           | aircraft  | Cape     |          | 252       |
|           |           |           | Tanak    |          | Steller   |
|           |           |           | and Sea  |          | Sea       |
|           |           |           | T        |          | Lions, 68 |
|           |           |           | ransects |          | Harbor    |
|           |           |           |          |          | Seals     |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/20/05   | USFWS     | Fixed     | Eider    | Marine   | 176 Sea   |
|           |           | wing      | Point to | Mammals  | Otters,   |
|           |           | aircraft  | Cape     |          | 295       |
|           |           |           | Tanak    |          | Steller   |
|           |           |           |          |          | Sea       |
|           |           |           |          |          | Lions,    |
|           |           |           |          |          | 112       |
|           |           |           |          |          | Harbor    |
|           |           |           |          |          | Seals     |
+-----------+-----------+-----------+----------+----------+-----------+
| 1/26/05   | USFWS     | Fixed     | Eider    | Marine   | 51 Sea    |
|           |           | wing      | Point to | Mammals  | Otters,   |
|           |           | aircraft  | Spray    |          | 318       |
|           |           |           | Cape and |          | Steller   |
|           |           |           | Sea      |          | Sea       |
|           |           |           | T        |          | Lions, 12 |
|           |           |           | ransects |          | Harbor    |
|           |           |           |          |          | Seals     |
+-----------+-----------+-----------+----------+----------+-----------+

\*Not included are 3 Harbor Seals and 1 Sea Otter reported to
International Wildlife Research by USFWS personnel in a cove on Peter
Island, which were not seen by International Wildlife Research observers
when they visited this cove later that day after receiving this report.

Materials relied upon to compile the report:

Data sheets from aerial surveys of marine mammals in the vicinity of the
*Selendang Ayu* oil spill collected by John Haddix and Ian Zelo, January
2005

International Wildlife Research, Final Report: Survey of sea otters
affected by the M/V Selendang Ayu fuel spill, January 2005.

Sowl/Doroff, Marine Mammal and Bird Response during the Selendang Ayu
Oil Spill Unalaska Island, Aleutian Archipelago

8-18 December 2004.

Necropsy results (2 reports)

U. S. Department of Commerce, National Oceanic and Atmospheric
Administration. 1988. West Coast of North America Coastal and Ocean
Zones Strategic Assessment: Data Atlas, Marine Mammal Volume,
pre-publication edition.