ACS/LA
GRAY WHALE CENSUS AND BEHAVIOR PROJECT: 2006-2007
By
Alisa Schulman-Janiger [email:
janiger@bcf.usc.edu] [web:
www.acs-la.org/GWCensus.htm]
Although gray whale counts dropped, sightings of
fin whales and bottlenose dolphin (including a birth!) rose, rewarding participants
in the 2006/2007 ACS/LA's Gray Whale Census and Behavior Project. This
is the 27th year (24th consecutive season) that the American Cetacean
Society's Los Angeles Chapter has sponsored a gray whale census project
from the Palos Verdes Peninsula. Trained volunteers collect data on gray whales
and other cetaceans (identifications, counts, and behaviors). In past seasons
we have operated from Long Point, Santa Catalina Island, and Santa Cruz Island.
This season we were back at our primary observation site - Point Vicente
Interpretive Center (PVIC) patio - which reopened in July 2006 after being
closed several years for remodeling. Our cliffside post towers ~125 feet above
kelp beds and rocky shoreline with a seafloor that drops off abruptly nearshore.
COVERAGE: The census station operated for 2019.75
hours over the 166 days between 1 December 2006 and 15 May 2007 (averaging
over 12 hours/day). 74 volunteers contributed 7696.75 effort hours.
The ten core anchors that donated over 200 hours each, totaling nearly 55%
of our effort hours (and their numbers of volunteered days) include: Joyce
Daniels (153), Michael White (115), Natalie Massey (92), Clyde Lambert (88),
Libby Helms (86), Joan Venette (83), Evi Meyer (76), Pam Ryono (47), John
Nieto (47), and Dee Whitehurst (32). Nine other volunteers donated over 100
hours each. The project binoculars are Fujinon 7x50 (with built-in reticle
and compass). All participants use binoculars; several use spotting scopes
to confirm and detail sightings. Weather data (visibility and sea conditions)
is recorded at least hourly.
NUMBERS OF GRAYS COUNTED: Observers counted fewer
southbound and northbound gray whales this season: 476 southbound and 783
northbound gray whales (529 southbound and 951 northbound whales last
season). Over 23 previous seasons, southbound numbers varied from 301-1291:
they decreased from peaks in 1986-87 to lows in 1990-91, increased, dropped
for three seasons, rose slightly, jumped 41% four seasons ago, and then dropped.
Northbound counts have ranged from 727-3412: they decreased from 1984 to 1991-92,
fluctuated in the lower range, rose two seasons, dropped four seasons, also
jumped (45%) four seasons ago, dropped and rose slightly, then dropped a bit.
Although most of the estimated 18,000 gray whales migrate past California,
we spot only a small proportion. Gray whales - especially adults - off Palos
Verdes tend to travel further offshore, notably during the southbound migration.
Northbound whales - particularly cow/calf pairs - tend to hug the coastline.
These trends, combined with extended springtime observation hours, produce
higher northbound counts. Shifting migratory corridors and weather conditions
result in annually fluctuating shore-based counts that do not necessarily
indicate abrupt gray whale population changes. Fog sometimes cut visibility
and reduced counts on 64 days, while record low rainfall - 20 days
of mostly light rain - had little impact on counts.
PEAKS AND TURNAROUND DATES: Low southbound counts
rose and fluctuated over 3 weeks, followed by weeks of low counts during migration
turnaround (when daily northbound whales exceed southbound whales). We
saw 34 gray whales on our peak southbound day (28 January);
previous peak counts ranged from 15-98. We saw a huge pod of 14 (1-2 is typical).
We spotted 118 southbound whales during the peak southbound week of 22 January-28
January (139 last season). Our official turnaround date was 18 February,
with some vacillations 14 February-21 February. We had a long "gap period",
with few whales passing our station mid-February. We counted 29 northbound
whales during the southbound migration period and 13 southbound whales during
the northbound period. Our peak northbound count (37 on 18 March) was low
compared to previous peak counts that ranged from 29-152. We recorded 188
whales during the peak northbound week of 13 March-19 March (161 last season).
CALF COUNTS FALL AFTER 5
HIGHER SEASONS: We spotted 20 newborn southbound calves (4.2% of southbound
migrants) from 20 December-7 February, peaking with 3 calves on
20 January; this is lower than last season's 38 southbound calves (7.2%
of the southbound migrants). This is our 6th lowest southbound calf count
- but our 8th highest calf percentage. The record was set during the 1997-98
season (106 calves - 8.6% of southbound migrants). Other southbound calf counts
ranged from 3-60 (0.5%-8.9% of southbound migrants). Our northbound calf counts
also dropped: 58 northbound calves (5.7% of northbound migrants) from
24 March-14 May, peaking with 7 calves on 25 April. Although
this count is higher than only 9 other seasons, the calf percentage - a more
important reproductive index - was higher than 12 previous seasons. Last season
we counted 106 northbound cow/calf pairs (11.1% of northbound migrants). Aside
from the record 222 calves counted in 1996-97, past northbound calf counts
have ranged from 11-196 (0.9%-18.5% of northbound migrants). Experienced
observers are needed to spot calves, especially southbound, since many
cows adopt low profiles with barely visible blows and rarely displayed flukes.
In addition to the calf counts listed above, there were probable sightings
of 2 southbound and 3 northbound cow/calf pairs.
OBSERVED BEHAVIORS AND HUMAN INTERACTIONS: We saw gray whales mill,
roll, lunge, breach, spyhop, blow bubbles, and nurse calves. We saw pods join
or split up. We witnessed harassment on 6 days involving private and commercial
boats and one helicopter. Whale reactions to near impacts included going
into stealth mode (disappearing or changing into lower profile traveling),
abruptly changing direction, or breaching repeatedly next to the boat. We
saw at least one gray whale with flukes entangled in netting; we tracked
the whale from shore, aiding Redondo Baywatch in the disentanglement effort.
LOWER CALF COUNTS-SKINNY
WHALES? Although our calf counts fell, we did not see the emaciated whales
that have been reported elsewhere. NMFS (National Marine Fisheries Service),
who conducts the official gray whale census, lowered the gray whale population
estimate from 26,635 in 1998 (a 35 year high) to 17,414 in 2002
(close to 1992-93 numbers). Gray whale counts are impacted by natural fluctuations
in wild populations and in the number of whales that complete the migration,
and by variable factors such as observer experience and weather conditions.
Feeding ground conditions affect migratory timing and paths. A major mortality
event - due to malnutrition - occurred from 1999-2000, followed by three seasons
of low calf counts. In 1998 and 1999, shifting arctic food webs decreased
the abundance of prey (mud-dwelling shrimp-like amphipods), while early extensive
icepack formation reduced prey accessibility; this resulted in two poor summer
feeding seasons, unusually high mortality rates, many emaciated whales, and
low calf counts. Although feeding ranges expanded and feeding occurred during
migration (usually a rare event), pregnancies failed and strandings increased
throughout their range. During the summer of 2000 a smaller icepack formed
late and receded during the winter, allowing extended feeding over larger
areas that expanded northward due to reduced prey abundance (amphipods
thrive in cooler water, feeding on algae that fall from ice sheets). Many
whales ignored the initial migration cue (shortened daylight hours) so that
they could rebuild blubber that allows them to fast during migration and on
Baja nursery grounds, and provides energy to withstand disease, storms, and
killer whale attacks. Delayed whales took the more direct route offshore southern
California through the Channel Islands, resulting in later sightings of fewer
but robust whales, low calf numbers (physical recovery must precede reproductive
success), and few juveniles. Reduced sea ice and expanded foraging produced
6 feeding seasons that improved the physical condition and reproductive success
of gray whales, resulting in 6 seasons with few strandings or emaciated
whales and 5 seasons with higher calf counts. However, when NMFS
conducted a 14th season of counting northbound gray whales from Piedras Blancas
this spring, they recorded skinnier whales and much lower calf counts
- very different from the rotund adults and high number of calves recorded
in 2006. Researchers in some Mexican lagoons also reported many skinny whales
and fewer calves. Important indicators of a healthy population are higher
adult and calf counts, both of which factored into the National Marine
Fisheries Service (NMFS) decision to recommend the removal of gray whales
in 1994 from the endangered species list. Arctic warming may be killing off
amphipods, prompting gray whales to expand their already extensive prey repertoire
and opportunistically feed during migration - potentially ingesting damaging
parasites. Although census observers did not record emaciated grays, during
boat encounters some of us noted several leaner whales. Gray whale strandings
were actually lower than usual, very unlike what was seen in 1999-2000. Reduced
amphipod prey, lean and emaciated whales, and lower calf counts all raise
concerns that we may be headed toward another gray whale mortality event.
We'll see - next season.
OTHER SPECIES SIGHTED: This season we saw at least
10 other marine mammal species. Fin whale and bottlenose
dolphin sightings increased. As before, Pacific white-sided dolphin
and Risso's dolphin sightings were inversely proportional and switched
in frequency. Comparing this season (to last season), we saw bottlenose
dolphin on 123-124 days - including an exciting birth on 21 January
(101), common dolphin on 112-113 days - some schools exceeded 10,000
(118), Pacific white-sided dolphin on 64 days (26-27), fin whales
on 40 days (4), Risso's dolphin on 23 days (62-63), humpback whales
on 9-14 days (4-8), minke whales on 7-9 days- one approached unusually
close to shore (9-11), blue whales on 2 days, unidentified large
fin or blue whales on 17 days (13), other unidentified whales
- probably grays - on 17 days (11), unidentified dolphins on
1 day (8), California sea lions almost daily - in numbers larger than
ever, harbor seals, and a probable sea otter on 15 April. (Some
volunteers saw ~25 killer whales just north of the census site on 5 December.
You can contribute to our California killer whale photo-identification
project by sending photographic and sighting information to: janiger@bcf.usc.edu;
we will try to match images to our catalog, and notify you with the results).
Other species sighted in past seasons included sperm whale, false
killer whale, pilot whale, northern right whale dolphin,
Dall's porpoise, and elephant seal. Gray whales interacted
with other marine mammals including sea lions, bottlenose dolphin,
common dolphin, and Pacific white-sided dolphin. We often recorded
groupings composed of mixed species of dolphins and sea lions. We saw 1-2
peregrine falcons on 13 days, 1-2 ospreys on 4 days, and a juvenile
bald eagle on 11 February; all are species recovering from DDT contamination.
50 green flash sunsets (amazing!) rewarded patient observers.
OBSERVERS' HOURS: : Joan Venette (nearly 17,000
hours over 22 seasons), Clyde Lambert (over 7600 hours in 21 seasons), and
Michael White anchored mornings, along with Libby Helms and Pam and Hugh Ryono.
Joyce Daniels (nearly 8000 hours over 13 seasons) anchored afternoons (and
updated graphs), along with Evi Meyer, Natalie Massey, John Nieto, Dee Whitehurst
and Jean DeGraff. This project would be impossible without the following
dedicated whalewatchers (with their volunteer hours: * = new observers):
Joyce Daniels (752), Michael White (696.5), Joan Venette (542.75), Libby Helms
(517.75), Clyde Lambert (402.75), Pam Ryono (310.75), Evi Meyer (298.25),
Natalie Massey (264.75), John Nieto (246.5), Dee Whitehurst (200.5), Jean
DeGraff (180.75), Hugh Ryono (172), Tina Hoff (154.25), Linda Jebo (134.75),
Andy Veek (133.75), Vickie Miskimen* (121.25), Karin Campbell (118.75), Stephanie
Bryan (116.5), Katie Penland* (109.5), Robin Riggs (96.75), Cathy Landrum*
(96.5), Jo Bonds (96), Barbara Stone* (94.25), Arthur Wertheim* (90), Bob
Daniels (88.5), Peggy Gilliam (85.75), Sharon Bosler* (85), Joyce Jessoe (80.75),
David Taylor (77.75), Erlinda Cortez (75), Gene Montgomery* (71), Kathleen
Russo* (68.5), Larry Desy (68.25), Cynthia Woo* (63), Jud Goodspeed (61.5),
Rick Beauregard (60), Carol Harrison* (58.5), Janet Herman (58.25), Gerrie
Cole (55.25), Larry Hess (51.75), Rose Hess (51.25), Mike Malone (50.5), Karen
Masinter (49), Ted Lester (46.25), Fran Austin - veteran from Colorado (44.25),
Nancy DeLong (41.5), and Dave Morse* (41.5). Volunteers who donated 20-39
hours each included Alisa Schulman-Janiger, Brenda Sais, Donna McLaughlin,
John Simpson*, and Kris Clifford. Volunteers with 10-19 hours each included
Dana McDermott*, Randy Landrum*, Terri Jennings*, Jan Malone*, Corinne Sutherland,
and Stephanie Brito. GUESTBOOK KEEPERS: Jud Goodspeed and Natalie Massey.
Natalie summarized the log: 995 visitors from 48 states and 22 countries -mostly
United Kingdom.
COMPUTER ENTRIES: We especially thank Dave Janiger for countless hours of computer entries. IN MEMORIUM: Beloved volunteers who passed away: Chuck Bernhardt -17 October 2006 (642 hours over 19 seasons), veteran anchor Jud Goodspeed - 10 March 2007 (8634 hours over 22 seasons), and Jim DeRouen-24 July 2007 (299 hours over 9 seasons). They will be dearly missed.
JOIN US! To join our census project,
contact Alisa Schulman-Janiger at: janiger@bcf.usc.edu. No experience necessary:
we will train you on-site in November and December. We highly recommend that
you attend the Whalewatch Training Class at the Cabrillo Marine Aquarium
[(310) 548-7563; www.cabrilloaq.org], co-sponsored by the Cabrillo
Marine Aquarium and ACS/LA. On Tuesday nights, October-December, volunteers
are trained to become Whalewatch boat guides and classroom lecturers. ACS/LA
offers free lectures from invited specialists the last Tuesday of each month
at the Cabrillo Marine Aquarium. Join us on all day whalewatching trips
- to Santa Catalina Island (spring) for gray whales, and to the Santa
Barbara Channel (spring, summer) for humpback whales and blue whales
(www.acs-la.org). Happy whalewatching!
**This data summary is provided
as a public service. Publication is pending. Please contact the project director
to cite this in publications. **