Marine Mammal Habitats
Niño Impacts on "Trophic Links" in Monterey
An ongoing MBNMS-funded study of critical marine
mammal habitats in the Sanctuary is studying the
relationship between oceanographic processes,
marine mammals, and feeding habits. The research
will help provide a better under-standing of the
relationship between animals - particularly
endangered species such as blue and humpback whales
- and their prey, and will provide further details
about the Sanctuary and its habitats.
The research project, coordinated by Research
Biologist Don Croll of the Institute for Marine
Sciences at UCSC, initially focused on the
correlation between the distribution of marine
mammals and their prey (particularly euphausiids,
also called krill) throughout the Sanctuary. In a
continuation of that study, Croll and his
colleagues have now turned their focus to the
relationship between physical processes in the
ocean and the prey.
"The abundance of krill in the Monterey Bay is
an important factor in the region's productivity,"
says Croll. "The krill act as a link between
phytoplankton in the upper part of the water column
and higher level organisms, such as seabirds,
marine mammals, and fishes." He explains that
zooplankton (of which krill is a type) can feed
upon the phytoplankton, whereas the higher-level
organisms cannot; they eat the zooplankton.
Therefore, the zooplankton - especially krill -
form an important "trophic link" between primary
production and the higher-level consumers.
During the first two years of the study, the
researchers studied the relationship between
oceanographic processes, the abundance of krill,
and whales. They learned about the whales' foraging
behavior and the size and density of the krill
patches that are good enough to be considered whale
food. (Please see the Winter 1997 newsletter for
details of this NOAA ship McArthur project.)
In this study, Croll and his colleagues are
particularly interested in the effects of El
Niño events. Their goals are to measure the
physical and biological processes that facilitate
the seasonal productivity of krill in Monterey Bay,
to determine how dependent zooplankton, seabird,
and marine mammals are upon these processes, and to
determine how the life history patterns
(reproduction, migration, maturation, etc.) of
these consumers relate to seasonal patterns in
SAC and Working
ADVISORY COUNCIL (SAC):
The Council regularly receives presentations about issues
of concern to the Sanctuary. This spring and summer, some of
those presentations covered coastal initiatives and bond
measures, effects of El Niño-driven storms, the UC
MBEST (Monterey Bay Education, Science, and Technology)
Center, vessel traffic management workshops, and the
Sustainable Seas Expeditions.
In April the SAC elected a new Chair, Dr. Steve Webster,
and a new Secretary, Ed Brown. Rachel Saunders continues to
serve as Co-Chair. The SAC thanked Karin Strasser Kauffman
for her dedicated service during her two terms as Chair.
A new federal regulatory amendment permitting
limited marine jade collection at Jade Cove took effect June
16, 1998. The collection protocols apply only to collection
at Jade Cove (southern Sand Dollar Beach to Cape San Martin
and to a depth of 90 feet) in accordance with regulatory
restrictions. Collection of jade in all other Sanctuary
areas remains prohibited.
(Note: Collection of marine jade from state submerged or
intertidal lands is still a violation of "State Law" unless
the collector has a permit or lease from the State Lands
Commission.) The SAC has sent a formal request to the State
Lands Commission asking that state regulations be amended to
be consistent with this new Sanctuary regulation.
SAC Retreat and
The SAC held its annual retreat this spring. The
meeting focused on communications and provided an
opportunity for the SAC and Superintendent Bill Douros to
get to know one another better. At the retreat, it was
decided to hold a joint meeting with Sanctuary staff.
That meeting, held in July, focused on establishing
priorities for the upcoming year and clarifying SAC and
ACTIVITY PANEL (RAP)
Recently the RAP has met at various institutions,
receiving update presentations on UC Sea Grant, the UC MBEST
Center, the Pacific Fisheries Environmental Laboratory, El
Niño Studies by the US Geological Survey, the Naval
Postgraduate School's oceanography activities, MBARI, and
recent sea floor habitat mapping projects.
Activities at Big
Superintendent Bill Douros gave the RAP a brief
history of CalTrans operations on the Big Sur Coast relating
to road repairs from this winter's severe storms. The group
provided suggestions regarding road debris dumping locations
and mitigation strategies.
The RAP heard results of a preliminary study of
disturbances caused by SCUBA divers to kelp ecosystems.
While the study covered a variety of disturbances, the
report states that determining the ecological effects of
these disturbances would be difficult. The report does
provide useful information for resource managers in general,
however. The RAP is working on a document that recommends
further research on how to use this information to educate
divers and other Sanctuary visitors.
The RAP formed a subcommittee to develop research
projects taking place under this program.
Following on from the NOC, the Monterey Bay
Crescent Ocean Research Consortium is using the RAP to guide
and coordinate regional research.
EDUCATION PANEL (SEP)
The SEP continues to meet at members' institutions,
where it learns about those organizations' activities. This
spring and summer the SEP visited Point Lobos (State Parks),
MBARI, and Save Our Shores.
1999 - 2003
A large part of the SEP's time has been spent developing
an Education Plan to guide future Sanctuary education
projects. The SEP has divided into planning teams, each
working on a specific target audience (such as families,
young adults, etc.).
Higher Education and to the
The SEP has been joined by representatives from
Monterey Peninsula College and CSU Monterey Bay. Chet
Forrest, Sanctuary Advisory Council member from the southern
end of MBNMS, is helping identify southern audience needs
and educational opportunities.
In May, many SEP members took part in an "Environmental
Issues Forum," in which participants explored a model for
helping people critically examine controversial
environmental issues. Later this year, forum participants
will be offered training to become an EIF facilitator, and
the chance to join development teams to produce an MBNMS
"Marine Biodiversity Environmental Issues Forum Packet" and
a national World Wildlife Fund "Marine Biodiversity
Curriculum Module" for middle school youth.
WORKING GROUP (CWG)
For information on the CWG, please see the focus
To conduct this research, the scientists have
established regularly-spaced stations from which
electronic instruments measure salinity,
temperature, and depth. These data, along with sea
surface temperature, provide the physical setting.
Simultaneously they conduct seabird, marine mammal,
and krill surveys along a series of seven survey
paths stretching from Santa Cruz to Cypress Point.
Finally, they use an echosounder to measure krill
density and - to interpret the echosounder data -
they use nets to sample the krill layers they
This year the scientists are seeking to
under-stand better how large-scale changes in the
physical and biological processes -such as those
brought on by El Niño events - affect those
organisms depending on krill as an important food
source. Past El Niño events have severely
limited the nutrient upwelling off Año
Nuevo/ Davenport and other coastal areas, and they
predict that the current El Niño will do the
same. They believe that the major impact for higher
trophic level species (birds, mammals, etc.) will
be that this "trophic link" is cut because the
krill won't reproduce and their decrease will cause
a sharp decline in bird, dolphin, and whale
According to Croll, initial indications are that
this El Niño may not have had as dramatic an
effect as anticipated on krill populations in some
parts of the Sanctuary. "Our current thought is
that while local krill abundance is high - i.e.,
there is quite a bit of krill close to shore -
offshore productivity is still very low," he says.
"Basically, due to coastal upwelling, the only
place to feed is close to shore, whereas normally,
many species (such as blue whales) would be feeding
further offshore. Because productivity (and krill
abundance) is so low offshore, everything seems to
have shifted inshore." Croll cautions, however,
that it is still too early to draw firm
Studies like this one are important in
developing a better understanding of the
relationship between sea floor geology, ocean
currents, plankton, fish, and large mammals. This
research also helps paint a picture of the general
health of biological populations in the Monterey
Other principal researchers involved in this
project include Dr. Baldo Marinovic (UCSC), Scott
Benson (MLML), Dr. Roger Hewitt (NMFS - SWFSC), Dr.
David Demer (NMFS - SWFSC), Dr. Francisco Chavez
(MBARI), Dr. Bernie Tershy (UCSC), and Dr. Dan
Costa (UCSC). The project has also received funding
from the Channel Islands NMS, NOAA's El Niño
Rapid Response Program, and the Office of Naval