An Integrated Ecosystem Study of the
Hanna Shoal Ecosystem, Northern Chukchi Sea, Alaska
Dr. Kenneth Dunton - University of Texas at Austin, Marine Science Institute
• Dr. Carin Ashjian, Woods Hole Oceanographic
Institute
• Dr. Robert Campbell, University of Rhode Island
• Dr. Lee Cooper, University of Maryland
• Jacqueline Grebmeier, University of Maryland
• Dr. Roger Harvey, Old Dominion University
•
•
•
•
Dr. Brenda Konar, University of Alaska Fairbanks
Dr. David Maidment, University of Texas at Austin
Dr. John Trefry, Florida Institute of Technology
Dr. Thomas Weingartner, University of Alaska
Fairbanks
Chukchi Sea Offshore Monitoring in Drilling Area
(COMIDA): Hanna Shoal Ecosystem Study
• multi-disciplinary investigation to examine the biological, chemical and
physical properties that define an ecosystem that lies on the boundary
between Chukchi and Arctic Ocean waters
• a key component of Chukchi Sea environmental studies pertinent to
Chukchi Sea Lease Sale 193 held in 2008
• builds upon the COMIDA Chemistry and Benthos (CAB), including
trophic structure, sediments, inventories of anthropogenic chemicals,
inventories of benthic and epibenthic fauna, with zooplankton standing
stocks and physical oceanographic measurements of circulation,
density fields, ice conditions and modeling
• Current study will refocus the ecological monitoring started under
COMIDA CAB to the region of Hanna Shoal, including nearby biological
“hot spots”
Hanna Shoal Ecosystem Study
9-25 August 2012 USCGC Healy
Science Components and PIs
Data Management (David Maidment, UT-Austin)
www.comidacab.org/
Physical Oceanography (Tom Weingartner, UAF)
Trace Metal Chemistry (John Trefry, FIT)
Organic Contaminants (Roger Harvey, ODU)
Epibenthic Communities (Brenda Konar, UAF)
Trophic Structure (Ken Dunton, UT-Austin)
Benthic Infauna and Sediments (Jackie Grebmeier,
and Lee Cooper UMCES)
Marine Birds (Kathy Kuletz, USF&WS)
Marine Mammal Observations (Sue Moore, NOAA)
Special Acknowledgements
•Heather Crowley, BOEM Program Manager and Jackie Grebmeier, Chief Scientist
•Bureau of Ocean Energy Management (BOEM) for Funding of Science, Field
Logistics and Ship Support (2012-2017)
•Shell Alaska (Program Mgr Michael Macrander) for fisheries and ship support in 2012
COMIDA CAB and HANNA SHOAL STUDY AREAS
HANNA SHOAL STUDY AREA
73 CTD Stations; Benthic Sampling at 31 Stations
CHUKCHI WATER CURRENT STRUCTURE AT 27.5 m DEPTH
Hanna
Shoal
Herald
Valley
Herald
Shoal
Central
Channel
Annual mean horizontal velocity at 27.5 m depth as a function of
bottom topography. Net flows denoted by colored arrows. From
Spall (2007) and Weingartner (pers. comm)
UAF COMIDA MOORINGS
(deployed 2012, Tom Weingartner)
HSNW60-12
HSNW50-12
HSNW40-12
HSNE60-12
HSNE50-12
HSNE40-12
CTD Transects
Vertical CTD Profiles
0m
20 m
30 m
50 m
0m
20 m
30 m
40 m
50 m
Benthic Sampling
Sediment Trace Metal
Chemistry
Sediment grain size plays an
important role in the distribution of
benthic infauna as well as sediment
trace metals.
The FIT group studies trace
metals and show here that
course-grained sediment on
Hanna Shoal contains very low
Hg values at 13 ± 6 ppb.
John Trefry
Jackie Grebmeier and Lee Cooper
Epibenthic Surveys
Brenda Konar and Lee Cooper
Zooplankton Sampling 2012
Carin Ashjian and Bob Campbell
•
Locations of Bongo Net Tows
•
•
Samples for abundance, total biomass,
and species composition collected at 38
stations using Bongo nets equipped
with 150 and 500 µm mesh nets
Samples to collect animals for genetic
and chemical analyses collected at 23
stations using a 1 m2 ring net equipped
with a 250 µm mesh net
Preliminary, qualitative observations:
- Calanus glacialis/marshallae
ubiquitous; more abundant off of
shoal
- Euphausiids/krill seen only in
Barrow Canyon
- Arctic C. hyperboreus seen only on
NE corner of study area
- Barnacle nauplii abundant on crest
Seabird and Marine Mammal
Observations
Kathy Kuletz and Sue Moore
•Examined seabird and marine mammal distribution and abundance relative to
oceanographic and biological features of the northern Bering, Chukchi, and
Beaufort seas.
•Survey data will also be submitted to BOEM and archived in the North Pacific
Pelagic Seabird Database (USFWS and USGS, Alaska).
M. Webber-USFWS
Bivalve Abundance and Walrus Sightings
Marine mammal aerial studies
funded by BOEM and
NOAA/NMML; infaunal abundance
data from Schonberg and Dunton
Amphipod Abundance and Gray Whale Sightings
Marine mammal aerial studies
funded by BOEM and
NOAA/NMML; amphipod
abundance data from
Schonberg and Dunton
Evidence for Consumer Assimilation of
Different Ultimate Carbon Sources?
Fish (H.
robustus)
Crab (C. opilio)
Copepods
(Calanus sp.)
Sea Cucumber (Ocnus)
Ctenophores
Phytoplankton
Bivalves
Benthic Microalgae
(derived from ice
algae??)
POM
From McTigue and Dunton
SUMMARY
• The infaunal biota is dominated by molluscs, polychaetes and
crustaceans.
• Highest benthic-feeding marine mammal populations correlate well
with the areas of high abundance of food items.
• Isotopic analyses reveal evidence that both phytoplankton and
benthic microalgae (or ice algae) are important carbon sources
• Age-dated sediment cores show only background levels of metals,
including mercury, over several centuries