An Integrated Ecosystem Study of the Hanna Shoal Ecosystem, Northern Chukchi Sea, Alaska

An Integrated Ecosystem Study of the An Integrated Ecosystem Study of the Hanna Shoal Ecosystem, Northern Chukchi Sea, AlaskaHanna Shoal Ecosystem, Northern Chukchi Sea, Alaska

• 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

Dr. Kenneth Dunton - University of Texas at Austin, Marine Science Institute

• 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”

Chukchi Sea Offshore Monitoring in Drilling Area (COMIDA): Hanna Shoal Ecosystem Study

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

Hanna Shoal Ecosystem Study9-25 August 2012 USCGC Healy

COMIDA CAB and HANNA SHOAL STUDY AREAS

HANNA SHOAL STUDY AREA

73 CTD Stations; Benthic Sampling at 31 Stations

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)

Hanna Shoal

CHUKCHI WATER CURRENT STRUCTURE AT 27.5 m DEPTH

Herald Shoal

Herald Valley

CentralChannel

UAF COMIDA MOORINGS (deployed 2012, Tom Weingartner)

HSNE60-12HSNE50-12

HSNE40-12

HSNW40-12

HSNW60-12

HSNW50-12

CTD Transects

0 m

20 m

30 m

50 m

0 m

20 m

30 m

40 m 50 m

55

Vertical CTD Profiles

Benthic Sampling

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

Sediment Trace Metal Chemistry

Jackie Grebmeier and Lee Cooper

Epibenthic Surveys Brenda Konar and Lee Cooper

Zooplankton Sampling 2012 Carin Ashjian and Bob Campbell

• 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

Locations of Bongo Net Tows

Seabird and Marine MammalObservations

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

Marine mammal aerial studies funded by BOEM and NOAA/NMML; amphipod abundance data from Schonberg and Dunton

Amphipod Abundance and Gray Whale Sightings

Evidence for Consumer Assimilation of Different Ultimate Carbon Sources?

POM

Phytoplankton

Sea Cucumber (Ocnus)

Bivalves

Fish (H. robustus)

Crab (C. opilio)

Benthic Microalgae(derived from ice algae??)

Ctenophores

Copepods (Calanus sp.)

From McTigue and Dunton

• 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

SUMMARY