My research focuses on benthic communities and their influence on the function of coastal ecosystems.  I am particularly interested in the interaction between benthic organisms and sediment geochemistry.  Recent research projects have examined: The effects of deposit-feeding (mud-eating) benthic organisms on the germination of cysts of dinoflagellates that cause harmful algal blooms, tube-dwelling benthos and methyl mercury formation in sediments, the effects of deposit feeder gut passage on transport and dissolution of radionuclides, and the food value of native and invasive marsh grass species for benthic invertebrates. 

My projects usually involve sampling of benthic organisms and sediment properties (by ship, SCUBA, or research submersibles), laboratory and field experiments, and mathematical modeling.  Mathematical models are used to develop hypotheses that can be quantitatively tested by appropriate field sampling.  Currently my students and I are studying the formation of hypoxia in Hood Canal and its effects on benthic communities.  We are continuing work on the role that benthic organisms play in determining the fate of methyl mercury produced in marine sediments.  We are also conducting research in the Bering Sea examining the effects of climate change on the benthic communities, nutrient cycling & denitrification in Bering Sea shelf sediments.

Cirratulid polychaete Cirriformia grandis from Boston Harbor

(Autofluorescent cyst of the dinoflagellate Alexandrium from the Gulf of Maine)

Recent grant support

BEST: Denitrification and global change in Bering Sea shelf sediments. NSF, Sept. 2006-Aug. 2010, $367,000

MRI: Acquisition of instruments for biogeochemical analyses of carbon, nitrogen and phosphorus. NSF, (co-PI with D. Hooper (Biology), P. Homann, and J. Rybczyk), August 2007 – July 2009, $191,800.

A window into Puget Sound: The WWU "Viking" ROV.  WWU Student Technology Fee Program, April 2006, $27,651.

Effects of macrofauna on monomethyl mercury transport in marine coastal sediments, (with J. M. Benoit of Wheaton College), MIT-SeaGrant, MWRA, March 2006 - February 2008, $107,000.

Excess ²¹⁰Po in marine sediments. Bureau of Faculty Research, Western Washington University, Grant in Aid, October 2005, $2,000.

Hypoxia and benthic community structure in Hood Canal, Washington, Hood Canal Salmon Enhancement Group. Mar 2005-Mar. 2006, $7,500.

Rates and mechanisms of mercury methylation in marine coastal sediments, (with J. M. Benoit of Wheaton College) MIT-SeaGrant, MWRA. March 2003 - February 2005, $126,500.

Some recent and selected publications

(Click title to access pdf)                                             

Shull, D.H., J.M. Benoit, C. Wojcik*, and J.R. Senning. 2009. Infaunal burrow ventilation and pore-water transport in muddy sediments. Est. Coast. and Shelf Sci. 83, 277-286.

Cox, A.M.,  D.H. Shull and R.A. Horner. 2008. Profiles of Alexandrium catenella cysts in Puget Sound sediments and the relationship to paralytic shellfish poisoning events. Harmful Algae 7, 379-388.

Shull, D.H. 2008. Bioturbation. In Encyclopedia of Ocean Sciences. Elsevier (pre print)

Benoit, J.A., D.H. Shull, P. Robinson*, L.R. Ulcran* 2006. Infaunal burrow densities and sediment monomethyl mercury distributions in Boston Harbor, Massachusetts. Marine Chemistry 102, 124-133.

Kremp, A., D.H. Shull and D.M. Anderson. 2003.  Effects of deposit-feeder gut passage and fecal pellet encapsulation on germination of dinoflagellate resting cysts.  Marine Ecology Progress Series 263, 65-73.

Shull, D.H. 2001. Transition-matrix model of bioturbation and radionuclide diagenesis. Limnology and Oceanography 45, 905-916. 

Shull, D.H. and M. Yasuda. 2001. Size-selective downward particle transport by cirratulid polychaetes. Journal of Marine Research 59, 453-473.

Piloting the WWU mini ROV under sea ice in the Bering Sea