I am an ecologist with a research program focused on exploring the fundamental principles that underpin the structure and function of biogenic habitats. I use a combination of observational and experimental approaches to elucidate the role that habitat forming species play in maintaining biodiversity and ecosystem function in the Anthropocene. I apply the findings of my research to tackle pressing issues in marine conservation by working directly with fisheries and resource managers to identify habitats in need of protection and developing monitoring methods grounded in cutting edge research. To this end my research is focused in three broad areas: 1) revealing the factors that maintain biodiversity and ecosystem function, 2) identifying drivers of decline in biogenic habitats, and 3) developing monitoring and restoration techniques for biogenic habitats.
Biogenic habitats, or habitats formed by living organisms, such as coral reefs, sponge grounds, and seagrass beds are among the most biodiverse ecosystems in the oceans. They provide us with many ecosystem services from food production and natural products chemistry to shoreline protection and storm buffering. They are also among the most impacted systems, suffering from a wide range of anthropogenic and natural stressors that combine to threaten their continued existence. My work is largely concentrated in two such habitats: nearshore seagrass beds and deep-sea glass sponge reefs.
Seagrass beds are hot spots of productivity with diverse communities of macroalgae, invertebrates, and fishes. Additionally, they help to attenuate wave energy, stabilize sediments, store large amounts of carbon, and are important sites for nutrient cycling. Unfortunately, seagrass habitats are under threat from myriad anthropogenic impacts that have driven significant worldwide declines. As a result, there have been large efforts at conservation and restoration. A primary goal of these efforts is to protect the diverse communities associated with seagrass beds. As such, a better understanding of the drivers of diversity within seagrass beds is of upmost importance. My work in seagrass ecosystems is focused on revealing how sponges interact with seagrass to maintain biodiversity and ecosystem function.
Glass sponge reefs are built by dictyonine sponges in the class Hexactinellida. These sponges are characterized by skeletons made of near pure glass fused into a rigid, but fragile, three-dimensional structure. In a process similar to the construction of coral reefs, glass sponge reefs are built by larval sponges settling on the skeletons of previous generations of sponges. This process ultimately results in the construction of large bioherms with dense aggregations of live reef-building sponges growing at the reef’s surface. Glass sponge reefs once formed the largest biogenic structure ever known, but were thought to be extinct until their rediscovery in Hecate Strait, British Columbia, Canada in 1987. Today, we are just beginning to understand the ecology of this ecosystem, whose known distribution is restricted to Pacific coast of Canada. These glass sponge reefs are extremely vulnerable to bottom contact fishing, and many of the known reefs have already been severely impacted. My work on glass sponge reefs is focused on determining the functional mechanisms that allow these systems to support abundant and diverse communities in the food poor deep-sea. Additionally I am working with multiple partners to develop new monitoring and restoration methods for this ecosystem.
Dunham, A°, SK Archer°, J Mossman, S Davies, J Pegg, L Burke. In Press. Assessing condition and ecological role of deep-water biogenic habitats: Glass sponge reefs in the Salish Sea. Marine Environmental Research. DOI:10.1016/j.marenvres.2018.08.002
Archer, SK°, WD Halliday°, A Riera, X. Mouy, JWF Chu, MK Pine, A Dunham, and F Juanes. 2018. The first description of a glass sponge reef soundscape reveals fish calls and elevated sound pressure levels. Marine Ecology Progress Series. 595:245-252 DOI:10.3354/meps12572
Archer, SK, S Buhler, and CA Layman. 2018. Ambient nutrient availability drives the outcome of an interaction between a sponge (Halichondria melanadocia) and a seagrass (Thalassia testudinum). Journal of Experimental Marine Biology and Ecology 503:86-91
Archer, SK, AS Kahn, SP Leys, T Norgard, F Girard, CP Du Preez, and A Dunham. 2018. Pyrosome consumption by benthic organisms during blooms in the NE Pacific and Gulf of Mexico. Ecology DOI:10.1002/ecy.2097
Archer, SK, JL Stevens, RE Rossi, KO Matterson, and CA Layman. 2017. Abiotic conditions drive significant variability in microbial activity and nutrient processing in a common Caribbean sponge, Ircinia felix. Limnology and Oceanography. DOI:10.1002/lno.10533
Easson, CG, SK Archer, KO Matterson, CJ Freeman, RW Thacker. 2015. Spatial variability in sponge community assemblages across an anthropogenic gradient in Bocas Del Toro, Panama. PeerJ 3:e1385. DOI:10.7717/peerj.1385.
Layman, CA, S Buhler, ST Giery, R Rossi, T Penland, M Henson, A Bogdanoff, M Cove, A Irizarry, C Schalke, and SK Archer. 2015. A primer on the history of food web ecology: Fundamental contributions of fourteen researchers. Food Webs 4: 14-24.
Archer, SK, EW Stoner, and CA Layman. 2015. A complex interaction between a sponge (Halichondria melanadocia) and a seagrass (Thalassia testudinum) in a subtropical coastal ecosystem. Journal of Experimental Marine Biology and Ecology 465:33-40.
Archer, SK, JE Allgeier, BX Semmens, SA Heppell, CV Pattengill-Semmens, AD Rosemond, PG Bush, CM McCoy, BC Johnson, and CA Layman. 2015. Hot moments in spawning aggregations: Implications for ecosystem-scale nutrient cycling. Coral Reefs 34(1):19-23. DOI: 10.1007/s00338-014-1208-4
Archer, SK and TA Crowl. 2014. Retention of learned predator recognition in an endangered sucker Chasmistes liorus liorus. Aquatic Biology 20:195-202. DOI: 10.3354/ab00558
Layman CA, ZR Jud, SK Archer, and D Riera. 2014. Provision of ecosystem services by artificial shoreline structures in a highly impacted estuary. Environmental Research Letters 9: 044009. DOI: 10.1088/17489326/9/4/044009.
Heppell, SA, BX Semmens, SK Archer, CV Pattengill-Semmens, PG Bush, BC Johnson, CM McCoy, and SS Heppell. 2012. Documenting recovery of a spawning aggregation through size frequency analysis from underwater laser calipers measurements. Biological Conservation 155: 119-127.
Archer, SK, SA Heppell, BX Semmens, CV Pattengill-Semmens, PG Bush, CM McCoy, and BC Johnson. 2012. Patterns of color phase indicate spawn timing at a Nassau grouper (Epinephelus striatus) spawning aggregation. Current Zoology 58(1):70-80.
° denotes equal contribution
After graduating from high school in Missouri I left the midwest to attend the University of Georgia. In 2004 I graduated with a BS in Ecology and a new love of Georgia football. After working for the US Forest Service and Forfar International Field Station I returned to school. In 2009 I received my MS in Ecology from Utah State University where I studied the antipredator behavior and learning capability of an endangered fish, the June Sucker, Chasmistes liorus liorus.
I recently completed my PhD at North Carolina State University where I worked in the Layman Lab studying how sponges alter community composition and ecosystem function in tropical and subtropical nearshore marine ecosystems. I am now an NSERC Visiting Fellow with Fisheries and Oceans Canada where I am studying species interactions and ecosystem function of Glass Sponge Reefs.