@article{archer_kahn_thiess_law_leys_johannessen_layman_burke_dunham_2020, title={Foundation Species Abundance Influences Food Web Topology on Glass Sponge Reefs}, volume={7}, ISBN={2296-7745}, DOI={10.3389/fmars.2020.549478}, abstractNote={Foundation species support communities across a wide range of ecosystems. Non-trophic interactions are considered the primary way foundation species influence communities, with their trophic interactions having little impact on community structure. Here we assess the relative trophic importance of a foundation species and assess how its abundance can influence food web topology. Using empirical data and published trophic interactions we built food web models for 20 glass sponge reefs to examine how average live reef-building sponge abundance (proxied by percent cover) at the reef level is correlated with community structure and food web network topology. Then, using a generalized food web model and stable isotope data we examined the relative importance of sponges. Sponges were consumed by all species examined and contributed significantly to their diets. Additionally, sponges were the second most important node in our generalized reef food web. Several metrics of food web topology (connectance, clustering, and median degree) and community structure exhibited a threshold response to reef-building sponge cover, with the change point occurring between 8 and 13% live sponge cover. Below this threshold, as average sponge cover increases, the consumers observed on a reef rely on fewer sources and are consumed by fewer predators, resulting in food webs that are more clustered and less connected. Above the threshold, as average sponge cover increases, the reefs’ food webs are less clustered and more connected, with consumers utilizing more sources and having more predators. This corresponds with the finding that several generalist predators (e.g., rockfishes) are associated with high sponge cover reefs. Our results are not consistent with previous reports that increasing foundation species abundance decreases connectance in food webs. We propose that the influence of foundation species on food web topology may be dependent on palatability, and therefore relative trophic importance, of the foundation species. Finally, our findings have important implications for sponge reef conservation and management, as they suggest that reefs below the 10% sponge cover threshold support different communities than high live sponge cover reefs.}, journal={FRONTIERS IN MARINE SCIENCE}, author={Archer, Stephanie K. and Kahn, Amanda S. and Thiess, Mary and Law, Lauren and Leys, Sally P. and Johannessen, Sophia C. and Layman, Craig A. and Burke, Lily and Dunham, Anya}, year={2020} }
 @article{rossi_archer_giri_layman_2020, title={The role of multiple stressors in a dwarf red mangrove (Rhizophora mangle) dieback}, volume={237}, ISSN={["1096-0015"]}, DOI={10.1016/j.ecss.2020.106660}, abstractNote={Mangroves are habitat-forming foundation species that provide the framework for entire coastal communities. Unfortunately, mangrove forests are declining globally, often due to multiple stressors. We report a recent mangrove dieback on Abaco Island, The Bahamas, that appears to be the result of multiple stressors. First, we investigated the role of hurricane and drought events in relation to green vegetation in the dieback area, as measured using Normalized Difference Vegetation Index (NDVI). We used historical Landsat imagery of the dieback region from 1989 to 2013 to identify changes in green vegetation and to determine when the dieback likely began. We determined that the dieback began around 2008, but found little evidence of a relationship between NDVI and hurricane or drought events, particularly in relation to the estimated start of the dieback. Preliminary observations in the dieback area suggested grazing by leaf-chewing organisms and disease were both present at high levels. We surveyed individual mangrove trees to determine the intensity of leaf-chewing herbivory and foliar disease on mangroves in the dieback area. We found leaf-chewing herbivory ranged from 0 to 79%, with a mean of 29% of leaves chewed per tree and disease incidence ranged from 0% to 97% with a mean of 47%. Finally, we conducted a simulated grazing experiment to test if experimental opening mimicking grazing could facilitate disease infection in mangroves . Experimental opening of plant tissues showed that grazing can increase disease. Our results suggest that drought and hurricanes did not initiate this dieback, but that herbivory likely facilitated the spread of disease thereby contributing to the dieback.}, journal={ESTUARINE COASTAL AND SHELF SCIENCE}, author={Rossi, R. E. and Archer, S. K. and Giri, C. and Layman, C. A.}, year={2020}, month={May} }
 @article{archer_stevens_rossi_matterson_layman_2017, title={Abiotic conditions drive significant variability in nutrient processing by a common Caribbean sponge, Ircinia felix}, volume={62}, ISSN={["1939-5590"]}, DOI={10.1002/lno.10533}, abstractNote={Abstract}, number={4}, journal={LIMNOLOGY AND OCEANOGRAPHY}, author={Archer, Stephanie K. and Stevens, Julia L. and Rossi, Ryann E. and Matterson, Kenan O. and Layman, Craig A.}, year={2017}, month={Jul}, pages={1783–1793} }
 @article{archer_stoner_layman_2015, title={A complex interaction between a sponge (Halichondria melanadocia) and a seagrass (Thalassia testudinum) in a subtropical coastal ecosystem}, volume={465}, ISSN={["1879-1697"]}, DOI={10.1016/j.jembe.2015.01.003}, abstractNote={Foundation species, such as oysters, corals, and seagrasses, form the basis for entire ecosystems and are characterized by positive interactions with community members. However, many species interactions are context dependent, where the outcome or strength of the interaction depends on the biotic or abiotic conditions. Therefore, a mechanistic knowledge of species interactions, especially those involving foundation species, may allow for a more complete understanding of how anthropogenic changes influence nearshore ecosystems. This study describes the interaction between the seagrass Thalassia testudinum and the sponge Halichondria melanadocia, a species that grows around the base of seagrass shoots. A combination of surveys and experimental manipulations on Abaco Island, The Bahamas, revealed that the interaction between T. testudinum and H. melanadocia is a commensal relationship with the sponge benefiting from the presence of T. testudinum up to medium shoot densities (589–615 shoots per m2). The net neutral effect of H. melanadocia on T. testudinum is likely a balance of the negative effect of the sponge shading the seagrass with the positive effect of nitrogen and phosphorus supplied by the sponge. The mechanisms underlying the interaction between H. melanadocia and T. testudinum suggest that the interaction is likely context dependent. As such, environmental change, namely eutrophication, has the potential to shift the nature of this interaction from commensal to parasitic. A simple simulation showed that if this relationship becomes parasitic, above ground production in seagrass beds could be reduced. This study highlights the importance of a mechanistic understanding of species interactions involving foundation species when predicting human impact on the environment.}, journal={JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY}, author={Archer, Stephanie K. and Stoner, Elizabeth W. and Layman, Craig A.}, year={2015}, month={Apr}, pages={33–40} }
 @article{archer_allgeier_semmens_heppell_pattengill-semmens_rosemond_bush_mccoy_johnson_layman_2015, title={Hot moments in spawning aggregations: implications for ecosystem-scale nutrient cycling}, volume={34}, ISSN={["1432-0975"]}, DOI={10.1007/s00338-014-1208-4}, number={1}, journal={CORAL REEFS}, author={Archer, Stephanie K. and Allgeier, Jacob E. and Semmens, Brice X. and Heppell, Scott A. and Pattengill-Semmens, Christy V. and Rosemond, Amy D. and Bush, Phillippe G. and McCoy, Croy M. and Johnson, Bradley C. and Layman, Craig A.}, year={2015}, month={Mar}, pages={19–23} }
 @article{easson_matterson_freeman_archer_thacker_2015, title={Variation in species diversity and functional traits of sponge communities near human populations in Bocas del Toro, Panama}, volume={3}, journal={PeerJ}, author={Easson, C. G. and Matterson, K. O. and Freeman, C. J. and Archer, S. K. and Thacker, R. W.}, year={2015} }
 @article{archer_crowl_2014, title={Retention of learned predator recognition in an endangered sucker Chasmistes liorus liorus}, volume={20}, number={3}, journal={Aquatic Biology}, author={Archer, S. K. and Crowl, T. A.}, year={2014}, pages={195–202} }