Biology & Marine Biology

Faculty & Staff

Patrick M. Erwin, Assistant Professor

 Image of Dr. Erwin

Patrick M. Erwin, Assistant Professor

PhD · 2007 · University of Alabama at Birmingham

MS · 2003 · University of Alabama at Birmingham

BS · 2001 · University of Richmond

Myrtle Grove 1337 · (910) 962-2326 · Center for Marine Science, 5600 Marvin K. Moss Lane, Wilmington, NC 28409 · · ·

Research Interests

My primary fields of interest are microbial ecology and environmental microbiology, with particular focus on symbiotic microbial communities in marine invertebrates, including:

  • The structure, function and dynamics of bacterial and archaeal symbiont communities, and
  • The contribution of symbiont metabolism to host ecology and marine nutrient cycles.

My secondary research interests include marine invertebrate life cycles, larval behavior of reef-building corals and the economic valuation of ecosystem resources for conservation initiatives.

Background Information

  • Invertebrates act as unique ecological niches for marine microbes and represent microbial biodiversity hotspots, hosting thousands of novel bacterial and archaeal taxa.
  • These rich symbiont communities are capable of numerous metabolic processes in carbon and nitrogen cycles that expand the nutrient acquisition pathways of host invertebrates and contribute to coastal ecosystem functioning as bioreactors for nutrient transformations.
  • The disruption of these relationships may offer a sensitive indicator of environmental stress, as well as a host resilience mechanism via symbiont shuffling to maximize ecological fitness.
  • Modern genomic techniques allow for unprecedented access to the functioning and ecology of symbiotic microbes, including their capacity for producing novel marine natural products.

Research Agenda

My research projects couple modern genetic techniques (next generation sequencing) with field and aquaria experimentation to investigate the contribution of microbial symbionts to marine biodiversity, host ecology and coastal ecosystem processes. Key areas of study include:

  • STRUCTURE · Biodiversity and Specificity · Utilize the depth afforded by next generation sequencing platforms to examine biodiversity and specificity patterns of microbial symbionts and test hypotheses on their cosmopolitan or endemic nature and their dispersal capabilities.
  • FUNCTION · Symbiont Metabolism and Host Ecology · Characterize key functional genes in symbiont metabolism and quantify nutrient fluxes in the invertebrate-microbe holobiont to examine the functional role of symbionts in host metabolism and marine nutrient cycles.
  • DYNAMICS · Symbiont Stability and Host Resilience · Integrate high-resolution microbial community profiling with environmental monitoring programs to determine factors triggering compositional and metabolic shifts and assess symbiont shuffling as a resilience mechanism.

Long-Term Goals

  • BASIC · Mechanistic understanding of biotic and abiotic factors structuring invertebrate-microbe relationships and their significance in coastal ecosystem ecology and nutrient cycles.
  • APPLIED · Apply model invertebrate-microbe systems to environmental monitoring programs and forecast the susceptibility and resilience of marine organisms and ecosystems.


Erwin PM, Rhodes RG, Kiser KB, Keenan-Bateman TF, McLellan WA, Pabst DA (in press) High diversity and unique composition of gut microbiomes in pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales. Scientific Reports

Gantt SE, López-Legentil S, Erwin PM (2017) Stable microbial communities in the sponge Crambe crambe from inside and outside a polluted Mediterranean harbor. FEMS Microbiology Letters 364: fnx105

Weigel BL, Erwin PM (2017) Effects of reciprocal transplantation on the microbiome and putative nitrogen cycling functions of the intertidal sponge, Hymeniacidon heliophila. Scientific Reports 7: 43247

Marino CM, Pawlik JR, López-Legentil S, Erwin PM (2017) Latitudinal variation in the microbiome of the sponge Ircinia campana correlates with host haplotype but not anti-predatory chemical defense. Marine Ecology Progress Series 565: 53-66

Riesgo A, Perez-Portela R, Pita L, Blasco G, Erwin PM, López-Legentil S (2016) Population structure and connectivity in the Mediterranean sponge Ircinia fasciculata are affected by mass mortalities and hybridization. Heredity 117(6): 427-439

Thomas T, Moitinho-Silva L, Lurgi M, Björk JR, Easson C, Astudillo C, Olson JB, Erwin PM, López-Legentil S, Luter H, Chaves-Fonnegra A, Costa R, Schupp P, Steindler L, Erpenbeck D, Gilbert J, Knight R, Ackerman G, Lopez JV, Taylor MW, Thacker RW, Montoya JM, Hentschel U, Webster N (2016) Diversity, structure and convergent evolution of the global sponge microbiome. Nature Communications 7: 11870

Erwin PM, Coma R, Lopez-Sendino P, Serrano E, Ribes M (2016) Stable symbionts across the HMA-LMA dichotomy: Low seasonal and inter-annual variation in sponge-associated bacteria from taxonomically diverse hosts. FEMS Microbiology Ecology 91(10):fiv115

Lopez-Legentil S, Turon X, Erwin PM (2016) Feeding cessation alters host morphology and bacterial communities in the ascidian Pseudodistoma crucigaster. Frontiers in Zoology 13:2

Weigel BL, Erwin PM (2016) Intraspecific variation in microbial symbiont communities of the sun sponge, Hymeniacidon heliophila, from intertidal and subtidal habitats. Applied and Environmental Microbiology 82(2): 650-658

López-Legentil S, Erwin PM, Turon M, Oded Y (2015) Diversity of fungi isolated from three temperate ascidians. Symbiosis 66(2): 99-106

López-Legentil S, Turon X, Espluga R, Erwin PM (2015) Temporal stability of bacterial symbionts in a temperate ascidian. Frontiers in Microbiology 6: 1022

Pawlik JR, McMurray SE, Erwin P, Zea S (2015) No evidence for food limitation of Caribbean reef sponges: Reply to Slattery & Lesser. Marine Ecology Progress Series 527: 281-284

López-Legentil S, Legentil ML, Erwin PM, Turon X (2015) Harbor networks as introduction patchworks: contrasting distribution patterns of native and introduced ascidians. Biological Invasions 17: 1623-1638

Pawlik JR, McMurray SE, Erwin P, Zea S (2014) A review of evidence for food limitation of sponges on Caribbean reefs. Marine Ecology Progress Series 519:265-283

Zhang F, Pita L, Erwin PM, Abaid S, López-Legentil S, Hill R (2014) Symbiotic archaea in marine sponges show stability and host specificity in community structure and ammonia oxidation functionality. FEMS Microbiology Ecology 90(3): 699-707

Burgsdorf I, Erwin PM, López-Legentil S, Cerrano C, Haber M, Frenk S, Steindler L (2014) Biogeography rather than association with cyanobacteria structures symbiotic microbial communities in the marine sponge Petrosia ficiformis. Frontiers in Microbiology 5(529): 1-11

Riesgo A, Blasco G, Erwin PM, Pérez-Portela R, López-Legentil S (2014) Optimization of fourteen microsatellite markers in a Mediterranean demosponge subjected to population decimation, Ircinia fasciculata. Conservation Genetics Resources 6: 301-303


Erwin PM, Pineda MC, Webster N, Turon X, López-Legentil S (2014) Down under the tunic: Bacterial biodiversity hotspots and widespread ammonia-oxidizing archaea in coral reef ascidians. The ISME Journal 8: 575-588

Pita L, Erwin PM, Turon X, López-Legentil S. Till death do us part: Stable sponge-bacteria associations under thermal and food shortage stresses. PLoS ONE 8(11): e80307.

Pita L, Turon X, Lopez-Legentil S, Erwin PM (2013) Host rules: Spatial stability of bacterial communities associated with Ircinia spp. in the Western Mediterranean Sea. FEMS Microbiology Ecology 86: 268-276

Turon X, Garriga A, Erwin PM (2013) Lights and shadows: Growth patterns in three sympatric and congeneric species (Ircinia spp.) with contrasting abundances of photosymbionts. Marine Biology 160: 2743-2754

Pita L, Lopez-Legentil S, Erwin PM (2013) Assessing the fidelity of sponge-bacteria relationships: Biogeography and host-specificity of bacterial communities in Ircinia spp. from the Bahamas. Microbial Ecology 66: 437-447

Erwin PM, Pineda MC, Webster N, Turon X, López-Legentil S (2013) Small core communities and high variability in bacteria associated with the introduced ascidian Styela plicata. Symbiosis 59(1): 35-46

López-Legentil S, Erwin PM, Velasco M, Turon X (2013) Growing or reproducing in a temperate sea: Optimization of resource allocation in a colonial ascidian. Invertebrate Biology 132(1): 69-80

Hirose E, Turon X, Lopez-Legentil S, Erwin PM, Hirose M (2012) First records of didemnid ascidians harboring Prochloron from the Caribbean Panama: Genetic relationships between Caribbean and Pacific photosymbionts and host ascidians. Systematics and Biodiversity 10(4): 435-445

Erwin PM, Pita L, López-Legentil S, Turon X (2012) Stability of sponge-bacteria symbioses over large seasonal shifts in temperature and irradiance. Applied and Environmental Microbiology 78(20): 7358-7368

Erwin PM, López-Legentil S, Turon X (2012) Ultrastructure, molecular phylogenetics and chlorophyll a content of novel cyanobacterial symbionts in temperate sponge hosts. Microbial Ecology 64: 771-783

Erwin PM, López-Legentil S, Gonzalez-Pech R, Turon X (2012) A specific mix of generalists: Bacterial symbionts in Mediterranean Ircinia spp. FEMS Microbiology Ecology 79: 619-637

Erwin PM, Olson JB, Thacker RW (2011) Phylogenetic diversity, host-specificity and community profiling of sponge-associated bacterial communities in the northern Gulf of Mexico. PLoS ONE 6(11): e26806

Erwin PM (2011) Corporate codes of conduct: The effects of code content and quality on ethical performance. Journal of Business Ethics 99(4): 535-548

Erwin PM, López-Legentil S, Schuhmann PW (2010) The pharmaceutical value of marine biodiversity for anti-cancer drug discovery.  Ecological Economics 70: 445-451

Erwin PM, Szmant AM (2010) Settlement induction of Acropora palmata planulae by a GLW-amide neuropeptide. Coral Reefs 29(4): 929-939

López-Legentil S, Erwin PM, Pawlik JR, Song B (2010) Effects of sponge bleaching on ammonia-oxidizing Archaea: Distribution and relative expression of ammonia monooxygenase genes associated with the barrel sponge Xestospongia muta. Microbial Ecology 60: 561-571

López-Legentil S, Erwin PM, Henkel TP, Pawlik JR (2010) Phenotypic plasticity in the sponge Callyspongia vaginalis (Porifera; Haplosclerida): Morphological and molecular data. Scientia Marina 74(3): 445-453

Erwin PM, Song B, Szmant AM (2009) Settlement behavior of Acropora palmata planulae: Effects of biofilm age and crustose coralline algal cover. Proceedings of the 11th International Coral Reef Symposium, pp. 1219-1224

Erwin PM, Thacker RW (2008) Cryptic diversity of the symbiotic cyanobacterium Synechococcus spongiarum among sponge hosts. Molecular Ecology 17(12): 2937-2947

Erwin PM, Thacker RW (2008) Phototrophic nutrition and symbiont diversity of two Caribbean sponge-cyanobacteria symbioses. Marine Ecology Progress Series 362: 139-147

Erwin PM, Thacker RW (2007) Incidence and identity of photosynthetic symbionts in Caribbean coral reef sponge assemblages. Journal of the Marine Biological Association of the UK 87(6): 1683-1692

Erwin PM, Thacker RW (2007) Phylogenetic analyses of marine sponges within the order Verongida: A comparison of morphological and molecular data. Invertebrate Biology 126(3): 220-234

Thacker RW, Diaz MC, Rützler K, Erwin PM, Kimble SJA, Pierce MJ, Dillard SL (2007) Phylogenetic relationships among the filamentous cyanobacterial symbionts of Caribbean sponges and a comparison of photosynthetic production between sponges hosting filamentous and unicellular cyanobacteria.  In: Custódio MR, Lôbo-Hajdu G, Hajdu E, and Muricy G (eds). Porifera research: biodiversity, innovation and sustainability. Série Livros 28.  Museu Nacional, Rio de Janeiro, pp. 621-626