New Publication Alert! Historic Wooden Shipwrecks Influence Dispersal of Deep-Sea Biofilms

The research article “Historic Wooden Shipwrecks Influence Dispersal of Deep-Sea Biofilms” by Rachel Moseley, Dr. Justyna Hampel, Rachel Mugge, and Dr. Leila Hamdan was published in Frontiers in Marine Science. This research was done as part of the Microbial Stowaways project.

Wood arrives on the seabed from natural and anthropogenic sources (e.g., wood falls and wooden shipwrecks, respectively) and creates seafloor habitats for macro-, meio- and microbiota. The way these habitats shape microbial communities and their biogeographic patterns in the deep sea requires study. The objective of this work was to investigate how historic wooden-hulled shipwrecks impact the dispersal of wood-colonizing microbial biofilms. The study addressed how proximity to wooden shipwrecks shapes diversity, richness, and community composition in the surrounding environment. Study sites included two historic shipwrecks in the northern Gulf of Mexico identified as wooden-hulled sailing vessels dating to the late 19th century. Two experimental microbial recruitment arrays containing pine and oak samples were deployed by remotely operated vehicle proximate (0–200 m) to each shipwreck and used to establish new wooden habitat features to be colonized by biofilms. The experiments remained in place for approximately 4 months, were subsequently recovered, and biofilms were analyzed using 16S rRNA gene amplification and sequencing for bacteria and archaea and ITS2 region amplification and sequencing for fungi to determine alpha diversity metrics and community composition. The work examined the influence of wood type, proximity to shipwrecks, and environmental context on the biofilms formed on the surfaces. Wood type was the most significant feature shaping bacterial composition, but not archaeal or fungal composition. Proximity to shipwrecks was also a significant influence on bacterial and archaeal composition and alpha diversity, but not on fungal communities. In all 3 domains, a peak in alpha diversity and richness was observed on pine and oak samples placed ~125 m from the shipwrecks. This peak may be evidence of an ecotone, or convergence zone, between the shipwreck influenced seabed and the surrounding seafloor. This study provides evidence that historic wooden shipwrecks influence microbial biofilm dispersal in the deep sea.

For the full article:

This article also received media attention including this article from Newsweek:

Thanks for following our research!!


New Publication Alert! “Microbiomes respond predictably to built habitats on the seafloor” published in Molecular Ecology

A new paper from the Hamdan Lab was published in Molecular Ecology. “Microbiomes respond predictably to built habitats on the seafloor” was led by Dr. Justyna Hampel with Rachel Moseley and Dr. Leila Hamdan. The study addresses the impact of shipwrecks on surrounding seafloor microbiomes by using 762 deep-sea sediment samples from around nine shipwrecks in the Gulf of Mexico.

The seafloor contains complex ecosystems where habitat heterogeneity influences biodiversity. Natural biological and geological features including vents, seeps and reefs create habitats that select for distinct populations of micro- and macrofauna. While largely studied for macrobiological diversity, built habitats may also select distinct microbiomes. Built habitat density on the seafloor is increasing with ocean sprawl expanding in the continental shelf and slope, potentially having widespread effects on benthic communities. This study addresses one type of built habitat, shipwrecks, on microbiomes in surrounding sediment. Using deep-sea sediment samples (762 total) from the Gulf of Mexico, we report elevated diversity and a predictable core microbiome around nine shipwrecks. We show the sphere of influence of built habitats extends up to 300 m onto the seafloor. Supervised learning made predictions of sample proximity to structures based on frequency of taxa. Strongest predictions occurred in sediments nearest and furthest from sites for archaea and mid-transect for bacteria. The response of archaea to built habitats was consistent across sites, while bacteria showed greater between site variability. The archaeal core shipwreck microbiome was enriched in taxa (e.g., Bathyarchaeia, Lokiarchaeia, Thermoplasmata) not present in the surrounding seafloor. Shipwrecks shaped microbiomes in expected ways, providing insight on how built habitats impact microbiome biodiversity in the Anthropocene.

Check out the full paper to learn more!


Smithsonian Magazine Quotes Dr. Hamdan

Smithsonian Magazine recently released an article titled “How Shipwrecks Shape the Seafloor”. The article interviews several shipwreck researchers, including Dr. Leila Hamdan, to discuss how sunken vessels influence marine ecosystems. Shipwreck ecosystems are vitally important to understand and our lab at The University of Southern Mississippi is continuing to make discoveries in the field.

As Dr. Hamdan said at the end of the article, ‘“All you need to do is, wherever you are right now, look out your window,” Hamdan said. Consider how humans have shaped the terrestrial world and the distribution of organisms within it. We’re doing that with the seafloor as well, we just don’t see it,” she said. “We now know that human debris is changing the most fundamental units of life on the seabed, just by being there.”’

Read the full article here:

Stay tuned to our website to continue learning about our research. We have two new publications coming soon!


Dr. Hamdan quoted in Popular Science article

Popular Science published an article February 23, 2022 titled “There’s a lot we don’t know about the International Space Station’s ocean grave”. This article interviewed deep-sea scientists, including Dr. Leila Hamdan, to understand how the sinking of the International Space Station in the Pacific Ocean may impact marine life.

A highlight of Dr. Hamdan from the article: ‘“That’s going to be a really large human structure with a lot of human materials in it, that is now sitting on the seafloor,” She says. “It would be naive to think that that’s not going to change the ecology that’s present.”’

The article explores how humans continue to impact the deep sea and how important it is to continue to study these important environments. Read the full article online here:


New Publication Alert! “Deep-sea wooden shipwrecks influence sediment microbiome diversity” published in Limnology and Oceanography

We have a new article published in Limnology and Oceanography titled “Deep-sea wooden shipwrecks influence sediment microbiome diversity”. The paper, by Dr. Justyna Hampel and colleagues, investigated the influence of two historic wooden shipwrecks, from the Microbial Stowaways project, on sediment microbiomes in the deep sea.

Historic shipwrecks function as habitats for benthic organisms by providing food, refuge, and structure. They also form islands of biodiversity on the seabed, shaping microbial ecology and ecosystem processes. This study examined two wooden deep-sea shipwrecks at 525 and 1800 m water depth and probed their influence on sediment microbiomes and geochemistry. Microbiomes were investigated with 16S rRNA gene amplicon sequencing along 60 m transects extending in four directions from the hulls of the shipwrecks. Distance from shipwrecks and sediment depth both shaped microbiome structure. Archaeal alpha diversity was significantly and positively correlated with proximity to the deeper shipwreck while bacterial diversity was not to either. Archaeal community structure differed at both sites; the deeper site had a higher proportion of Bathyarchaeia and Lokiarchaeia proximate to shipwreck compared to the shallow location. Major bacterial communities were consistent at both sites, however, at the deeper site had higher abundance of Bacteroidetes, Chloroflexi, Desulfofarculales, and Desulfobacteriales. Core microbiome and differential abundance analyses revealed unique taxa nearest the shipwrecks compared to the surrounding seabed including organoheterotrophs, and cellulolytic and sulfur cycling taxa. Sediment carbon content influenced microbiome structure near the shipwrecks (5–10 m). We show that shipwrecks have a distinct sediment microbiome and form unique habitat patches on seabed, resembling those surrounding organic falls. The shipwreck influence was more pronounced at the deeper site, further from terrestrial influences, signaling shipwrecks may be a significant source of organic matter in far-shore oligotrophic settings.

The full paper is available online now! And stay tuned, the next paper from the Microbial Stowaways project is coming soon!


Coastal Sciences Graduate Fellowship in Support of Diversity

The Department of Coastal Sciences of the University of Southern Mississippi School of Ocean Science and Engineering is pleased to announce the availability of graduate fellowships in support of diversity to prospective students seeking a M.S. or Ph.D. degree. These fellowships are awarded competitively and are intended to support the recruitment of graduate students from historically underrepresented groups in coastal and marine science who demonstrate scholarly promise. Additional information on the Department of Coastal Sciences and the Coastal Sciences graduate program are available at Candidates must contact potential faculty advisors in the Department of Coastal Sciences to discuss their research and educational interests and must identify a faculty sponsor prior to submitting a fellowship application. The graduate school application fee for students applying to the Coastal Sciences Graduate Fellowship in Support of Diversity will be waived. Mississippi residents who fall under historically underrepresented groups in coastal and marine science are particularly encouraged to apply.

Application Deadline

June 30, 2021

(Spring 2022 admission to the graduate program)

Additional Information

Location: The University of Southern Mississippi Gulf Coast Research Laboratory in Ocean Springs, MS

Salary: $1,900/month (M.S.) or $1,950/month (Ph.D). Salary increases $50/month when the student advances to candidacy. Additional benefits include a tuition waiver and health insurance.

Contact:, 228.818.8887

How to Apply

To be considered for a fellowship, applicants will be required to submit the following by the application deadline:

1. A CV

2. Official transcripts

3. A statement of purpose

4. Three letters of recommendation. (It is the responsibility of the applicant to ensure recommendation letters are submitted by the deadline.)

5. An essay that speaks to the candidate’s inclusion in one or more historically underrepresented groups in higher education. This essay is separate and in addition to the statement of purpose but should be submitted with the statement of purpose as a single PDF.

For all admission applications (undergraduate, graduate, or international) visit

The Essay

Applicants should use the essay to articulate how their experiences and background have influenced their career to this point (including how those experiences influenced their decision to apply for graduate school). Within this statement, applicants should provide insight about how they could contribute to a scholarly environment that values inclusivity and diversity. Applicants should also consider their potential in contributing to the inclusivity of COA, USM, and their broader field of study, as applicable. The essay should be a maximum of two pages. Applicants should use this essay to address how one or more of the following identities or experiences, and their intersections,
apply to them.
• Member of an ethnic or racial group underrepresented or marginalized in graduate education and coastal and marine science, including but not limited to Black, Indigenous (American Indian/Alaskan Native, Native Hawaiian or other Native Pacific Islander) and/or Latinx
• First-generation college student
• McNair or Mellon Mays Undergraduate Scholar
• Other identities and experiences including, but not limited to:
− Being of a gender and/or sexual orientation identity historically underrepresented
− Those who identify as a military veteran
− Those that manage a disability
− Those who have experienced housing or food insecurity
− Single parents

The candidates will be initially evaluated based on the completeness of their application, their academic records (as evidenced through their CV and transcripts), their potential to flourish in the COA program (as evidenced through their statement of purpose and letters of recommendation), and potential to contribute to diversity, equity, and inclusion in the Division of Coastal Sciences (as evidenced in their essay). The three top candidates will then be asked for an on-campus or virtual interview with faculty and students from the Division of Coastal Sciences. Preference for Mississippi residents from historically underrepresented groups in coastal and marine science may be shown if all other marks between applicants are equal.

New Publication Alert! Study revealing deep-sea shipwrecks represent island-like ecosystems for marine microbiomes published in The ISME Journal

In April, we published a research article in The ISME Journal titled “Deep-sea shipwrecks represent island-like ecosystems for marine microbiomes”. The paper, by Dr. Leila Hamdan and colleagues, investigated the influence a deep-sea shipwreck, Anona, exerts on sediment microbiomes in the deep sea.

Biogeography of macro- and micro-organisms in the deep sea is, in part, shaped by naturally occurring heterogeneous habitat features of geological and biological origin such as seeps, vents, seamounts, whale and wood-falls. Artificial features including shipwrecks and energy infrastructure shape the biogeographic patterns of macro-organisms; how they influence microorganisms is unclear. Shipwrecks may function as islands of biodiversity for microbiomes, creating a patchwork of habitats with influence radiating out into the seabed. Here we show microbiome richness and diversity increase as a function of proximity to the historic deep-sea shipwreck, Anona, in the Gulf of Mexico. Diversity and richness extinction plots provide evidence of an island effect on microbiomes. A halo of core taxa on the seabed was observed up to 200 m away from the wreck indicative of the transition zone from shipwreck habitat to the surrounding environment. Transition zones around natural habitat features are often small in area compared to what was observed at Anona, indicating shipwrecks may exert a large sphere of influence on seabed microbiomes. Historic shipwrecks are abundant, isolated habitats with global distribution, providing a means to explore contemporary processes shaping biogeography on the seafloor. This work is a case study for how built environments impact microbial biodiversity and provides new information on how arrival of material to the seafloor shapes benthic microbiomes.

Check out the full paper online! Also, check out Dr. Hamdan’s “Behind the Paper” here:


A Thesis & A Thank You

I recently defended my Master’s Thesis “How Historic Shipwrecks Influence Dispersal of Deep-sea Microbiomes”. My thesis investigated how historic (> 50 years old) wooden shipwrecks influence dispersal of deep-sea microbiomes by placing introduced wood on the seafloor in near proximity (0-200 m) to wooden-hulled historic shipwrecks in the northern Gulf of Mexico (GoM). Biofilms formed on experiments were analyzed for microbiome richness, diversity, and phylogenetic composition. Richness and diversity decreased with decreasing proximity to both shipwrecks revealing historic shipwrecks may function as island-like habitats. The phylogenetic composition analysis shows strong selection by wood type for bacteria, and highlights differences in bacteria, archaea, and fungi dispersal patterns. The results of my thesis show that built structures, like shipwrecks, impact microbial biogeography in the deep sea. I will be working through the summer to publish this research.

Conducting this research was challenging, but extremely exciting. I am grateful to all the people who assisted me and helped make this thesis and my defense a success. I could not have done it without my advisor and lab mates standing with me (even through 8-foot seas on the recovery cruise for my experiments). I could not have done it without our collaborators and those who helped on the research cruises aboard USM’s R/V Point Sur. I could also not have done it without the support of my family. Thank you all. I have thoroughly enjoyed my time as a graduate student in the Hamdan Lab and at USM. #SMTTDeep

-Rachel D Moseley

A historic wooden shipwreck, Site 15470, that was discovered during the course of this thesis work.

Hamdan Lab in New York Times

We are very excited to share that our research on shipwreck microbiomes was recently featured in the New York Times! Article “Microbes Point the Way to Shipwrecks” by Katherine Kornei was published in February 2020 and highlights our newest findings from two studies presented at the Ocean Sciences Meeting 2020 in San Diego. Check out the article to find out more about steel yacht Anona, the two wooden shipwrecks we explored last summer, and their microbiomes!


Bow of Anona, sank in 1944 in the Gulf of Mexico