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: https://naturemicrobiologycommunity.nature.com/posts/the-shipwreck-anona-a-microbial-island-under-sea

-RDM

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