Extracting ecological metrics from archeological surveys of shipwrecks using submersible video and laser-line scanning

Ecological metrics derived from habitat surveys can provide information necessary to understand population, community, and ecosystem processes. Here, we present a case study on the feasibility of extracting ecological metrics from archeological studies of shipwrecks. Even though shipwrecks that are the focus of archeological surveys also form habitat for diverse flora and fauna, shipwrecks are often studied separately by archeologists and ecologists. Conducting joint archeological and ecological surveys promises to maximize research resources and outputs, yet this cross-disciplinary approach is rare. Here, we test the feasibility of extracting ecological metrics from archeological surveys of two historically significant and deep (200 m) shipwrecks, the German U-boat U-576 and the Nicaraguan freighter SS Bluefields, which sank in close proximity to one another on the continental shelf of North Carolina, USA during World War II. First, we assessed fish density, community composition, behavior, and spatial distribution on these shipwrecks using video and laser-line scanning data collected from human-occupied submersibles during archeological surveys. Second, we examined the ecological benefits and biases of pairing laser-line scanning and video surveys designed for archeological specifications. Our approach allowed us to pinpoint locations of fish around the shipwrecks and to identify these fish to fine taxonomic levels. The extracted ecological data revealed that both shipwrecks hosted high densities (U-576 38.2 ± 4.0; SS Bluefields 32.0 ± 18.0 per along-ship transect) of demersal fishes, including grouper species, and that fish concentrated around high-relief shipwreck features. More broadly, our findings demonstrate the utility and benefits of collecting multipurpose and cross-disciplinary data and provide a proof-of-concept for conducting joint archeological and ecological studies.

Duke Scholars

Author Avery Paxton Marine Science and Conservation