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A Machine Learning, Multi-Band Spectral Reflectance Clustering Approach for Examining Physical Transformations in Landfast Sea Ice Environments Affected by Spring Freshets

SSRN

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SSRN 2025年

作者： Catipovic, Luka Laney, Samuel R. Woods Hole Oceanographic Institution Woods HoleMA United States The MIT-WHOI Joint Program in Oceanography/Applied Ocean Science and Engineering Cambridge and Woods Hole MA United States City College of New York New YorkNY United States

Highlights• ML algorithms can classify water and sea ice characteristics in the coastal Arctic.• Spring freshet runoff over sea ice is optically distinct from surface melt ponds.• Time-series analyses of satellite ima... 详细信息

关键词： Sea ice

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Novel presentation and pathophysiology of heavy parasitic burdens in Weddell seals (Leptonychotes weddellii) during sedation

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BMC Veterinary Research 2025年第1期21卷 1-12页

作者： Shero, Michelle R. Burek-Huntington, Kathy McCorkell, Robert Nadler, Steven A. Rzucidlo, Caroline L. Klink, Amy C. Hindle, Allyson G. Burns, Jennifer M. Johnson, Shawn Biology Department Woods Hole Oceanographic Institution Woods Hole MA United States Alaska Veterinary Pathology Services Eagle River AK United States Faculty of Veterinary Medicine University of Calgary Calgary Canada Department of Entomology and Nematology University of California Davis Davis CA United States MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering Woods Hole and Cambridge MA United States School of Life Sciences University of Nevada Las Vegas Las Vegas NV United States Department of Biological Sciences Texas Tech University Lubbock TX United States Sea Change Health Sunnyvale CA United States

Background: Marine mammals act as sentinel species, with top predators’ overall health reflecting their ecosystem, integrated across multiple trophic levels. Yet apparently healthy wild animals may have significant subclinical pathology that goes undetected due to unknown medical histories. Marine mammals, particularly phocid seals, often suffer from heavy parasite burdens. While there are documented cases of severe respiratory infections resulting in complications during sedation, there have been no reports of gastrointestinal parasites contributing to poor outcomes during examinations requiring sedation or anesthesia. This report describes two unique presentations of high intestinal parasite loads that purportedly predisposed Weddell seals (Leptonychotes weddellii) to complications under sedation, and characterizes underlying pathology. Case presentation: Two adult female Weddell seals exhibited prolonged apnea and vomiting while under intravenous sedation, that led to aspiration and mortality despite resuscitation attempts. Post-mortem examination revealed a severe Diphyllobothrium tapeworm impaction in the duodenum, with the parasitic mass causing a partial or complete obstruction. In both cases, the stomach was remarkably distended, suggesting the parasitic mass slowed gastric emptying. Both animals’ stomachs contained a high parasite burden with roundworms embedded into the mucosa. Histological analysis identified underlying pathological conditions that were likely parasite related, including chronic pneumonia associated with lungworm infestations, reactive, depleted and fibrosed lymph nodes, granulomatous lymphadenitis and hepatitis. Further examination in one of the animals revealed severe gastritis and necrotizing duodenitis at the site of the cestode infection. Conclusions: To our knowledge, this is the first description of a significant gastrointestinal parasitic impaction being linked to acute distress during sedation in a marine mammal. We provide an in

关键词： Cestode Duodenitis Gastritis Inflammation Nematode Obstruction Parasite Pinniped Weddell seal

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Distributed Certifiably Correct Range-Aided SLAM

arXiv

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arXiv 2025年

作者： Thoms, Alexander Papalia, Alan Velasquez, Jared Rosen, David M. Narasimhan, Sriram Sensing and Robotics for Infrastructure Laboratory University of California Los Angeles Los Angeles United States The Massachusetts Institute of Technology The MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering Woods Hole CambridgeMA United States Robust Autonomy Lab Northeastern University BostonMA United States

Reliable simultaneous localization and mapping (SLAM) algorithms are necessary for safety-critical autonomous navigation. In the communication-constrained multi-agent setting, navigation systems increasingly use point-to-point range sensors as they afford measurements with low bandwidth requirements and known data association. The state estimation problem for these systems takes the form of range-aided (RA) SLAM. However, distributed algorithms for solving the RA-SLAM problem lack formal guarantees on the quality of the returned estimate. To this end, we present the first distributed algorithm for RA-SLAM that can efficiently recover certifiably globally optimal solutions. Our algorithm, distributed certifiably correct RA-SLAM (DCORA), achieves this via the Riemannian Staircase method, where computational procedures developed for distributed certifiably correct pose graph optimization are generalized to the RA-SLAM problem. We demonstrate DCORA’s efficacy on real-world multi-agent datasets by achieving absolute trajectory errors comparable to those of a state-of-the-art centralized certifiably correct RA-SLAM algorithm. Additionally, we perform a parametric study on the structure of the RA-SLAM problem using synthetic data, revealing how common parameters affect DCORA’s performance. Copyright © 2025, The Authors. All rights reserved.

关键词： Navigation systems

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Domoic acid induces developmental stage-specific effects on microglia in zebrafish

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Harmful Algae 2025年 146卷 102862页

作者： Hidayat, Alia S. Pitt, Jordan A. Fredricks, Helen Hahn, Mark E. Aluru, Neelakanteswar Biology Department and Woods Hole Center for Oceans and Human Health Woods Hole Oceanographic Institution Woods Hole 02543 MA United States Massachusetts Institute of Technology (MIT) – Woods Hole Oceanographic Institution (WHOI) Joint Graduate Program in Oceanography and Oceanographic Engineering United States Marine Chemistry and Geochemistry department Woods Hole Oceanographic Institution Woods Hole 02543 MA United States Center for American Progress WA 20002 DC United States Exponent Inc 1075 Worcester Street Natick 01760 MA United States

Harmful algal blooms (HABs), driven by warming oceans and increased eutrophication, are negatively affecting aquatic ecosystems as well as human health. Blooms of diatom Pseudo-nitzschia spp. produce a neurotoxin, domoic acid (DA), which can be concentrated by filter feeders, including shellfish. Consumption of DA-contaminated seafood causes amnesic shellfish poisoning. DA causes well-established effects on neurons, inducing neurotoxicity by binding to ionotropic glutamate receptors. However, its effects on non-neuronal cells including microglia, the resident immune cells in the brain, are less well understood. Microglia play critical roles in brain health, and disruptions in microglial activity during development can have long-term impacts on brain function and disease risk. The objective of this study was to examine the effects of developmental DA exposure on microglia using zebrafish (Danio rerio). We characterized effects of DA exposure on microglial abundance and morphology at two developmental stages (2 and 4 days post-fertilization (dpf)). We additionally assessed impacts on cell death, cytokine expression, and startle response behavior. In older larvae (4 dpf), microglial effects occurred only at the highest dose (0.3 ng DA per larvae) and coincided with severe morphological defects. In contrast, 2 dpf exposure to lower doses (0.1 ng DA per embryo) caused transient tremors without gross abnormalities but exposure to either 0.1 or 0.3 ng DA per larvae increased microglial abundance and altered microglial morphology. In contrast, 4 dpf exposure to 0.3 ng DA per larvae reduced microglial numbers. Increases in mRNA levels of il1b, il4, and tgfb were observed after 4 dpf exposure, but no significant cytokine changes were detected at 2 dpf. Overall, the effects of DA are highly developmental stage-specific, with microglial reactivity occurring at doses that do not cause gross morphological changes. These findings suggest that neuroinflammation may arise at lower D

关键词： Amnesic shellfish poisoning Brain Glial cells Glutamate receptor Harmful algal blooms Neurotoxicity

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Rapid recovery of an arctic lake ecosystem from a pulse disturbance caused by thermokarst failure

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Oecologia 2025年第6期207卷 1-16页

作者： Budy, Phaedra Pennock, Casey. A. Messenger, Sarah Pehrson, Hunter Adler, Emily Thiede, Gary P. Christman, Natasha R. Crump, Byron C. Giblin, Anne E. Kling, George W. U.S. Geological Survey Utah Cooperative Fish and Wildlife Research Unit Utah State University Logan UT United States Department of Watershed Sciences Utah State University Logan UT United States Department of Evolution Ecology and Organismal Biology and Aquatic Ecology Laboratory The Ohio State University Columbus OH United States The Ecosystems Center Marine Biological Laboratory Woods Hole Falmouth MA United States College of Earth Ocean and Atmospheric Sciences Oregon State University Corvallis OR United States Department of Ecology and Evolutionary Biology University of Michigan Ann Arbor MI United States MIT-WHOI Joint Program in Oceanography and Applied Ocean Science and Engineering Department of Marine Chemistry and Geochemistry Woods Hole Oceanographic Institution Woods Hole Falmouth MA United States Department of Integrative Biology University of Wisconsin Madison WI United States

Due to rapid climate change, arctic ecosystems are experiencing an increase in disturbances including localized land-surface failures caused by melting ground ice (thermokarst failures). These failures result in the mass transport of sediment and organic materials into surface waters, with the potential to dramatically alter aquatic ecosystem function and biotic interactions. We coupled direct comparisons and long-term data of a suite of abiotic and biotic variables in a thermokarst-impacted lake and nearby reference lake to assess the impacts of thermokarst failure. After the thermokarst failure and relative to long-term averages, water transparency was substantially reduced. We hypothesized there would be subsequent changes to lower trophic levels and profound declines in fish foraging efficiency. However, these characteristics were within the range of natural variability and/or rapidly recovered to values within the range of long-term variability. In addition, although there was limited evidence of taxa-specific changes, we did not observe any strong changes in the total relative densities, growth rates, or composition of the bacterioplankton and zooplankton communities, benthic macroinvertebrates, or changes in fish diet, that could be attributed statistically to the thermokarst event. In sum, the thermokarst disturbance had substantial effects on water transparency and some lower trophic levels, which surprisingly were not manifested in higher trophic levels. Overall, the lake ecosystem appeared resistant to thermokarst disturbance with rapid recovery within two years after the disturbance. © The Authors. Parts of this work were authored by US Federal Government authors and are not under copyright protection in the US;foreign copyright protection may apply. 2025.

关键词： Climate change Fish Microbe Warming Water quality Zooplankton

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Corrigendum to “Biochemical implications of the Bottom Boundary Layer Detachment at the Mid-Atlantic Bight shelf-break front” [Continent. Shelf Res. 286 (2025) 105408]

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Continental Shelf Research 2025年 288卷

作者： Serena Negroni Dennis J. McGillicuddy Glen G. Gawarkiewicz Paolo Oddo Nadia Pinardi Department of Physics and Astronomy (DIFA) University of Bologna Bologna 40126 Italy MIT/WHOI Joint Program in Oceanography/Applied Ocean Sciences and Engineering Woods Hole 02543 MA USA Woods Hole Oceanographic Institution Woods Hole 02543 MA USA

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CUREE: A Curious Underwater Robot for Ecosystem Exploration

CUREE: A Curious Underwater Robot for Ecosystem Exploration

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IEEE International Conference on Robotics and Automation (ICRA)

作者： Yogesh Girdhar Nathan McGuire Levi Cai Stewart Jamieson Seth McCammon Brian Claus John E. San Soucie Jessica E. Todd T. Aran Mooney Woods Hole Oceanographic Institution (WHOI) MIT-WHOI Joint Program in Oceanography/Applied Ocean Science and Engineering

The current approach to exploring and monitoring complex underwater ecosystems, such as coral reefs, is to conduct surveys using diver-held or static cameras, or deploying sensor buoys. These approaches often fail to capture the full variation and complexity of interactions between different reef organisms and their habitat. The CUREE platform presented in this paper provides a unique set of capabilities in the form of robot behaviors and perception algorithms to enable scientists to explore different aspects of an ecosystem. Examples of these capabilities include low-altitude visual surveys, soundscape surveys, habitat characterization, and animal following. We demonstrate these capabilities by describing two field deployments on coral reefs in the US Virgin Islands. In the first deployment, we show that CUREE can identify the preferred habitat type of snapping shrimp in a reef through a combination of a visual survey, habitat characterization, and a soundscape survey. In the second deployment, we demonstrate CUREE's ability to follow arbitrary animals by separately following a barracuda and stingray for several minutes each in midwater and benthic environments, respectively.

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An Algorithm for the Numerical Evaluation of the Hankel Transform

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Proceedings of the IEEE 1978年第2期66卷 264-265页

作者： Oppenheim, Alan V. Frisk, George V. Martinez, David R. Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge MA 02139 United States Woods Hole Oceanographic Institution Woods Hole MA. United States MIT-WHOI Joint Program in Oceanography/Oceanographic Engineering Woods Hole MA. United States

A. procedure is proposed for the numerical evaluation of the Hankel (Fourier-Bessel) transform of any integer order using die FFT algorithm. The basis for the procedure is the “projection-slice” theorem associated with the Two-Dimensional Fourier transform. Copyright © 1978 by The Institute of Electrical and Electronics Engineers, Inc.

关键词： Fourier transforms Coordinate measuring machines Sea measurements Contracts Equations Oceans Acoustic waves Optical reflection Acoustic reflection Biomedical optical imaging

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Development of a six-degree of freedom simulation model for the REMUS autonomous underwater vehicle

Development of a six-degree of freedom simulation model for ...

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OCEANS

作者： T. Prestero MIT/WHOI Joint Program in Oceanographic Engineering USA

Describes the development and verification of a six degree of freedom, non-linear simulation model for the REMUS AUV, the first such model for this platform. In this model, the external forces and moments resulting from hydrostatics, hydrodynamic lift and drag, added mass, and the control inputs of the vehicle propeller and fins are all defined in terms of vehicle coefficients. The paper briefly describes the derivation of these coefficients. The equations determining the coefficients, as well as those describing the vehicle rigid-body dynamics, are left in non-linear form to better simulate the inherently non-linear behavior of the vehicle. Simulation of the vehicle motion is achieved through numeric integration of the equations of motion. The simulator output is then verified against vehicle dynamics data collected in experiments performed at sea. The simulator is shown to accurately model the motion of the vehicle. The paper concludes with recommendations for future model validation experiments.

关键词： Underwater vehicles Vehicle dynamics Remotely operated vehicles Propellers Nonlinear equations Marine vehicles Hydrodynamics Automotive engineering Life testing Costs

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oceanographic pursuit: Networked control of multiple vehicles tracking dynamic ocean features

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Methods in oceanography 2014年 10卷 21-43页

作者： Reed, Brooks Hover, Franz Massachusetts Institute of Technology Department of Mechanical Engineering Cambridge 02139 MA United States MIT-WHOI Joint Program Woods Hole Oceanographic Institution Woods Hole MA United States

We present an integrated framework for joint estimation and pursuit of dynamic features in the ocean, over large spatial scales and with multiple collaborating vehicles relying on limited communications. Our approach uses ocean model predictions to design closed-loop networked control at short time scales, and the primary innovation is to represent model uncertainty via a projection of ensemble forecasts into local linearized vehicle coordinates. Based on this projection, we identify a stochastic linear time-invariant model for estimation and control design. The methodology accurately decomposes spatial and temporal variations, exploits coupling between sites along the feature, and allows for advanced methods in communication-constrained control. Simulations with three example datasets successfully demonstrate the proof-of-concept. © 2014 The Authors.

关键词： Autonomous underwater vehicles Collaborative control Ensemble forecasts Feature tracking Linearization System identification

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