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1. Burrowing dynamics of aquatic worms in soft sediments

   https://doi.org/10.1073/pnas.1911317116  

   Kudrolli, Arshad; Ramirez, Bernny (December 2019, Proceedings of the National Academy of Sciences)

   We investigate the dynamics of Lumbriculus variegatus in water-saturated sediment beds to understand limbless locomotion in the benthic zone found at the bottom of lakes and oceans. These slender aquatic worms are observed to perform elongation–contraction and transverse undulatory strokes in both water-saturated sediments and water. Greater drag anisotropy in the sediment medium is observed to boost the burrowing speed of the worm compared to swimming in water with the same stroke using drag-assisted propulsion. We capture the observed speeds by combining the calculated forms based on resistive-force theory of undulatory motion in viscous fluids and a dynamic anchor model of peristaltic motion in the sediments. Peristalsis is found to be effective for burrowing in noncohesive sediments which fill in rapidly behind the moving body inside the sediment bed. Whereas the undulatory stroke is found to be effective in water and in shallow sediment layers where anchoring is not possible to achieve peristaltic motion. We show that such dual strokes occur as well in the earthworm Eisenia fetida which inhabits moist sediments that are prone to flooding. Our analysis in terms of the rheology of the medium shows that the dual strokes are exploited by organisms to negotiate sediment beds that may be packed heterogeneously and can be used by active intruders to move effectively from a fluid through the loose bed surface layer which fluidizes easily to the well-consolidated bed below. 

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2. Formation of diagenetic siderite in modern ferruginous sediments

   https://doi.org/10.1130/G46100.1  

   Vuillemin, Aurèle; Wirth, Richard; Kemnitz, Helga; Schleicher, Anja M.; Friese, André; Bauer, Kohen W.; Simister, Rachel; Nomosatryo, Sulung; Ordoñez, Luis; Ariztegui, Daniel; et al (April 2019, Geology)
3. Persistence of aerially-sprayed naled in coastal sediments

   https://doi.org/https://doi.org/10.1016/j.scitotenv.2021.148701  

   Bamiduro, Gbemisola J.; Kumar, Naresh; Solo-Gabriele, H.M.; Zahran, Elsayed M. (January 2021, Science of the total environment)

   null (Ed.)

   Aerial sprays of the organophosphate pesticide, naled, were intensified over beach areas during the summer of 2016 to control the locally-acquired Zika outbreak in the continental U.S. Concerns were raised in beach frequented areas about contaminated sediments. The aim of this study was to evaluate the persistence and levels of naled and its byproduct, dichlorvos, in sediments obtained from the affected areas. Laboratory experiments were designed to simulate the effect of various natural conditions on the decomposition of naled in three sediment types (beach sand, marl, and calcinated beach sand). The three sediment samples were also exposed to field aerial sprays. After 30 min of exposure, more dichlorvos was detected in the sediments than naled, with 33 to 43% of the molar concentration initially applied as either naled or dichlorvos. Under dark conditions, trace levels of naled were observed after 24 h on sediments. Higher temperature accelerated the natural decomposition of both naled and dichlorvos in sediments. The half-life of naled ranged from 3 to 5 h at 22.5 °C and ranged from 1 to 3 h at 30 °C. Expedited decomposition of naled was observed under sunlight conditions with a half-life of naled of 20 min. In the field, only dichlorvos was detected in the sediment samples at concentrations between 0.0011 and 0.0028 μmol/g 1 h after aerial sprays. This data can be used towards a risk assessment that evaluates exposures to naled and dichlorvos through beach sands impacted by aerial spray activities. 

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4. Resuscitation of Microalgae from Mississippi River Plume Sediments

   https://doi.org/10.18785/gcr.3001.15  

   Chaplin, Chase C.; Tabor, Marnie; Marquez, Israel A.; Maiti, Kanchan; Krause, Jeffrey W. (January 2019, Gulf and Caribbean Research)
5. Preservation of brevetoxins in Southwest Florida coastal sediments

   https://doi.org/10.1016/j.hal.2022.102222  

   Javaruski, James; Adhikari, Puspa L.; Muller, Joanne; Parsons, Michael L. (May 2022, Harmful Algae)