Sonification and science pedagogy: preliminary experiences and assessments of earth science data presented in an undergraduate general education course

This paper describes preliminary investigations into how sonifications of scientific graphs are perceived by undergraduate students in an introductory course in oceanography at the University of Rhode Island. The goal is to gather data that can assist in gauging students’ levels of engagement with sonification as a component of science education. The results, while preliminary, show promise that sonified graphs improve understanding, especially when they are presented in combination with visual graphs

The metabolic response of pteropods to acidification reflects natural CO2-exposure in oxygen minimum zones

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeosciences 9 (2012): 747-757, doi:10.5194/bg-9-747-2012.Shelled pteropods (Thecosomata) are a group of holoplanktonic mollusks that are believed to be especially sensitive to ocean acidification because their aragonitic shells are highly soluble. Despite this concern, there is very little known about the physiological response of these animals to conditions of elevated carbon dioxide. This study examines the oxygen consumption and ammonia excretion of five pteropod species, collected from tropical regions of the Pacific Ocean, to elevated levels of carbon dioxide (0.10%, 1000 ppm). Our results show that pteropods that naturally migrate into oxygen minimum zones, such as Hyalocylis striata, Clio pyramidata, Cavolinia longirostris and Creseis virgula, were not affected by carbon dioxide at the levels and duration tested. Diacria quadridentata, which does not migrate, responds to high carbon dioxide conditions with reduced oxygen consumption and ammonia excretion. This indicates that the natural chemical environment of individual species may influence their resilience to ocean acidification.Funding of the National Science Foundation (grant OCE-0526502 to Wishner and Seibel, OCE – 0526545 to Daly, and OCE – 0851043 to Seibel), the University of Rhode Island, and the Rhode Island Experimental Program to Stimulate Competitive Research Fellowship Program

Control of deep-sea benthic community structure by oxygen and organic-matter gradients in the eastern Pacific Ocean

At boundaries of oxygen minimum zones (OMZs), bathyal faunas experience steep gradients in oxygen and organic-matter availability. The present study compares changes in microbial, meiofaunal, macrofaunal and megafaunal benthic assemblages along these gradients on Volcano 7, a 2.3-km high seamount in the eastern tropical Pacific. Faunal tolerance to dysaerobic (low oxygen) conditions varies with organism size; microbial and meiofaunal abundances are less affected than macro- and megafaunal abundances. At the exceedingly low concentrations (\u3c0.1 ml/l) encountered on the upper summit of Volcano 7, oxygen appears to exert primary control over abundance, composition and diversity of macrofauna, overriding other factors such as food availability and sediment grain size. When oxygen concentration is sufficient, food availability in sediments (indicated by the presence of labile material such as chlorophyll a) is highly correlated with meiofaunal and macrofaunal abundance. Four distinct physical zones were identified on Volcano 7: (1) the coarse-grained upper summit zone (730–770 m) where near-bottom oxygen concentrations were usually lowest (often \u3c0.1 ml/l) and organic-matter (% organic carbon and chlorophyll a) availability was high, (2) the coarse-grained lower summit (770–1000 m) where near-bottom oxygen concentrations were usually slightly higher (0.11 to 0.16 ml/l) and organic-matter availability remained high, (3) the coarse-grained flank (1000–2000 m) where oxygen concentration was intermediate (0.7–0.9 ml/l) and sediment organic-matter content was very low, and (4) the finer-grained base (2000–3500 m) where oxygen values exceeded 2.5 ml/l, sediment organic carbon was moderate, and chlorophyll a was low. Abundances of larger forms (megafauna and macrofauna) were severely reduced on the upper summit, but attained high values (2.25/m2 and 8,457/m2 respectively) just tens of meters below. The smaller forms (bacteria and meiofauna) attained peak abundances on the low-oxygen upper summit, however, abundances of harpacticoid copepods were greatly reduced on the upper and lower summit, presumably due to oxygen limitation. Macrofaunal abundance and diversity patterns along the Volcano 7 oxygen/enrichment gradient resembled those typically observed along shallow-water gradients of organic pollution. Low densities of a few soft-bodied, low-oxygen tolerant species resided on the upper summit, a high-density, low-diversity assemblage inhabited the lower summit, and low-density, high-diversity assemblages occupied the flank and base sediments. The infaunal communities on Volcano 7 support the idea that OMZ boundaries are regions of enhanced biological activity. Modern faunal distributions and biogenic structures at OMZ boundaries may be useful in reconstructing oxygenation histories of ancient marine basins

Vertical Distribution of Planktic Foraminifera through an Oxygen Minimum Zone: How Assemblages and Shell Morphology Reflect Oxygen Concentrations

Oxygen-depleted regions of the global ocean are rapidly expanding, with important implications for global biogeochemical cycles. However, our ability to make projections of a future deoxygenated ocean is limited by a lack of empirical data with which to test and constrain the behavior of global climatic and oceanographic models. We use depth-stratified plankton tows to demonstrate that some species of planktic foraminifera are adapted to life in the heart of the pelagic Oxygen Minimum Zone (OMZ). In particular, we identify two species, Globorotaloides hexagonus and Hastigerina parapelagica, living within the Eastern Tropical North Pacific OMZ. The shells of the former are preserved in marine sediments and could be used to trace the extent and intensity of low-oxygen pelagic habitats in the fossil record. Additional morphometric analyses of G. hexagonus show that shells found in the lowest oxygen environments are larger, more porous, less dense, and have more chambers in the final whorl. The association of this species with the OMZ and the apparent plasticity of its shell in response to ambient oxygenation invites the use of G. hexagonus shells in sediment cores as potential proxies for both the presence and intensity of overlying OMZs

Biological Signature of Scotian Shelf Water Crossovers on Georges Bank During Spring 1997

Episodic crossovers of cold low salinity Scotian Shelf Water (SSW) onto the Northeast Peak of Georges Bank are a potentially important mechanism transporting plankton species, including the copepod Calanus finmarchicus and its prey and predators, onto the Bank each spring. We provide the first detailed investigation of horizontal and vertical zooplankton distributions in SSW crossovers compared to other onbank locations from three GLOBEC cruises during spring 1997. SSW crossovers are physically and biologically distinct from other Bank locations. In late spring, chlorophyll concentrations and in vivo fluorescence are elevated and light transmission is reduced in SSW, while during early spring, these parameters are more variable. SSW communities do not contain a unique zooplankton assemblage or indicator species but instead show differences in abundance and life history parameters for various taxa compared to other Bank locations. SSW has high abundances of young C. finmarchicus life history stages, almost no diel vertical migration of zooplankton, low abundances of invertebrate predators, and low fish egg abundance. Population development of C. finmarchicus in SSW lags that in adjacent water. The potential biological impact of SSW crossovers on Georges Bank varies seasonally. In April, density inversions and interleaving of SSW and non‐SSW suggest active mixing, resulting in similar community composition of SSW and adjacent non‐SSW. SSW crossovers are probably an important source to Georges Bank of young stages of C. finmarchicus in early spring. In May, after stratification strengthens, the greater differentiation between SSW plankton and elsewhere indicates that mixing between communities is more limited

Journey of a Swallowed Toothbrush to the Colon

Toothbrush swallowing is a rare event. Because no cases of spontaneous passage have been reported, prompt removal is recommended to prevent the development of complications. Most swallowed toothbrushes have been found in the esophagus or the stomach of affected patients, and there has been no previously reported case of a toothbrush in the colon. Here, we report a case of a swallowed toothbrush found in the ascending colon that caused a fistula between the right colon and the liver, with a complicating small hepatic abscess. This patient was successfully managed using exploratory laparotomy. To our knowledge, this is the first documented case of a swallowed toothbrush found in the colon

Distribution and diel vertical movements of mesopelagic scattering layers in the Red Sea

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Biology 159 (2012): 1833-1841, doi:10.1007/s00227-012-1973-y.The mesopelagic zone of the Red Sea represents an extreme environment due to low food concentrations, high temperatures and low oxygen waters. Nevertheless, a 38 kHz echosounder identified at least four distinct scattering layers during the daytime, of which the 2 deepest layers resided entirely within the mesopelagic zone. Two of the acoustic layers were found above a mesopelagic oxygen minimum zone (OMZ), one layer overlapped with the OMZ, and one layer was found below the OMZ. Almost all organisms in the deep layers migrated to the near-surface waters during the night. Backscatter from a 300 kHz lowered Acoustic Doppler Current Profiler indicated a layer of zooplankton within the OMZ. They carried out DVM, yet a portion remained at mesopelagic depths during the night. Our acoustic measurements showed that the bulk of the acoustic backscatter was restricted to waters shallower than 800 m, suggesting that most of the biomass in the Red Sea resides above this depth.This research is based in part on work supported by Award Nos. USA 00002, KSA 00011 and KSA 00011/02 made by KAUST to the Woods Hole Oceanographic Institution