Sensitivity of the mussel Mytilus edulis to substrate‑borne vibration in relation to anthropogenically generated noise

© 2015 Inter-Research. Many anthropogenic activities in the oceans involve direct contact with the seabed (for example pile driving), creating radiating particle motion waves. However, the consequences of these waveforms to marine organisms are largely unknown and there is little information on the ability of invertebrates to detect vibration, or indeed the acoustic component of the signal. We quantified sensitivity of the marine bivalve Mytilus edulis to substrate-borne vibration by exposure to vibration under controlled conditions. Sinusoidal excitation by tonal signals at frequencies within the range 5 to 410 Hz was applied during the tests, using the 'staircase' method of threshold determination. Thresholds were related to mussel size and to seabed vibration data produced by anthropogenic activities. Clear behavioural changes were observed in response to the vibration stimulus. Thresholds ranged from 0.06 to 0.55 m s -2 (acceleration, root mean squared), with valve closure used as the behavioural indicator of reception and response. Thresholds were shown to be within the range of vibrations measured in the vicinity of anthropogenic operations such as pile driving and blasting. The responses show that vibration is likely to impact the overall fitness of both individuals and mussel beds of M. edulis due to disruption of natural valve periodicity, which may have ecosystem and commercial implications. The observed data provide a valuable first step to understanding the impacts of such vibration upon a key coastal and estuarine invertebrate which lives near industrial and construction activity, and illustrate that the role of seabed vibration should not be underestimated when assessing the impacts of noise pollution

Water Quality Modeling of the Nitra River (Slovakia): A Comparison of Two Models

IIASA's Water Resources Project deals with the development of least-cost water quality control strategies for degraded river basins in Central and Eastern Europe, which is an important issue due to the lack of financial resources available for environmental management. The Nitra River basin in Slovakia serves as a case study with collaborative research by IIASA, the Water Research Institute (VUVH, Bratislava), and the Vah River Basin Authority from Slovakia. The Nitra River receives large loads of partially or untreated wastewater mostly of municipal origin. The present paper compares the results of two relatively complex water quality models implemented on the Nitra River (which are important elements of developing ambient criteria based control strategies): QUAL2E and RMA2/4q. The well-known QUAL2E is a result of systematic developments by the US EPA over the past twenty years and solves the steady-state advection-diffusion equation for temperature, biochemical oxygen demand (BOD), dissolved oxygen (DO), nitrogen and phosphorus forms, and algae. RMA2/4q was initially developed in the mid-1970s for the US Army Corps of Engineers and has been consistently maintained and extended by Resource Management Associates and researchers at the University of California--Davis. State variables and reaction terms of RMA4q is practically identical to QUAL2E, but it offers more details in computing the flow and physical transport. For the current case, this model was used to solve the unsteady one-dimensional hydrodynamic and advection-diffusion equations for temperature, BOD, and DO. Model comparisons and calibration results showed similar BOD decay rates. DO was overestimated in both models in comparison with DO observations when the O'Connor-Dobbins reaeration method was used. Fixed reaeration coefficients gave better results, with QUAL2E having a larger value than for RMA4q. Sediment oxygen demand was included in the QUAL2E simulations and resulted in better agreement with observed data. Additional data requirements for improved understanding of water quality processes in the Nitra River system are discussed

EVALUATION OF ALPHA AMYLASE CONTAINING CORN ON FINISHING CATTLE PERFORMANCE AND DIGESTIBILTY

One digestion and four finishing trials were conducted to evaluate the effect of a new corn hybrid containing an α-amylase trait, Syngenta Enogen Feed Corn (SYT-EFC) on site and extent of digestion, ruminal fermentation parameters, and feedlot performance. Experiments utilized corn containing the enzymatic gene compared to controls, the near isoline parental corn (NEG) or commercially available corn grain (CON), processed as dry-rolled corn (DRC) or high moisture corn (HMC) in diets with dry [distillers grains plus solubles (DGS)] or wet (Sweet Bran) milling byproducts. The corn grain of the experimental diets were fed as the sole grain source, comprising 100% of the concentrate in the diet. Cattle fed SYT-EFC, processed as DRC with Sweet Bran had increased G:F resulting in feeding values ranging from 103 to 116% of CON or NEG. Steers fed SYT-EFC, processed as DRC with DGS had increased G:F resulting in feeding values ranging from 101 to 107% of CON or 105% of NEG. However, when processed as HMC, feeding SYT-EFC resulted in 96 and 102% that of NEG when fed with Sweet Bran or DGS, respectively. Marbling and 12th rib fat thickness data were mixed among trials with being increased in cattle fed SYT-EFC or observing no detectable difference among treatments. Cattle fed SYT-EFC had greater postruminal starch digestibility compared to NEG resulting in a 2.2 and 6.3% increase in total tract starch digestibility in DGS and Sweet Bran diets, respectively. Overall, feeding corn containing an α-amylase trait as DRC would suggest a slight improvement in feed efficiency. Advisors: James C. MacDonald and Galen E. Erickso

Effects of Field Pea Supplementation on Digestibility and Rumen Volatile Fatty Acid Concentration of Diets Containing High and Low Quality Forages

Five ruminally cannulated steers were used to evaluate the effects of supplementation (no supplement, field peas, or dry rolled corn; 0.43% BW) with high and low quality forages on diet digestibility and rumen volatile fatty acid concentrations. Th e inclusion of field peas increased dry matter intake and organic matter digestibility over dry rolled corn and unsupplemented steers. Propionate proportions were less for field peas and control treatments than dry rolled corn, while acetate proportions increased in field peas, and control treatments as compared to dry rolled corn. As a result, acetate to propionate ratio was reduced when dry rolled corn was supplemented. Inclusion of field peas alters the volatile fatty acid concentrations, increases dry matter intake, and improves organic matter digestibility when supplemented to forage fed steers

Effect of Corn Residue Harvest Method on In Vivo and In Vitro Digestibility

A digestion study was conducted using 18 crossbred wether lambs to evaluate the effects of corn residue harvesting method and ensiling on the digestibility of corn residue. Husks had the greatest digestibility compared to any of the harvesting methods. No differences were observed for the digestibility of husklage, ensiled husklage, or stalklage. None of the harvest methods resulted in residue digestibilities similar to husks

Effect of Harvest Method and Ammoniation on Digestibility and Intake of Corn Residue

The effects of three harvest methods, both with and without ammonia treatment, on the in vivo digestibility and intake of baled corn residue were assessed in a digestion trial with lambs. Treatments included three corn residue harvest methods (conventional rake and bale, New Holland Cornrower™ with eight rows or with two rows of corn stalks chopped into the windrow containing the tailings [leaf, husk and upper stalk] from eight harvested rows) and the effects of ammoniation at 5.5% of DM compared to no ammoniation of the residue. Th e 2- Row baled residue (51.7%) had greater dry matter digestibility than both 8- Row (47.3%) and CONV (44.7%). Ammoniation increased dry matter digestibility by 24% (10 percentage units) across all residue types. Additionally, ammoniation increased intake. Utilizing alternative harvesting technologies and ammoniation can improve the digestibility of baled residue. These effects are additive and combining the two technologies resulted in the greatest improvement in digestibility

Site and Extent of Digestion of Finishing Diets Containing Syngenta Enhanced Feed Corn

Four ruminally and duodenally fistulated steers were utilized to evaluate the effects of Syngenta Enhanced Feed Corn™ containing an alpha amylase enzyme trait (SYT- EFC) compared to the isoline parental control corn without the alpha amylase enzyme trait (Negative Isoline) on site and extent of digestion in finishing diets. Cattle fed SYT- EFC dry rolled corn had numerically greater postruminal starch digestibility, excreted lower fecal starch, and had greater total tract starch digestibility compared to cattle fed Negative Isoline corn. These data would suggest that cattle are able to utilize more starch from corn containing the SYT- EFC trait, which has resulted in greater gains and efficiencies

First Report of ‘CandidatusLiberibacter asiaticus’ Associated with Huanglongbing in Sweet Orange in Ethiopia

Huanglongbing (HLB) is a serious disease of citrus worldwide. Three different ‘Candidatus Liberibacter’ species are associated with HLB: ‘Ca. Liberibacter asiaticus’, ‘Ca. L. africanus’, and ‘Ca. L. americanus’ (1). ‘Ca. L. africanus’ and its vector, Trioza erytreae, are both heat sensitive, and when present, occur in citrus when temperatures remain below 30 to 32°C. In Africa, ‘Ca. L. africanus’ and T. erytreae have been reported in South Africa, Zimbabwe, Malawi, Burundi, Kenya, Somalia, Ethiopia, Cameroon, and Madagascar (1). Inspection of citrus trees in orchards and budwood sources in nurseries located in the warmer citrus-growing areas of Tigray and North Wollo in northern Ethiopia revealed nearly 100 trees with symptoms of leaf yellowing with a blotchy mottle pattern, dead branches, and decreased fruit quality and yield. Two symptomatic sweet orange budwood trees and three symptomatic orchard plants were sampled in April 2009, along with three healthy-looking sweet orange plants. DNA was extracted from 200 mg of desiccated leaf midribs using the CTAB method (4) and subjected to conventional PCR using the primer pairs A2/J5 (2) and OI2/23S1 (3) that amplify the ribosomal protein gene in the rplKAJL-rpoBC operon and the 16S/23S ribosomal intergenic regions, respectively, of ‘Ca. L. africanus’ and ‘Ca. L. asiaticus’. Positive PCR reactions were obtained for all five symptomatic samples with both primer pairs. PCR amplicons of 703 bp (A2/J5) and 892 bp (OI2/23S) recovered from two of these samples were purified, cloned, and sequenced. BLAST analysis revealed that the nucleotide sequences we obtained for the ribosomal protein (GenBank Accessions Nos. GQ890155 and GQ890156) shared 100% identity with each other and 99% identity with sequences of ‘Ca. L. asiaticus’ from Brazil (DQ471904), Indonesia (AB480161), China (DQ157277), and Florida (CP001677). Similarly, the 16S/23S ribosomal intergenic sequences (GU296538 and GU296539) shared 100% identity with each other and 99% identity with homologous ‘Ca. L. asiaticus’ sequences from Brazil (DQ471903), Indonesia (AB480102), China (DQ778016), and Florida (CP001677) and contained two tRNA genes as occurs in ‘Ca. L. asiaticus’ but not in ‘Ca. L. africanus’ (3). To our knowledge, this is the first report of ‘Ca. L. asiaticus’ in Africa. The presence of ‘Ca. L. asiaticus’ is a threat for warmer citrus-growing areas of Africa that are less favorable for ‘Ca. L. africanus’ and T. erytreae. In areas where ‘Ca. L. asiaticus’ was confirmed, symptomatic trees must be promptly eradicated and surveys to determine spread of the disease and its vectors are necessary

Effect of Harvest Method on Digestibility of Corn Residue

Corn residues can be an economical forage source for producers and advanced harvest methods have increased the quality of baled residue. A digestion study was conducted to evaluate the effects of harvest method of corn residues (low- stem, highstem, and conventional) on digestibility in lambs. Samples from total fecal collection were dried 1 of 3 ways to determine effects on digestibility estimates. Corn residue containing low- stem had greatest overall digestibility with high- stem residue being intermediate and conventional harvesting having the lowest digestibility. Drying method had no effect on digestibility estimates

Exposure of benthic invertebrates to sediment vibration: From laboratory experiments to outdoor simulated pile-driving

This is the final version of the article. Available from Acoustical Society of America via the DOI in this record.Fourth International Conference on the Effects of Noise on Aquatic Life, Dublin, Ireland, 10-16 July 2016Activities directly interacting with the seabed, such as pile-driving, can produce vibrations that have the potential to impact benthic invertebrates within their vicinity. This stimuli may interfere with crucial behaviors such as foraging and predator avoidance, and the sensitivity to vibration is largely unknown. Here, the responsiveness of benthic invertebrates to sediment vibration is discussed in relation to laboratory and semi-field trials with two marine species: the mussel (Mytilus edulis) and hermit crab (Pagurus bernhardus). Sensory threshold curves were produced for both species in controlled laboratory conditions, followed by small-scale pile-driving exposures in the field. The merits of behavioral indicators are discussed, in addition to using physiological measures, as a method of determining reception and measuring responses. The measurement and sensors required for sediment vibration quantification are also discussed. Response and threshold data were related to measurements taken in the vicinity of anthropogenic sources, allowing a link between responsiveness and actual operations. The impact of pile-driving on sediment-dwelling invertebrates has received relatively little research, yet the data here suggest that such activities are likely to impact key coastal species which play important roles within the marine environment.LR would like to thank the organizers and sponsors of the 2016 conference for supporting her attendance for which she is extremely grateful. This study was partially funded by a research award from the Malacological Society of London to LR. The authors would also like to acknowledge Defra and NERC who funded the laboratory and field work aspects respectively, and the staff at the OREC field site, Blyth