scholarly journals Precision of Hard Structures Used to Estimate Age of Mountain Whitefish (Prosopium williamsoni)

2015 ◽  
Vol 75 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Carson J. Watkins ◽  
Tyler J. Ross ◽  
Ryan S. Hardy ◽  
Michael C. Quist
Keyword(s):  
Prosopium Williamsoni ◽  
Hard Structures

Sodium dodecyl sulphate as a rapid clearing agent for studying the hard parts of monogeneans and nematodes

2006 ◽  
Vol 80 (1) ◽  
pp. 87-90 ◽  
Author(s):  
W.L. Wong ◽  
W.B. Tan ◽  
L.H.S. Lim
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Simple Technique ◽  
Sodium Dodecyl ◽  
Taxonomic Identification ◽  
Conventional Methods ◽  
Hard Structures

AbstractHard structures of helminths have often been used for taxonomic identification but are usually not clearly defined when treated with conventional methods such as ammonium picrate-glycerin for monogeneans and glycerin for nematodes. The present study reports a rapid and simple technique to better resolve the hard parts of selected monogeneans and nematodes using 5–10% alkaline sodium dodecyl sulphate (SDS). In comparison with established methods, SDS-treated worms become more transparent. In monogeneans treated with SDS, clear details of the hooks, hook filaments, anchors, bars and the sclerotized copulatory organs could be observed. In SDS-treated nematodes, spicules and ornamentations of the buccal capsules could be clearly seen.

Occurrence of the eyefluke, Diplostomum (Diplostomum) baeri bucculentum Dubois et Rausch, 1948, in salmonid fishes of northern British Columbia

1985 ◽  
Vol 63 (2) ◽  
pp. 396-399 ◽  
Author(s):  
Hilda Lei Ching
Keyword(s):  
Rainbow Trout ◽  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Lake Trout ◽  
Infected Fish ◽  
Salmo Gairdneri ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Dolly Varden Salvelinus Malma ◽  
Prosopium Williamsoni

As a result of experimental infections in chicks, diplostomula found in the retina of chinook salmon from the Nechako River were identified as Diplostomum (Diplostomum) baeri bucculentum. Eyeflukes in other salmonids were considered to be the same species based on similar measurements and site in the eyes. These eyeflukes varied in prevalence and mean intensity in seven salmonid species surveyed in nine localities in 1979–1981. The following fish were sampled: rainbow trout (Salmo gairdneri), 505; mountain whitefish (Prosopium williamsoni), 334; lake whitefish (Coregonus clupeaformis), 32; Dolly Varden (Salvelinus malma), 66; lake trout (S. namaycush), 13; kokanee or sockeye salmon (Oncorhynchus nerka), 323; and chinook salmon (O. tshawytscha), 164. Eyeflukes had prevalences ranging from 84 to 100% in six lakes, 64% in the river, 53% in one reservoir site, and a prevalence of 15% in the other reservoir site. Mountain and lake whitefishes had high mean intensities while kokanee had low mean intensities. Correlation of increased intensity with increased fish size was significant for 6 of 27 samples. Four samples of lake whitefish, mountain whitefish, rainbow trout, and chinook salmon showed significant asymmetry when numbers of diplostomula were compared between eyes. More of the heavily infected fish showed asymmetry than did the lightly infected fish.

Beach protection and restoration part I: hard structures and Beach erosion

1989 ◽  
Vol 33 (1-2) ◽  
pp. 29-44 ◽  
Author(s):  
R. H. Charlier ◽  
De Meyer ◽  
D. Decroo
Keyword(s):  
Beach Erosion ◽  
Hard Structures

scholarly journals LARGE-SCALE LABORATORY EXPERIMENTS AND NUMERICAL MODELING OF WAVE FORCE AND PRESSURE ACTING ON THE URBAN STRUCTURES

2020 ◽  
pp. 28
Author(s):  
Dayeon Lee ◽  
Sungwon Shin ◽  
Hyoungsu Park ◽  
Dan Cox
Keyword(s):  
Sea Level ◽  
Large Scale ◽  
Wave Force ◽  
High Elevation ◽  
Coastal Communities ◽  
Submerged Breakwater ◽  
Sea Levels ◽  
Urban Structures ◽  
Overland Flows ◽  
Hard Structures

Low lying coastal communities are most vulnerable to the flooding which causes from sea-level rise (SLR), and extreme coastal flooding events such as hurricanes and tsunami. Notably, the high elevation of sea-levels due to SLR and local tidal conditions could accelerate the damages on the coastal communities. Hard coastal structures such as a submerged breakwater and seawall would consider minimizing the impacts of overland flows to the urban area from the extreme coastal events, but the effectiveness of those hard structures are significantly alter depending on the various waves and sea-level conditions.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/GCOOpB4C3tA

scholarly journals Analysis of beak morphometry of the horned octopus Eledone cirrhosa (Cephalopoda: Octopoda) in the Thracian Sea (NE Mediterranean)

2004 ◽  
Vol 5 (1) ◽  
pp. 143 ◽  
Author(s):  
E. LEFKADITOU ◽  
P. BEKAS
Keyword(s):  
Body Weight ◽  
High Resistance ◽  
Growth Pattern ◽  
Size Estimation ◽  
Digestive Process ◽  
Lower Beak ◽  
New Information ◽  
Ne Mediterranean ◽  
Hard Structures ◽  
Species Taxonomy

Cephalopod beaks are chitinous structures situated in the buccal mass lying at the base of their arms. Because they are among the few hard structures of cephalopods with high resistance to erosion during digestive process in predator stomachs, the study of the beak morphometry is of major importance for the species taxonomy, as well as, for the size estimation of the cephalopods consumed. In this study new information is provided on the dimensions and pigmentation process of the upper and lower beak of the horned octopus Eledone cirrhosa derived from 67 female and 47 male specimens caught by trawl in the Thracian Sea (NE Mediterranean). The growth of both beaks was allometric in relation to the mantle length and body weight. According to the results of covariance analysis, no difference was found in growth pattern of beaks between sexes. Four degrees of pigmentation were identified in both upper and lower beaks, the darkening process starting in females at a smaller size.

scholarly journals The significance and vulnerability of Australian saltmarshes: implications for management in a changing climate

2013 ◽  
Vol 64 (1) ◽  
pp. 66 ◽  
Author(s):  
Neil Saintilan ◽  
Kerrylee Rogers
Keyword(s):  
Sea Level ◽  
Atmospheric Carbon Dioxide ◽  
Services Research ◽  
Goods And Services ◽  
Migratory Shorebirds ◽  
Sporobolus Virginicus ◽  
Past Half Century ◽  
Eastern Australia ◽  
Hard Structures ◽  
Flexible Management

We review the distribution, status and ecology of Australian saltmarshes and the mechanisms whereby enhanced atmospheric carbon dioxide and associated climate change have influenced and will influence the provision of ecosystem goods and services. Research in temperate and subtropical saltmarsh has demonstrated important trophic contributions to estuarine fisheries, mediated by the synchronised mass-spawning of crabs, which feed predominantly on the C4 saltmarsh grass Sporobolus virginicus and microphytobenthos. Saltmarshes also provide unique feeding and habitat opportunities for several species of threatened microbats and birds, including migratory shorebirds. Saltmarshes increased in extent relative to mangrove in Australia in both tide- and wave-dominated geomorphic settings through the latter Holocene, although historic trends have seen a reversal of this trend. Australian saltmarshes have some capacity to maintain elevation with respect to rising sea level, although in south-eastern Australia, the encroachment of mangrove and, in Tasmania, conversion of shrubland to herbfield in the past half-century are consistent with changes in relative sea level. Modelling of the impacts of projected sea-level rise, incorporating sedimentation and other surface-elevation drivers, suggests that the survival of saltmarsh in developed estuaries will depend on the flexible management of hard structures and other impediments to wetland retreat.

Evidence of a geographical variation in Mesochaetopterus (Polychaeta: Chaetopteridae) from the Pacific Ocean

2005 ◽  
Vol 85 (6) ◽  
pp. 1409-1423 ◽  
Author(s):  
Michel R. Bhaud
Keyword(s):  
Pacific Ocean ◽  
New South ◽  
Solomon Islands ◽  
New South Wales ◽  
Morphological Variations ◽  
Geographical Variations ◽  
South Wales ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Hard Structures

Specimens of Mesochaetopterus (Chaetopteridae) from seven geographical sources in the Pacific Ocean are compared on the basis of their hard structures: specialized chaetae, uncinal plates and tubes. There geographical variations are investigated both locally (New South Wales and the Solomon Islands) and over the whole Pacific Ocean from Australia (New South Wales) through the Solomon Islands to Galapagos and Hawaii. The most interesting result is the existence of intra-regional morphological variations with the hard structures differing on specimens sampled in two areas from New South Wales or in two areas from the Solomon Islands out of a total of three areas. These newly described morphologies imply that M. minutus, isolated in a first step from M. sagittarius and confined to the Pacific, is a pseudo-sibling species complex. Each element of this complex is morphologically distinguishable. Consequently the generally accepted role of the long-lived planktonic larvae characteristic of Mesochaetopterus, as a source of geographical homogeneity must be re-examined.

DATA SMOOTHING TECHNIQUES APPLIED TO PROTON MICROPROBE SCANS OF TELEOST HARD PARTS

1992 ◽  
Vol 02 (03) ◽  
pp. 313-323 ◽  
Author(s):  
I.F. WEST ◽  
G.E. COOTE ◽  
R.W. GAULDIE
Keyword(s):  
Life Histories ◽  
Moving Average ◽  
Sampling Point ◽  
Smoothing Techniques ◽  
Data Smoothing ◽  
X Ray ◽  
Proton Microprobe ◽  
Median Filters ◽  
Data Points ◽  
Hard Structures

We use a proton microprobe to examine the distribution of elements in otoliths and scales of teleost (bony) fish. The elements of principal interest are calcium and strontium in otoliths and calcium and fluorine in scales. Changes in the distribution of these elements across hard structures may allow inferences about the life histories of fish. Otoliths and scales of interest are up to a centimeter in linear dimension and to reveal the structures of interest up to 200 sampling points are required in each dimension. The time needed to accumulate high X-ray counts at each sampling point can be large, particularly for strontium. To reduce microprobe usage we use data smoothing techniques to reveal changing patterns with modest X-ray count accumulations at individual data points. In this paper we review performance for revealing pattern at modest levels of X-ray count accumulations of a selection of digital filters (moving average smoothers), running median filters, robust locally weighted regression filters and adaptive spline filters.

scholarly journals Shore Protection Structures Increase and Evolution on the Northern Tuscany Coast (Italy): Influence of Tourism Industry

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1647 ◽  
Author(s):  
Enzo Pranzini ◽  
Giorgio Anfuso ◽  
Irene Cinelli ◽  
Marco Piccardi ◽  
Giovanni Vitale
Keyword(s):  
Negative Impact ◽  
Management Plan ◽  
Tourism Industry ◽  
Beach Erosion ◽  
Shore Protection ◽  
Natural Sediment ◽  
Forcing Function ◽  
Hard Structures ◽  
The 19Th Century ◽  
Protection Structures

Analysis of a large shoreline database (from 1878 to 2017) and recompilation of information on type/age of shore protection structures along the Northern Tuscany, allowed a deep insight of the progressive armouring of this coastal sector. The area experienced beach erosion since the end of the 19th century due to reduced sediment inputs from rivers and harbour constructions. Shore protection structures started to develop at the beginning of the 20th century, first to protect settlements and coastal roads, later to maintain a beach for tourist activity. The changing of the goal and the increasing awareness of the negative impact of some structures resulted in an evolution of coastal defence projects: initially, seawalls and revetments, later detached breakwaters and, more recently, groins. Today, a reduction in hard structures is perceived by removing or lowering detached breakwaters and groins below mean sea level. The forcing function of the growing tourism industry is producing a demand for projects and their design is detailed in this paper: results will be of use in the correct design of a long-term, general, erosion management plan to restore the natural sediment circulation patterns.

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