Mesoscale Aggregations of Euphausiid Sound Scattering Layers on the Continental Shelf of Vancouver Island

1989 ◽  
Vol 46 (7) ◽  
pp. 1238-1249 ◽  
Author(s):  
Yvan Simard ◽  
David L. Mackas
Keyword(s):  
Continental Shelf ◽  
High Frequency ◽  
Dry Weight ◽  
Distribution Patterns ◽  
Vancouver Island ◽  
Horizontal Distribution ◽  
Swimming Behavior ◽  
Shelf Break ◽  
Shelf Area ◽  
Vertical And Horizontal Distribution

High frequency acoustics (104 kHz) and stratified (BIONESS) net tows were used to map the vertical and horizontal distribution of macrozooplankton scattering layers on and seaward of the continental shelf off Vancouver Island, in June and August of 1986. The macrozooplankton scattering layers were dominated by euphausiids, primarily Euphausia pacifica and Thysanoessa spinifera. During both surveys, dense aggregations were found in the same two general regions. The first was along the shelf break, where highest biomass was observed (averages over a few kilometres of transect reaching to about 200 mg dry weight∙m−3 = about 40 individuals∙m−3 and > 4 g dry weight∙m−2). A second, broader and more diffuse aggregation occupied the deeper southeast end of the shelf (area about 200 km2, biomass 1–2 g∙m−2). The scattering layers showed a consistent diel vertical migration. Daytime depth was deeper at the shelf break (~ 150–200 m) than on the shelf (~ 100–150 m) and occasionally extended to the bottom. These day-depths corresponded to the California Undercurrent waters of 6–7 °C, a salinity of 33.75–34‰ and sigma-T > 26.5. Distribution patterns were coincident with those of upwelled regions, high phytoplankton biomass, and high hake and herring biomass. They were also associated with the shelf break jet and the recurrent Tully eddy. There is a strong possibility of aggregation in restricted areas through the coupling of advection and vertical swimming behavior of the animals.

Size divergence and dietary partitioning enhance coexistence of two herbivorous species of Diaptomus (Copepoda: Calanoida) in some shallow Quebec lakes

1992 ◽  
Vol 70 (5) ◽  
pp. 1016-1028 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
Edward J. Maly
Keyword(s):  
Distribution Patterns ◽  
Significant Negative Correlation ◽  
Geographic Region ◽  
Horizontal Distribution ◽  
Sympatric Populations ◽  
Blue Green Algae ◽  
Diet Preference ◽  
Diaptomus Oregonensis ◽  
Vertical And Horizontal Distribution ◽  
Herbivorous Species

We examined the vertical and horizontal distribution patterns of Diaptomus minutus Lilljeborg and Diaptomus oregonensis Forbes in several shallow Quebec lakes where they occurred allopatrically and sympatrically within a small geographic region. Both species overlapped extensively in their vertical and temporal distributions and were found to be positively associated within and among lakes. Although size displacement could not be detected when body lengths of sympatric and allopatric populations were compared, in lakes where there was a reduction in size overlap between species, the two species coexisted at relatively high densities. This contrasted with situations where convergence in size between species was accompanied by a limited abundance of one or both diaptomids. We conducted stomach-content analyses on the sympatric populations of two of these lakes to determine if diet preference was related to copepod size divergence, and if algae were selected as a function of copepod size. We found that D. minutus, the smaller copepod, preferentially ingested a number of small algal particles (< 10 μm), whereas D. oregonensis, the larger copepod, tended to ingest a greater number of larger particles. Although preference for small algae (Selenastrum and small blue–green algae) was negatively correlated with prosome length, preference for larger algal taxa (Planktosphaerium, centric diatoms such as Melosira, and Achnanthes) was positively correlated with diaptomid size. There were, however, differences with respect to the degree of diet overlap between species in the two lakes, which was reflected in a significant negative correlation between dietary and size overlap. These observations are consistent with the hypothesis that reduction in size overlap has resulted in reduced exploitative competition, and that divergence in size and diet may be the mechanism that allows D. minutus and D. oregonensis to coexist when food becomes limiting.

Distribution of intertidal benthic algae in the vicinity of Townsville, tropical Australia

1980 ◽  
Vol 31 (2) ◽  
pp. 175 ◽  
Author(s):  
Y Ngan ◽  
IR Price
Keyword(s):  
Animal Species ◽  
Benthic Algae ◽  
Distribution Patterns ◽  
Horizontal Distribution ◽  
Vertical And Horizontal Distribution ◽  
Tropical Australia ◽  
Marine Algal

The vertical and horizontal distribution of 144 benthic marine algal taxa (25 of the Chlorophyta, 21 of the Phaeophyta, 92 of the Rhodophyta and 6 of the Cyanophyta) in the intertidal region in the vicinity of Townsville was investigated. The distribution patterns are discussed in relation to the zonation of animal species in the region and compared with information available for other tropical shores.

scholarly journals Spatial distribution by Canistropsis microps (E. Morren ex Mez) Leme (Bromeliaceae: Bromelioideae) in the Atlantic rain forest in Ilha Grande, Southeastern Brazil

2007 ◽  
Vol 67 (3) ◽  
pp. 467-474 ◽  
Author(s):  
AF. Nunes-Freitas ◽  
CFD. Rocha
Keyword(s):  
Rain Forest ◽  
Vegetative Reproduction ◽  
Inverse Correlation ◽  
Distribution Patterns ◽  
Horizontal Distribution ◽  
High Rate ◽  
Southeastern Brazil ◽  
Atlantic Rain Forest ◽  
Maximum Height ◽  
Vertical And Horizontal Distribution

Canistropsis microps (Bromeliaceae: Bromelioideae) is an endemic species of Atlantic rain forest areas in Rio de Janeiro State, which are very abundant in not very disturbed forests in Ilha Grande, on the southern coast of the State. In this study, we analyzed the vertical and horizontal distribution patterns of the species in an area of rain forest with little evidence of disturbance at Vila Dois Rios, Ilha Grande, relating the patterns to sunlight in the microhabitat. We also identified the types of substrate used by the species and the rate of asexual reproduction. Canistropsis microps had high densities (estimated at 84,425 rosettes/ha), and has an aggregated distribution (Id = 2.86). About 80% of the rosettes were generated by clonal growth, whereas less than 20% were produced from seedlings. Most of the rosettes were found on straight tree trunks (DBH > 50 cm). There was a significant inverse correlation between the incidence of sunlight in the habitat and the abundance of individuals. Rosettes were found up to a maximum height of 9.5 m, but most occured between 1.5 and 5.5 m, where light varied from 25 to 50 µmol.s-1.m-2. We conclude that vertical and horizontal distribution patterns in C. microps may be partially explained by the occurrence of appropriate substrate, an intensity of sunlight favorable to the development of the species and to a high rate of vegetative reproduction.

scholarly journals Influence of the Columbia River plume (USA) on the vertical and horizontal distribution of mesozooplankton over the Washington and Oregon shelf

2008 ◽  
Vol 65 (3) ◽  
pp. 477-483 ◽  
Author(s):  
Jay O. Peterson ◽  
William T. Peterson
Keyword(s):  
Continental Shelf ◽  
Juvenile Fish ◽  
Columbia River ◽  
Horizontal Distribution ◽  
River Plume ◽  
Zooplankton Abundance ◽  
Depth Sensor ◽  
River Plumes ◽  
Vertical And Horizontal Distribution ◽  
Columbia River Plume

Abstract Peterson, J. O., and Peterson, W. T. 2008. Influence of the Columbia River plume (USA) on the vertical and horizontal distribution of mesozooplankton over the Washington and Oregon shelf. – ICES Journal of Marine Science, 65: 477–483. River plumes extending out over continental shelf waters have distinct frontal boundaries along their leading edges that concentrate highly buoyant particles, including zooplankton. The margin between the base of the plume and the underlying oceanic waters is often many times larger in spatial extent than the visible surface front, but the influence of this region of a river plume on the vertical and horizontal distribution of zooplankton is less well understood. Using a laser optical plankton counter (LOPC) and a conductivity–temperature–depth sensor (CTD) mounted to a rapidly undulating tow body, we examined the horizontal and vertical distribution of zooplankton proximate to the Columbia River plume, to study how plume waters affect zooplankton over the continental shelf. Overall, vertically integrated zooplankton abundance and biovolume was elevated close to “aged” plume waters. Zooplankton tended to aggregate near the surface close to river plume waters. When plume waters are present at the surface, zooplankton aggregations tended to be in the upper 10 m of the water column, compared with 25 m when the plume was not present. The presence of river plumes may be ecologically and energetically important to surface feeding planktivores such as larval and juvenile fish.

scholarly journals Musik Gamelan Bali Meningkatkan Pertumbuhan dan Produktivitas Tanaman Sawi Pakcoy (Brassica rafa L.)

2018 ◽  
Vol 6 (2) ◽  
pp. 73
Author(s):  
Dewa Putu Yoga Gautama ◽  
I Made Anom S. Wijaya ◽  
I Wayan Widia
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
High Frequency ◽  
Dry Weight ◽  
Sound Waves ◽  
High Frequency Sound ◽  
Frequency Sound ◽  
Green Leaves ◽  
Mustard Plant ◽  
Canopy Area

Pemberian gelombang suara dengan frekuensi tinggi dapat merangsang mulut daun  (stomata) tetap terbuka, akibatnya laju dan efisiensi penyerapan pupuk meningkat yang bermanfaat bagi tanaman. Hasil penggunaan sonic bloom pada tanaman adalah mampu menstimulir metabolisme sel-sel tanaman, sehingga terjadi peningkatan penyerapan nutrisi dan uap air lewat daun yang berpengaruh pada pertumbuhan dan produktivitas tanaman. Tujuan dari penelitian ini yaitu (1) untuk mengetahui pengaruh pemberian musik Gamelan Bali terhadap pertumbuhan dan produktivitas tanaman sawi pakcoy dan (2) untuk menentukan jenis musik Gamelan Bali yang memberikan pertumbuhan dan produktivitas sawi pakcoy yang terbaik. Penelitan ini menggunakan tanaman sawi pakcoy (Brassica Rafa L.).  Perlakuan yang diberikan  dalam penelitian adalah pemberian musik gamelan bali dengan nuansa musik yang berbeda. Perlakuan 1 menggunakan musik gamelan Angklung, Perlakuan 2 menggunakan musik gamelan Semarpagulingan dan Perlakuan 3 menggunakan musik gamelan Gong Kebyar. Data yang diperoleh dianalis ANOVA dengan program IBM SPSS 20. Variabel yang diamati yaitu tinggi tanaman, luas kanopi daun tanaman, tingkat kehijauan daun tanaman, dan berat kering. Hasil penelitian menunjukan bahwa pemberian musik gong kebyar menghasilkan nilai tertinggi pada variabel tinggi tanaman, luas kanopi daun, tingkat kehijauan daun, dan berat kering yang  masing menghasilkan nilai yaitu yaitu 29,98 cm, 1684 cm2, 186,79, dan 68,61 gr. Pemberian musik memberikan pengaruh yang positif dan berbeda nyata pada pertumbuhan tanaman sawi pakcoy. Semakin tinggi frekuensi musik yang diberikan maka semakin baik pertumbuhan tanaman sawi pakcoy yang dihasilkan.  High frequency sound waves can stimulate the mouth of leaf (stomata) remains opened.The stomata remains open leading to efficient absorption of fertilizer. The purposes of this research were (1) to find out the effect of Balinese instrument music on the growth and productivity of pakcoy mustard plant and (2) to determine the type of Balinese instrument music that gives the best growth and productivity of mustard pakcoy. The treatment of this research was the application of Balinese instrument music with different musical nuances for 3 hours. Treatment 1 was using Angklung instruments music, treatment 2 was using Semarpagulingan instrument music and treatment 3 using Gong Kebyar instrument music. The obtained data was analized by ANOVA with the IBM SPSS 20 program. The observed variables include plant height, canopy area of plant leaf, green leaves level and dry weight. The results showed that Gong Kebyar instrument music application produces the highest value of 29.98 on the height of the plant variables, the widest value of 1684 cm2  on the canopy area variables, the biggest value that is 68,61 gr on the dry weight variables and the largest value of 186.79 on the green leaves level variables. Balinese instrument music application effect to the growth of pakcoy mustard plant. The best plant growth was the plant with gong kebyar instrument music application from all observed variables.

Sign in / Sign up

Export Citation Format

Share Document