scholarly journals CHANGES DUE TO JETTIES AT TILLAMOOK BAY, OREGON

1976 ◽  
Vol 1 (15) ◽  
pp. 103 ◽  
Author(s):  
Paul D. Komar ◽  
Thomas A. Terich
Keyword(s):  
Coastal Erosion ◽  
New South ◽  
Littoral Drift ◽  
Erosion And Deposition ◽  
Oregon Coast ◽  
The North ◽  
The Pacific ◽  
Tillamook Bay ◽  
Severe Erosion ◽  
The Pacific Ocean

Bayocean Spit, separating Tillamook Bay from the Pacific Ocean on the north Oregon coast, underwent severe erosion following construction of a north jetty at the bay entrance in 1914-17. This erosion ultimately led to the complete breaching of the spit in 1952. Simultaneous to the spit erosion south of the entrance, the shoreline north of the north jetty advanced seaward by some 600 m (2000 ft). This pattern of erosion and deposition following jetty construction has generally been interpreted as the jetty blocking a large north to south net littoral drift in the area, estimated by a previous study at 620,000 m3/yr (800,000 yd3/yr). Our reexamination of the shoreline changes and patterns of erosion and deposition following jetty construction disagrees with this interpretation, and instead we conclude that all of the changes resulted from local rearrangements of the beach due to the disrupted equilibrium following jetty construction, but at the same time maintaining an overall condition of zero net littoral drift. This interpretation is supported by other evidence that indicates a near-zero net drift on this portion of the Oregon coast. Thus severe coastal erosion can result from jetty construction even in areas of zero net littoral drift. A new south jetty has been recently completed (1974). The result has been further realignments of the shoreline with accretion and shore-: line advance immediately south of the south jetty. This provides further confirmation that a zero net littoral drift exists in the area. This study also demonstrates the effects of building only a single jetty rather than a pair of jetties. Following construction of the north jetty, the outer bar or ebb-tide delta at the Tillamook Bay inlet grew appreciably in size.

scholarly journals Research Gap Analysis of Remote Sensing Application in Fisheries: Prospects for Achieving the Sustainable Development Goals

2021 ◽  
Vol 13 (5) ◽  
pp. 1013
Author(s):  
Kuo-Wei Yen ◽  
Chia-Hsiang Chen
Keyword(s):  
Sustainable Development ◽  
Indian Ocean ◽  
Atlantic Ocean ◽  
The Sustainable Development ◽  
The North ◽  
The Pacific ◽  
Development Goals ◽  
The Indian Ocean ◽  
The Pacific Ocean ◽  
Research Hotspots

Remote sensing (RS) technology, which can facilitate the sustainable management and development of fisheries, is easily accessible and exhibits high performance. It only requires the collection of sufficient information, establishment of databases and input of human and capital resources for analysis. However, many countries are unable to effectively ensure the sustainable development of marine fisheries due to technological limitations. The main challenge is the gap in the conditions for sustainable development between developed and developing countries. Therefore, this study applied the Web of Science database and geographic information systems to analyze the gaps in fisheries science in various countries over the past 10 years. Most studies have been conducted in the offshore marine areas of the northeastern United States of America. In addition, all research hotspots were located in the Northern Hemisphere, indicating a lack of relevant studies from the Southern Hemisphere. This study also found that research hotspots of satellite RS applications in fisheries were mainly conducted in (1) the northeastern sea area in the United States, (2) the high seas area of the North Atlantic Ocean, (3) the surrounding sea areas of France, Spain and Portugal, (4) the surrounding areas of the Indian Ocean and (5) the East China Sea, Yellow Sea and Bohai Bay sea areas to the north of Taiwan. A comparison of publications examining the three major oceans indicated that the Atlantic Ocean was the most extensively studied in terms of RS applications in fisheries, followed by the Indian Ocean, while the Pacific Ocean was less studied than the aforementioned two regions. In addition, all research hotspots were located in the Northern Hemisphere, indicating a lack of relevant studies from the Southern Hemisphere. The Atlantic Ocean and the Indian Ocean have been the subjects of many local in-depth studies; in the Pacific Ocean, the coastal areas have been abundantly investigated, while offshore local areas have only been sporadically addressed. Collaboration and partnership constitute an efficient approach for transferring skills and technology across countries. For the achievement of the sustainable development goals (SDGs) by 2030, research networks can be expanded to mitigate the research gaps and improve the sustainability of marine fisheries resources.

Little-known arctic species Montacuta spitzbergensis (Bivalvia: Montacutidae) from the north-western Pacific with notes on Montacuta substriata and Tellimya ferruginosa

2008 ◽  
Vol 88 (2) ◽  
pp. 347-356 ◽  
Author(s):  
Gennady M. Kamenev
Keyword(s):  
Sea Of Okhotsk ◽  
First Record ◽  
Western Pacific ◽  
The Arctic ◽  
Arctic Species ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
North Western ◽  
North Western Pacific

An expanded description of a little-known arctic species Montacuta spitzbergensis from the Sea of Okhotsk with new data on its morphology, ecology and geographical distribution is given. This is the first record of M. spitzbergensis from the north-western Pacific. It differs from other species of Montacuta in its large (to 8.4 mm), elongate–ovate, thick shell with wide, slightly curved hinge plate, wide, short, and shallow resilifer, and weakly developed external ligament. This species occurs in the Arctic Ocean (Spitsbergen, Barents, Kara, Laptev and Chukchi Seas) and the Pacific Ocean (Sea of Okhotsk) at depths from 9 to 232 m at a bottom temperature from −1.62°C to +2.50°C. The hinge structure of the type species of the genera Montacuta and Tellimya is also discussed.

scholarly journals Quaternary Marine Mollusk Associations of the Last Interglacials in North Patagonia (Argentina): Paleoecology and Paleoclimates

2021 ◽  
Author(s):  
M.P. Charó
Keyword(s):  
Habitat Heterogeneity ◽  
Buenos Aires ◽  
Global Changes ◽  
Buenos Aires Province ◽  
The North ◽  
Rio Negro ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Crassostrea Rhizophorae ◽  
Mis 5E

Deposits of different Quaternary marine transgressions are largely exposed in the Argentine north Patagonian littoral (39°15′S–41°02′S), south of the Buenos Aires and north of Río Negro provinces. The malacological associations of 84 sites were studied. Among them, 31 belong to Pleistocene deposits of the interglacials ≥ MIS 9, MIS 7, MIS 5e, 29 to Holocene deposits of the interglacial MIS 1, and 24 sites of modern beaches. These sites yielded 7385 fossils among valves and shells, of 78 species (42 bivalves and 36 gastropods), including 11 micromolluskan species. The record of the bivalves Crassostrea rhizophorae in the south of the Buenos Aires Province, and Anomalocardia brasiliana (both currently inhabiting lower latitudes), and very likely the gastropod Tegula atra (inhabiting today the Pacific Ocean) in the north of Río Negro Province, suggests that interglacials MIS 7, MIS 5e and MIS 1 were warmer than today. However, the associations determined for the studied interglacials have not changed in their composition, but in abundance of species, except for the latitudinal shifts of the three mentioned species, and the presence of cold to temperate water taxa since the MIS 1 in the ecotonal area of the north of Río Negro Province. Changes in the associations of northern Patagonia during the Quaternary derived from global changes (sea surface temperature, salinity, etc.), and the existence of habitat heterogeneity in each of the areas, that enabled the co-existence of different bivalve and gastropod species of the local benthic marine malacofauna.

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.

scholarly journals Biogeochemistry of the North Atlantic during oceanic anoxic event 2: role of changes in ocean circulation and phosphorus input

2014 ◽  
Vol 11 (4) ◽  
pp. 977-993 ◽  
Author(s):  
I. Ruvalcaba Baroni ◽  
R. P. M. Topper ◽  
N. A. G. M. van Helmond ◽  
H. Brinkhuis ◽  
C. P. Slomp
Keyword(s):  
Pacific Ocean ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Primary Productivity ◽  
Low Oxygen ◽  
Deep Basin ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The North Atlantic

Abstract. The geological record provides evidence for the periodic occurrence of water column anoxia and formation of organic-rich deposits in the North Atlantic Ocean during the mid-Cretaceous (hereafter called the proto-North Atlantic). Both changes in primary productivity and oceanic circulation likely played a role in the development of the low-oxygen conditions. Several studies suggest that an increased input of phosphorus from land initiated oceanic anoxic events (OAEs). Other proposed mechanisms invoke a vigorous upwelling system and an ocean circulation pattern that acted as a trap for nutrients from the Pacific Ocean. Here, we use a detailed biogeochemical box model for the proto-North Atlantic to analyse under what conditions anoxia could have developed during OAE2 (94 Ma). The model explicitly describes the coupled water, carbon, oxygen and phosphorus cycles for the deep basin and continental shelves. In our simulations, we assume the vigorous water circulation from a recent regional ocean model study. Our model results for pre-OAE2 and OAE2 conditions are compared to sediment records of organic carbon and proxies for photic zone euxinia and bottom water redox conditions (e.g. isorenieratane, carbon/phosphorus ratios). Our results show that a strongly elevated input of phosphorus from rivers and the Pacific Ocean relative to pre-OAE2 conditions is a requirement for the widespread development of low oxygen in the proto-North Atlantic during OAE2. Moreover, anoxia in the proto-North Atlantic is shown to be greatly influenced by the oxygen concentration of Pacific bottom waters. In our model, primary productivity increased significantly upon the transition from pre-OAE2 to OAE2 conditions. Our model captures the regional trends in anoxia as deduced from observations, with euxinia spreading to the northern and eastern shelves but with the most intense euxinia occurring along the southern coast. However, anoxia in the central deep basin is difficult to achieve in the model. This suggests that the ocean circulation used in the model may be too vigorous and/or that anoxia in the proto-North Atlantic was less widespread than previously thought.

IX. Contributions to terrestrial magnetism.—No. IV

1843 ◽  
Vol 133 ◽  
pp. 113-143 ◽  
Keyword(s):  
Pacific Ocean ◽  
West Coast ◽  
China Seas ◽  
North West ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Times ◽  
The China Seas

In the present number of these Contributions, I resume the consideration of Captain Sir Edward Belcher’s magnetic observations, of which the first portion, viz. that of the stations on the north-west coast of America and adjacent islands, was discussed in No. II. The return to England of Her Majesty’s ship Sulphur by the route of the Pacific Ocean, and her detention for some months in the China Seas, have enabled Sir Edward Belcher to add magnetic determinations at thirty-two stations to those at the twenty-nine stations previously recorded. In the notice of the earlier observations, a provisional coefficient was employed in the formula for the temperature corrections of the results with the intensity needles, as no experiments had then been made for the determination of their individual co­efficients. As soon therefore as Sir Edward Belcher had completed the observation of the times of vibration of those needles at Woolwich, as the concluding station of the series made with them, Lieut. Riddell, R. A. undertook the determination of their several coefficients, which was performed in the manner and with the results described in the subjoined memorandum.

scholarly journals Species Composition and New Records of Diatom Taxa on Phyllodictyon pulcherrimum (Chlorophyceae) from the Gulf of California

Diversity ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 339
Author(s):  
Francisco Omar López-Fuerte ◽  
David Alfaro Siqueiros Beltrones ◽  
María del Carmen Altamirano-Cerecedo
Keyword(s):  
Gulf Of California ◽  
New Records ◽  
American Continent ◽  
Epiphytic Diatoms ◽  
Taxonomic Analysis ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
First Time ◽  
The North Pacific

A taxonomic analysis of diatoms found on Phyllodictyon pulcherrimum yielded a total of 244 diatom taxa (all illustrated) within 27 orders, 45 families, and 86 genera. The Taxa were briefly documented in a list including identification references and morphometric data. Thirty-eight of the taxa identified at the species and infraspecific levels represent new records for the coasts of Mexico. Seven were recorded for the first time on the American continent: Auricula flabelliformis, A. pulchra, Campylodiscus scalaris, Coscinodiscus mesoleius, Dimeregramma fulvum, Navicula palpebralis var. angulosa, and Seminavis barbarae, and one, Nitzschia fusiformis, for the Pacific Ocean. This is the second record of the chlorophyte P. pulcherrimum in the north Pacific and the third for Mexican waters. The results confirm that surveying rare macroalgae species as hosts for epiphytic diatoms provides opportunities to seek new records of diatom taxa, or even new taxa, in regions around the world.

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