COMPETITION AND COEXISTENCE IN A RARE NORTHEASTERN PACIFIC MULTISPECIES SEAGRASS BED

The increase of temperature might affect the distribution and reproduction of seagrass. This research aims to determine the seagrass bed coverage and the ecosystem condition. Three line transects were established perpendicular to the coastal line with the distance of 50-100 m, or up to the border of the intertidal area. In each transect, sampling points were determined with a distance of 10-20 m. At the sampling points, a plot of 50 cm x 50 cm was established to measure the coverage percentage of seagrass vegetation. The seagrass species were also observed and recorded along the line transects. The percentage of seagrass coverage was measured using a method from Saito and Atobe (1994). The results showed that the coastal area of Jelenga has the highest percentage of seagrass coverage (>60%, healthy) among other coastal areas. This may be caused by the characteristic of Jelenga coast which was relatively calm, few visitors, low water turbidity, and high light penetration. While, other transects have percentage coverage of less than 60% (less healthy). There was one transect on Maluk coast which has coverage percentage of less than 29% (lack of seagrass species). The small coverage percentage on Maluk coast can be caused by the high number of visitors and high activity of fishing boats around the coast which results in high turbidity. Keywords: coverage, ecosystem condition, seagrass bed, west Sumbawa.

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Distribution of Growth-Inhibiting Bacteria against the Toxic Dinoflagellate Alexandrium catenella (Group I) in Akkeshi-Ko Estuary and Akkeshi Bay, Hokkaido, Japan

Applied Sciences ◽

10.3390/app11010172 ◽

2020 ◽

Vol 11 (1) ◽

pp. 172

Author(s):

Yuka Onishi ◽

Akihiro Tuji ◽

Atsushi Yamaguchi ◽

Ichiro Imai

Keyword(s):

Surface Waters ◽

Seagrass Bed ◽

Bacterial Strains ◽

Toxic Dinoflagellate ◽

Sequence Analyses ◽

Alexandrium Catenella ◽

Group I ◽

Colony Forming Units ◽

Rrna Sequences ◽

Growth Inhibiting

The distribution of growth-inhibiting bacteria (GIB) against the toxic dinoflagellate Alexandrium catenella (Group I) was investigated targeting seagrass leaves and surface waters at the seagrass bed of Akkeshi-ko Estuary and surface waters of nearshore and offshore points of Akkeshi Bay, Japan. Weekly samplings were conducted from April to June in 2011. GIBs were detected from surface of leaves of the seagrass Zostera marina in Akkeshi-ko Estuary (7.5 × 105–4.7 × 106 colony-forming units: CFU g−1 wet leaf) and seawater at the stations in Akkeshi Bay (6.7 × 100–1.1 × 103 CFU mL−1). Sequence analyses revealed that the same bacterial strains with the same 16S rRNA sequences were isolated from the surface biofilm of Z. marina and the seawater in the Akkeshi Bay. We therefore strongly suggested that seagrass beds are the source of algicidal and growth-inhibiting bacteria in coastal ecosystems. Cells of A.catenella were not detected from seawaters in Akkeshi-ko Estuary and the coastal point of Akkeshi Bay, but frequently detected at the offshore point of Akkeshi Bay. It is suggested that A.catenella populations were suppressed by abundant GIBs derived from the seagrass bed, leading to the less toxin contamination of bivalves in Akkeshi-ko Estuary.

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Climate change and a poleward shift in the distribution of the Pacific white-sided dolphin in the northeastern Pacific

Endangered Species Research ◽

10.3354/esr00252 ◽

2010 ◽

Vol 11 ◽

pp. 13-19 ◽

Cited By ~ 20

Author(s):

CJ Salvadeo ◽

D Lluch-Belda ◽

A Gómez-Gallardo ◽

J Urbán-Ramírez ◽

CD MacLeod

Keyword(s):

Climate Change ◽

The Pacific ◽

Northeastern Pacific ◽

Poleward Shift

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Orbiniella nuda new species (Orbiniidae) and nine new records of other sedentariate polychaetous annelids from Washington and British Columbia

Canadian Journal of Zoology ◽

10.1139/z74-011 ◽

1974 ◽

Vol 52 (1) ◽

pp. 69-75 ◽

Cited By ~ 3

Author(s):

Katharine D. Hobson

Keyword(s):

British Columbia ◽

New Species ◽

Pacific Ocean ◽

New Records ◽

Descriptive Information ◽

Northeastern Pacific

Orbiniella nuda, new species, is newly described from Washington. Naineris quadricuspida, Pygospio elegans, Pherusa negligens, Asclerocheilus beringianus, Euzonus williamsi, Barantolla americana, Decamastus gracilis, Mediomastus capensis, and Stygocapitella subterranea are newly recorded from Washington or from Washington and British Columbia. Most of these species have not previously been reported from the cold temperate northeastern Pacific Ocean. In addition, new descriptive information is provided for some species.

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A Climatology of 500-hPa Closed Lows in the Northeastern Pacific Ocean, 1948–2011

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-13-0223.1 ◽

2014 ◽

Vol 53 (6) ◽

pp. 1578-1592 ◽

Cited By ~ 19

Author(s):

Nina S. Oakley ◽

Kelly T. Redmond

Keyword(s):

United States ◽

Pacific Ocean ◽

Interannual Variability ◽

West Coast ◽

The United States ◽

Western United States ◽

The West ◽

Reanalysis Dataset ◽

The Pacific ◽

Northeastern Pacific

AbstractThe northeastern Pacific Ocean is a preferential location for the formation of closed low pressure systems. These slow-moving, quasi-barotropic systems influence vertical stability and sustain a moist environment, giving them the potential to produce or affect sustained precipitation episodes along the west coast of the United States. They can remain motionless or change direction and speed more than once and thus often pose difficult forecast challenges. This study creates an objective climatological description of 500-hPa closed lows to assess their impacts on precipitation in the western United States and to explore interannual variability and preferred tracks. Geopotential height at 500 hPa from the NCEP–NCAR global reanalysis dataset was used at 6-h and 2.5° × 2.5° resolution for the period 1948–2011. Closed lows displayed seasonality and preferential durations. Time series for seasonal and annual event counts were found to exhibit strong interannual variability. Composites of the tracks of landfalling closed lows revealed preferential tracks as the features move inland over the western United States. Correlations of seasonal event totals for closed lows with ENSO indices, the Pacific decadal oscillation (PDO), and the Pacific–North American (PNA) pattern suggested an above-average number of events during the warm phase of ENSO and positive PDO and PNA phases. Precipitation at 30 U.S. Cooperative Observer stations was attributed to closed-low events, suggesting 20%–60% of annual precipitation along the West Coast may be associated with closed lows.

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New terpenoid metabolites from the skin extracts, an egg mass, and dietary sponges of the Northeastern Pacific dorid nudibranch Cadlinaluteomarginata

Canadian Journal of Chemistry ◽

10.1139/v97-094 ◽

1997 ◽

Vol 75 (6) ◽

pp. 773-789 ◽

Cited By ~ 34

Author(s):

Eric J. Dumdei ◽

Julia Kubanek ◽

John E. Coleman ◽

Jana Pika ◽

Raymond J. Andersen ◽

...

Keyword(s):

Structure Elucidation ◽

Egg Mass ◽

The Novel ◽

Egg Masses ◽

Northeastern Pacific ◽

First Time

Chemical investigations of Cadlinaluteomarginata skin extracts, egg masses, and dietary sponges have led to the identification of the novel terpenoids cadlinaldehyde (30), spongian 32, seco-spongian 35, 20-acetoxy-12-marginatone (38), and lutenolide (39) from the nudibranch skin extracts, the new drimane sesquiterpenoid 1α,2α-diacetoxyalbicanyl acetate (40) from the nudibranch's egg mass, and the new sesquiterpenoids O-methyl-9-oxofurodysininlactone (47), 2-oxomicro-cionin-2-lactone (48), and O-methyl-2-oxomicrocionin-2-lactone (49), from the dietary sponge Pleraplysilla sp. The known terpenoids furodysinin (1), furodysin (16), marginatafuran (21), and 9,11-dihydrogracillin A (37), which have been frequently isolated from C. luteomarginata skin extracts, were found for the first time in extracts of the dietary sponges Pleraplysilla sp. and Aplysilla sp. One of the new terpenoids, cadlinaldehyde (30), has an unprecedented degraded sesterterpenoid skeleton. Keywords: nudibranch, sponge, terpenoids, structure elucidation.

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