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Institution

National Ocean Service

GovernmentSilver Spring, Maryland, United States
About: National Ocean Service is a government organization based out in Silver Spring, Maryland, United States. It is known for research contribution in the topics: Algal bloom & Population. The organization has 500 authors who have published 643 publications receiving 46096 citations.


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Journal ArticleDOI
TL;DR: In this article, a multibeam high-resolution bathymetric survey of the channels between the islands, coupled with observations and video-transects utilizing DeepWorker-2000 submersibles, has revealed the existence of numerous drowned reef features including concentric solution basins, solution ridges (rims), sand and sediment plains, and conical-shaped reef pinnacles.
Abstract: During the last glacial maximum (LGM), about 21,000 years ago, the Hawaiian Islands of Maui, Lanai, and Molokai were interconnected by limestone bridges, creating a super-island known as Maui-Nui. Approximately 120 m of sea-level rise during the Holocene Transgression flooded, and then drowned, these bridges separating the islands by inter-island channels. A new multibeam high-resolution bathymetric survey of the channels between the islands, coupled with observations and video-transects utilizing DeepWorker-2000 submersibles, has revealed the existence of numerous drowned reef features including concentric solution basins, solution ridges (rims), sand and sediment plains, and conical-shaped reef pinnacles. The concentric basins contain flat lagoon-like bottoms that are rimmed by steep-sided limestone walls. Undercut notches rim the basins at several depths, marking either sea-level still stands or paleo-lake levels. All of the solution basins shallower than 120 m were subaerial at the LGM, and at one stage or another may have been shallow shoreline lakes. Today, about 70 drowned reef pinnacles are scattered across the Maui–Lanai underwater bridge and all are situated in wave-sheltered positions. Most drowned during the interval between 14,000 and 10,000 years ago when sea-level rise averaged 15 mm/year. Virtually all of the surficial topography in the Au'au Channel today is a product of karst processes accentuated by marginal reef growth during the Holocene. Both the submerged basins and the drowned reefs represent an archive of sea-level and climate history in Hawaii during the late Quaternary.

75 citations

Journal ArticleDOI
TL;DR: The objective of this study was to determine inorganic and organic contaminant concentrations in edible tissue of fish collected from eight coastal areas receiving wastewater discharges and from two reference locations, and trace metal residues were statistically similar regardless of the collection site.

75 citations

Journal ArticleDOI
01 Oct 2010-Toxicon
TL;DR: Dinoflagellate species isolated from the green calcareous seaweed, Halimeda sp.

75 citations

Journal ArticleDOI
TL;DR: This review will evaluate experimental domoic acid neurotoxicity in developing rodents and, aided by comparative allometric projections, will analyze potential prenatal toxicity and exposure susceptibility in the California sea lion.
Abstract: California sea lions have been a repeated subject of investigation for early life toxicity, which has been documented to occur with increasing frequency from late February through mid-May in association with organochlorine (PCB and DDT) poisoning and infectious disease in the 1970's and domoic acid poisoning in the last decade. The mass early life mortality events result from the concentrated breeding grounds and synchronization of reproduction over a 28 day post partum estrus cycle and 11 month in utero phase. This physiological synchronization is triggered by a decreasing photoperiod of 11.48 h/day that occurs approximately 90 days after conception at the major California breeding grounds. The photoperiod trigger activates implantation of embryos to proceed with development for the next 242 days until birth. Embryonic diapause is a selectable trait thought to optimize timing for food utilization and male migratory patterns; yet from the toxicological perspective presented here also serves to synchronize developmental toxicity of pulsed environmental events such as domoic acid poisoning. Research studies in laboratory animals have defined age-dependent neurotoxic effects during development and windows of susceptibility to domoic acid exposure. This review will evaluate experimental domoic acid neurotoxicity in developing rodents and, aided by comparative allometric projections, will analyze potential prenatal toxicity and exposure susceptibility in the California sea lion. This analysis should provide a useful tool to forecast fetal toxicity and understand the impact of fetal toxicity on adult disease of the California sea lion.

73 citations

Journal ArticleDOI
TL;DR: Results indicate that photosynthetic tolerance to higher irradiances and presence of UV-absorbing pigments (UVP) in H. johnsonii may allow this species to exploit the shallowest waters without competition from the closely related, but UVP-lacking H. decipiens.
Abstract: The threatened seagrass Halophila johnsonii Eiseman coexists subtidally with H. decipiens Ostenfeld in southeastern Florida, but only H. johnsonii also oc- curs intertidally. Pulse amplitude modulated fluorome- try and fiber-optic spectrometry were used to investigate the photobiology of two populations of H. johnsonii and H. decipiens in an attempt to explain these distribution patterns. Maximum photosynthetic quantum yields (Fv/ Fm) were measured in situ as a function of depth dis- tribution within, and between, these two species at two sites (Jupiter Sound, 26� 57¢N; 80� 04¢W, and northern Biscayne Bay, 25� 55¢N; 80� 07¢W) along the east coast of Florida, USA, during 6-10 March 2001. Reciprocal transplants at the northern site were used to evaluate the plasticity of photosynthetic patterns and pigment absorption spectra and to gain insights into the mecha- nisms responsible for variations in the observed depth- distribution patterns. Subtidal-population Fv/Fm values were generally higher for H. johnsonii than for H. deci- piens, at both sites. At the northern site, intertidal H. johnsonii had significantly lower Fv/Fm (0.494±0.138) than both subtidal H. johnsonii (0.696±0.045) and subtidal H. decipiens (0.668±0.048). In contrast, at the southern site intertidal H. johnsonii had the highest Fv/ Fm (0.663±0.047) and were the largest plants. Fv/Fm values of subtidal plants of both species decreased when they were transplanted into shallow, intertidal beds. Correspondingly, Fv/Fm increased for intertidal H. johnsonii transplanted into the subtidal, 2 m deep beds. Rapid light curves indicated that H. decipiens had lower maximum relative electron transport rates (RE- TRmax) than did H. johnsonii. In addition, the onset of photoinhibition occurred at lower irradiances for H. decipiens (537-820 lmol photons m )2 s )1 ) compared to H. johnsonii (1141-2670 lmol photons m )2 s )1 ). RETRmax values decreased for intertidal H. johnsonii transplanted into subtidal beds, but they increased for both species when transplanted from subtidal to inter- tidal beds. Absorption spectra for the acetone-soluble leaf pigments of intertidal H. johnsonii exhibited a dominant peak near 345 nm; this UV peak was 30% lower for subtidal plants. Pigment absorption spectra for H. decipiens lacked the 345 nm peak and absorbances, normalized to leaf pairs, were lower across the spectrum. Our results indicate that photosynthetic tolerance to higher irradiances and presence of UV-absorbing pig- ments (UVP) in H. johnsonii may allow this species to exploit the shallowest waters without competition from the closely related, but UVP-lacking H. decipiens.

73 citations


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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20222
202129
202017
201917
201831
201719