Age validation of the blue shark (Prionace glauca) in the eastern Pacific Ocean

2017 ◽  
Vol 68 (6) ◽  
pp. 1130 ◽  
Author(s):  
R. J. David Wells ◽  
Natalie Spear ◽  
Suzanne Kohin
Keyword(s):  
Pacific Ocean ◽  
Eastern Pacific ◽  
Age And Growth ◽  
Eastern Pacific Ocean ◽  
Blue Shark ◽  
Deposition Rates ◽  
Prionace Glauca ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Band Pair

The blue shark (Prionace glauca) is subjected to high levels of fishery catch and by-catch worldwide; thus, knowledge of their productivity and population status is vital, yet basic assumptions of band-pair deposition rates in vertebrae used for age and growth models are being made without direct validation studies in the Pacific Ocean. As such, the purpose of the present study was to validate vertebral band-deposition rates of blue sharks tagged and recaptured in the eastern Pacific Ocean. Vertebrae of 26 blue sharks marked with oxytetracycline (OTC) were obtained from tag–recapture activities to determine timing of centrum growth-band deposition. Results from band counts distal to the OTC mark on each vertebra indicated that a single band pair (1 translucent and 1 opaque) is formed per year for blue sharks ranging from 1 to 8 years of age. Length–frequency modal analysis was also used to obtain growth estimates from a dataset spanning 26 years of research and commercial catch data. Results provide support for annual band-pair deposition in blue shark vertebrae and will aid in future blue shark age and growth studies in the Pacific Ocean.

Mercury and Cadmium Concentrations in Muscle Tissue of the Blue Shark (Prionace glauca) in the Central Eastern Pacific Ocean

2021 ◽  
Author(s):  
Rubén D. Castro-Rendón ◽  
Marcos D. Calle-Morán ◽  
Isabel García-Arévalo ◽  
Alfredo Ordiano-Flores ◽  
Felipe Galván-Magaña
Keyword(s):  
Pacific Ocean ◽  
Muscle Tissue ◽  
Eastern Pacific ◽  
Eastern Pacific Ocean ◽  
Blue Shark ◽  
Prionace Glauca ◽  
Central Eastern

Biomagnification of Mercury and Selenium in Blue Shark Prionace glauca from the Pacific Ocean off Mexico

2011 ◽  
Vol 144 (1-3) ◽  
pp. 550-559 ◽  
Author(s):  
Ofelia Escobar-Sánchez ◽  
Felipe Galván-Magaña ◽  
René Rosíles-Martínez
Keyword(s):  
Pacific Ocean ◽  
Blue Shark ◽  
Prionace Glauca ◽  
The Pacific ◽  
The Pacific Ocean

scholarly journals SUSPENSIONS TRANSPORT PREDICTIVE MODELING UNDER VARIOUS SCENARIOS OF FERROMANGANESE NODULES EXTRACTION FROM THE PACIFIC OCEAN BOTTOM

2021 ◽  
pp. 1-9
Author(s):  
A. A. Sukhinov ◽  
A. A. Sukhinov ◽  
S. B. Kirilchik
Keyword(s):  
Pacific Ocean ◽  
Aqueous Medium ◽  
Granulometric Composition ◽  
Water Mass ◽  
Propagation Model ◽  
Ocean Bottom ◽  
Eastern Pacific Ocean ◽  
Ferromanganese Nodules ◽  
The Pacific ◽  
The Pacific Ocean

The article is devoted to the suspensions’ distribution mathematical modeling in the Eastern Pacific Ocean for various scenarios for the ferromanganese nodules extraction. The suspensions propagation model with complex granulometric composition that can interact in an aqueous medium takes into account the suspensions microturbulent diffusion caused by the turbulent aqueous medium movement and the suspensions convection caused by the advective movement of water mass in the ocean; gravitational suspensions deposition under the gravity influence; mutual transitions between different fractions that make up the suspension; interaction of particles with the bottom and with the free surface.

scholarly journals Can seafloor voltage cables be used to study large-scale circulation? An investigation in the Pacific Ocean

Ocean Science ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. 383-392
Author(s):  
Jakub Velímský ◽  
Neesha R. Schnepf ◽  
Manoj C. Nair ◽  
Natalie P. Thomas
Keyword(s):  
Pacific Ocean ◽  
Flow Velocity ◽  
Ocean Circulation ◽  
Large Scale ◽  
Eastern Pacific ◽  
Low Flow ◽  
Large Scale Circulation ◽  
Numerical Predictions ◽  
The Pacific ◽  
The Pacific Ocean

Abstract. Marine electromagnetic (EM) signals largely depend on three factors: flow velocity, Earth's main magnetic field, and seawater's electrical conductivity (which depends on the local temperature and salinity). Because of this, there has been recent interest in using marine EM signals to monitor and study ocean circulation. Our study utilizes voltage data from retired seafloor telecommunication cables in the Pacific Ocean to examine whether such cables could be used to monitor circulation velocity or transport on large oceanic scales. We process the cable data to isolate the seasonal and monthly variations and then evaluate the correlation between the processed data and numerical predictions of the electric field induced by an estimate of ocean circulation. We find that the correlation between cable voltage data and numerical predictions strongly depends on both the strength and coherence of the model velocities flowing across the cable, the local EM environment, as well as the length of the cable. The cable within the Kuroshio Current had good correlation between data and predictions, whereas two of the cables in the Eastern Pacific Gyre – a region with both low flow speeds and interfering velocity directions across the cable – did not have any clear correlation between data and predictions. Meanwhile, a third cable also located in the Eastern Pacific Gyre showed good correlation between data and predictions – although the cable is very long and the speeds were low, it was located in a region of coherent flow velocity across the cable. While much improvement is needed before utilizing seafloor voltage cables to study and monitor oceanic circulation across wide regions, we believe that with additional work, the answer to the question of whether or not seafloor voltage cables can be used to study large-scale circulation may eventually be yes.

scholarly journals Long-range transport of black carbon to the Pacific Ocean and its dependence on aging timescale

2015 ◽  
Vol 15 (12) ◽  
pp. 16945-16983 ◽  
Author(s):  
J. Zhang ◽  
J. Liu ◽  
S. Tao ◽  
G. A. Ban-Weiss
Keyword(s):  
Pacific Ocean ◽  
Black Carbon ◽  
Source Region ◽  
Climate Impacts ◽  
Average Lifetime ◽  
Deposition Rates ◽  
Source Regions ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Impact

Abstract. Improving the ability of global models to predict concentrations of black carbon (BC) over the Pacific Ocean is essential to evaluate the impact of BC on marine climate. In this study, we tag BC tracers from 13 source regions around the globe in a global chemical transport model MOZART-4. Numerous sensitivity simulations are carried out varying the aging timescale of BC emitted from each source region. The aging timescale for each source region is optimized by minimizing errors in vertical profiles of BC mass mixing ratios between simulations and HIAPER Pole-to-Pole Observations (HIPPO). For most HIPPO deployments, in the Northern Hemisphere, optimized aging timescales are less than half a day for BC emitted from tropical and mid-latitude source regions, and about 1 week for BC emitted from high latitude regions in all seasons except summer. We find that East Asian emissions contribute most to the BC loading over the North Pacific, while South American, African and Australian emissions dominate BC loadings over the South Pacific. Dominant source regions contributing to BC loadings in other parts of the globe are also assessed. The lifetime of BC originating from East Asia (i.e., the world's largest BC emitter) is found to be only 2.2 days, much shorter than the global average lifetime of 4.9 days, making East Asia's contribution to global burden only 36 % of BC from the second largest emitter, Africa. Thus, evaluating only relative emission rates without accounting for differences in aging timescales and deposition rates is not predictive of the contribution of a given source region to climate impacts. Our simulations indicate that lifetime of BC increases nearly linearly with aging timescale for all source regions. When aging rate is fast, the lifetime of BC is largely determined by factors that control local deposition rates (e.g. precipitation). The sensitivity of lifetime to aging timescale depends strongly on the initial hygroscopicity of freshly emitted BC. Our findings suggest that the aging timescale of BC varies significantly by region and season, and can strongly influence the contribution of source regions to BC burdens around the globe. Improving parameterizations of the aging process for BC is important for enhancing the predictive skill of air quality and climate models. Future observations that investigate the evolution of hygroscopicity of BC as it ages from different source regions to the remote atmosphere are urgently needed.

New paedomorphic brachiopods from the abyssal zone of the north-eastern Pacific Ocean

Zootaxa ◽  
2013 ◽  
Vol 3613 (3) ◽  
pp. 281-288 ◽  
Author(s):  
MARIA ALEKSANDRA BITNER ◽  
VJACHESLAV P. MELNIK ◽  
OLGA N. ZEZINA
Keyword(s):  
Pacific Ocean ◽  
Deep Sea ◽  
New Genera ◽  
Eastern Pacific Ocean ◽  
The North ◽  
The Pacific ◽  
North Eastern ◽  
The Pacific Ocean ◽  
Abyssal Zone ◽  
Sexually Mature

New Recent very small but sexually mature brachiopods have been found at abyssal depths (4580–4850 m) in the Clarion- Clipperton Zone of the Pacific Ocean. They are characterized by simple (under-developed, juvenile) morphological fea-tures, which are interpreted here as paedomorphic, indicating the importance of heterochrony in the evolution of deep-sea brachiopods. We have described these brachiopods as representing two new genera and species, i.e. Oceanithyris juveni-formis Bitner & Zezina (Family ?Dyscoliidae) and Simpliciforma profunda Bitner & Zezina (Superfamily Gwynioidea).

Can seafloor voltage cables be used to study large scale transport? An investigation in the Pacific Ocean.

2020 ◽  
Author(s):  
Neesha Schnepf ◽  
Manoj Nair ◽  
Jakub Velimsky ◽  
Natalie Thomas
Keyword(s):  
Pacific Ocean ◽  
Ocean Circulation ◽  
Large Scale ◽  
Eastern Pacific ◽  
Clear Correlation ◽  
Numerical Predictions ◽  
Main Challenge ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Oceanic Transport

<p>Marine electromagnetic (EM) signals largely depend on three factors: oceanic transport (i.e., depth-integrated flow), the local main magnetic field, and the local seawater conductivity (which depends on the local temperature and salinity). Thus, there is interest in using seafloor telecommunication cables to isolate marine EM signals and study ocean processes because these cables measure voltage differences between their two ends. Data from such cables can provide information on the depth-integrated transport occurring in the water column above the cable. However, these time-varying data are a superposition of all EM fields present at the observatory, no matter what source or process created the field. The main challenge in using such submarine voltage cables to study ocean circulation is properly isolating its signal.</p><p> </p><p>Our study utilizes voltage data from retired seaoor telecommunication cables in the Pacific Ocean to examine whether such cables could be used to monitor transport on large-oceanic scales. We process the cable data to isolate the seasonal and monthly variations, and evaluate the correlation between the processed data and numerical predictions of the electric field induced by ocean circulation. We find that the correlation between cable voltage data and numerical predictions strongly depends on both the strength and coherence of the transport owing across the cable. The cable within the Kuroshio Current had the highest correlation between data and predictions, whereas two of the cables in the Eastern Pacific gyre (a region with both low transport values and interfering transport signals across the cable) did not have any clear correlation between data and predictions. Meanwhile, a third cable also located in the Eastern Pacific gyre did have correlation between data and predictions, because although the transport values were low, it was located in a region of coherent transport flow across the cable. While much improvement is needed before utilizing seafloor voltage cables to study and monitor oceanic transport across wide oceanic areas, we believe that the answer to our title's questions is yes: seafloor voltage cables can eventually be used to study large-scale transport.</p>

Revision of the genus Pozziella (Porifera: Poecilosclerida) with description ofthree new species from the eastern Pacific

Zootaxa ◽  
2008 ◽  
Vol 1866 (1) ◽  
pp. 69
Author(s):  
GUILLERMO DÍAZ-AGRAS
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
Central America ◽  
Eastern Pacific ◽  
Similarity Analysis ◽  
Galapagos Archipelago ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Three New Species ◽  
Pacific Species

To date, the poecilosclerid sponge genus Pozziella Topsent, 1896 was represented by two species: Pozziella clavisepta Topsent, 1896 and Pozziella aperta (Topsent, 1920), which are presently redescribed. During the campaign SO 144-3a of the project PAGANINI in the Pacific Ocean between the Galapagos Archipelago and Central America, three new species were recovered and are described here: Pozziella cerilla sp. nov., Pozziella neuhausi sp. nov. and Pozziella lueteri sp. nov. The present study led to a revision of the genus and an attempt to resolve the relationships between the species, based on the likeness of spicule complements and biometric characters. A similarity analysis revealed that Atlantic and Pacific species clustered separately. In addition, a key to all species of the genus based on spicular characters is provided.

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