scholarly journals The Recent Carbonate Sediments of Palmyra Atoll, Northern Line Islands, Central Pacific Ocean

2021 ◽  
Author(s):  
◽  
Oscar Clark
Keyword(s):  
Pacific Ocean ◽  
Carbonate Sediments ◽  
Central Pacific ◽  
Outer Reef ◽  
Central Pacific Ocean ◽  
Fine Material ◽  
The Pacific ◽  
Red Algal ◽  
Recent Sediments ◽  
Line Islands

<p>Palmyra Atoll is an isolated carbonate reef system located approximately 1600 km south of Hawaii in the northern Line Islands, central Pacific Ocean. Sediment samples from the lagoons and tidal zones were analyzed for grainsize and composition, and the results used to compile detailed maps and interpret the environments and lithofacies present. A distinct grainsize distribution was observed forming concentric bands ranging from coarse gravel rubble on the outer reef through to finer material in the interior of the atoll in the deep lagoons, where peloidal muds prevail. Five lithologic facies have been identified and typical sediments are poorly sorted and near-symmetrical in their grainsize distribution. On average, sediments are medium sand. A distinct chlorozoan assemblage was observed with coral and calcareous red algal fragments forming half of the sediment, with varying amounts of molluscs, Halimeda and foraminifera being the lesser major constituents. Lagoonal and tidal sediments showed little variation in composition between locations and lacked clear compositional zonation, characteristic of other larger atolls of the Pacific. Palmyra Atoll is unique in that it has had little human intervention for the last sixty years and as a result uninhibited natural processes are occurring. It is also unique in that it displays relatively deep for its size (<55 m), steep-sided compartmentalized lagoons that have abundant fine material (upward of 70% silt or finer), a feature not commonly observed at other Pacific atolls. This fine material has been identified as a peloidal mud and its mode and rate of deposition may be partly controlled by the abundant zooplankton in the lagoons. Recent sediments of Palmyra Atoll are almost entirely carbonate, originating from reef organisms inhabiting the atoll. The only other material is small amounts of siliceous sponge skeletons.</p>

scholarly journals The Recent Carbonate Sediments of Palmyra Atoll, Northern Line Islands, Central Pacific Ocean

2021 ◽  
Author(s):  
◽  
Oscar Clark
Keyword(s):  
Pacific Ocean ◽  
Carbonate Sediments ◽  
Central Pacific ◽  
Outer Reef ◽  
Central Pacific Ocean ◽  
Fine Material ◽  
The Pacific ◽  
Red Algal ◽  
Recent Sediments ◽  
Line Islands

<p>Palmyra Atoll is an isolated carbonate reef system located approximately 1600 km south of Hawaii in the northern Line Islands, central Pacific Ocean. Sediment samples from the lagoons and tidal zones were analyzed for grainsize and composition, and the results used to compile detailed maps and interpret the environments and lithofacies present. A distinct grainsize distribution was observed forming concentric bands ranging from coarse gravel rubble on the outer reef through to finer material in the interior of the atoll in the deep lagoons, where peloidal muds prevail. Five lithologic facies have been identified and typical sediments are poorly sorted and near-symmetrical in their grainsize distribution. On average, sediments are medium sand. A distinct chlorozoan assemblage was observed with coral and calcareous red algal fragments forming half of the sediment, with varying amounts of molluscs, Halimeda and foraminifera being the lesser major constituents. Lagoonal and tidal sediments showed little variation in composition between locations and lacked clear compositional zonation, characteristic of other larger atolls of the Pacific. Palmyra Atoll is unique in that it has had little human intervention for the last sixty years and as a result uninhibited natural processes are occurring. It is also unique in that it displays relatively deep for its size (<55 m), steep-sided compartmentalized lagoons that have abundant fine material (upward of 70% silt or finer), a feature not commonly observed at other Pacific atolls. This fine material has been identified as a peloidal mud and its mode and rate of deposition may be partly controlled by the abundant zooplankton in the lagoons. Recent sediments of Palmyra Atoll are almost entirely carbonate, originating from reef organisms inhabiting the atoll. The only other material is small amounts of siliceous sponge skeletons.</p>

scholarly journals Understanding large-scale, long-term larval connectivity patterns: The case of the Northern Line Islands in the Central Pacific Ocean

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0182681
Author(s):  
Lorenzo Mari ◽  
Luca Bonaventura ◽  
Andrea Storto ◽  
Paco Melià ◽  
Marino Gatto ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Large Scale ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
Larval Connectivity ◽  
Connectivity Patterns ◽  
Line Islands

Recreational billfish catches and gamefishing facilities of Pacific Island nations in the Western and Central Pacific Ocean

2003 ◽  
Vol 54 (4) ◽  
pp. 463 ◽  
Author(s):  
Wade Whitelaw
Keyword(s):  
Pacific Ocean ◽  
Purse Seine ◽  
Pacific Island ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
Tax Relief ◽  
The Pacific ◽  
Pacific Island Nations ◽  
Subsistence Fishing ◽  
Pacific Community

Gamefishing is a developing industry for many of the Pacific Island nations, with a number of countries encouraging the industry with tax relief and tourism promotion. This paper was prepared to provide a preliminary appraisal of gamefish facilities and recreational billfish catches of Pacific Island countries in the Western and Central Pacific Ocean. The level of development of gamefishing varies among Pacific Island nations, with fishers of some countries only carrying out subsistence fishing (including billfish), whereas others have a well-developed gamefishing infrastructure. The gamefish facilities of each country are described, including charter operations, number of private vessels and berthing facilities. Estimates of recreationally caught billfish are also provided for each Pacific Island nation. These estimates have been facilitated by the development of a gamefish catch and effort database by the Secretariat of the Pacific Community. Presently, an estimated 1050 metric tonnes of marlin are caught by gamefishing in the Western and Central Pacific Ocean, which compares with an estimate of around 18 000 metric tonnes caught by commercial longline and purse seine vessels.

Moving towards a Rights-Based Fisheries Management Regime for the Tuna Fisheries in the Western and Central Pacific Ocean

2007 ◽  
Vol 22 (1) ◽  
pp. 125-142 ◽  
Author(s):  
Transform Aqorau
Keyword(s):  
Pacific Ocean ◽  
Fisheries Management ◽  
Pacific Island ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
Island States ◽  
Management Regime ◽  
The Pacific ◽  
Pacific Island States ◽  
Tuna Fisheries

AbstractThe 2000 Convention for the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean (WCPF Convention) establishes a Commission which will be responsible for setting catch limits and effort controls for the fishery. The Convention will require the Pacific Island States to impose some form of catch limits and this presents them with the opportunity to explore ways to enhance the fisheries regimes they manage. This paper explores the legal issues surrounding a possible rights-based regime, both as a collective approach by the Pacific Island States, and individually. The paper suggests possible legal approaches to the introduction of a rights-based fisheries management regime, drawing on ways in which they may structure their fisheries legislation, and on experiences from other regions. The paper concludes by examining the implications for the Pacific Island States of such an approach.

scholarly journals Reply

2011 ◽  
Vol 24 (19) ◽  
pp. 5192-5194 ◽  
Author(s):  
S. M. Penny ◽  
G. H. Roe ◽  
D. S. Battisti
Keyword(s):  
Pacific Ocean ◽  
Interannual Variability ◽  
Storm Track ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
Recent Comment ◽  
Full Dataset ◽  
The Pacific ◽  
Midwinter Suppression

Penny et al. recently showed that the midwinter suppression in storminess over the western and central Pacific Ocean is due to a reduction in the number and amplitude of “seed” disturbances entering the Pacific storm track from midlatitude Asia. In this reply, the authors strengthen the conclusions that were originally put forth and show that the apparent departure from this behavior presented in a recent comment originates in the commenters having undersampled the full dataset of interannual variability. It is shown that when the Pacific storm track is only weakly “seeded” by an upstream source, as is common during winter and uncommon during fall and spring, it is likely to be weaker than average, and this reduction is highly statistically significant and the amplitude compares well with the midwinter suppression.

scholarly journals Persistence of deeply sourced iron in the Pacific Ocean

2015 ◽  
Vol 112 (5) ◽  
pp. 1292-1297 ◽  
Author(s):  
Tristan J. Horner ◽  
Helen M. Williams ◽  
James R. Hein ◽  
Mak A. Saito ◽  
Kevin W. Burton ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Carbon Fixation ◽  
Global Ocean ◽  
Oceanic Circulation ◽  
Multiple Sources ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
The Past ◽  
The Pacific ◽  
The Pacific Ocean

Biological carbon fixation is limited by the supply of Fe in vast regions of the global ocean. Dissolved Fe in seawater is primarily sourced from continental mineral dust, submarine hydrothermalism, and sediment dissolution along continental margins. However, the relative contributions of these three sources to the Fe budget of the open ocean remains contentious. By exploiting the Fe stable isotopic fingerprints of these sources, it is possible to trace distinct Fe pools through marine environments, and through time using sedimentary records. We present a reconstruction of deep-sea Fe isotopic compositions from a Pacific Fe−Mn crust spanning the past 76 My. We find that there have been large and systematic changes in the Fe isotopic composition of seawater over the Cenozoic that reflect the influence of several, distinct Fe sources to the central Pacific Ocean. Given that deeply sourced Fe from hydrothermalism and marginal sediment dissolution exhibit the largest Fe isotopic variations in modern oceanic settings, the record requires that these deep Fe sources have exerted a major control over the Fe inventory of the Pacific for the past 76 My. The persistence of deeply sourced Fe in the Pacific Ocean illustrates that multiple sources contribute to the total Fe budget of the ocean and highlights the importance of oceanic circulation in determining if deeply sourced Fe is ever ventilated at the surface.

Reconstructing ecosystem dynamics in the central Pacific Ocean, 1952–1998. II. A preliminary assessment of the trophic impacts of fishing and effects on tuna dynamics

2002 ◽  
Vol 59 (11) ◽  
pp. 1736-1747 ◽  
Author(s):  
Sean P Cox ◽  
Timothy E Essington ◽  
James F Kitchell ◽  
Steven J.D. Martell ◽  
Carl J Walters ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Ecosystem Dynamics ◽  
Fishing Mortality ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
Predation Mortality ◽  
The Pacific ◽  
Multispecies Model ◽  
Predator Abundance ◽  
Large Predators

Pelagic fisheries in the Pacific Ocean target both large (Thunnus spp.) and small tunas (juveniles of Thunnus spp; Katsuwonus pelamis) but also take billfishes (Xiphias gladius, Makaira spp., Tetrapturus spp., Istiophorus platypterus) and sharks (Prionace glauca, Alopias superciliosus, Isurus oxyrinchus, Carcharhinus longimanus, Galeocerdo cuvieri) as bycatch. We developed a multispecies model using the Ecopath with Ecosim software that incorporated time-series estimates of biomass, fishing mortality, and bycatch rates (1952–1998) to evaluate the relative contributions of fishing and trophic impacts on tuna dynamics in the central Pacific (0°N to 40°N and 130°E to 150°W). The Ecosim model reproduced the observed trends in abundance indices and biomass estimates for most large tunas and billfishes. A decline in predation mortality owing to depletion of large predators was greatest for small yellowfin tuna and could possibly account for apparent increases in biomass. For other tunas, however, predicted changes in predation mortality rates were small (small bigeye) or were overwhelmed by much larger increases in fishing mortality (skipjack and small albacore). Limited evidence of trophic impacts associated with declining apex predator abundance likely results from the difficulties of applying detailed trophic models to open ocean systems in which ecological and fishery data uncertainties are large.

scholarly journals Multiple melt source origin of the Line Islands (Pacific Ocean)

Geology ◽  
2021 ◽  
Author(s):  
Robert Pockalny ◽  
Ginger Barth ◽  
Barry Eakins ◽  
Katherine A. Kelley ◽  
Christina Wertman
Keyword(s):  
Pacific Ocean ◽  
Source Region ◽  
Central Pacific ◽  
Age Progression ◽  
Central Pacific Ocean ◽  
Volcanic Chain ◽  
History Of ◽  
Tectonic Reconstructions ◽  
Seamount Chain ◽  
Line Islands

The Line Islands volcanic chain in the central Pacific Ocean exhibits many characteristics of a hotspot-generated seamount chain; however, the lack of a predictable age progression has stymied previous models for the origin of this feature. We combined plate-tectonic reconstructions with seamount age dates and available geochemistry to develop a new model that involves multiple melt regions and multiple melt delivery styles to explain the spatial and temporal history of the Line Islands system. Our model identifies a new melt source region (Larson melt region at ~17°S, ~125°W) that contributed to the formation of the Line Islands, as well as the Mid-Pacific Mountains and possibly the Pukapuka Ridge.

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