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The Gulf of Guayaquil, the largest estuary on the Pacific coast of South America, provides livelihoods for fishing communities that supply seafood to national markets. Activities like mining and agriculture are major sources of co...
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The Gulf of Guayaquil, the largest estuary on the Pacific coast of South America, provides livelihoods for fishing communities that supply seafood to national markets. Activities like mining and agriculture are major sources of contamination in the estuary, yet their effects on the ecosystem have not been determined. Publicly-available data were compiled to provide an overview of the level of contamination in water, sediment and seafood in this system. Measured concentrations (C m ) were compared with their corresponding permitted levels (C sl ) defined in international regulations. Comparison outcomes were classified using a traffic-light color scale: green for ideal conditions (C m C sl × 10). A total of 24 studies were found. Cadmium, mercury and lead were the most commonly analyzed elements. Water samples showed the highest percentage of dangerous levels (> 70 % for Cd, > 80 % for Hg). Extreme concentrations of Hg (1000 times > C sl ) were reported for clams ( Anadara spp.) and crabs ( Ucides occidentalis ) collected in the southern zone impacted by gold mining. Studies evidenced the limited use of quality assurance and control procedures on the data-gathering process, resulting in uncertainty. By using orders of magnitude to assess contamination levels, the effects of low precision in the pattern of contamination were reduced. This contribution intends to inform stakeholders about the implications for public health.
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Observations of coastal-trapped waves (CTW) are limited by instrumentation technologies and temporal and spatial resolutions; hence, their complete description is still limited. In the present work, we used measurements from high-...
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Observations of coastal-trapped waves (CTW) are limited by instrumentation technologies and temporal and spatial resolutions; hence, their complete description is still limited. In the present work, we used measurements from high-frequency radio scatterometers (HFR) to analyze the subinertial dynamics of the Gulf of Tehuantepec in the Mexican Pacific, a region strongly influenced by offshore gap winds. The data showed subinertial oscillations that may be explained by poleward propagating CTWs. The oscillations showed higher coherence (95% confidence) with gap winds in the Gulfs of Papagayo and Panama than with local winds. Vertical thermocline oscillations, measured with a moored thermistor-chain, also showed subinertial oscillations coherent with Papagayo and Panama winds. The period of the observed oscillations was í4 days, which corresponds to the inertial period of the Gulf of Panama. This suggests that inertial oscillations generated by offshore wind outbursts over Panama may have traveled northward along the coastal shelf, and were detected as surface current pulses by the HFR installed approximately 2000 km further north in the Gulf of Tehuantepec. To further explore the presence of CTWs, the 4 day band-pass filtered currents measured by the HFR were analyzed using empirical orthogonal functions. We found that the first mode behaved like a CTW confined to the shelf break. Additionally, the observed oscillations were compared with baroclinic and barotropic CTW models. The results support the notion that nearly inertial baroclinic CTWs are generated in the Gulfs of Panama and Papagayo and then propagate toward the Gulf of Tehuantepec.
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Land is not the only barrier to dispersal encountered by marine organisms. For sedentary shallow water species, there is an additional, marine barrier, 5000 km of uninterrupted deep-water stretch between the central and the easter...
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Land is not the only barrier to dispersal encountered by marine organisms. For sedentary shallow water species, there is an additional, marine barrier, 5000 km of uninterrupted deep-water stretch between the central and the eastern Pacific. This expanse of water, known as the 'Eastern Pacific Barrier', has been separating faunas of the two oceanic regions since the beginning of the Cenozoic. Species with larvae that cannot stay in the plankton for the time it takes to cross between the two sides have been evolving independently. That the eastern Pacific does not share species with the rest of the Pacific was obvious to naturalists two centuries ago (Darwin 1860). Yet, this rule has exceptions. A small minority of species are known to straddle the Eastern Pacific Barrier. One such exception is the scleractinian coral Porites lobata (Fig.). This species is spread widely throughout the Indo-Pacific, where it is one of the major reef-builders, but it is also encountered in the eastern Pacific. Are eastern and central Pacific populations of this coral connected by gene flow? In this issue of Molecular Ecology, Baums et al. (2012) use microsatellite data to answer this question. They show that P. lobata populations in the eastern Pacific are cut off from genetic influx from the rest of the Pacific. Populations within each of the two oceanic regions are genetically connected (though those in the Hawaiian islands are also isolated). Significantly, the population in the Clipperton Atoll, the westernmost island in the eastern Pacific, genetically groups with populations from the central Pacific, suggesting that crossing the Eastern Pacific Barrier by P. lobata propagules does occasionally occur.
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Bycatch taken by the tuna purse-seine fishery from the Indian Ocean pelagic ecosystem was estimated from data collected by scientific observers aboard Soviet purse seiners in the western Indian Ocean (WIO) during 1986-92. A total ...
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Bycatch taken by the tuna purse-seine fishery from the Indian Ocean pelagic ecosystem was estimated from data collected by scientific observers aboard Soviet purse seiners in the western Indian Ocean (WIO) during 1986-92. A total of 494 sets on free-swimming schools, whale-shark-associated schools, whale-associated schools, and log-associated schools were analyzed. More than 40 fish species and other marine animals were recorded. Among them only two species, yellow-fin and skipjack tunas, were target species. Average levels of bycatch were 0.518 metric tons (t) per set, and 27.1 t per 1000 t of target species. The total annual purse-seine catch of yellow-fin and skipjack tunas by principal fishing nations in the WIO during 1985-94 was 118,000-277,000 t. Nonrecorded annual bycatch for this period was estimated at 944-2270 t of pelagic oceanic sharks, 720-1877 t of rainbow runners, 705-1836 t of dolphinfishes, 507-1322 t of triggerfishes, 113-294 t of wahoo, 104-251 t of billfishes, 53-112 t of mobulas and mantas, 35-89 t of mackerel scad, 9-24 t of barracudas, and 67-174 t of other fishes. In addition, turtle bycatch and whale mortalities may have occurred. Because the bycatches were not recorded by some purse-seine vessels, it was not possible to assess the full impact of the fisheries on the pelagic ecosystem of the Indian Ocean. The first step to solving this problem is for the Indian Ocean Tuna Commission to establish a program in which scientific observers are placed on board tuna purse-seine and longline vessels fishing in the WIO.
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New records are provided for four species of decapod crustaceans in the eastern Pacific. Hymenopenaeus nereus (Faxon, 1893) was collected further north and further from the coast than previously known. The distribution of Heteroca...
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New records are provided for four species of decapod crustaceans in the eastern Pacific. Hymenopenaeus nereus (Faxon, 1893) was collected further north and further from the coast than previously known. The distribution of Heterocarpus hostilis Faxon, 1893 is extended from off Panama to off Mexico. Parhippolyte cavernicola Wicksten, 1996, previously known only from the type locality in the Gulf of California, Mexico, has been found in a cave in the Galapagos Islands, Ecuador. Moloha faxoni (Schmitt, 1921) is reported for the first time within the Gulf of California, Mexico.
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Two recent 18S ribosomal RNA-based surveys of protist diversity near hydrothermal vents in the Pacific and Atlantic oceans allowed the identification of a variety of sequences related to several parasitic protist lineages. These i...
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Two recent 18S ribosomal RNA-based surveys of protist diversity near hydrothermal vents in the Pacific and Atlantic oceans allowed the identification of a variety of sequences related to several parasitic protist lineages. These include the Apicomplexa, Perkinsozoa, Syndiniales and Kinetoplastida. This diversity of parasitic protists could be hosted by the dense animal populations that thrive around these hydrothermal vents which contrasts with the scarcely populated cold deep-sea waters. These protist parasites might explain some of the mysterious sudden mortality episodes affecting the hydrothermal vent fauna.
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The data on the species composition and occurrence of the termophilic and Eastern Pacific representatives of ichthyofauna in the Pacific waters off the northern Kuril Islands and eastern Kamchatka in the 20th—21st centuries are p...
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The data on the species composition and occurrence of the termophilic and Eastern Pacific representatives of ichthyofauna in the Pacific waters off the northern Kuril Islands and eastern Kamchatka in the 20th—21st centuries are provided. Thirty-threespecies of termophilic and twelve species of Eastern Pacific fish and lampreys from 35 families have been registered during this period in the Pacific waters near the Kuril Islands and Kamchatka. Annual and seasonal dynamics of appearance of some fish species in the surveyed region in 1992—2002 are analyzed.
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During the past century eight species of sea hares of the genus Aplysia were recorded from Peru. However, there is disagreement about how many of these species are valid and their taxonomy needs to be critically evaluated. Based o...
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During the past century eight species of sea hares of the genus Aplysia were recorded from Peru. However, there is disagreement about how many of these species are valid and their taxonomy needs to be critically evaluated. Based on detailed morphological examinations, this study presents a redescription of Aplysia nigra d'Orbigny, 1837 and Aplysia inca d'Orbigny, 1837, the most common species of Aplysia along the Peruvian coast. They showed consistent morphological differences, mainly in the foot, parapodia development, opaline gland, jaws, radular teeth and penial morphology. Anatomical data for both species are provided for the first time, as well as a comparison with other species of Aplysia reported for the Eastern Pacific. The records of Aplysia keraudreni Rang, 1828, Aplysia dactylomela Rang, 1828 and Aplysia juliana Quoy & Gaimard, 1832 for Peruvian waters are likely erroneous and need to be verified based on collected specimens.
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During the past century eight species of sea hares of the genus Aplysia were recorded from Peru. However, there is disagreement about how many of these species are valid and their taxonomy needs to be critically evaluated. Based o...
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During the past century eight species of sea hares of the genus Aplysia were recorded from Peru. However, there is disagreement about how many of these species are valid and their taxonomy needs to be critically evaluated. Based on detailed morphological examinations, this study presents a redescription of Aplysia nigra d'Orbigny, 1837 and Aplysia inca d'Orbigny, 1837, the most common species of Aplysia along the Peruvian coast. They showed consistent morphological differences, mainly in the foot, parapodia development, opaline gland, jaws, radular teeth and penial morphology. Anatomical data for both species are provided for the first time, as well as a comparison with other species of Aplysia reported for the Eastern Pacific. The records of Aplysia keraudreni Rang, 1828, Aplysia dactylomela Rang, 1828 and Aplysia juliana Quoy & Gaimard, 1832 for Peruvian waters are likely erroneous and need to be verified based on collected specimens.
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During the WHP-P17N re-visit cruise in 2001 summer in the eastern North Pacific (30-55°N), we carried out hydrographic observations and collected more than 700 seawater samples for AMS radiocarbon measurement. Comparison of hydro...
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During the WHP-P17N re-visit cruise in 2001 summer in the eastern North Pacific (30-55°N), we carried out hydrographic observations and collected more than 700 seawater samples for AMS radiocarbon measurement. Comparison of hydrographic data, including radiocarbon, between the first visit in the early 1990s and the re-visit elucidated temporal change of surface and intermediate waters during the past decade in the eastern North Pacific. In the intermediate water (≈ 200-600 m depth) concentration of dissolved oxygen decreased with increase of nutrients concentration. Intermediate radiocarbon decreased slightly or did not change. These results are consistent with decrease trend of intermediate oxygen in the whole North Pacific Ocean in the past decades and suggest recent stagnation of the intermediate water formation in the eastern North Pacific.
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