Chilean Coastal Waters Research Articles

Identification of bacteria in potential mutualism with toxic Alexandrium catenella in Chilean Patagonian fjords by in vitro and field monitoring.

The dinoflagellate Alexandrium catenella is a well-known paralytic shellfish toxin producer that forms harmful algal blooms, repeatedly causing damage to Chilean coastal waters. The causes and behavior of algal blooms are complex and vary across different regions. As bacterial interactions with algal species are increasingly recognized as a key factor driving algal blooms, the present study identifies several bacterial candidates potentially associated with Chilean Alexandrium catenella. This research narrowed down the selection of bacteria from the Chilean A. catenella culture using antibiotic treatment and 16S rRNA metabarcoding analysis. Subsequently, seawater from two Chilean coastal stations, Isla Julia and Isla San Pedro, was monitored for two years to detect Alexandrium species and the selected bacteria, utilizing 16S and 18S rRNA gene metabarcoding analyses. The results suggested a potential association between Alexandrium species and Spongiibacteraceae at both stations. The proposed candidate bacteria within the Spongiibacteraceae family, potentially engaging in mutualistic relationships with Alexandrium species, included the genus of BD1-7 clade, Spongiibbacter, and Zhongshania.

Secondary Metabolites Isolated from Chilean Marine Algae: A Review.

Chile is in the extreme southwestern part of America, and it has an extreme length, of approximately 4300 km that increases to 8000 km considering the Chilean Antarctic Territory. Despite the large extent of its coastal territory and the diversity of geographic environments and climates associated with Chilean coasts, the research on marine resources in Chile has been rather scarce. From marine organisms found in Chilean coastal waters, algae have been the most studied, since they contain a wide range of interesting secondary metabolites that have some structural traits that make them unique and uncharacteristic. Thus, a wide structural variety of natural products including terpenoids (monoterpenes, sesquiterpenes, diterpenes, and meroterpenoids), furanones, and C15-acetogenins have been isolated and identified. This review describes the existing literature on bioprospecting and exploration of secondary metabolites from Chilean coasts.

Intra-individual variability in biochemical constituents and fatty acid composition of adult jumbo squid (Dosidicus gigas) in the southeastern Pacific Ocean

In marine invertebrates, the bioenergetic fuel available for fundamental physiological processes (growth, reproduction) may present intra-individual variability depending on the storage organ, sex and state of sexual maturity. This variability is considered relevant information for fishery management. In the squid Dosidicus gigas, an important fishery resource, we analyzed adult males (immature vs. mature) and females (immature I vs. immature II) off the coast of Chile. Their bioenergetic fuel (protein, glucose, lipid and fatty acid content-FAs) was quantified in different organs of the body (digestive gland, gonad and mantle). When comparing the organs of males at both stages of maturity, a greater amount of glucose and lipids were observed in the digestive gland than in the gonad and mantle, while a higher protein content was recorded in the gonad. In turn, the same tendency of biochemical variations among the organs was observed for the female at both stages. Regarding the FA profiles of the analyzed organs, the digestive gland had the highest mean proportion of FAs. However, no significant differences were observed related to sex and sexual maturity. According to the multivariate analyses for both sexes and maturity stages, the FA profiles of the mantle and gonad showed overlap and a high similarity, while the profile of the digestive gland was completely dissimilar. Our findings indicate that D. gigas from Chilean coastal waters showed, mainly in the digestive gland, high levels of all biochemical constituents, which are obtained through food and stored in their organs as bioenergetic fuel, and may then be used for the subsequent process of migration and reproduction in oceanic waters.

Suitcase Lab: new, portable, and deployable equipment for rapid detection of specific harmful algae in Chilean coastal waters

Phytoplankton blooms, including harmful algal blooms (HABs), have serious impacts on ecosystems, public health, and productivity activities. Rapid detection and monitoring of marine microalgae are important in predicting and managing HABs. We developed a toolkit, the Suitcase Lab, to detect harmful algae species in the field. We demonstrated the Suitcase Lab’s capabilities for sampling, filtration, DNA extraction, and loop-mediated isothermal amplification (LAMP) detection in cultured Alexandrium catenella cells as well as Chilean coastal waters from four sites: Repollal, Isla García, Puerto Montt, and Metri. A LAMP assay using the Suitcase Lab in the field confirmed microscopic observations of A. catenella in samples from Repollal and Isla García. The Suitcase Lab allowed the rapid detection of A. catenella, within 2 h from the time of sampling, even at a single cell per milliliter concentrations, demonstrating its usefulness for quick and qualitative on-site diagnosis of target toxic algae species. This method is applicable not only to detecting harmful algae but also to other field studies that seek a rapid molecular diagnostic test.

Characterization and comparison of lipid and PUFA production by native thraustochytrid strains using complex carbon sources

The thraustochytrid are marine heterotrophic protists that are widely distributed in the marine world. They are characterized by producing and accumulating great amount of lipids in their cells, especially long chain polyunsaturated fatty acids (LC-PUFA), highlighting the docosahexaenoic acid (DHA, 22:6, n-3), eicosapentaenoic acid (EPA, 20:5, n-3) and arachidonic acid (ARA, 20:4, n-6), as well as pigments of interest for human health and animal nutrition, such as carotenoids. Therefore, the objective of this study was to isolate and characterize three natives isolated of thraustochytrids and assess the potential of the by-products of the manufacture of beer (RB) and protein extraction of Lupine flour (RL) as complex carbon sources to produce biomass, lipid and polyunsaturated fatty acids. Three native strains of thraustochytrid (AS5-B2, IQ81 y VAL-B1), isolated from Chilean coastal waters were morphologically and genetically identified as thraustochytrid. For the determination of biomass production cultures were quantified by gravimetry and the fatty acids quantification and identification were carried out by gas chromatography (GC-FID). Our results show that the culture with any sources of complex carbon used, increased significantly the production of both biomass and total lipids in the strains IQ81 and VAL-B1, compared to glucose as pure carbon source. On the other hand, strain AS5-B2 showed a decrease in the total production of lipids in RB compared to the pure carbon source. For the production of fatty acids, the strains IQ81 and VAL-B1 showed a significant increase in DHA when growing in RB. In conclusion strains IQ81 and VAL-B1 can be used to biotransform industrial waste, such as RB and RL, into a more valuable product such as DHA, EPA, ARA and lipids.

Nitrospina bacteria in a rocky intertidal habitat (Quintay Bay, central Chile).

Nitrospina bacteria are among the most important nitrite oxidizers in coastal and open‐ocean environments, but the relevance of the genus contrasts with the scarceness of information on their ecophysiology and habitat range. Thus far, Nitrospina bacteria have been the only nitrite oxidizers detected at high abundance in Chilean coastal waters. These levels are often higher than at other latitudes. In this study, the abundance of 16S‐rRNA gene transcripts of Nitrospina (hereafter just transcripts) was measured by reverse transcription quantitative PCR in a rocky intertidal gradient and compared with the nearshore counterpart off central Chile (~33°S). Rocky pond transcripts were also compared with the taxonomic composition of the macrobiota and bacterioplankton (by 16S‐rRNA gene‐based T‐RFLP) in the intertidal gradient. Transcripts increased from warmer, saltier, and low‐nitrite ponds in the upper intertidal zone (19.5 ± 1.6°C, 39.0 ± 1.0 psu, 0.98 ± 0.17 μmol/L) toward cooler, less salty, and high‐nitrite ponds (17.8 ± 2.6°C, 37.7 ± 0.82 psu, 1.23 ± 0.21 μmol/L) from middle and low zones. These varied from ~1,000 up to 62,800 transcripts. This increasing trend in the number of transcripts toward the lower zone was positively associated with the Shannon's diversity index for the macrobiota (r = .81, p < .01). Moreover, an important increase in the average number of transcripts was observed in ponds with a greater number of fish in the upper (7,846 transcripts during 2013) and lower zones (62,800 transcripts during 2015). Altogether, intertidal and nearshore transcripts were significantly correlated with nitrite concentrations (r = .804, p ˂ .01); rocky pond transcripts outnumbered nearshore ones by almost two orders of magnitude. In summary, rocky ponds favored both the presence and activity of Nitrospina bacteria that are tolerant to environmental stress. This in turn was positively influenced by the presence of ammonia‐ or urea‐producing macrobiota.

Hybridization betweenHaliotis rufescensandHaliotis discus hannai: evaluation of fertilization, larval development, growth and thermal tolerance

Two introduced abalone species are currently produced in Chile, red abalone Haliotis rufescens and Japanese abalone Haliotis discus hannai. However, red abalone accounts for 99% of total production, while the Japanese abalone has not adapted well to Chilean coastal waters. This study reports the hatching, growth and thermal tolerance performance in interspecific hybrids produced between red (R) and Japanese (J) abalone. Our results show that egg age and sperm concentration were critical factors to produce hybrids. The cross R♀ 9 J♂ showed a fertilization rate of 55.3 ± 3.5% using 20-min-old eggs and sperm concentrations of 14 9 10 6 cells mL 1 , while the reciprocal cross (J♀ 9 R♂) was not successful. Further, larval development stages were similar in RR, JJ and RJ hybrid abalones. Among the experimental trials, settlement rate varied from 12.3% to 18.6% and final survival from 20.1% to 31.7%, being the RJ hybrid rates intermediate between parental species. The final shell lengths were similar between RR and RJ hybrids, but significantly higher in JJ abalones. In addition, thermal tolerance was ascertained due its pivotal role for the abalone physiology. Thus, RJ hybrids showed the highest HSP70 gene expression and offers new possibilities to expand Chilean abalone production in warm waters zones.

Air-sea CO2fluxes along the coast of Chile: From CO2outgassing in central northern upwelling waters to CO2uptake in southern Patagonian fjords

[1] Carbon system parameters measured during several expeditions along the coast of Chile (23°S–56°S) have been used to show the main spatial and temporal trends of air-sea CO2 fluxes in the coastal waters of the eastern South Pacific. Chilean coastal waters are characterized by strong pCO2 gradients between the atmosphere and the surface water, with high spatial and temporal variability. On average, the direction of the carbon flux changes from CO2 outgassing at the coastal upwelling region to CO2 sequestering at the nonupwelling fjord region in Chilean Patagonia. Estimations of surface water pCO2 along the Patagonian fjord region showed that, while minimum pCO2 levels (strong CO2 undersaturation) occurs during the spring and summer period, maximum levels (including CO2 supersaturation) occur during the austral winter. CO2 uptake in the Patagonia fjord region during spring-summer is within the order of −5 mol C m−2 yr−1, indicating a significant regional sink of atmospheric CO2 during that season. We suggest that the CO2 sink at Patagonia most probably exceeds the CO2 source exerted by the coastal upwelling system off central northern Chile.

Primer registro para Chile de las diatomeas marinas Nitzschia amabilis, Nitzschia elegantula y Chaetoceros muelleri var. subsalsum

The marine small diatoms Nitzschia amabilis, Nitzschia elegantula and Chaetoceros muelleri var. subsalsum are reported for the first time from Chilean coastal waters. A short diagnosis is included for each taxon, and photomicrographs provide information about the main morphological characteristics.

Pectenotoxins and yessotoxin from Arica Bay, North Chile as determined by tandem mass spectrometry

Lipophilic phycotoxins were measured by tandem mass spectrometry coupled to liquid chromatography (LC–MS/MS) in size-fractionated plankton samples taken at five stations in Arica Bay, northern Chile in the southern summer 2007/2008. Pectenotoxins-2 (PTX-2), -11 (PTX-11), -2 seco acid (PTX-2sa) and yessotoxin (YTX) were identified by comparison of retention times and collision-induced mass spectra of certified standards and field sample extracts. This is the first report of PTXs and YTX from planktonic samples in Chilean coastal waters.

Microbial degradation rates of small peptides and amino acids in the oxygen minimum zone of Chilean coastal waters

Abstract We found similar microbial degradation rates of labile dissolved organic matter in oxic and suboxic waters off northern Chile. Rates of peptide hydrolysis and amino acid uptake in unconcentrated water samples were not low in the water column where oxygen concentration was depleted. Hydrolysis rates ranged from 65 to 160 nmol peptide L −1 h −1 in the top 20 m, 8–28 nmol peptide L −1 h −1 between 100 and 300 m (O 2 -depleted zone), and 14–19 nmol peptide L −1 h −1 between 600 and 800 m. Dissolved free amino acid uptake rates were 9–26, 3–17, and 6 nmol L −1 h −1 at similar depth intervals. Since these findings are consistent with a model of comparable potential activity of microbes in degrading labile substrates of planktonic origin, we suggest, as do other authors, that differences in decomposition rates with high and low oxygen concentrations may be a matter of substrate lability. The comparison between hydrolysis and uptake rates indicates that microbial peptide hydrolysis occurs at similar or faster rates than amino acid uptake in the water column, and that the hydrolysis of peptides is not a rate-limiting step for the complete remineralization of labile macromolecules. Low O 2 waters process about 10 tons of peptide carbon per h, double the amount processed in surface-oxygenated water. In the oxygen minimum zone, we suggest that the C balance may be affected by the low lability of the dissolved organic matter when this is upwelled to the surface. An important fraction of dissolved organic matter is processed in the oxygen minimum layer, a prominent feature of the coastal ocean in the highly productive Humboldt Current System.

Polydora uncinata (Polychaeta: Spionidae) in Chile: an accidental transportation across the Pacific

A Polydora species was found boring in shells of the abalone Haliotis discus hannai cultivated in land-based tanks in Coquimbo, Chile. Spionid polychaetes of Polydora and related genera have been reported from Chile but no worms similar to those found in abalone have been described. The abalone pest corresponds in morphology to Polydora uncinata Sato-Okoshi, 1998, a shell-boring species which was originally described from Japan and never reported from outside the country. It is suggested that occurrence of the species in Chile resulted from its accidental transportation from Japan. Adult worms were most likely transported to Coquimbo with imported abalone brood stock. Prevalence of abalone infestation by worms in Coquimbo varied substantially among cultivation tanks, reaching values as high as 98.8%. Up to 42 worms were found in one shell. The worms often caused formation of nacreous blisters which covered up to 50% of the inner shell surface. Egg capsules with developing larvae were present in female burrows. Larval development was entirely lecithotrophic, with larvae feeding on numerous nurse eggs, staying inside egg capsules until 16–17-segment stage and hatching shortly before metamorphosis. Polydora uncinata is redescribed based on individuals from Coquimbo to alert zoologists in case of accidental release of worms into Chilean coastal waters. Regardless of how the species was transported to Chile, its release to the natural ecosystem may have negative unforeseen impacts on the native fauna.

Oceanographic observations in Chilean coastal waters between Valdivia and Concepción

The physical oceanography of the biologically productive coastal waters of central Chile (36° to 40°S) is relatively unknown. In December 1998 we made a short exploratory cruise between Valdivia (40°S) and Concepción (37.8°S) taking temperature, salinity, oxygen, and current velocity profiles. Coincident sea surface temperature and color measurements were obtained by satellite. The results showed an area dominated by wind‐induced coastal upwelling, river runoff, intrusion of offshore eddies, mixing, and heating. Upwelling centers were found over the shelf at three locations: inshore of Mocha Island, off Valdivia, and off Lavapie Point. At these centers, equatorial subsurface water (ESSW) intrudes into the coastal waters, sometimes affecting the surface waters. Since ESSW has characteristically low‐oxygen and high‐salinity values, it is easily detected. Off Valdivia, runoff imparts stratification, while farther north, solar heating and reduced mixing may facilitate stratification. In some areas, even strong winds would not destroy the stratification imparted by the advection of buoyancy that occurs during the upwelling process. Strong equatorward currents (&gt;1 m s−1) in the form of an upwelling jet were found off Lavapie Point. This is also the location of an intruding anticyclone. Elsewhere, currents were mainly northward but highly variable because of intrusions from offshore eddies. The sea surface temperature and ocean color images show a complex field of onshore and offshore intrusions combined with the effects of mixing on chlorophyll concentrations. The residence time of upwelled water on the shelf is estimated to be less than 1 week.

Copper, copper mine tailings and their effect on marine algae in Northern Chile

Results are presented of a long-term research programme on the effect of copper contamination on biota in Chilean coastal waters. In spite of the magnitude of the copper mining tailings that affected Caleta Palito and surroundings in northern Chile, the effects on the intertidal assemblages remain restricted to a small geographic area. Even within the affected area, the effects are not homogeneous and there is evidence of active recovery in biological diversity in recent few years. Experimental evidence suggests that the current low algal diversity and abundance is strongly influenced by herbivory, although chronic effects of the discharges cannot be ruled out. Cellular changes in Enteromorpha compressa from the impacted area were characterised by abnormal granules in the cytoplasm, though these granules did not contain detectable levels of copper or other heavy metals.

Distribution and life cycle of Calanus chilensis and Centropages brachiatus (Copepoda) in Chilean coastal waters:a GIS approach

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 165:109-117 (1998) - doi:10.3354/meps165109 Distribution and life cycle of Calanus chilensis and Centropages brachiatus (Copepoda) in Chilean coastal waters: a GIS approach Alejandro Gonzalez*, Victor H. Marín** Depto. Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile *Present address: Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, California 92093-0202, USA **Addressee for correspondence. E-mail: vmarin@antar.ciencias.uchile.cl Calanus chilensis and Centropages brachiatus are 2 of the most abundant species of copepods (Crustacea) off the Chilean coast. However, knowledge of their life cycle and distribution is fragmentary. We have analysed the distribution of both species in Chilean coastal waters by means of a Geographic Information System (ARC/INFO). We studied vertically integrated (0 to 100 m) zooplankton samples and ancillary physical oceanographic data collected during 1989 by the Instituto de Fomento Pesquero, Chile. Point estimates of abundance and physical data were transformed to a grid format in ARC/INFO. We show that both species are abundant within 10 km from shore, and that high abundances further offshore may be interpreted as the result of advection. We also show that both species remain year-round in the upper water column with no evidence of seasonal vertical migration. We then discuss potential life cycle mechanisms that might explain their dominance in the coastal area of the Humboldt Current ecosystem. Crustacea · Calanidae · Marine ecosystems · GIS · Pelagic ecology · Plankton distribution · Eastern South Pacific Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 165. Publication date: May 07, 1998 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1998 Inter-Research.

Morphological Study of Atypical Dinophysis acuta Ehrenberg from Chilean Coastal Waters by a Digital Pattern - Recognition System

spp.taxonomy are the size and shape of cells, the mor-phology of the left sulcal list, the presence or absenceof chloroplasts and 'presumably' the plate patternand thecal ornamentation. Nevertheless, there isincreasing evidence of considerable intraspecific mor-phological variations in several species

Morphometric and electrophoretic evidences for two species of the genus Liopetrolisthes (crustacea: decapoda: porcellanidae) and some aspects of their variability

1. 1. Four colour forms of the porcellanid commensal crab Liopetrolisthes from Chilean coastal waters were compared by canonical discriminant analysis (DCA) over 10 morphological variables and by horizontal starch gel electrophoresis of 16 enzymes and total proteins with the aim of determining whether they correspond to the single species L. mitra or to different species. 2. 2. The morphometric analysis showed the existence of two morphological groups which were principally discriminated by the dactylus and propodus dimensions of the chelipods. 3. 3. Nine enzymatic systems were successfully tested: α-glycerophosphate dehydrogenase (α-GPDH), malic enzyme (ME), alkaline phosphatase (ALP), phosphoglucose isomerse (PGI), phosphoglucomutase (PGM), glutamate-oxalacetate transaminase (GOT), isocitrate dehydrogenase (IDH), lactae dehydrogenase (LDH), malate dehydrogenase (MDH) and total proteins (PT), which gave a total of 16 loci analyzed. 4. 4. The biochemical analysis demonstrated that there were no electrophoretic differences within the two morphological groups discriminated by the DCA. However there was great genetic divergence among them, expressed by eight diagnostic loci and by an unbiased estimate of Nei's [ Gentics, Austin, Texas 89, 583–590 (1978)] genetic distance of 0.979. 5. 5. The magnitude of this divergence and the lack of evidence of gene flow between the two morphological groups, allows us to conclude that Liopetrolisthes shows two valid species. 6. 6. A following study [Weber, Gayana Zool. (in press, 1991)] demonstrated that these two species are L. mitra [Dana, United States Exploring Expedition during the years 1838–1842, under the command of Charles Wilkes, U.S.N., Vol. 13, Crustacea, Part 1, p. 685 (1852)] and L. patagonicus [Cunningham, Trans. Linn. Soc. London 27, 465–502 (1871)]. 7. 7. Liopetrolisthes mitra showed a polymorphism of 0.200 and an unbiased observed heterozygosity of 0.089 which are nearly values given for anomurans. Liopetrolisthes patagonicus, which lives on the overexploited sea-urchin Loxechinus albus, showed much reduced variability with a polymorphism of 0.066 and an unbiased mean observed heterozygosity of 0.008, which may be related to the fishing pressure-bottleneck hypothesis.

Heavy metals in molluscan, crustacean, and other commercially important Chilean marine coastal water species.

The work reported here is part of a general program to monitor the marine chemical pollution along the Chilean coast. The present investigation was designated to provide information on the nature and levels of the heavy metals present in the marine species commonly consumed by the population, and to learn whether these levels may constitute a hazard to consumers. The authors report here the typical contents of 10 heavy metals in 12 commercially significant marine species from the Chilean coastal waters (Valparaiso, Concepcion and Puerto Montt). The analyzed species included 7 molluscs, 3 curstacea, and 2 other shellfish species of wide consumption. The metals chosen for analysis were copper, zinc, cadmium, lead, mercury, nickel, antimony, selenium, iron and chromium.

MORPHOLOGY AND EVOLUTIONARY SIGNIFICANCE OFADONEIS PACIFICAGEN. ET SP.NOV. (FRAGILARIACEAE, BACILLARIOPHYTA), A MARINE ARAPHID DIATOM FROM CHILE

A new marine diatom genus and species, Adoneis pacifica G.W. Andrews and P. Rivera, has been identified in Chilean coastal waters. This taxon shows obvious affinities to the genera Rhaphoneis and Delphineis, but cannot be classified in either, as they are currently construed. Adoneis pacifica resembles Rhaphoneis in outline and to some degree in the pseudocelli, whereas it resembles Delphineis in the structure of the vela and the positioning of the apical rimoportulae. However, distinctive characters of this new monotypic genus are: (1) the usual positioning of a single rimoportula near the centre of each lateral margin of the valve, and (2) the occurrence of well organized apical pore fields (pseudocelli), in which the pores are much smaller than elsewhere on the valve. These appear to be primitive traits for the araphid diatom family Fragilariaceae, and they suggest that Adoneis pacifica may be a conservative species important in the study of the evolution of the family.