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Hayden B, Harrod C, Thomas SM, Eloranta AP, Myllykangas J, Siwertsson A, Præbel K, Knudsen R, Amundsen P, Kahilainen KK. From clear lakes to murky waters – tracing the functional response of high‐latitude lake communities to concurrent ‘greening’ and ‘browning’. Ecol Lett 2019; 22:807-816. [DOI: 10.1111/ele.13238] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/21/2018] [Accepted: 01/20/2019] [Indexed: 12/24/2022]
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Phillips ND, Elliott Smith EA, Newsome SD, Houghton JDR, Carson CD, Alfaro-Shigueto J, Mangel JC, Eagling LE, Kubicek L, Harrod C. Bulk tissue and amino acid stable isotope analysis reveal global ontogenetic patterns in ocean sunfish trophic ecology and habitat-use. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr13166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Elliott Smith EA, Harrod C, Newsome SD. The importance of kelp to an intertidal ecosystem varies by trophic level: insights from amino acid δ13C analysis. Ecosphere 2018. [DOI: 10.1002/ecs2.2516] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Zwerschke N, Rein H, Harrod C, Reddin C, Emmerson MC, Roberts D, O'Connor NE. Competition between co‐occurring invasive and native consumers switches between habitats. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13211] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Phillips ND, Kubicek L, Payne NL, Harrod C, Eagling LE, Carson CD, Cappanera V, Houghton JDR. Isometric growth in the world's largest bony fishes (genus Mola)? Morphological insights from fisheries bycatch data. J Morphol 2018; 279:1312-1320. [PMID: 30187934 DOI: 10.1002/jmor.20872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/30/2018] [Accepted: 06/23/2018] [Indexed: 11/07/2022]
Abstract
For teleost fishes, the relationship between morphometric traits can provide significant insight into species life history, however gathering such data for noncommercial species can prove challenging. Here, we use data collected opportunistically from fisheries bycatch and stranding events to assess growth scaling over orders of magnitude in the ocean sunfish (genus Mola). Intriguingly, the confidence intervals for the relationship between length and mass suggests that isometric scaling is likely, a growth pattern rarely observed in fishes owing to the scaling of supportive structures. These data also enabled assessment of geometric morphometrics, which indicated that Mola sp shape varies subtly but significantly ontogenetically, with increased fin area comparative to body area as fish increase in size. More practically, total length emerged as an effective predictor for a range of morphological traits, including mass, fin lengths and surface area, which can provide vital baseline data for fisheries modeling and management.
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Gomez-Uchida D, Sepúlveda M, Ernst B, Contador TA, Neira S, Harrod C. Chile's salmon escape demands action. Science 2018; 361:857-858. [PMID: 30166480 DOI: 10.1126/science.aau7973] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Dorador C, Fink P, Hengst M, Icaza G, Villalobos AS, Vejar D, Meneses D, Zadjelovic V, Burmann L, Moelzner J, Harrod C. Microbial community composition and trophic role along a marked salinity gradient in Laguna Puilar, Salar de Atacama, Chile. Antonie van Leeuwenhoek 2018; 111:1361-1374. [PMID: 29744693 DOI: 10.1007/s10482-018-1091-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 04/23/2018] [Indexed: 10/16/2022]
Abstract
The geological, hydrological and microbiological features of the Salar de Atacama, the most extensive evaporitic sedimentary basin in the Atacama Desert of northern Chile, have been extensively studied. In contrast, relatively little attention has been paid to the composition and roles of microbial communities in hypersaline lakes which are a unique feature in the Salar. In the present study biochemical, chemical and molecular biological tools were used to determine the composition and roles of microbial communities in water, microbial mats and sediments along a marked salinity gradient in Laguna Puilar which is located in the "Los Flamencos" National Reserve. The bacterial communities at the sampling sites were dominated by members of the phyla Bacteroidetes, Chloroflexi, Cyanobacteria and Proteobacteria. Stable isotope and fatty acid analyses revealed marked variability in the composition of microbial mats at different sampling sites both horizontally (at different sites) and vertically (in the different layers). The Laguna Puilar was shown to be a microbially dominated ecosystem in which more than 60% of the fatty acids at particular sites are of bacterial origin. Our pioneering studies also suggest that the energy budgets of avian consumers (three flamingo species) and dominant invertebrates (amphipods and gastropods) use minerals as a source of energy and nutrients. Overall, the results of this study support the view that the Salar de Atacama is a heterogeneous and fragile ecosystem where small changes in environmental conditions may alter the balance of microbial communities with possible consequences at different trophic levels.
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Tapia JS, Valdés J, Orrego R, Tchernitchin A, Dorador C, Bolados A, Harrod C. Geologic and anthropogenic sources of contamination in settled dust of a historic mining port city in northern Chile: health risk implications. PeerJ 2018; 6:e4699. [PMID: 29707438 PMCID: PMC5922233 DOI: 10.7717/peerj.4699] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/12/2018] [Indexed: 11/20/2022] Open
Abstract
Chile is the leading producer of copper worldwide and its richest mineral deposits are found in the Antofagasta Region of northern Chile. Mining activities have significantly increased income and employment in the region; however, there has been little assessment of the resulting environmental impacts to residents. The port of Antofagasta, located 1,430 km north of Santiago, the capital of Chile, functioned as mineral stockpile until 1998 and has served as a copper concentrate stockpile since 2014. Samples were collected in 2014 and 2016 that show elevated concentrations of As, Cu, Pb, and Zn in street dust and in residents' blood (Pb) and urine (As) samples. To interpret and analyze the spatial variability and likely sources of contamination, existent data of basement rocks and soil geochemistry in the city as well as public-domain airborne dust were studied. Additionally, a bioaccessibility assay of airborne dust was conducted and the chemical daily intake and hazard index were calculated to provide a preliminary health risk assessment in the vicinity of the port. The main conclusions indicate that the concentrations of Ba, Co, Cr, Mn, Ni, and V recorded from Antofagasta dust likely originate from intrusive, volcanic, metamorphic rocks, dikes, or soil within the city. However, the elevated concentrations of As, Cd, Cu, Mo, Pb, and Zn do not originate from these geologic outcrops, and are thus considered anthropogenic contaminants. The average concentrations of As, Cu, and Zn are possibly the highest in recorded street dust worldwide at 239, 10,821, and 11,869 mg kg-1, respectively. Furthermore, the contaminants As, Pb, and Cu exhibit the highest bioaccessibilities and preliminary health risk indices show that As and Cu contribute to elevated health risks in exposed children and adults chronically exposed to dust in Antofagasta, whereas Pb is considered harmful at any concentration. Therefore, an increased environmental awareness and greater protective measures are necessary in Antofagasta and possibly other similar mining port cities in developing countries.
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Quezada‐Romegialli C, Jackson AL, Hayden B, Kahilainen KK, Lopes C, Harrod C. tRophicPosition
, an
r
package for the Bayesian estimation of trophic position from consumer stable isotope ratios. Methods Ecol Evol 2018. [DOI: 10.1111/2041-210x.13009] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Molina V, Dorador C, Fernández C, Bristow L, Eissler Y, Hengst M, Hernandez K, Olsen LM, Harrod C, Marchant F, Anguita C, Cornejo M. The activity of nitrifying microorganisms in a high-altitude Andean wetland. FEMS Microbiol Ecol 2018; 94:4969675. [DOI: 10.1093/femsec/fiy062] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 04/09/2018] [Indexed: 11/13/2022] Open
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Østbye K, Taugbøl A, Ravinet M, Harrod C, Pettersen RA, Bernatchez L, Vøllestad LA. Ongoing niche differentiation under high gene flow in a polymorphic brackish water threespine stickleback (Gasterosteus aculeatus) population. BMC Evol Biol 2018; 18:14. [PMID: 29402230 PMCID: PMC5800020 DOI: 10.1186/s12862-018-1128-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 01/22/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Marine threespine sticklebacks colonized and adapted to brackish and freshwater environments since the last Pleistocene glacial. Throughout the Holarctic, three lateral plate morphs are observed; the low, partial and completely plated morph. We test if the three plate morphs in the brackish water Lake Engervann, Norway, differ in body size, trophic morphology (gill raker number and length), niche (stable isotopes; δ15N, δ13C, and parasites (Theristina gasterostei, Trematoda spp.)), genetic structure (microsatellites) and the lateral-plate encoding Stn382 (Ectodysplasin) gene. We examine differences temporally (autumn 2006/spring 2007) and spatially (upper/lower sections of the lake - reflecting low versus high salinity). RESULTS All morphs belonged to one gene pool. The complete morph was larger than the low plated, with the partial morph intermediate. The number of lateral plates ranged 8-71, with means of 64.2 for complete, 40.3 for partial, and 14.9 for low plated morph. Stickleback δ15N was higher in the lower lake section, while δ13C was higher in the upper section. Stickleback isotopic values were greater in autumn. The low plated morph had larger variances in δ15N and δ13C than the other morphs. Sticklebacks in the upper section had more T. gasterostei than in the lower section which had more Trematoda spp. Sticklebacks had less T. gasterostei, but more Trematoda spp. in autumn than spring. Sticklebacks with few and short rakers had more T. gasterostei, while sticklebacks with longer rakers had more Trematoda. spp. Stickleback with higher δ15N values had more T. gasterostei, while sticklebacks with higher δ15N and δ13C values had more Trematoda spp. The low plated morph had fewer Trematoda spp. than other morphs. CONCLUSIONS Trait-ecology associations may imply that the three lateral plate morphs in the brackish water lagoon of Lake Engervann are experiencing ongoing divergent selection for niche and migratory life history strategies under high gene flow. As such, the brackish water zone may generally act as a generator of genomic diversity to be selected upon in the different environments where threespine sticklebacks can live.
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Reddin CJ, Bothwell JH, O'Connor NE, Harrod C. The effects of spatial scale and isoscape on consumer isotopic niche width. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Keva O, Hayden B, Harrod C, Kahilainen KK. Total mercury concentrations in liver and muscle of European whitefish (Coregonus lavaretus (L.)) in a subarctic lake - Assessing the factors driving year-round variation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 231:1518-1528. [PMID: 28923342 DOI: 10.1016/j.envpol.2017.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 06/07/2023]
Abstract
Subarctic lakes are characterised by extreme seasonal variation in light and temperature which influences growth, maturation, condition and resource use of fishes. However, our understanding of how seasonal changes affect mercury concentrations of fishes is limited. We conducted a year-round study (3 ice-covered months, 3 open-water months) with open-water inter-annual aspect (3 years: samples from August/September), focusing on total mercury (THg) concentrations and ecological characteristics of a common freshwater fish, European whitefish (Coregonus lavaretus (L.)) from a subarctic lake. We measured THg concentrations from tissues with fast (liver, n = 164) and moderate (muscle, n = 225) turnover rates, providing information on THg dynamics over different temporal scales. In both tissues, lipid-corrected THg concentrations were highest in winter (liver: 1.70 ± 0.88 μg/g, muscle: 0.24 ± 0.05 μg/g) and lowest in summer (liver: 0.87 ± 0.72 μg/g, muscle: 0.19 ± 0.04 μg/g). THg concentrations increased in winter following the summer-autumn dietary shift to pelagic zooplankton and starvation after spawning. Whitefish THg concentrations decreased towards summer, and were associated with consumption of benthic macroinvertebrates and subsequent growth dilution. Mercury bioaccumulated in both tissues with age, both showing the strongest regression slopes in winter and lowest in summer. THg concentrations in liver and muscle tissue were correlated throughout the year, however the correlation was lowest in summer, indicating high metabolism during somatic growing season in summer and growth dilution. Multiple linear regression models explained 50% and 55% of the THg variation in liver and muscle both models dominated by seasonally-variable factors i.e. sexual maturity, δ13C, and condition factor. Seasonally varying bioaccumulation slopes and the higher level of intra-annual variation (21%) in whitefish THg concentration in muscle than the inter-annual accumulation (8%) highlight the importance of including seasonal factors in future THg studies.
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Docmac F, Araya M, Hinojosa IA, Dorador C, Harrod C. Habitat coupling writ large: pelagic-derived materials fuel benthivorous macroalgal reef fishes in an upwelling zone. Ecology 2017. [DOI: 10.1002/ecy.1936] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Molina V, Hernández K, Dorador C, Eissler Y, Hengst M, Pérez V, Harrod C. Bacterial Active Community Cycling in Response to Solar Radiation and Their Influence on Nutrient Changes in a High-Altitude Wetland. Front Microbiol 2016; 7:1823. [PMID: 27909430 PMCID: PMC5112256 DOI: 10.3389/fmicb.2016.01823] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 10/31/2016] [Indexed: 01/08/2023] Open
Abstract
Microbial communities inhabiting high-altitude spring ecosystems are subjected to extreme changes in solar irradiance and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA) we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon, and afternoon) to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Solar irradiance, temperature, and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e.g., Parcubacteria, Gracilibacteria, OP3, TM6, SR1). Diversity increased at noon, when the highest irradiances were measured (3.3-3.9 H', 1125 W m-2) compared to morning and afternoon (0.6-2.8 H'). This shift was associated with a decrease in the contribution to pyrolibraries by Cyanobacteria and an increase of Proteobacteria and other initially low frequently and rare bacteria phyla (< 0.5%) in the pyrolibraries. A potential increase in the activity of Cyanobacteria and other phototrophic groups, e.g., Rhodobacterales, was observed and associated with UVR, suggesting the presence of photo-activated repair mechanisms to resist high levels of solar radiation. In addition, the percentage contribution of cyanobacterial sequences in the afternoon was similar to those recorded in the morning. The shifts in the contribution by Cyanobacteria also influenced the rate of change in nitrate, nitrite, and phosphate, highlighted by a high level of nitrate accumulation during hours of high radiation and temperature associated with nitrifying bacteria activity. We did not detect ammonia or nitrite oxidizing bacteria in situ, but both functional groups (Nitrosomona and Nitrospira) appeared mainly in pyrolibraries generated from dark incubations. In total, our results reveal that both the structure and the diversity of the active bacteria community was extremely dynamic through the day, and showed marked shifts in composition that influenced nutrient recycling, highlighting how abiotic variation affects potential ecosystem functioning.
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Reddin CJ, O’Connor NE, Harrod C. Living to the range limit: consumer isotopic variation increases with environmental stress. PeerJ 2016; 4:e2034. [PMID: 27280067 PMCID: PMC4893340 DOI: 10.7717/peerj.2034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 04/22/2016] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Theoretically, each species' ecological niche is phylogenetically-determined and expressed spatially as the species' range. However, environmental stress gradients may directly or indirectly decrease individual performance, such that the precise process delimiting a species range may not be revealed simply by studying abundance patterns. In the intertidal habitat the vertical ranges of marine species may be constrained by their abilities to tolerate thermal and desiccation stress, which may act directly or indirectly, the latter by limiting the availability of preferred trophic resources. Therefore, we expected individuals at greater shore heights to show greater variation in diet alongside lower indices of physiological condition. METHODS We sampled the grazing gastropod Echinolittorina peruviana from the desert coastline of northern Chile at three shore heights, across eighteen regionally-representative shores. Stable isotope values (δ13C and δ15N) were extracted from E. peruviana and its putative food resources to estimate Bayesian ellipse area, carbon and nitrogen ranges and diet. Individual physiological condition was tracked by muscle % C and % N. RESULTS There was an increase in isotopic variation at high shore levels, where E. peruviana's preferred resource, tide-deposited particulate organic matter (POM), appeared to decrease in dietary contribution, and was expected to be less abundant. Both muscle % C and % N of individuals decreased with height on the shore. DISCUSSION Individuals at higher stress levels appear to be less discriminating in diet, likely because of abiotic forcing, which decreases both consumer mobility and the availability of a preferred resource. Abiotic stress might be expected to increase trophic variation in other selective dietary generalist species. Where this coincides with a lower physiological condition may be a direct factor in setting their range limit.
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Østbye K, Harrod C, Gregersen F, Klepaker T, Schulz M, Schluter D, Vøllestad LA. The temporal window of ecological adaptation in postglacial lakes: a comparison of head morphology, trophic position and habitat use in Norwegian threespine stickleback populations. BMC Evol Biol 2016; 16:102. [PMID: 27178328 PMCID: PMC4866279 DOI: 10.1186/s12862-016-0676-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/29/2016] [Indexed: 12/02/2022] Open
Abstract
Background Studying how trophic traits and niche use are related in natural populations is important in order to understand adaptation and specialization. Here, we describe trophic trait diversity in twenty-five Norwegian freshwater threespine stickleback populations and their putative marine ancestor, and relate trait differences to postglacial lake age. By studying lakes of different ages, depths and distance to the sea we examine key environmental variables that may predict adaptation in trophic position and habitat use. We measured trophic traits including geometric landmarks that integrated variation in head shape as well as gillraker length and number. Trophic position (Tpos) and niche use (α) were estimated from stable isotopes (δ13C, δ15N). A comparison of head shape was also made with two North American benthic-limnetic species pairs. Results We found that head shape differed between marine and freshwater sticklebacks, with marine sticklebacks having more upturned mouths, smaller eyes, larger opercula and deeper heads. Size-adjusted gillraker lengths were larger in marine than in freshwater stickleback. Norwegian sticklebacks were compared on the same head shape axis as the one differentiating the benthic-limnetic North American threespine stickleback species pairs. Here, Norwegian freshwater sticklebacks with a more “limnetic head shape” had more and longer gillrakers than sticklebacks with “benthic head shape”. The “limnetic morph” was positively associated with deeper lakes. Populations differed in α (mean ± sd: 0.76 ± 0.29) and Tpos (3.47 ± 0.27), where α increased with gillraker length. Larger fish had a higher Tpos than smaller fish. Compared to the ecologically divergent stickleback species pairs and solitary lake populations in North America, Norwegian freshwater sticklebacks had similar range in Tpos and α values, but much less trait divergences. Conclusions Our results showed trait divergences between threespine stickleback in marine and freshwater environments. Freshwater populations diverged in trophic ecology and trophic traits, but trophic ecology was not related to the elapsed time in freshwater. Norwegian sticklebacks used the same niches as the ecologically divergent North American stickleback species pairs. However, as trophic trait divergences were smaller, and not strongly associated with the ecological niche, ecological adaptations along the benthic-limnetic axis were less developed in Norwegian sticklebacks.
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Baltazar-Soares M, Bracamonte SE, Bayer T, Chain FJ, Hanel R, Harrod C, Eizaguirre C. Evaluating the adaptive potential of the European eel: is the immunogenetic status recovering? PeerJ 2016; 4:e1868. [PMID: 27077000 PMCID: PMC4830236 DOI: 10.7717/peerj.1868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 03/09/2016] [Indexed: 02/03/2023] Open
Abstract
The recent increased integration of evolutionary theory into conservation programs has greatly improved our ability to protect endangered species. A common application of such theory links population dynamics and indices of genetic diversity, usually estimated from neutrally evolving markers. However, some studies have suggested that highly polymorphic adaptive genes, such as the immune genes of the Major Histocompatibility Complex (MHC), might be more sensitive to fluctuations in population dynamics. As such, the combination of neutrally- and adaptively-evolving genes may be informative in populations where reductions in abundance have been documented. The European eel (Anguilla anguilla) underwent a drastic and well-reported decline in abundance in the late 20th century and still displays low recruitment. Here we compared genetic diversity indices estimated from neutral (mitochondrial DNA and microsatellites) and adaptive markers (MHC) between two distinct generations of European eels. Our results revealed a clear discrepancy between signatures obtained for each class of markers. Although mtDNA and microsatellites showed no changes in diversity between the older and the younger generations, MHC diversity revealed a contemporary drop followed by a recent increase. Our results suggest ongoing gain of MHC genetic diversity resulting from the interplay between drift and selection and ultimately increasing the adaptive potential of the species.
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Crook DA, Lowe WH, Allendorf FW, Erős T, Finn DS, Gillanders BM, Hadwen WL, Harrod C, Hermoso V, Jennings S, Kilada RW, Nagelkerken I, Hansen MM, Page TJ, Riginos C, Fry B, Hughes JM. Human effects on ecological connectivity in aquatic ecosystems: Integrating scientific approaches to support management and mitigation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 534:52-64. [PMID: 25917446 DOI: 10.1016/j.scitotenv.2015.04.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 03/30/2015] [Accepted: 04/10/2015] [Indexed: 06/04/2023]
Abstract
Understanding the drivers and implications of anthropogenic disturbance of ecological connectivity is a key concern for the conservation of biodiversity and ecosystem processes. Here, we review human activities that affect the movements and dispersal of aquatic organisms, including damming of rivers, river regulation, habitat loss and alteration, human-assisted dispersal of organisms and climate change. Using a series of case studies, we show that the insight needed to understand the nature and implications of connectivity, and to underpin conservation and management, is best achieved via data synthesis from multiple analytical approaches. We identify four key knowledge requirements for progressing our understanding of the effects of anthropogenic impacts on ecological connectivity: autecology; population structure; movement characteristics; and environmental tolerance/phenotypic plasticity. Structuring empirical research around these four broad data requirements, and using this information to parameterise appropriate models and develop management approaches, will allow for mitigation of the effects of anthropogenic disturbance on ecological connectivity in aquatic ecosystems.
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Phillips ND, Harrod C, Gates AR, Thys TM, Houghton JDR. Seeking the sun in deep, dark places: mesopelagic sightings of ocean sunfishes (Molidae). JOURNAL OF FISH BIOLOGY 2015; 87:1118-1126. [PMID: 26377954 DOI: 10.1111/jfb.12769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/30/2015] [Indexed: 06/05/2023]
Abstract
Evidence is presented from publicly available remotely operated vehicle (ROV) footage that suggests deep-water ranging in ocean sunfishes (family Molidae) is more common than typically thought, including a new maximum depth recorded for the southern sunfish Mola ramsayi.
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Reddin CJ, Docmac F, O’Connor NE, Bothwell JH, Harrod C. Coastal Upwelling Drives Intertidal Assemblage Structure and Trophic Ecology. PLoS One 2015; 10:e0130789. [PMID: 26214806 PMCID: PMC4516361 DOI: 10.1371/journal.pone.0130789] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 05/26/2015] [Indexed: 12/05/2022] Open
Abstract
Similar environmental driving forces can produce similarity among geographically distant ecosystems. Coastal oceanic upwelling, for example, has been associated with elevated biomass and abundance patterns of certain functional groups, e.g., corticated macroalgae. In the upwelling system of Northern Chile, we examined measures of intertidal macrobenthic composition, structure and trophic ecology across eighteen shores varying in their proximity to two coastal upwelling centres, in a hierarchical sampling design (spatial scales of >1 and >10 km). The influence of coastal upwelling on intertidal communities was confirmed by the stable isotope values (δ13C and δ15N) of consumers, including a dominant suspension feeder, grazers, and their putative resources of POM, epilithic biofilm, and macroalgae. We highlight the utility of muscle δ15N from the suspension feeding mussel, Perumytilus purpuratus, as a proxy for upwelling, supported by satellite data and previous studies. Where possible, we used corrections for broader-scale trends, spatial autocorrelation, ontogenetic dietary shifts and spatial baseline isotopic variation prior to analysis. Our results showed macroalgal assemblage composition, and benthic consumer assemblage structure, varied significantly with the intertidal influence of coastal upwelling, especially contrasting bays and coastal headlands. Coastal topography also separated differences in consumer resource use. This suggested that coastal upwelling, itself driven by coastline topography, influences intertidal communities by advecting nearshore phytoplankton populations offshore and cooling coastal water temperatures. We recommend the isotopic values of benthic organisms, specifically long-lived suspension feeders, as in situ alternatives to offshore measurements of upwelling influence.
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Fleming NEC, Harrod C, Newton J, Houghton JDR. Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology. PeerJ 2015; 3:e1110. [PMID: 26244116 PMCID: PMC4517961 DOI: 10.7717/peerj.1110] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/27/2015] [Indexed: 11/20/2022] Open
Abstract
Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their oversimplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >2,000 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata) within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ13C and δ15N stable isotope values, we examined: (1) whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2) Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3) When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ15N (trophic position) were evident between all three species, with size-based and temporal shifts in δ15N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous assertions that jellyfish require more robust inclusion in marine fisheries or ecosystem models.
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Sarmiento-Devia RA, Harrod C, Pacheco AS. Ecology and Conservation of Sea Turtles in Chile. CHELONIAN CONSERVATION AND BIOLOGY 2015. [DOI: 10.2744/ccab-14-01-21-33.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Quezada-Romegialli C, Véliz D, Docmac F, Harrod C. The complete mitochondrial genome of the rocky reef fish Cheilodactylus variegatus Valenciennes, 1833 (Teleostei: Cheilodactylidae). Mitochondrial DNA A DNA Mapp Seq Anal 2015; 27:2359-60. [PMID: 25970628 DOI: 10.3109/19401736.2015.1025263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cheilodactylus variegatus is a common benthivorous marine fish inhabiting in rocky subtidal habitats in the eastern south Pacific coast of Chile and Peru. However, its biology and ecology are relatively understudied and its taxonomic assignment has been debated recently. The complete mitochondrial genome was assembled de novo and mapped to a reference using 5.97 million of reads obtained through Ion Torrent next generation sequencing, resulting in a circular sequence of 16,652 bp in length. Gene composition and arrangement comprised to that reported for most fishes and contained the typical structure of 2 rRNAs, 13 protein-coding genes, 22 tRNAs and 1 non-coding region. This mitogenome provides a valuable resource for studies of fish molecular systematics, phylogeography and population genetics.
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Ravinet M, Hynes R, Poole R, Cross TF, McGinnity P, Harrod C, Prodöhl PA. Where the lake meets the sea: strong reproductive isolation is associated with adaptive divergence between lake resident and anadromous three-spined sticklebacks. PLoS One 2015; 10:e0122825. [PMID: 25874617 PMCID: PMC4397041 DOI: 10.1371/journal.pone.0122825] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/14/2015] [Indexed: 11/28/2022] Open
Abstract
Contact zones between divergent forms of the same species are often characterised by high levels of phenotypic diversity over small geographic distances. What processes are involved in generating such high phenotypic diversity? One possibility is that introgression and recombination between divergent forms in contact zones results in greater phenotypic and genetic polymorphism. Alternatively, strong reproductive isolation between forms may maintain distinct phenotypes, preventing homogenisation by gene flow. Contact zones between divergent freshwater-resident and anadromous stickleback (Gasterosteus aculeatus L.) forms are numerous and common throughout the species distribution, offering an opportunity to examine these contrasting hypotheses in greater detail. This study reports on an interesting new contact zone located in a tidally influenced lake catchment in western Ireland, characterised by high polymorphism for lateral plate phenotypes. Using neutral and QTL-linked microsatellite markers, we tested whether the high diversity observed in this contact zone arose as a result of introgression or reproductive isolation between divergent forms: we found strong support for the latter hypothesis. Three phenotypic and genetic clusters were identified, consistent with two divergent resident forms and a distinct anadromous completely plated population that migrates in and out of the system. Given the strong neutral differentiation detected between all three morphotypes (mean FST = 0.12), we hypothesised that divergent selection between forms maintains reproductive isolation. We found a correlation between neutral genetic and adaptive genetic differentiation that support this. While strong associations between QTL linked markers and phenotypes were also observed in this wild population, our results support the suggestion that such associations may be more complex in some Atlantic populations compared to those in the Pacific. These findings provide an important foundation for future work investigating the dynamics of gene flow and adaptive divergence in this newly discovered stickleback contact zone.
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