scholarly journals Isotopic evidence of connectivity between an inshore vegetated lagoon (nursery habitat) and coastal artificial reefs (adult habitats) for the reef fish Lethrinus lentjan on the Terengganu coast, Malaysia

2019 ◽  
Vol 70 (12) ◽  
pp. 1675 ◽  
Author(s):  
Dung Quang Le ◽  
Siau Yin Fui ◽  
Rumeaida Mat Piah ◽  
Toyoho Ishimura ◽  
Yuji Sano ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Nursery Habitat ◽  
Artificial Reefs ◽  
Conservation Strategies ◽  
Adult Fish ◽  
Spatial Change ◽  
Opaque Zone ◽  
Coastal Conservation ◽  
Nursery Habitats ◽  
Isotope Analyses

Stable isotope analyses of muscle tissue (δ13Cmuscle and δ15Nmuscle) and otoliths (δ13Cotolith and δ18Ootolith) were used to retrospectively track habitat uses of Lethrinus lentjan, and to determine any association between Setiu Lagoon (nursery habitat) and coastal artificial reefs (CARs; adult habitats) on the Terengganu coast, Malaysia. Muscle stable isotopes exhibited a spatial change from inshore to offshore habitats associated with growth, possibly related to the reef-ward movement of the fish. Otolith stable isotopes of adult fish from CARs were measured in juvenile (from outside the core to the first opaque zone of otolith) and adult (the edge of otolith) portions and were compared with those of juveniles from Setiu Lagoon, suggesting that the adult fish may not primarily use the lagoon as a nursery before ontogenetically migrating to CARs. The effects of coastal currents between monsoonal seasons could reorientate offshore juvenile migration; hence, adult cohorts in CARs may be replenished from various nursery habitats along the coast. Additionally, similarities in the δ18Ootolith values of juvenile and adult sections suggested that some individuals may not spend their juvenile phases in shallow estuarine habitats. Based on the findings of this study, we recommend that coastal conservation strategies take into account multiple nursery habitats rather than a single one.

scholarly journals Offshore wind farms and the attraction–production hypothesis: insights from a combination of stomach content and stable isotope analyses

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Ninon Mavraki ◽  
Steven Degraer ◽  
Jan Vanaverbeke
Keyword(s):  
Stable Isotope ◽  
Stomach Content ◽  
Wind Farms ◽  
Offshore Wind ◽  
Artificial Reefs ◽  
Dietary Composition ◽  
Trachurus Trachurus ◽  
Offshore Wind Farms ◽  
Scomber Scombrus ◽  
Isotope Analyses

AbstractOffshore wind farms (OWFs) act as artificial reefs, attracting high abundances of fish, which could potentially increase their local production. This study investigates the feeding ecology of fish species that abundantly occur at artificial habitats, such as OWFs, by examining the short- and the long-term dietary composition of five species: the benthopelagic Gadus morhua and Trisopterus luscus, the pelagic Scomber scombrus and Trachurus trachurus, and the benthic Myoxocephalus scorpioides. We conducted combined stomach content and stable isotope analyses to examine the short- and the time-integrated dietary composition, respectively. Our results indicated that benthopelagic and benthic species utilize artificial reefs, such as OWFs, as feeding grounds for a prolonged period, since both analyses indicated that they exploit fouling organisms occurring exclusively on artificial hard substrates. Trachurus trachurus only occasionally uses artificial reefs as oases of highly abundant resources. Scomber scombrus does not feed on fouling fauna and therefore its augmented presence in OWFs is probably related to reasons other than the enhanced food availability. The long-termed feeding preferences of benthic and benthopelagic species contribute to the hypothesis that the artificial reefs of OWFs could potentially increase the fish production in the area. However, this was not supported for the pelagic species.

scholarly journals A Shattered Tomb of Scattered People: The Alvastra Dolmen in Light of Stable Isotopes

2021 ◽  
Vol 19 (1) ◽  
pp. 113-141
Author(s):  
Elin Fornander
Keyword(s):  
Stable Isotopes ◽  
Sacred Space ◽  
Focal Point ◽  
Skeletal Remains ◽  
Radiocarbon Dates ◽  
Burial Practices ◽  
Geographic Origins ◽  
Isotope Analyses

Skeletal remains from the dolmen in Alvastra are ap- proached from the perspective of isotope analyses, providing insights into dietary and residential pat- terns. Radiocarbon dates from the interred individu- als provide evidence of long-lasting burial practices which were still active when the Alvastra Pile Dwell- ing was built. The isotopic record indicates dispersed geographic origins among the buried individuals. It is suggested that Alvastra, with the dolmen as a focal point, was established as a meeting place and sacred space already several centuries before the time of the Pile Dwelling.

scholarly journals Nursery habitat availability limits adult stock sizes of predatory coastal fish

2013 ◽  
Vol 71 (3) ◽  
pp. 672-680 ◽  
Author(s):  
Göran Sundblad ◽  
Ulf Bergström ◽  
Alfred Sandström ◽  
Peter Eklöv
Keyword(s):  
Fish Species ◽  
Generalized Additive Models ◽  
Nursery Habitat ◽  
Additive Models ◽  
Predatory Fish ◽  
Habitat Availability ◽  
Adult Density ◽  
Habitat Protection ◽  
Nursery Habitats ◽  
Population Sizes

Abstract Habitat protection is a strategy often proposed in fisheries management to help maintain viable populations of exploited species. Yet, quantifying the importance of habitat availability for population sizes is difficult, as the precise distribution of essential habitats is poorly known. To quantify the contribution from coastal nursery habitats to exploited fish population sizes, we related adult density to the amount of nursery habitat available for 12 populations of the two dominant predatory fish species in a 40 000-km2 archipelago area of the Baltic Sea. Habitat distribution was mapped using three conceptually different techniques, Maxent, generalized additive models, and random forest, using spawning and 0-group point samples. Adult densities were estimated from gillnet surveys. Regressions demonstrated no evident effect from fishing, whereas habitat availability had a positive effect, explaining almost half of the variation in population sizes of both species. This result shows that a substantial proportion of the potential production of adult fish can be estimated by mapping essential nursery habitats distribution. Responses were non-linear, indicating that habitat protection has largest effects where there is little available habitat. By demonstrating the importance of habitat limitation of two exploited fish species, we provide quantitative support to the benefits of habitat protection for fisheries.

scholarly journals Stable isotopes of Hawaiian spiders reflect substrate properties along a chronosequence

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4527 ◽  
Author(s):  
Susan R. Kennedy ◽  
Todd E. Dawson ◽  
Rosemary G. Gillespie
Keyword(s):  
Stable Isotopes ◽  
Soil Chemistry ◽  
Trophic Levels ◽  
Plant Leaves ◽  
Chemical Signatures ◽  
Soil Stoichiometry ◽  
Substrate Properties ◽  
Age Structured ◽  
Isotope Analyses ◽  
Predatory Arthropods

The Hawaiian Islands offer a unique opportunity to test how changes in the properties of an isolated ecosystem are propagated through the organisms that occur within that ecosystem. The age-structured arrangement of volcanic-derived substrates follows a regular progression over space and, by inference, time. We test how well documented successional changes in soil chemistry and associated vegetation are reflected in organisms at higher trophic levels—specifically, predatory arthropods (spiders)—across a range of functional groups. We focus on three separate spider lineages: one that builds capture webs, one that hunts actively, and one that specializes on eating other spiders. We analyze spiders from three sites across the Hawaiian chronosequence with substrate ages ranging from 200 to 20,000 years. To measure the extent to which chemical signatures of terrestrial substrates are propagated through higher trophic levels, we use standard stable isotope analyses of nitrogen and carbon, with plant leaves included as a baseline. The target taxa show the expected shift in isotope ratios ofδ15N with trophic level, from plants to cursorial spiders to web-builders to spider eaters. Remarkably, organisms at all trophic levels also precisely reflect the successional changes in the soil stoichiometry of the island chronosequence, demonstrating how the biogeochemistry of the entire food web is determined by ecosystem succession of the substrates on which the organisms have evolved.

scholarly journals Sensitivity of a shark nursery habitat to a changing climate

2020 ◽  
Vol 652 ◽  
pp. 123-136
Author(s):  
DP Crear ◽  
RJ Latour ◽  
MAM Friedrichs ◽  
P St-Laurent ◽  
KC Weng
Keyword(s):  
Climate Change ◽  
Chesapeake Bay ◽  
Foraging Ecology ◽  
Life Stage ◽  
Nursery Habitat ◽  
Habitat Model ◽  
Suitable Habitat ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Nursery Habitats

Nursery area habitats such as estuaries are vital for the success of many fish populations. Climate change is altering conditions in these areas, which can thus impact the availability of suitable nursery habitat. The sandbar shark Carcharhinus plumbeus uses Chesapeake Bay (USA) as a nursery habitat during the summer months from birth up to 10 yr of age. To assess the impacts of climate change on juvenile sandbar sharks, we developed a habitat model using longline data collected from a fishery-independent survey within Chesapeake Bay. With this model, we projected contemporary and future distributions of suitable habitat for juvenile sandbar sharks in Chesapeake Bay under varying environmental regimes. Predicted suitable juvenile sandbar shark habitat was negatively impacted by future increases in temperature, but positively influenced by future decreases in dissolved oxygen. The latter trend was likely related to the habitat partitioning that occurs between different life stages. Changes in salinity had relatively small impacts. By end-of-century the projected amount of suitable bottom habitat decreased; however, when incorporating the entire water column, projected suitable habitat increased. This suggests that juvenile sandbar sharks may need to make a behavioral shift to avoid non-preferred conditions, which could alter their foraging ecology or refuge strategies. As nursery habitats change with climate change, it is crucial to understand how a species may be impacted during this vital life stage when trying to predict overall species success in the future.

scholarly journals Protecting nursery areas without fisheries management is not enough to conserve the most endangered parrotfish of the Atlantic Ocean

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Natalia C. Roos ◽  
Guilherme O. Longo ◽  
Maria Grazia Pennino ◽  
Ronaldo B. Francini-Filho ◽  
Adriana R. Carvalho
Keyword(s):  
Marine Protected Areas ◽  
Fish Population ◽  
Marine Conservation ◽  
Conservation Strategies ◽  
Multiple Use ◽  
Conservation Policies ◽  
Nursery Habitats ◽  
Population Maintenance ◽  
Effective Conservation ◽  
Shed Light

AbstractMarine protected areas (MPAs) are a primary strategy for marine conservation worldwide, having as a common goal the protection of essential habitats to enhance fish population recovery. However, MPAs alone may not be effective because species are not isolated from critical impacts occurring outside their boundaries. We evaluated how protecting critical nursery habitats affect the population of an important fishing target, using a 6-year database to predict juvenile hotspots and estimate population trends of the endemic and endangered parrotfish Scarus trispinosus within a mosaic of MPAs at the Abrolhos Bank, NE Brazil. We found that important nursery habitats are within no-take areas, but both juvenile and adult populations still show a declining trend over time. MPAs failed to ensure population maintenance and recovery likely due to overfishing in adjacent areas and the lack of compliance to management rules within multiple-use and within no-take MPAs. MPAs alone are not enough to protect ecologically important endangered species, but is still one of the only conservation strategies, particularly in developing countries. Our results shed light on the need for a wider adoption of more effective conservation policies in addition to MPAs, both in Brazil and in countries with similar governance contexts.

scholarly journals Application of Statistical Techniques to Study Stable Isotopes (18O and 2H) Characteristics of Precipitation in Iran (Southwest Asia)

2021 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Mojtaba Heydarizad ◽  
Rogert Sorí
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Close Correlation ◽  
Statistical Techniques ◽  
Southwest Asia ◽  
Climatic Zones ◽  
Stable Isotope Signatures ◽  
Isotope Analyses ◽  
Precipitation Sampling

Various climatic and geographic parameters influence precipitation in Iran, which makes the interpretation of stable isotope signatures in precipitation very complicated. Thus, precipitation sampling stations for stable isotope analyses in Iran have been classified by cluster analysis (CA) into 10 clusters, based on their stable isotope characteristics. The classification of stations by CA also has a close correlation with the Koppen climatic zones across Iran. Finally, the stations in each cluster were plotted on the GMWL and EMMWL. This study shows that classifying precipitation sampling stations can simplify the interpretation of stable isotopes in the precipitation of regions with complicated climatic systems.

scholarly journals Exploring New Ways to Reconstruct the Forma Urbis Romae: An Archaeometric Approach (CL Color and Stable Isotope Analyses)

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1400
Author(s):  
Lluís Casas ◽  
Roberta Di Febo ◽  
Mauro Brilli ◽  
Francesca Giustini ◽  
Marco Gozzi ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Statistical Methods ◽  
The Other ◽  
Isotopic Ratios ◽  
Ancient Rome ◽  
Stable Isotope Analyses ◽  
Isotope Analyses ◽  
Δ18o And Δ13c

The Forma Urbis Romae (F.U.) was a 3rd-century-AD monumental map of ancient Rome consisting of 151 rectangular marble slabs. Several efforts have been made to reconstruct it from its current incomplete and fragmentary condition. In this paper, we explore the potential of an archaeometric approach to serve this purpose. Almost a hundred F.U. fragments have been characterized, particularly focusing on cathodoluminescence (CL) microscopy and stable isotopes (δ18O and δ13C). Different statistical methods have been used to quantify the similarity between samples. The central assumption is that samples from a given slab share similar CL colors and isotopic ratios. The assumption has been verified for samples from single fragments and then it has been used to check ten debated reconstruction hypotheses. The measured isotopic ratios confirm the Proconnesian nature of the F.U. marble, except for a fragment. Beyond provenance, the results cast doubts on four out of the ten checked reconstruction hypotheses and support the other six. The reconstruction of the F.U. remains a fascinating challenge, and both isotopic and CL analyses have demonstrated their potential to tackle it. Further research could extend the presented methodology to a higher number of samples. The innovative use of CL to reconstruct a fragmented artwork could be applied to other projects.

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