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13,519 Research products, page 1 of 1,352

  • European Marine Science
  • Research data
  • Other research products
  • 2013-2022
  • Open Access

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  • Open Access English
    Authors: 
    Larson, Wes;
    Publisher: Dryad

    Freshwater mussels (family Unionidae) are among the world’s most endangered taxa, with almost 75% of North American taxa classified as a species of concern, threatened, or endangered. Despite the critical importance of comprehensive distributional data for the conservation of unionids and fishes, these data are often lacking because of the labor and resources associated with traditional survey methods. During their larval stage, unionid mussels use various fish species as obligate hosts, making native fish species vital to unionid persistence and an understanding of host distribution similarly important. Here, we utilized an eDNA metabarcoding approach to evaluate patterns of co-distribution of unionid mussels and fishes along ~362 km of the densely sampled Grand River network as well as the outlets of 19 tributaries along the eastern shore of Lake Michigan, USA. We detected a total of 21 mussel and 40 fish taxa, with distinctive composition of both mussel and fish assemblages across tributaries and differences in fish taxa between sampling periods. Notably, we detected more mussel taxa within the Grand River watershed than at the outlets of all 20 rivers combined. Within the Grand River network, two fish taxa (Pylodictus olivaris and Cyprinella) were found more frequently in areas of high mussel diversity, and three fish taxa more frequently in areas of low mussel diversity (Umbra, Leuciscidae, and Etheostoma). There was little difference between eDNA detections of mussels from samples collected in June versus August, but we detected significantly more fish taxa in August compared to June. Taken together, our findings demonstrate the value of eDNA metabarcoding for evaluating co-distribution of ecologically connected taxa. The use of eDNA as a tool for determining distributions of mussels and their obligate hosts may facilitate conservation efforts for these imperiled taxa. See manuscript.

  • Open Access
    Authors: 
    van Leeuwen, Stefan; Leenders, Liz; Hoogenboom, Ron; Nijrolder, Antoine;
    Publisher: Wageningen University & Research
    Country: Netherlands

    On behalf of the Ministry of Agriculture, Nature and Food Quality (LNV), Wageningen Food Safety Research (WFSR) analyses samples of agricultural products of animal origin for dioxins, PCBs, brominated flame retardants (BFRs) and poly- and perfluorinated alkyl substances (PFASs). This includes meat, milk, eggs and fish. The samples are taken at the primary production or processing stage (e.g. in slaughterhouses or raw milk collection services). For dioxin-like compounds, 350 samples are screened first with the DR CALUX® method. Samples giving a signal indicating a level above the lowest action level are regarded as suspected. These samples are further examined using GC/HRMS as confirmatory method. Concerning fish, shellfish and crustaceans, approx. 25 samples are collected at sea by research vessels, at the fish auction, or from whole-sale traders (farmed fish).

  • Open Access
    Authors: 
    Gazert, Volker; Luedecke, Cornelia;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Open Access English
    Authors: 
    Frid, Ori;
    Publisher: Dryad

    The positive effect of fully protected Marine Protected Areas (MPAs) on marine biodiversity, specifically on fishes, has been widely documented. In contrast, the potential of MPAs to mitigate the impact of adverse climatic conditions has seldom been investigated. Here, we assessed the effectiveness of MPAs, quantified as increasing fish biomass, across wide geographic and environmental gradients across the Mediterranean Sea. We performed underwater visual surveys within and outside MPAs to characterize fish assemblages in 52 rocky reef sites across an extent of over 3,300 km. We used the steep spatial temperature gradient across the Mediterranean as a 'space-for-time' substitution to infer climate-driven temporal changes. We found that, as expected, Mediterranean MPAs increased fish biomass. At the same time, higher seawater temperatures are associated with decreased fish biomass, changes in species composition, and shifts towards more thermophilic species. Importantly, we found that the rate of decrease in fish biomass with temperature was similar between protected and fished sites. Taken together, these results suggest that the capacity of MPAs to harbor higher fish biomass, compared to surrounding areas, is maintained across a broad temperature range. At the same time, MPAs will not be able to offset larger-scale biotic alterations associated with climate change. Policy implications: Our results suggest that sustained warming will likely reduce fish biomass in the Mediterranean Sea and shift community structure, requiring more conservative targets for fishery regulations. At the same time, protection from fishing will remain an important management tool even with future high-water temperatures, and MPAs are expected to continue to provide local-scale benefits to conservation and fisheries.

  • Research data . 2022
    Open Access
    Authors: 
    Centre for Earth Observation Science;
    Publisher: Canadian Watershed Information Network (CanWIN)

    Fish larvae collected via horizontal tows in the Hudson Bay system on the CCGS Amundsen in 2005, 2010, 2012, 2017 and 2018.

  • Open Access English
    Authors: 
    Yates, Matthew;
    Publisher: Dryad

    Relating environmental DNA (eDNA) signal strength to organism abundance requires a fundamental understanding of eDNA production. A number of studies have demonstrated that eDNA production may scale allometrically – that is, larger organisms tend to exhibit lower mass-specific eDNA production rates, likely due to allometric scaling in key processes related to eDNA production (e.g. surface area, excretion/egestion). While most previous studies have examined intra-specific allometry, physiological rates and organism surface area also scale allometrically across species. We therefore hypothesize that eDNA production will similarly exhibit inter-specific allometric scaling. To evaluate this hypothesis, we reanalyzed previously published eDNA data from Stoeckle et al. (2021) which compared metabarcoding read count to organism count and biomass data obtained from trawl surveys off the New Jersey coast. Using a Bayesian model we empirically estimated the value of the allometric scaling coefficient (‘b’) for Northwestern Atlantic bony fishes to be 0.77 (credible interval = 0.64 – 0.92), although our model failed to converge for Chondrichthyan species. We found that integrating allometry significantly improved correlations between organism abundance and metabarcoding read count relative to traditional metrics of abundance (density and biomass) for bony fishes. Although substantial unexplained variation remains in the relationship between read count and organism abundance, our study provides evidence that eDNA production may scale allometrically across species in some contexts. Future studies investigating the relationship between eDNA signal strength and metrics of fish abundance could potentially be improved by accounting for allometry; to this end, we developed an online tool that can facilitate the integration of allometry in eDNA/abundance relationships. This is a curated dataset obtained from: Stoeckle, M.Y., Adolf, J., Charlop-powers, Z., Dunton, K.J., Hinks, G., and Vanmorter, S.M. 2021. Trawl and eDNA assessment of marine fish diversity, seasonality, and relative abundance in coastal New Jersey, USA. ICES J. Mar. Sci. 78(1): 293–304. doi:10.1093/icesjms/fsaa225. We separated Chondrichtyan and Osteichthyan species into separate datasets, including only species which were detected using eDNA. Values of 0.001 were added to 'zeroes' for abundance data, due to the inclusion of a heteroscedastic residual error term in some of the models.

  • Open Access
    Authors: 
    van Leeuwen, Stefan; Leenders, Liz; Hoogenboom, Ron; Nijrolder, Antoine;
    Publisher: 4TU.ResearchData
    Country: Netherlands

    On behalf of the Ministry of Agriculture, Nature and Food Quality (LNV), Wageningen Food Safety Research (WFSR) analyses samples of agricultural products of animal origin for dioxins, PCBs, brominated flame retardants (BFRs) and poly- and perfluorinated alkyl substances (PFASs). This includes meat, milk, eggs and fish. The samples are taken at the primary production or processing stage (e.g. in slaughterhouses or raw milk collection services). For dioxin-like compounds, 350 samples are screened first with the DR CALUX® method. Samples giving a signal indicating a level above the lowest action level are regarded as suspected. These samples are further examined using GC/HRMS as confirmatory method. Concerning fish, shellfish and crustaceans, approx. 25 samples are collected at sea by research vessels, at the fish auction, or from whole-sale traders (farmed fish).

  • Open Access English
    Authors: 
    Dagestad, Knut-Frode; Röhrs, Johannes;
    Publisher: Zenodo

    Ocean drifters from oil-on-water exercise in North Sea (Frigg oil field) June 2019. Described in more detail in Brekke, C., Espeseth, M. M., Dagestad, K.-F., Röhrs, J., Hole, L. R., & Reigber, A. (2021). Integrated analysis of multisensor datasets and oil drift simulations - a free-floating oil experiment in the open ocean. Journal of Geophysical Research: Oceans, 126, e2020JC016499. https://doi.org/10.1029/2020JC016499 Work is funded by grant no. 237906 (CIRFA) of the Norwegian Research Council. Work is funded by grant no. 237906 (CIRFA) of the Norwegian Research Council

  • Open Access
    Authors: 
    Wesche, Christine; Regnery, Julia;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Open Access
    Authors: 
    Fraser, Ainsley L.; El-Sabaawi, Rana;
    Publisher: Dryad

    General Methodology of the Project Between May – July 2019, a total of 534 fish were collected from 15 sites around Vancouver Island and Southern BC, Canada. At each site, sticklebacks were caught with beach seines at 1-2m depth and 2-3m offshore, or with un-baited minnow traps. We sampled in all four oceanographic regions of Vancouver Island: the Strait of Georgia, the Juan de Fuca Strait, and the western and northern coasts of Vancouver Island. Within each region we sampled from three different coastal habitat types: tidal flats, salt marshes, and lagoons. Stickleback Head and Body Photograph Files The original image files were converted into tps format using the software tps.Util version 1.61, and then organized into files for superimposition. The tps images were uploaded into tps.Dig version 2.05 to digitize landmarks on the head and body photographs. The TPS files are included as well, labelled as “All_Body_Fraser_El-Sabaawi.TPS” and “All_Head_Fraser_El-Sabaawi.TPS”. For the head photographs 13 anatomical landmarks were placed around the left side of the head in tps.Dig. For body photographs, 15 landmarks were placed on the left side of the body. After the landmarks were digitized, landmark coordinates (X and Y positions) were uploaded into R. We extracted linear distances from each image using the “linear.dist” function in the landvR package for R. Head length (mm) was extracted from head shots (landmarks 1 and 12) as a proxy for head size. Standard length (cm) was extracted from body shots (landmarks 1 and 8) as a proxy for body size. These lengths, plus individual ID tag, sex, site names, habitat type, oceanographic region, plate morphology, salinity, temperature, mean head length/mean standard length and latitude were included in classifier excel spreadsheets to upload into R. There is one for the head size/shape analysis and another classifier file for body size/shape analysis. Generalized Procrustes Analysis The head and body shape coordinates were analyzed separately. In the geomorph package, the “gpagen” function was used to perform a Generalized Procrustes Analysis (GPA), which is the most common approach for separating shape from size. Following GPA, 26 vectors of shape were produced for the head dataset (X and Y coordinates for 13 landmarks), while 30 vectors of shape were produced for the body dataset (X and Y coordinates for 15 landmarks). Additionally, an extra vector was produced for each dataset which described the geometric size of each specimen’s head or body (i.e. CS) . The threespine stickleback (Gasterosteus aculeatus) is an important model for studying the evolution of vertebrate morphology. Sticklebacks inhabit freshwater, brackish, and marine northern hemisphere waters. Anadromous and marine populations (hereafter marine) are assumed to have remained unchanged morphologically from ancestral marine sticklebacks, despite marine environments varying on regional and local scales. Recent studies suggest that genetic and phenotypic structure exists in marine populations, yet the scale of this variation, and its ecological causes remain unclear. Our goal was to assess morphological trait variation in marine stickleback populations around Southern British Columbia (BC) and determine if oceanographic and habitat characteristics were associated with this variation. Between May-July 2019, we sampled 534 sticklebacks from 15 sites around Vancouver Island, a region characterized by a large diversity of oceanographic and habitat features. We characterized trait variation using two-dimensional (2D) geometric morphometric analysis, comparing individuals between oceanographic regions and habitats. We focused on head and body shape. We found that marine sticklebacks varied morphologically among and between regions and habitats, but the variation did not appear to be related to environmental variation. Sexual dimorphism was the largest source of variation, but oceanographic and habitat variables influenced differences between sexes. We concluded that marine sticklebacks offer abundant opportunities for expanding our knowledge of drivers of morphology. Programs: tps.Util version 1.61 and tps.Dig version 2.05. In R, we used the landvR package and the geomorph package.

Advanced search in Research products
Research products
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Searching FieldsTerms
Any field
arrow_drop_down
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Include:
The following results are related to European Marine Science. Are you interested to view more results? Visit OpenAIRE - Explore.
13,519 Research products, page 1 of 1,352
  • Open Access English
    Authors: 
    Larson, Wes;
    Publisher: Dryad

    Freshwater mussels (family Unionidae) are among the world’s most endangered taxa, with almost 75% of North American taxa classified as a species of concern, threatened, or endangered. Despite the critical importance of comprehensive distributional data for the conservation of unionids and fishes, these data are often lacking because of the labor and resources associated with traditional survey methods. During their larval stage, unionid mussels use various fish species as obligate hosts, making native fish species vital to unionid persistence and an understanding of host distribution similarly important. Here, we utilized an eDNA metabarcoding approach to evaluate patterns of co-distribution of unionid mussels and fishes along ~362 km of the densely sampled Grand River network as well as the outlets of 19 tributaries along the eastern shore of Lake Michigan, USA. We detected a total of 21 mussel and 40 fish taxa, with distinctive composition of both mussel and fish assemblages across tributaries and differences in fish taxa between sampling periods. Notably, we detected more mussel taxa within the Grand River watershed than at the outlets of all 20 rivers combined. Within the Grand River network, two fish taxa (Pylodictus olivaris and Cyprinella) were found more frequently in areas of high mussel diversity, and three fish taxa more frequently in areas of low mussel diversity (Umbra, Leuciscidae, and Etheostoma). There was little difference between eDNA detections of mussels from samples collected in June versus August, but we detected significantly more fish taxa in August compared to June. Taken together, our findings demonstrate the value of eDNA metabarcoding for evaluating co-distribution of ecologically connected taxa. The use of eDNA as a tool for determining distributions of mussels and their obligate hosts may facilitate conservation efforts for these imperiled taxa. See manuscript.

  • Open Access
    Authors: 
    van Leeuwen, Stefan; Leenders, Liz; Hoogenboom, Ron; Nijrolder, Antoine;
    Publisher: Wageningen University & Research
    Country: Netherlands

    On behalf of the Ministry of Agriculture, Nature and Food Quality (LNV), Wageningen Food Safety Research (WFSR) analyses samples of agricultural products of animal origin for dioxins, PCBs, brominated flame retardants (BFRs) and poly- and perfluorinated alkyl substances (PFASs). This includes meat, milk, eggs and fish. The samples are taken at the primary production or processing stage (e.g. in slaughterhouses or raw milk collection services). For dioxin-like compounds, 350 samples are screened first with the DR CALUX® method. Samples giving a signal indicating a level above the lowest action level are regarded as suspected. These samples are further examined using GC/HRMS as confirmatory method. Concerning fish, shellfish and crustaceans, approx. 25 samples are collected at sea by research vessels, at the fish auction, or from whole-sale traders (farmed fish).

  • Open Access
    Authors: 
    Gazert, Volker; Luedecke, Cornelia;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Open Access English
    Authors: 
    Frid, Ori;
    Publisher: Dryad

    The positive effect of fully protected Marine Protected Areas (MPAs) on marine biodiversity, specifically on fishes, has been widely documented. In contrast, the potential of MPAs to mitigate the impact of adverse climatic conditions has seldom been investigated. Here, we assessed the effectiveness of MPAs, quantified as increasing fish biomass, across wide geographic and environmental gradients across the Mediterranean Sea. We performed underwater visual surveys within and outside MPAs to characterize fish assemblages in 52 rocky reef sites across an extent of over 3,300 km. We used the steep spatial temperature gradient across the Mediterranean as a 'space-for-time' substitution to infer climate-driven temporal changes. We found that, as expected, Mediterranean MPAs increased fish biomass. At the same time, higher seawater temperatures are associated with decreased fish biomass, changes in species composition, and shifts towards more thermophilic species. Importantly, we found that the rate of decrease in fish biomass with temperature was similar between protected and fished sites. Taken together, these results suggest that the capacity of MPAs to harbor higher fish biomass, compared to surrounding areas, is maintained across a broad temperature range. At the same time, MPAs will not be able to offset larger-scale biotic alterations associated with climate change. Policy implications: Our results suggest that sustained warming will likely reduce fish biomass in the Mediterranean Sea and shift community structure, requiring more conservative targets for fishery regulations. At the same time, protection from fishing will remain an important management tool even with future high-water temperatures, and MPAs are expected to continue to provide local-scale benefits to conservation and fisheries.

  • Research data . 2022
    Open Access
    Authors: 
    Centre for Earth Observation Science;
    Publisher: Canadian Watershed Information Network (CanWIN)

    Fish larvae collected via horizontal tows in the Hudson Bay system on the CCGS Amundsen in 2005, 2010, 2012, 2017 and 2018.

  • Open Access English
    Authors: 
    Yates, Matthew;
    Publisher: Dryad

    Relating environmental DNA (eDNA) signal strength to organism abundance requires a fundamental understanding of eDNA production. A number of studies have demonstrated that eDNA production may scale allometrically – that is, larger organisms tend to exhibit lower mass-specific eDNA production rates, likely due to allometric scaling in key processes related to eDNA production (e.g. surface area, excretion/egestion). While most previous studies have examined intra-specific allometry, physiological rates and organism surface area also scale allometrically across species. We therefore hypothesize that eDNA production will similarly exhibit inter-specific allometric scaling. To evaluate this hypothesis, we reanalyzed previously published eDNA data from Stoeckle et al. (2021) which compared metabarcoding read count to organism count and biomass data obtained from trawl surveys off the New Jersey coast. Using a Bayesian model we empirically estimated the value of the allometric scaling coefficient (‘b’) for Northwestern Atlantic bony fishes to be 0.77 (credible interval = 0.64 – 0.92), although our model failed to converge for Chondrichthyan species. We found that integrating allometry significantly improved correlations between organism abundance and metabarcoding read count relative to traditional metrics of abundance (density and biomass) for bony fishes. Although substantial unexplained variation remains in the relationship between read count and organism abundance, our study provides evidence that eDNA production may scale allometrically across species in some contexts. Future studies investigating the relationship between eDNA signal strength and metrics of fish abundance could potentially be improved by accounting for allometry; to this end, we developed an online tool that can facilitate the integration of allometry in eDNA/abundance relationships. This is a curated dataset obtained from: Stoeckle, M.Y., Adolf, J., Charlop-powers, Z., Dunton, K.J., Hinks, G., and Vanmorter, S.M. 2021. Trawl and eDNA assessment of marine fish diversity, seasonality, and relative abundance in coastal New Jersey, USA. ICES J. Mar. Sci. 78(1): 293–304. doi:10.1093/icesjms/fsaa225. We separated Chondrichtyan and Osteichthyan species into separate datasets, including only species which were detected using eDNA. Values of 0.001 were added to 'zeroes' for abundance data, due to the inclusion of a heteroscedastic residual error term in some of the models.

  • Open Access
    Authors: 
    van Leeuwen, Stefan; Leenders, Liz; Hoogenboom, Ron; Nijrolder, Antoine;
    Publisher: 4TU.ResearchData
    Country: Netherlands

    On behalf of the Ministry of Agriculture, Nature and Food Quality (LNV), Wageningen Food Safety Research (WFSR) analyses samples of agricultural products of animal origin for dioxins, PCBs, brominated flame retardants (BFRs) and poly- and perfluorinated alkyl substances (PFASs). This includes meat, milk, eggs and fish. The samples are taken at the primary production or processing stage (e.g. in slaughterhouses or raw milk collection services). For dioxin-like compounds, 350 samples are screened first with the DR CALUX® method. Samples giving a signal indicating a level above the lowest action level are regarded as suspected. These samples are further examined using GC/HRMS as confirmatory method. Concerning fish, shellfish and crustaceans, approx. 25 samples are collected at sea by research vessels, at the fish auction, or from whole-sale traders (farmed fish).

  • Open Access English
    Authors: 
    Dagestad, Knut-Frode; Röhrs, Johannes;
    Publisher: Zenodo

    Ocean drifters from oil-on-water exercise in North Sea (Frigg oil field) June 2019. Described in more detail in Brekke, C., Espeseth, M. M., Dagestad, K.-F., Röhrs, J., Hole, L. R., & Reigber, A. (2021). Integrated analysis of multisensor datasets and oil drift simulations - a free-floating oil experiment in the open ocean. Journal of Geophysical Research: Oceans, 126, e2020JC016499. https://doi.org/10.1029/2020JC016499 Work is funded by grant no. 237906 (CIRFA) of the Norwegian Research Council. Work is funded by grant no. 237906 (CIRFA) of the Norwegian Research Council

  • Open Access
    Authors: 
    Wesche, Christine; Regnery, Julia;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Open Access
    Authors: 
    Fraser, Ainsley L.; El-Sabaawi, Rana;
    Publisher: Dryad

    General Methodology of the Project Between May – July 2019, a total of 534 fish were collected from 15 sites around Vancouver Island and Southern BC, Canada. At each site, sticklebacks were caught with beach seines at 1-2m depth and 2-3m offshore, or with un-baited minnow traps. We sampled in all four oceanographic regions of Vancouver Island: the Strait of Georgia, the Juan de Fuca Strait, and the western and northern coasts of Vancouver Island. Within each region we sampled from three different coastal habitat types: tidal flats, salt marshes, and lagoons. Stickleback Head and Body Photograph Files The original image files were converted into tps format using the software tps.Util version 1.61, and then organized into files for superimposition. The tps images were uploaded into tps.Dig version 2.05 to digitize landmarks on the head and body photographs. The TPS files are included as well, labelled as “All_Body_Fraser_El-Sabaawi.TPS” and “All_Head_Fraser_El-Sabaawi.TPS”. For the head photographs 13 anatomical landmarks were placed around the left side of the head in tps.Dig. For body photographs, 15 landmarks were placed on the left side of the body. After the landmarks were digitized, landmark coordinates (X and Y positions) were uploaded into R. We extracted linear distances from each image using the “linear.dist” function in the landvR package for R. Head length (mm) was extracted from head shots (landmarks 1 and 12) as a proxy for head size. Standard length (cm) was extracted from body shots (landmarks 1 and 8) as a proxy for body size. These lengths, plus individual ID tag, sex, site names, habitat type, oceanographic region, plate morphology, salinity, temperature, mean head length/mean standard length and latitude were included in classifier excel spreadsheets to upload into R. There is one for the head size/shape analysis and another classifier file for body size/shape analysis. Generalized Procrustes Analysis The head and body shape coordinates were analyzed separately. In the geomorph package, the “gpagen” function was used to perform a Generalized Procrustes Analysis (GPA), which is the most common approach for separating shape from size. Following GPA, 26 vectors of shape were produced for the head dataset (X and Y coordinates for 13 landmarks), while 30 vectors of shape were produced for the body dataset (X and Y coordinates for 15 landmarks). Additionally, an extra vector was produced for each dataset which described the geometric size of each specimen’s head or body (i.e. CS) . The threespine stickleback (Gasterosteus aculeatus) is an important model for studying the evolution of vertebrate morphology. Sticklebacks inhabit freshwater, brackish, and marine northern hemisphere waters. Anadromous and marine populations (hereafter marine) are assumed to have remained unchanged morphologically from ancestral marine sticklebacks, despite marine environments varying on regional and local scales. Recent studies suggest that genetic and phenotypic structure exists in marine populations, yet the scale of this variation, and its ecological causes remain unclear. Our goal was to assess morphological trait variation in marine stickleback populations around Southern British Columbia (BC) and determine if oceanographic and habitat characteristics were associated with this variation. Between May-July 2019, we sampled 534 sticklebacks from 15 sites around Vancouver Island, a region characterized by a large diversity of oceanographic and habitat features. We characterized trait variation using two-dimensional (2D) geometric morphometric analysis, comparing individuals between oceanographic regions and habitats. We focused on head and body shape. We found that marine sticklebacks varied morphologically among and between regions and habitats, but the variation did not appear to be related to environmental variation. Sexual dimorphism was the largest source of variation, but oceanographic and habitat variables influenced differences between sexes. We concluded that marine sticklebacks offer abundant opportunities for expanding our knowledge of drivers of morphology. Programs: tps.Util version 1.61 and tps.Dig version 2.05. In R, we used the landvR package and the geomorph package.