19:I[42426,["/_next/static/immutable/chunks/1xctgzqre-wsy.js","/_next/static/immutable/chunks/06_-wz6pdtp2b.js","/_next/static/immutable/chunks/30e52g49hg40p.js","/_next/static/immutable/chunks/02yq6tul2z-oh.js","/_next/static/immutable/chunks/10bx_ec2vj7n_.js","/_next/static/immutable/chunks/33bfn03fo8xnt.js","/_next/static/immutable/chunks/0tfjf78scu61b.js","/_next/static/immutable/chunks/31xnvej4n1bi9.js"],"default"] 1a:Tbbb,

To test the hypothesis that the effects of both intra- and interspecific competition on performance vary geographically in a range-shifting species, we experimentally manipulated the densities of L. gigantea and L. scabra at the five study sites across the range. The sites included 3 range core sites (Vandenberg, Soberanes Point, and Hopkins Marine Station) and 2 expanding edge sites (Bodega Marine Reserve and Kruse Ranch).

To manipulate densities, we used hand tools to clear ~650 cm² sections of rocky intertidal substrate of all invertebrates and algae. To ensure habitat suitability, we selected gently sloping areas in the mid-intertidal zone with relatively high L. gigantea abundance. Once cleared, we enclosed these areas with 650 cm² octagonal cages with walls made of stainless-steel mesh with 3 mm wide openings (McMaster Carr). Cages were covered with a plastic vexar mesh lid with 1.27 cm wide openings to prevent most small grazers from entering the cages. We bolted cages to the rock to secure them to the substratum and then sealed the edges to the rock with marine epoxy (Z-spar splash zone compound).

Cages were deployed in a complete block design, with four cages in each block randomly assigned one of four treatments in spring 2023. Each treatment included a focal L. gigantea collected from that site (initial shell length = 25-40 mm) used to quantify growth rate. The control treatment included only the focal owl limpet; the “intraspecific competition” treatment included the focal owl limpet along with a second, slightly larger owl limpet (initial shell length = 30-40 mm); the “interspecific competition” treatment included the focal owl limpet and nine L. scabra (initial shell length 18-22 mm); and the “combined” treatment included the focal owl limpet, a larger owl limpet, and nine L. scabra. The densities in each treatment reflected the upper end of natural abundances that occur in the range core (Walkes, unpublished data). Each block was replicated 8 times, for a total of 32 experimental cages at each site distributed over ~200m of shoreline. In each cage, we tagged the single focal L. gigantea using a small (6 mm) Floy tag attached to surface of the shell using a small dab of marine epoxy (Z-spar splash zone epoxy compound). To assess performance as a response to each treatment, we recorded absolute growth rate based on change in shell length through time for the focal L. gigantea in each cage. Shell length was measured using calipers along the posterior to anterior axis of the shell at the beginning and end of the experiment to calculate growth rate. Cages were checked approximately every three months at each site to remove algae and other fouling organisms, and to replace any dead focal limpets (N = 7) and competing limpets. The experiment ended after 10 months in November-December 2023.

1b:T57c,This section documents curation actions performed prior to publication review with the submitter, and additional information relevant to understanding and reusing this dataset. It distinguishes changes made to the submitted (meta)data from unresolved issues and/or enhancements that improve future reuse and interoperability. CURATION ACTIONS PERFORMED ON DATA - Loaded lottia_exp.csv as table "lottia_exp" in CSV format, treating empty string, "nd", and "na" as missing values - Renamed columns to BCO-DMO conventions: date_i to date_initial, Length_i to Length_initial, Length_f to Length_final, date_f to date_final - Converted date_initial from M/D/YY format to ISO 8601 YYYY-MM-DD date type - Converted date_final from M/D/YY format to ISO 8601 YYYY-MM-DD date type - Output written to 1000489_v1_lottia_growth_experiment.csv CURATION ACTIONS PERFORMED ON METADATA - Standard metadata entry and text formatting steps were performed. - Adjusted methods to reference the five sites found in the dataset, as opposed to six originally stated. Also added site names to the text. If another edge zone was included, no information is provided here. - Adjusted title from 2022-2023 to 2022 to align with the extent provided. ISSUES POTENTIALLY IMPACTING REUSE - No contacts or publishing plans were provided about the data source (Walkes, unpublished data). No citation is included. 1c:T67a,We harnessed an ongoing poleward range shift of the giant owl limpet (Lottia gigantea) in California, USA to test whether the effects of competition vary between the range core and expanding edge. To assess the strength of competition across the range, we experimentally manipulated densities of L. gigantea, and a competing grazer (L. scabra), at five rocky intertidal sites and measured limpet growth over ~10 months as a metric of performance. As predicted, field surveys confirmed that L. gigantea density was higher in the range core than the range edge. Contrary to theory, range-core limpets that evolved in these dense populations were more strongly impacted by intra- and interspecific competition than range-edge limpets when both were held under standardized experimental densities of competitors. Importantly, both forms of competition had similar effects across the range, even though interspecific competition is rarely integrated into range-expansion theory. Consistent with theory, growth rates were fastest at the expanding edge. However, growth in range-edge limpets did not decline under high intra- and interspecific densities, suggesting that rapid growth rate did not come at the cost of reduced competitive ability. Growth in the expanded range may be enhanced by greater food availability as cooler temperatures lower metabolic demand and ameliorate competition. Our findings suggest that predicting the dynamics of range expansions will require greater consideration of how diverse recipient communities and environmental heterogeneity mediate the strength of competition and performance across an expanding species’ range.1d:Tb91,NSF abstract: Anthropogenic climate change is shifting the distributions of species across the globe. Such contemporary shifts in species’ ranges may have cascading effects on entire ecosystems. This project disentangles the mechanisms underlying climate-driven species range shifts in marine systems using the intertidal owl limpet as a case study. During the recent marine heatwaves off the Pacific coast of North America, populations at the northern range limit in northern California have expanded, with ongoing reproduction even after termination of the heatwave events. This is therefore an ideal system to explore the dynamics of natural selection that occur as species occupy new regions. Broadly, this project deepens understanding of how range shifts occur in marine systems and furthers the ability to predict future species distributions in response to climate change. The project provides research experiences for high school and undergraduate students from historically underrepresented groups by engaging with existing, demonstrably-effective programs. The investigators host leadership and skill-building workshops for senior female graduate students and engage the public in partnership with the California Academy of Sciences, Bodega Marine Lab, and San Francisco Exploratorium. Finally, the project provides training for a postdoctoral scholar and two graduate students. Although phenomenological studies suggest that climate-associated range shifts are common in marine systems, to date, mechanistic studies of the climate-organism interactions that alter geographic distributions have largely focused on terrestrial systems. However, dispersal dynamics greatly differ in many marine systems, as currents may frequently transport planktonic larvae into new environmental regimes. This project integrates detailed demographic observations of the recent range expansion of the intertidal owl limpet, Lottia gigantea, with ecological, phenotypic, and genomic measurements of divergence across its range. Specifically, the work 1) documents phenotypic divergence in larval and juvenile traits across the zone of range expansion, 2) uses whole genome sequencing to estimate gene flow across the entire range, 3) identifies genomic patterns of selection across the zone of range expansion and through time, and 4) identifies drivers of variation in performance over latitudinal and microgeographic scales. The ability to monitor this range shift in real time, along with the suitability of this system for tracking individuals across multiple years, allows the investigators to examine the impact of selection in novel range-edge conditions at the phenotypic and genomic levels, and scale from individuals to species-level responses to ongoing environmental change. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.6:["$","$L19",null,{"dataset":{"_id":"1000489","description":"","problem":"Several entries are missing final growth measurements due to animal loss. Missing growth measurements are indicated as empty cells. \r\n\r\n(See BCO-DMO Processing section for additional considerations.)","acquisition":"$1a","processing":"

We recorded absolute growth rate (AGR) as the change in shell length (in mm) through time.

\n","bcodmoProcessing":"$1b","title":"Lottia gigantea growth data from field experiments of experimentally manipulated competitor densities on the Northern and Central California coast from Feb to Dec 2023","nickname":"Lottia field experiment 2023","dataUrl":"","currentState":"Final no updates expected","currentStateId":"7","validated":false,"restricted":false,"version":"1","version_date":"2026-06-09T04:00:00.000Z","abstract":"$1c","citation":"Walkes, S., Bay, R., Sanford, E. (2026) Lottia gigantea growth data from field experiments of experimentally manipulated competitor densities on the Northern and Central California coast from Feb to Dec 2023. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-06-09 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.1000489.1 [access date]","citationParts":{"identifier":"doi:10.26008/1912/bco-dmo.1000489.1","versionDate":"2026-06-09","versionId":"1","year":"2026","title":"Lottia gigantea growth data from field experiments of experimentally manipulated competitor densities on the Northern and Central California coast from Feb to Dec 2023","authors":"Walkes, S., Bay, R., Sanford, E.","publisher":"Biological and Chemical Oceanography Data Management Office (BCO-DMO)."},"doi":"10.26008/1912/bco-dmo.1000489.1","release_date":null,"field_dataset_location":"Northern and Central California coast ","temporal_extent":{"start":"2023-02-20T05:00:00.000Z","end":"2023-12-13T05:00:00.000Z"},"temporal":{"resolution":"time:unitDay","type":"time:Interval","start":{"value":"1676869200","label":"2023-02-20"},"end":{"value":"1702443600","label":"2023-12-13"}},"spatial_extent":{"shape":"polygon","center":{"latitude":36.59255,"longitude":-121.9887},"wkt":"POLYGON ((-123.363 34.5878, -120.6144 34.5878, -120.6144 38.5973, -123.363 38.5973, -123.363 34.5878))","north":38.5973,"east":-120.6144,"south":34.5878,"west":-123.363},"dataset_type":["Other Field Results","experimental"],"keywords":["biota","oceans"],"data_files":[{"id":"1007507","title":"1000489_v1_lottia_growth_experiment.csv","url":"https://datadocs.bco-dmo.org/dataset/1000489/file/0AWDAZ2uJjQ2X/1000489_v1_lottia_growth_experiment.csv","showTableUrl":"https://www.bco-dmo.org/dataset/1000489/data/view/1007507","description":"Primary data file for dataset ID 1000489, version 1","filename":"1000489_v1_lottia_growth_experiment.csv","bytesize":14980,"checksum":{"value":"1ff0017ce1056cc5be80a115e8ccd67e","Algorithm":{"_id":"190","name":"MD5"}},"mimetype":"text/csv","fileType":{"_id":"192","name":"Comma Separated Values (.csv)"},"isErddap":"","date":"","isPublicDuringEmbargo":false,"primaryDataFile":true,"showTable":true,"restricted":false}],"supplemental_files":[],"roles":[{"role":{"_id":"138","name":"Principal Investigator"},"performedBy":{"_id":"777106","name":"Rachael Bay"},"performedAtOrganization":{"_id":"147","name":"University of California-Davis"}},{"role":{"_id":"140","name":"Co-Principal Investigator"},"performedBy":{"_id":"51064","name":"Eric Sanford"},"performedAtOrganization":{"_id":"147","name":"University of California-Davis"}},{"role":{"_id":"130","name":"Scientist"},"performedBy":{"_id":"958655","name":"Samuel Walkes"},"performedAtOrganization":{"_id":"147","name":"University of California-Davis"}},{"role":{"_id":"145","name":"BCO-DMO Data Manager"},"performedBy":{"_id":"924467","name":"Audrey Mickle"},"performedAtOrganization":{"_id":"191","name":"Woods Hole Oceanographic Institution"}}],"deployments":[],"funding":[{"_id":"867542","name":"OCE-2023297","fundingSource":{"_id":"355","name":"NSF Division of Ocean Sciences"},"url":"https://www.nsf.gov/awardsearch/show-award?AWD_ID=2023297"}],"instruments":[{"_id":"1000715","name":"calipers","description":"Shell length was measured using calipers along the posterior to anterior axis of the shell at the beginning and end of the experiment to calculate growth rate.","type_id":"820156","type_name":"calipers","type_desc":"A caliper (or \"pair of calipers\") is a device used to measure the distance between two opposite sides of an object. Many types of calipers permit reading out a measurement on a ruled scale, a dial, or a digital display.","type_acronym":""},{"_id":"1000716","name":"Floy tag","description":"In each cage, we tagged the single focal L. gigantea using a small (6 mm) Floy tag attached to surface of the shell using a small dab of marine epoxy (Z-spar splash zone epoxy compound).","type_id":"918572","type_name":"labeling tag","type_desc":"Passive devices attached to captured organisms to specifically identify them when recaptured after release.","type_acronym":""}],"parameters":[{"_id":"1000719","name":"Block","format":"","frictionlessType":"integer","description":"

Cages were placed in a block design, with four cages adjacent to each other at each site. Each block contained one of the four treatments: (control, intraspecific, interspecific, or combined), though several limpets (n = 7) died over the course of the experiment. Note that the identifier is not unique in the spreadsheet

","units":{"_id":"","name":"unitless"},"type":{"_id":"1124","name":"site","description":"

Sampling site identification.

"}},{"_id":"1000720","name":"Treatment","format":"","frictionlessType":"string","description":"

The experimental treatment the limpet received. Either control, intraspecific, interspecific, or combined

","units":{"_id":"","name":"unitless"},"type":{"_id":"489066","name":"treatment","description":"

Experimental conditions applied to experimental units. In comparative experiments, members of the complementary group, the control group, receive either no treatment or a standard treatment.

"}},{"_id":"1000721","name":"Tag","format":"","frictionlessType":"integer","description":"

Tag number for each focal limpet. Blank values represent lost tags

","units":{"_id":"","name":"unitless"},"type":{"_id":"991","name":"tagid","description":"

Animal tag identification, e.g. flipper tag

"}},{"_id":"1000722","name":"Site","format":"","frictionlessType":"string","description":"

The site at which the growth data were recorded; Vandenberg, Soberanes, Hopkins, Bodega Marine Reserve, or Kruse Ranch

","units":{"_id":"","name":"unitless"},"type":{"_id":"1124","name":"site","description":"

Sampling site identification.

"}},{"_id":"1000723","name":"date_initial","format":"%Y-%m-%d","frictionlessType":"date","description":"

Date of initial size measurement

","units":{"_id":"","name":"unitless"},"type":{"_id":"1109","name":"date_begin","description":"

date sampling begins such as YYYYMMDD

"}},{"_id":"1000724","name":"Length_initial","format":"","frictionlessType":"number","description":"

Initial shell length measured using handheld calipers along the longest posterior to anterior axis of the shell

","units":{"_id":"","name":"mm"},"type":{"_id":"1097","name":"length","description":"

Length is a one-dimensional extent equal to the distance between two points.

"}},{"_id":"1000725","name":"Length_final","format":"","frictionlessType":"number","description":"

Final shell length measured using handheld calipers along the longest posterior to anterior axis of the shell

","units":{"_id":"","name":"mm"},"type":{"_id":"1097","name":"length","description":"

Length is a one-dimensional extent equal to the distance between two points.

"}},{"_id":"1000726","name":"date_final","format":"%Y-%m-%d","frictionlessType":"date","description":"

Date of final size measurement

","units":{"_id":"","name":"unitless"},"type":{"_id":"1110","name":"date_end","description":"

date sampling ends; as YYYYMMDD

"}},{"_id":"1000727","name":"dt","format":"","frictionlessType":"integer","description":"

Days between initial and final shell length measurements

","units":{"_id":"","name":"Days"},"type":{"_id":"473067","name":"days","description":"

Days as in days spent sampling or days post treatment for sampling

"}},{"_id":"1000728","name":"AGR","format":"","frictionlessType":"number","description":"

Absolute growth rate. Measured as the change in shell length through time ((Length_final – Length_initial)/dt)

","units":{"_id":"","name":"mm/day"},"type":{"_id":"953033","name":"rate_measurements","description":"

Rate measurements (including production, excretion, and grazing). These parameters describe the rate of change any chemical species or biological entity. Rates may be the result of biological (e.g. production), chemical (e.g. photochemical degradation), or biogeochemical (e.g. particulate phase metal uptake rate) processes.

"}},{"_id":"1000729","name":"Latitude","format":"","frictionlessType":"number","description":"

Latitude of study site, positive is North

","units":{"_id":"","name":"Decimal degrees"},"type":{"_id":"730","name":"latitude","description":"

latitude, in decimal degrees, North is positive, negative denotes South; Reported in some datasets as degrees, minutes

"}},{"_id":"1000731","name":"Longitude","format":"","frictionlessType":"number","description":"

Longitude of study site, negative is West

","units":{"_id":"","name":"Decimal degrees"},"type":{"_id":"731","name":"longitude","description":"

longitude, in decimal degrees, East is positive, negative denotes West; Reported in some datasets as degrees, minutes

"}}],"related_publications":[],"related_datasets":[{"_id":"1000482","name":"Intertidal temperature data 2022-2023","url":"","relation_type":"IsRelatedTo","type_desc":"

The dataset is related to another dataset.

\n","relation_desc":"Data were collected in conjunction with a manipulative field experiment to assess how the strength of competition varies across the range edge and range core for Lottia gigantea.","citation":"Walkes, S., Bay, R., Sanford, E. (2026) TidBiT logger temperature data for intertidal ocean temperatures in Northern and Central California between May 2022 and Dec 2023. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-06-09 doi:10.26008/1912/bco-dmo.1000482.1"}],"services":[{"grouping":"","items":[{"name":"View Data","description":"An in-browser view of the primary tabular data file","url":"https://www.bco-dmo.org/dataset/1000489/data/view","contentType":"text/html","actionType":"view"}]},{"grouping":"Metadata","items":[{"name":"HTML","description":"A simple HTML page of the dataset metadata","url":"https://www.bco-dmo.org/dataset/1000489/description","contentType":"text/html","actionType":"view"},{"name":"PDF","description":"A PDF of the HTML dataset metadata","url":"https://www.bco-dmo.org/dataset/1000489/Dataset_description.pdf","contentType":"application/pdf","actionType":"download"},{"name":"ISO 19115-2 (NOAA Profile)","description":"","url":"https://www.bco-dmo.org/dataset/1000489/iso","contentType":"application/xml","actionType":"download"}]}],"programs":[],"projects":[{"_id":"867543","name":"Evolutionary and ecological dynamics of a contemporary climate-driven range expansion","acronym":"LottiaRangeExp","description":"$1d"}],"archives":[{"id_value":"10.26008/1912/bco-dmo.1000489.1","url":"https://doi.org/10.26008/1912/bco-dmo.1000489.1","date_assigned":"2026-09-10","version_date":"2026-06-09","archiver":"Woods Hole Oceanographic Institution (WHOI BCO-DMO)","archiver_id":"191"}],"license":{"name":"Creative Commons Attribution 4.0","id":"CC-BY-4.0","uri":"https://creativecommons.org/licenses/by/4.0/","spdxUri":"https://spdx.org/licenses/CC-BY-4.0"},"metrics":{"views":{"count":33},"downloads":{"count":54}}}}]