Manomet Intertidal Green Crab Project - Powered by Anecdata.org

Registros

Los datos en este recurso de registros biológicos han sido publicados como Archivo Darwin Core(DwC-A), el cual es un formato estándar para compartir datos de biodiversidad como un conjunto de una o más tablas de datos. La tabla de datos del core contiene 11 registros.

Este IPT archiva los datos y, por lo tanto, sirve como repositorio de datos. Los datos y los metadatos del recurso están disponibles para su descarga en la sección descargas. La tabla versiones enumera otras versiones del recurso que se han puesto a disposición del público y permite seguir los cambios realizados en el recurso a lo largo del tiempo.

Versiones

La siguiente tabla muestra sólo las versiones publicadas del recurso que son de acceso público.

Derechos

Los usuarios deben respetar los siguientes derechos de uso:

El publicador y propietario de los derechos de este trabajo es The Community Environmental Health Laboratory at MDI Biological Laboratory. Esta obra está bajo una licencia Creative Commons de Atribución/Reconocimiento (CC-BY 4.0).

Registro GBIF

Este recurso ha sido registrado en GBIF con el siguiente UUID: 3151231f-0ad5-480d-8529-456dd4a74e55.  The Community Environmental Health Laboratory at MDI Biological Laboratory publica este recurso y está registrado en GBIF como un publicador de datos avalado por GBIF-US.

Palabras clave

Occurrence

Contactos

Cobertura geográfica

Maine, United States

Cobertura temporal

Datos del proyecto

Anecdata is a free online citizen science platform developed by the Community Lab at the MDI Biological Laboratory in Bar Harbor, Maine. Anecdata is used by hundreds of individuals and organizations to gather and access citizen science observations and provides a platform to easily collect, manage, and share their citizen science data. How Anecdata works: Project managers create projects, creating datasheets that participants fill out to share their observations. Participants join projects and use the Anecdata website or mobile app to share their observations with the project. Project data is now available for anyone to view and download!

Personas asociadas al proyecto:

Métodos de muestreo

Collecting data using quadrat surveys.

Descripción de la metodología paso a paso:

1. 1) Timing of survey work: 1.1) Conduct surveys between May-November, during the height of productivity in the intertidal zone. 1.2) Schedule surveys around negative or zero tides (generally new and full moon cycles) to allow for adequate time in the low intertidal zone (i.e., at least 2 hours).
2. 2. Pre-survey preparation: 2.1) Locate and print all field guides and data collection sheets (see Appendices) prior to conducting the survey if that is the preferred method. If using the Anecdata app for field guides and data collection, visit the Anecdata website and join the Intertidal Green Crab Project. The data collection sheet and Anecdata collection categories are identical.
3. 4. Conducting survey 4.1) Prior to arriving at the survey site, record the following information on the Intertidal Survey Data Sheet (Appendix 3) or directly into the Intertidal Green Crab Project on Anecdata: site name, sampling date, participants, time and height of low tide at the location/date you will be sampling (determined using the NOAA Tide Predications website, or an app such as Tides), and lunar phase (determined using a lunar calendar such as www.moongiant.com). 4.2) Upon arriving at the survey site, locate the 100 m section of low intertidal shoreline where the survey will be conducted, unpack gear, and organize data sheets and field guides. 4.3) *Optional: Measure water temperature using a waterproof digital thermometer in the shallow water adjacent to the sampling area. Measure salinity by placing several drops of water collected adjacent to the sampling area onto the refraction prism of a salinity refractometer. Record water temperature in ℃ and salinity in parts per thousand (ppt) on the Intertidal Survey Data Sheet or directly into the Intertidal Green Crab Project on the Anecdata app. 4.4) Begin the survey by haphazardly tossing the 1 m2 quadrat within the predefined low intertidal zone area that runs parallel to the shoreline (a transect tape is not needed to conduct the survey because the sample area has already been defined). Record a visual estimate of the percent of both moveable rock (i.e., cobble/gravel that you can look underneath) and algae canopy cover (e.g. Ascophyllum or Fucus spp.) within the quadrat to the nearest quarter percent (i.e., 0, 25, 50, 75, or 100%). Rocky intertidal habitat is often patchy and can contain areas of sand, mud, ledge, or other habitats where green crabs are not found. To avoid skewing density estimates by sampling unsuitable habitat, only sample quadrats with greater than 50% movable rock, or greater than 50% algal canopy. Also avoid sampling areas where boulders or ledges are noticeably elevated above the profile of the shoreline within the low intertidal zone, as this habitat may be more representative of the mid intertidal zone. 4.5) Within each quadrat, lift moveable rocks or cobble and carefully move aside algae to look for crabs. Be sure to replace all rocks and algae as you found them. Collect all of the crabs you find and store them in a bucket until the entire quadrat has been searched. 4.6) Identify the species of each crab using the Intertidal Crab Field Guide (Appendix 1, or source on Anecdata project platform) and record using the species codes listed on the Intertidal Survey Data Sheet (Appendix 3) or on the Intertidal Green Crab Project on the Anecdata app. 4.7) Measure the carapace width (CW) of each crab across the widest part of the carapace, spanning from tip to tip of the terminal spines, to the nearest 1 mm using Vernier calipers. 4.8) Use the abdomen (or ‘apron’) on the ventral side of the crab to determine sex. Male crabs tend to have a narrow, pointed abdomen and female crabs tend to have a wider, beehive shaped abdomen (Appendix 1). Only record sex for crabs ≥ 10 mm CW. 4.9) For all crabs, record number of claws, number of legs, shell condition (i.e., hard- or soft-shell as determined by whether the carapace resists (hard) or gives (soft) when finger pressure is applied), and the presence (i.e., ovigerous) or absence of extruded eggs for females. 4.10) *Optional: Record color for green crabs, but not other crab species, using the color protocol developed by Young and Elliot (Appendix 2). This protocol should only be used if the actual paint chips can be sourced and brought into the field, as printed versions can vary substantially. Identify pre-molt shell condition for green crabs using external pre-molt indicators (Appendix 4, or source on Anecdata project platform). Pre-molt green crabs are within 3 weeks of molting and are of particular interest to the emerging soft-shell green crab fishery. 4.11) Return all crabs to the habitat within the quadrat once all measurements and characteristics have been recorded. 4.12) Continue haphazardly tossing the quadrat within the predefined low intertidal area until you have sampled a total of 10 m2. Continually move forward along the low intertidal area of shoreline and ensure that quadrats are separated by a minimum of 1 m so that resampling does not occur and a maximum of 10 m so that the survey area does not exceed 100 m.
4. 5. Data management and analysis 5.1) If using data sheets, check all raw data sheets for errors and legibility post-survey, photocopy, scan, and archive. Use the photocopy for data entry into an excel spreadsheet (see Appendix 5 for example) or into the Intertidal Green Crab Project on Anecdata. Store scanned data sheets electronically. 5.2) Conduct data analyses appropriate to the design of the study. Useful population metrics include crab density (total number of crabs divided by total number of quadrats sampled), sex ratio, cumulative size frequency, injury rate, shell condition ratio, and overall species encounter rates (e.g., % of native vs. invasive crabs).

Metadatos adicionales