Dataset: Identity and heights of Octocoral species found on transects at 6 sites on the south shore of St John, U.S. Virgin Islands in 2021 and 2022

Data not availableVersion 1 (2023-04-18)Dataset Type:Other Field Results

Principal Investigator, Contact: Howard Lasker (State University of New York at Buffalo)

Co-Principal Investigator: Peter J. Edmunds (California State University Northridge)

Scientist: Christopher Wells (State University of New York at Buffalo)

BCO-DMO Data Manager: Taylor Heyl (Woods Hole Oceanographic Institution)


Project: Collaborative Research: Pattern and process in the abundance and recruitment of Caribbean octocorals (Octocoral Community Dynamics)


Abstract

Transect surveys were conducted at 6 sites on the south shore of St John, within the U.S. Virgin Islands National Park during the summers of 2021 and 2022. Depending on the site, 3 to 6 transects were established. Identity and heights of all arborescent octocorals greater than or equal to 5 centimeters were recorded from 1 square meter quadrats on the transects. The position of colonies relative to the site, meter on the transect, and side of the quadrat are included. Surveys were conducted...

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To investigate community dynamics of octocorals on Caribbean coral reefs, transect surveys were conducted at 6 sites on the south shore of St John, within the Virgin Islands National Park during the summers of 2021 and 2022.  Depending on the site, 3 to 6 transects were established. All sites were located at 6 to 9 meters depth and samples were collected by SCUBA from small boats. The identity and heights of all arborescent octocorals greater than or equal to 5 centimeters were recorded from 1 square meter quadrats on the transects.  The position of colonies relative to the site, meter on the transect, and side of the quadrat are included.

Censuses at sites Grootpan, Europa, and Tektite were based on 50-meter x 10-meter areas that were arbitrarily selected and permanently marked with stainless steel eyebolts at the corners of the sites. A total of six transect lines, also marked with eyebolts, were laid out at 10 m intervals. At Booby Rock, a 50-meter line running parallel to the approximately 7-meter depth contour was established, and survey transects (3 in 2021 and 6 in 2022) were positioned at random points along the line.  All octocorals present in 1 x 1-meter quadrats along the 10-meter long transects were identified and their heights were measured. Small branch tip samples were collected from colonies that could not be identified in the field.  Sclerites were digested from those colonies with a commercial bleach solution and sclerites were observed with a compound scope for identification. Octocoral adults were defined as individuals greater than or equal to 5 centimeters in height, with height determined to the nearest centimeter.

Known Issues:
Field identifications of Pseudoplexaura flagellosa and P. wagenaari  are difficult among small colonies and for analysis purposes, the two species should be lumped as a single group.

Field identifications of Eunicea mammosa, E. laxispica and E. succinea  are sometimes difficult, thus, for analysis purposes the three species should be lumped as a single group.

aa2 is an undescribed Antillogorgia sp. that is very similar to A. americana.

 


Related Datasets

IsRelatedTo

Dataset: octocoral transects - adult colony height
Lasker, H. (2018) Adult octocoral height measurements from transects conducted at St. John, US Virgin Islands between 2014-2016 (St. John LTREB project, VI_Octocorals). Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 3) Version Date 2018-04-05 http://lod.bco-dmo.org/id/dataset/682966
IsRelatedTo

Dataset: Octocoral species abundances 2018
Lasker, H. (2019) Octocoral colony heights measured during transect surveys at four sites on the south shore of St. John, US Virgin Islands in June-August 2018. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2019-09-23 doi:10.1575/1912/bco-dmo.765328.1
IsRelatedTo

Dataset: Octocoral Recruitment
Lasker, H., Edmunds, P. J. (2023) Octocoral Recruitment surveys on transects at 6 sites on the south shore of St. John, U.S. Virgin Islands in 2021 and 2022. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2023-04-18 http://lod.bco-dmo.org/id/dataset/893866
References

Dataset: octocoral
Lasker, H. (2019) Octocoral species abundance during transect surveys at four sites on the south shore of St. John, US Virgin Islands from November to December 2017. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2019-11-04 doi:10.1575/1912/bco-dmo.751176.1
References

Dataset: St John Octocoral Abundances 2019
Lasker, H., Edmunds, P. (2020) Octocoral colony heights measured during transect surveys at four sites on the south shore of St. John, US Virgin Islands during June-October 2019. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2020-02-12 doi:10.1575/1912/bco-dmo.793259.1

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