Benthic invertebrate biomass from Ship Shoal, Louisiana 2020-2022
Johnson, David S.
Johnson, David S.
Abstract
The overall goal of this project is to determine the changes in biological function of Ship Shoal in response to excavation of sand. To achieve this goal this study used a multidisciplinary approach that combined measurements of the changing physical setting of the shoal with potential changes in water column and benthic primary production, benthic faunal community and associated nekton, and stable isotope tracers to delineate changes in the shoal food web. The data included here are the biomass (ash-free dry weights) of benthic invertebrates per box core.
NOTE: There are two dregde areas (i.e., pits).
The Caminada pit is older and deeper. It was last dredged prior to our sampling (2014-2016) so we have no pre-dredge samples in our dataset for Caminada.
The Terrebone pit (previously called Timbalier). It was dredged from Spring 2021 - Summer 2022. We consider the start of the dredging in March as 'post-dredging' as we sampled only in dredged areas. Reference areas are undredged.
NOTE: Due to rough seas, we were only able to sample the Terrebonne pit in Fall 2020. No sampling occurred in 2023.
Location
Ship Shoal, Louisiana
Bounding box:
29°N, -90.8°W; 29°N, -90.5°W
28.8°N, -90.8°W; 28.8°N, -90.5°W
Methods
Samples were collected from Ship Shoal, a large transgressive sand shoal located approximately 10 miles off the central coast of Louisiana. Sampling was focused on three areas: the Caminada borrow pit (Caminada), the Terrebonne borrow pit (aka Timbalier), and a control area two km west of the Terrebonne pit (n=9 per level, each three areas subdivided, for a total of 27 samples). At each site sediment were collected using a GOMEX box corer (30cm x 30cm) and fixed and preserved in 5% buffered formalin and returned to the laboratory. After 48 hours, box core samples were sieved on a 1000 um sieve stacked on a 500 um sieve using seawater. Formalin was replaced with 70% ethanol after 48 hours. Benthic organisms were picked and identified to the lowest possible taxon.
To estimate biomass, animals were grouped by the following categories within each box core: Amphioxus, Amphipods, Annelids, Bivalves, Anomurans, Brachyurans, Gastropods, and Other. 'Other' are all remaining categories of animals (e.g., phoronids, ribbon worms, flatworms, cumaceans, etc).
NOTE: Biomass data are reported per core as ash-free dry weights in grams. To scale up to g/m2, multiply by 11.11. NA=Data not available
Description
Biomass of taxonomic groups of benthic invertebrates in .xlsx spreadsheets. Can be opened with Microsoft Excel or imported into common statistical programs such as R.
Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Virginia Institute of Marine Science
Collections
Download Dataset
Rights Holder
Usage License
Embargo
Research Projects
Organizational Units
Journal Issue
Keywords
Benthic invertebrates, sand mining, dredging, recovery, sand shoal
Citation
Advisor
Department
DOI
https://doi.org/10.25773/0S50-KE89