Mariah T. Noveh Megan K. La Peyre 20260318 1 spreadsheet https://doi.org/10.5066/P1C8KQWH Eastern oyster (Crassostrea virginica) produced in a hatchery were maintained in cages at multiple sites in coastal Louisiana, and shell height, mortality, fecundity, and dermo were monitored to compare performance between genomically selected groups. Oysters were produced using genomic selection techniques targeting low-salinity tolerant oysters (high breeding value). To test performance among these groups in the field, oysters were deployed at two coastal Louisiana sites representing low and high salinity grow-out areas. From December 2024 through December 2025, a total of six replicate cages with n = 100 initial oysters from each of the three breeding groups (HBV, LBV, RC) were grown on long-lines at both sites with a randomized block design (total of 3200 oysters). Mortality and shell height were monitored monthly; condition index every other month; sex ration and histology and sex ration determined quarterly, and Perkinsus marinus infection levels estimated in October 2025. These data provide field performance data to assess performance of low-salinity tolerant selected oysters. These data were collected for a field validation study of oyster performance (e.g. growth, mortality, condition) for oysters genomically selected for low salinity tolerance from wild populations after undergoing challenge studies in the lab to identify better tolerance for low salinity. Using genomic selection techniques, three groups of oysters were spawned targeting low salinity tolerant oysters and producing progeny with High Breeding Values (HBV; most tolerant to low salinity), Low Breeding Values (LBV; least tolerant to low salinity), and Random Controls (RC). Two coastal Louisiana sites with historically different mean salinities were selected for a field study with a duration of one year. LUMCON (Louisiana Universities Marine Consortium) located in Cocodrie, LA, served as the site with naturally lower salinity. The higher salinity site was located at the Michael C. Voisin Oyster Hatchery in Grand Isle, LA (GI). A total of six replicate cages with n = 100 initial oysters from each of the three breeding groups (HBV, LBV, RC) were grown on long-lines at both sites with a randomized block design (total of 3200 oysters). The duration of the experiment was December 2024 – December 2025 with monthly visits to each site where mortality was monitored and shell heights were measured from 20 haphazardly selected oysters from 4 cages (n = 80 for each HBV, LBV and RC group from each site). These measurements were used to calculate interval (monthly; standardized to 30 days) and cumulative (annual) growth and mortality over the duration of the experiment. The two remaining cages for each group held oysters used for monthly destructive sampling to measure condition index, development, sex ratio and fecundity. Oysters were sampled for condition index (n = 120 total; n = 20 each HBV, LBV, RC from both GI and LUMCON) in December 2024, February 2025, April 2025, July 2025, and October 2025. Additional samples (n = 120; n = 20 each HBV, LBV, RC from both GI and LUMCON) were obtained during the April, July, and October 2025 sampling events for histology (gametogenesis observations), fecundity (egg counts; eggs/g), and sex ratios. Perkinsus marinus infection levels (dermo body burdens) were also estimated in additional October 2025 samples (n = 20 each of HBV, LBV, and RC from both sites for a total of n = 120 oysters). 20241201 20251231 ground condition Complete None planned Coastal Louisiana -93.2629 -88.9233 30.2875 28.7291 ISO 19115 Topic Category biota Common geographic areas Louisiana Louisiana Coastal USGS Thesaurus organism growth and development Marine Realms Information Bank (MRIB) keywords bivalves disease research USGS Metadata Identifier USGS:698615fbb66b0145c9a8c6d9 No access constraints. Please see 'Distribution Information' for details. These data are marked with a Creative Commons Zero v1.0 Universal (CC0-1.0) public domain dedication and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Megan K LaPeyre USGS - ECOSYSTEMS Fish and Wildlife Coop Unit mailing and physical

227 Renewable Natural Resources Building

Baton Rouge LA 70803 U.S.A. 225-235-1624 mlapeyre@usgs.gov Jerome La Peyre, Sandra Casas-Liste These data were generated using Windows 11 version 23H2 in Microsoft Excel spreadsheets. There are six files associated with this dataset, all in Comma Separated Values (.csv) format as follows: 1. LOSPATfield2025_oyster_growth.csv (171 kb) 2. LOSPATfield2025_oyster_mortality.csv (13 kb) 3. LOSPATfield2025_oyster_condition.csv (57 kb) 4. LOSPATfield2025_oyster_fecundity.csv (26 kb) 5. LOSPATfield2025_oyster_maturation.csv (24 kb) 6. LOSPATfield2025_oyster_dermo.csv (11 kb) We used a digital caliper to measure the oysters to the nearest 10th of a millimeter. The same person took the measurements each month for consistency. Samples were weighed using a high precision balance and recorded to the nearest 10th of a gram. These data were vigorously assessed for quality control and outliers and many cases of incomplete observations were removed to ensure it is as correct and complete as possible. These data were vigorously assessed for quality control and outliers and many cases of incomplete observations were removed to ensure it is as correct and complete as possible. These data were collected at two coastal Louisiana sites for genomically selected oysters and therefore only represent specific populations within a relatively small geographic area. Additionally, certain data were collected during specific intervals and are therefore not a complete representation of true annual data for fecundity, maturation, dermo, etc. Oyster growth data: A total of six replicate cages with n = 100 initial oysters from each of the three breeding groups (HBV, LBV, RC) were grown on long-lines at both sites with a randomized block design (total of 3200 oysters). Shell heights were measured from 20 haphazardly selected oysters (when possible) from 4 cages (n = 80 for each HBV, LBV and RC group from each site). These measurements were used to calculate interval (monthly; standardized to 30 days) and cumulative (annual) growth and over the duration of the experiment. 20260101 Oyster mortality data: A total of six replicate cages with n = 100 initial oysters from each of the three breeding groups (HBV, LBV, RC) were grown on long-lines at both sites with a randomized block design (total of 3200 oysters). Mortality was monitored by counting the number of live, dead, and total oysters in each cage monthly. These data were used to calculate interval (monthly; standardized to 30 days) and cumulative (annual) mortality over the duration of the experiment. 20260101 Oyster condition data: Oysters were sampled for condition index (n = 120 total; n = 20 each HBV, LBV, RC from both GI and LUMCON) in December 2024, February 2025, April 2025, July 2025, and October 2025. Oysters were processed for meat condition index (CI) using methods modified from Abbe & Albright (2003), where CI is the ratio of the soft tissue weight relative to the capacity of the internal shell cavity [= 100*(Dry Tissue (g)+Slice Factor))/(Whole Oyster weight (g) - Shell only weight (g)]. Because the oysters sampled for condition index were also used to prepare histological slides, the amount of tissue taken was estimated using a slice factor. The tissue removed was weighed and that ratio/factor could be added back to the estimate for condition index as a proportion of the total oyster tissue, when applicable. Values obtained for “Whole Oyster + Shell WW” , “Whole Oyster WW” and "Shell WW" were not subtracted, they were weighed separately and the discrepancy is from the seawater within the shells that evaporated so is not part of the CI calculation. 20260101 Oyster fecundity data: Additional samples (n = 120; n = 20 each HBV, LBV, RC from both GI and LUMCON) were obtained during the April, July, and October 2025 sampling events for fecundity (egg counts; eggs/g), and sex ratios. Oyster fecundity was determined by estimating the number of eggs per g of oyster tissue in reproductive females. For each sample, gonadal tissue was removed so that connective tissue could be ruptured and eggs isolated in a seawater solution after passing the sample through a series of fine sieves. Samples were diluted as necessary in order to effectively count the number of eggs on a 1000 square counting slide (1 mL total volume) allowing for extrapolation to estimate the number of eggs in each female. Therefore, fecundity could be estimated as the egg concentration of the subsample multiplied by both the volume of dilution(s) used and the volume of the original samples isolated egg solution. Some samples that could be identified as female had too few eggs to count using the extrapolation methods and so counts were not estimated. 20260101 Oyster maturation data: Additional samples (n = 120; n = 20 each HBV, LBV, RC from both GI and LUMCON) were obtained during the April, July, and October 2025 sampling events for histology (gametogenesis observations). Oysters were prepared for histological examination under a compound light microscope after using hematoxylin and eosin (H&E) staining techniques. Sex was determined by presence of eggs/oocytes and/or sperm, or lack thereof for undifferentiated individuals. Qualitative observations of gametogenic stage in the gonadal tissues were made with oysters being in one of the following stages: 1. Early to late development- includes both early and late stage in gametic development (gametogenesis) 2. Ripe -ready to spawn, gametes present in gonadal ducts, follicles often distended in lamellar arrangement 3. Spawning- some gametic material has been released indicated by contracted follicles surrounded by areas of connective tissue and void cells. Includes observations of gonadal recycling (Supan & Wilson 2001) 4. Spent- Advanced stages of spawning with some regression- some gametic material remains but follicles are contracted/regressing; Hemocytes often present 5. Resting –non-reproductive stage with sex undifferentiated, connective tissue comprises majority of gonads 20260101 Oyster dermo data: Perkinsus marinus infection levels (body burden) were estimated for October 2025 samples (n = 20 each of HBV, LBV, and RC from both sites for a total of n = 120 oysters). Prevalence (percent of oysters infected) of P. marinus was determined using previously described culture methods to investigate mortality potentially caused by high infection rates (body burden- total parasite cells per oyster). After culturing, the number of hypnospores were counted in wells with serial dilutions so the parasite load could be estimated and enumerated from data recorded for each oyster and the dilution factor. Additionally, infection intensities were classified in four categories where: 1. Uninfected: no parasite detected 2. Lightly Infected: <1x104 parasites per gram of wet oyster tissue 3. Moderately Infected: 1x104 to 5 x105 parasites per gram of wet oyster tissue 4. Heavily Infected: >5 x105 parasites per gram of wet oyster tissue 20260101 LOSPATfield2025_oyster_growth.csv Comma Separated Value (CSV) file containing data. Producer Defined Date Date of sampling and/or measurement Producer Defined 12/16/2024 12/11/2025 Site Site where oyster was sampled/measured Producer Defined GI Sampling site at the Michael C. Voisin Oyster Hatchery in Grand Isle, LA Producer defined LUMCON Sampling site at Louisiana Universities Marine Consortium (LUMCON) in Cocodrie, LA Producer defined Stock group of oysters with with the same associated breeding values Producer Defined HBV High Breeding Value group/stock Producer defined LBV Low Breeding Value group/stock Producer defined RC Random Control group/stock Producer defined Cage cage number (1-6) Producer Defined 1 6 Oyster ID Sample ID for individual oysters Producer Defined 1 20 Shell Height (mm) oyster shell height (measured from umbo to ventral margin) Producer Defined << empty cell >> No Data Producer defined 35.17 131.05 mm LOSPATfield2025_oyster_mortality.csv Comma Separated Value (CSV) file containing data. Producer Defined Date Date of sampling and/or measurement Producer Defined 12/16/2024 12/11/2025 Site Site where oyster was sampled/measured Producer Defined GI Sampling site at the Michael C. Voisin Oyster Hatchery in Grand Isle, LA Producer defined LUMCON Sampling site at Louisiana Universities Marine Consortium (LUMCON) in Cocodrie, LA Producer defined Stock group of oysters with with the same associated breeding values Producer Defined HBV High Breeding Value group/stock Producer defined LBV Low Breeding Value group/stock Producer defined RC Random Control group/stock Producer defined Cage cage number (1-6) Producer Defined 1 6 N_LIVE Number of live oysters counted Producer Defined 0 100 N_DEAD Number of dead oysters counted Producer Defined 0 51 TOTAL Total number of live and dead oysters Producer Defined 0 100 LOSPATfield2025_oyster_condition.csv Comma Separated Value (CSV) file containing data. Producer Defined Date Date of sampling and/or measurement Producer Defined 12/16/2024 10/23/2025 Site Site where oyster was sampled/measured Producer Defined GI Sampling site at the Michael C. Voisin Oyster Hatchery in Grand Isle, LA Producer defined LU Sampling site at Louisiana Universities Marine Consortium (LUMCON) in Cocodrie, LA Producer defined Stock group of oysters with with the same associated breeding values Producer Defined HBV High Breeding Value group/stock Producer defined LBV Low Breeding Value group/stock Producer defined RC Random Control Value group/stock Producer defined Oyster ID Sample ID for individual oysters Producer Defined Oyster ID Shell Height (mm) oyster shell height (measured from umbo to ventral margin) Producer Defined 39.07 116.09 mm Shell Length (mm) Shell length (at widest point across shell) Producer Defined << empty cell >> No Data Producer defined 37.07 77.59 mm Shell Width (mm) Shell width (thickness at widest point between right and left shell) Producer Defined << empty cell >> No Data Producer defined 17.76 57.27 mm Whole Oyster + Shell WW (g) Whole wet weight of oyster (shell + tissue) Producer Defined 13.73 206.19 g Whole Oyster WW (pre-slice)(g) Whole wet weight of oyster tissue (before histology slice) Producer Defined << empty cell >> No Data Producer defined 1.97 29.99 g Partial Oyster WW (post-slice) (g) Wet weight of oyster tissue (after histology slice) Producer Defined << empty cell >> No Data Producer defined 1.47 NA g Slice WW (g) Wet weight of the sliced tissue used for histology (difference between whole and partial WW) Producer Defined << empty cell >> No Data Producer defined 0.5 NA g Shell WW (g) Shell (only) wet weight Producer Defined << empty cell >> No data Producer defined 11.14 171.0 g Pan (g) Weight of the pan holding tissue Producer Defined 1.1 1.31 g Pan+Dry Tissue (g) Weight of the pan + dry tissue Producer Defined 1.39 4.99 g Dry Tissue (g) = Pan+Dry Tissue - Pan Producer Defined 0.11 3.69 g Slice Factor = Whole Oyster WW (pre-slice)/ Slice WW Producer Defined 0.0 0.679091688 CI Condition Index (CI) = [100*((Dry Tissue+Slice Factor)/(Whole-Shell))] Producer Defined << empty cell >> No Data Producer defined 3.755838656 25.3493014 LOSPATfield2025_oyster_fecundity.csv Comma Separated Value (CSV) file containing data. Producer Defined Date Date of sampling and/or measurement Producer Defined 4/16/2025 10/23/2025 Site Site where oyster was sampled/measured Producer Defined GI Sampling site at the Michael C. Voisin Oyster Hatchery in Grand Isle, LA Producer defined LUMCON Sampling site at Louisiana Universities Marine Consortium (LUMCON) in Cocodrie, LA Producer defined Stock group of oysters with the same associated breeding values Producer Defined HBV High Breeding Value group/stock Producer defined LBV Low Breeding Value group/stock Producer defined RC Random Control group/stock Producer defined Cage cage number (1-6) Producer Defined 1 6 Oyster ID Sample ID for individual oysters Producer Defined Unique sample ID for each oyster Height (mm) oyster shell height (measured from umbo to ventral margin) Producer Defined 47.92 117.25 mm Whole Oyster + Shell WW (g) Whole wet weight of oyster (shell + tissue) Producer Defined 32.89 240.59 g Sex Sex of the oyster Producer Defined M Male (sperm present) Producer defined F Female (eggs present) Producer defined U Undifferentiated (neither egg nor sperm present) Producer defined Whole Oyster WW (g) Whole wet weight of oyster tissue Producer Defined << empty cell >> No Data Producer defined 2.91 19.76 g Non-gonad weight (g) Wet weight of oyster tissue after removal of gonadal tissue Producer Defined << empty cell >> No Data Producer defined 1.79 15.11 g Total volume (mL) Volume of initial egg concentrate solution Producer Defined << empty cell >> No Data Producer defined 15 NA mL Dilution Dilution factor is the total ratio of egg concentrate solution to seawater (e.g. 1:9 dilution has a dilution factor of 10) Producer Defined 1 15 mL Egg count in gridded slide Count of eggs in solution in a 1 mL gridded slide Producer Defined << empty cell >> No Data Producer defined 0 281 Number of squares number of squares used to determine egg count in gridded slide Producer Defined << empty cell >> No Data Producer defined 0 118 Extrapolated Egg Count = (Egg count in gridded slide/Number of squares)* Total Volume (mL) * Dilution * 1000 Producer Defined << empty cell >> No Data Producer defined 2.54E+04 5.70E+07 Egg Count per g = Extrapolated Egg Count / Whole Oyster WW (g) Producer Defined << empty cell >> No Data Producer defined 3.74E+03 5.19E+06 LOSPATfield2025_oyster_maturation.csv Comma Separated Value (CSV) file containing data. Producer Defined Date Date of sampling and/or measurement Producer Defined 4/16/2025 10/23/2025 Site Site where oyster was sampled/measured Producer Defined GI Sampling site at the Michael C. Voisin Oyster Hatchery in Grand Isle, LA Producer defined LUMCON Sampling site at Louisiana Universities Marine Consortium (LUMCON) in Cocodrie, LA Producer defined Stock group of oysters with with the same associated breeding values Producer Defined HBV High Breeding Value group/stock Producer defined LBV Low Breeding Value group/stock Producer defined RC Random Control group/stock Producer defined Cage cage number (5-6) Producer Defined 5 6 Oyster ID Sample ID for individual oysters Producer Defined GI.H.001 LU.R.100 Shell Height (mm) oyster shell height (measured from umbo to ventral margin) Producer Defined 45.14 116.09 mm Shell Length (mm) Shell length (at widest point across shell) Producer Defined 37.07 77.59 mm Shell Width (mm) Shell width (thickness at widest point between right and left shell) Producer Defined 18.64 57.27 mm Whole Oyster + Shell WW (g) Whole wet weight of oyster (shell + tissue) Producer Defined 25.05 206.19 g Sex Sex of the oyster Producer Defined F Female (eggs present) Producer defined M Male (sperm present) Producer defined H Hermaphrodite (both egg and sperm present) Producer defined U Undifferentiated (neither egg nor sperm present) Producer defined Stage Stage of oyster gametogenesis/maturation (1. early/late development; 2. ripe; 3. spawning/recycling; 4. spent/advanced spawning; 5. resting) Producer Defined Ripe Oyster is ready to spawn, gametes present in gonadal ducts, follicles often distended in lamellar arrangement Producer defined Late Development late stage in gametic development (gametogenesis) Producer defined Spawning Some gametic material has been released indicated by contracted follicles surrounded by areas of connective tissue and void cells. Includes observations of gonadal recycling Producer defined Spent Advanced stages of spawning with some regression- some gametic material remains but follicles are contracted/regressing; Hemocytes often present Producer defined Late development late stage in gametic development (gametogenesis) Producer defined Resting Non-reproductive stage with sex undifferentiated, connective tissue comprises majority of gonads Producer defined Stage Number Numeric stage of oyster gametogenesis/maturation (1. resting, 2. early/late development, 3. ripe, 4. spawning/recycling, 5. spent/advanced spawning) Producer Defined 1 5 LOSPATfield2025_oyster_dermo.csv Comma Separated Value (CSV) file containing data. Producer Defined Date Date of sampling and/or measurement Producer Defined 10/16/2025 10/23/2025 Site Site where oyster was sampled/measured Producer Defined GI Sampling site at the Michael C. Voisin Oyster Hatchery in Grand Isle, LA Producer defined LUMCON Sampling site at Louisiana Universities Marine Consortium (LUMCON) in Cocodrie, LA Producer defined Stock group of oysters with with the same associated breeding values Producer Defined HBV High Breeding Value group/stock Producer defined LBV Low Breeding Value group/stock Producer defined RC Random Control group/stock Producer defined Cage cage number (5-6) Producer Defined 5 6 Oyster ID Sample ID for individual oysters Producer Defined GI.H.241 LU.R.360 Whole Oyster WW (g) Whole wet weight of oyster tissue Producer Defined 2.16 20.01 g Seawater added (g) amount of seawater used to dilute and homogenize sample Producer Defined 5.5 39.31 g Oyster Tissue + Seawater (g) = Whole Oyster WW (g) + Seawater added (g) Producer Defined 7.66 59.32 g Volume in 15 mL tube (mL) volume of original sample in seawater used to prepare counting plate Producer Defined 0.2 4.0 mL Hypnospore Count in well number of hypnospores counted in each 50 uL sample well Producer Defined 0 854 Well Dilution Dilution factor of sample counted in prepared wells Producer Defined 0 64 Hypnospore Count per Sample = (Hypnospore Count in well * Well Dilution) * ((Volume in 15 mL tube (mL)*1000)/50 uL in each sample well)) Producer Defined 0 3850240 Hypnospore Count per Oyster = Hypnospore Count per Sample * Oyster Tissue + Seawater (g) Producer Defined 0 55322803 Hypnospore Count per g Oyster = Hypnospore Count per Oyster/Whole Oyster WW (g) Producer Defined 0 12140042 Infection Intensity Intensity of Infection (classifications) Producer Defined uninfected 1. Uninfected: no parasite detected Producer defined lightly infected 2. Lightly Infected: <1x104 parasites per gram of wet oyster tissue Producer defined moderately infected 3. Moderately Infected: 1x104 to 5 x105 parasites per gram of wet oyster tissue Producer defined heavily infected 4. Heavily Infected: >5 x105 parasites per gram of wet oyster tissue Producer defined U.S. Geological Survey - ScienceBase mailing address

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Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P1C8KQWH None 20260318 Megan K LaPeyre USGS - ECOSYSTEMS Fish and Wildlife Coop Unit mailing and physical

227 Renewable Natural Resources Building

Baton Rouge LA 70803 U.S.A. 225-235-1624 mlapeyre@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999