1. Bayesian estimation of the age and growth of the round stingray (Urobatis halleri) in the Gulf of California in Mexico. Fernando Marquez-Fanas, Raul E. Lara-Mendoza, L. Daniel Carrillo-Colin, Oscar G. Zamora-Garcia, and Allan Rosales Valencia Abstract-Life-history studies of species discarded in fisheries are a low priority, particularly those of age and growth estimation. Consequently, almost everything is unknown about such species despite their having been caught as bycatch over the long term. In this study, age estimates were obtained by using the vertebrae of round stingrays (Urobatis halleri). We fitted 3 different growth models (von Bertalanffy, Gompertz, and logistic) to length-at-age data. Bayesian estimation of the various growth parameters was done by using the Markov chain Monte Carlo algorithm. Prior distributions of the parameters disc width at birth (DW,) and the theoretical maximum disc width (DW.,) were included and considered informative. The priors for the growth coefficient (k) and the completion gr-..2> parameter (k,) were set as nonin { >: m: - tive (k for the von Bertalanffy 2-¢..:4 function and k, for the Gompertz and logistic growth models). Results of our analyses indicate that growth bands are annual and that the round stingray lives up to 8 years. According to the Watanabe-Akaike information criterion for model selection, the von Bertalanffy growth function for sexes combined was selected as the best model. The mean values of marginal posteriors were as follows: DW)=9.52 cm (95% credible interval [CI]: 9.25-9.79), DW..=32.50 cm (95% CI: 30.60-34.46), and k=0.114 year"! (95% CI: 0.101-0.129).--2. Evaluation of factors contributing to postrelease mortality of greater amberjack (Seriola durmerili) in the northern Gulf of Mexico with depth and acceleration data from acoustic tags. Kelly S. Boyle, Crystal L. Hightower and Sean P. Powers. Abstract-Management of recreational fishing for greater amberjack Sert a dumerili:) in the Gulf of Mexico size regulations and cos d Water temperature, salinity handling times, can influence survival of examined postrelease 1 behavior by using acoustic t of the movements of 78 fish, monitored for up to 58 d across 3 sampling efforts in 2018, 2019, and 2020 over a depth gradient of 29-64 m. To assess descender devices as a mitigation tool, we assigned fish to 2 treatments: surface release without swim bladder venting and release with a descender device. Cox proportional hazards models were used to assess the effects of site depth, release treatment, bait type (jigging or live bait), fishing injury, tagging injury, fight and handling times, surface and bottom temperatures, and fish length. We found neither a positive association between mortality risk and site depth, as might be expected from barotrauma, nor increased survivorship for fish released with a descender device. The best-supported model considered only fish length as a factor in postrelease mortality; legal-size fish (2864 mm in fork length) had a mortality risk 20 times greater than that of smaller fish. Our results indicate that sublegal-size fish released because of size restrictions face much lower mortality risk than legal-size fish.--3.Life history differences between 2 anadromous populations of the northern form of the Dolly Varden (Salvelinus malma malma) in Bristol Bay in southwestern. Alaska Thomas P. Quinn. Abstract-The Dolly Varden (Salvelinus maima), an iteroparous, facultatively anadromous Pacific salmonid, displays diverse life history and migration patterns. Using otolith microchemistry, we inferred that individuals sampled in the Nushagak Commercial Salmon Fishery Management District, Alaska (sample size (n}=30; mean fork length=597 mm), had entered saltwater at ages 4-7 and were in their first (26%) or second (74%) summer at sea. Most (88%) of the fish that had spent 2 summers at sea migrated in consecutive years, but 2 of them skipped a migration to marine waters, remaining in fresh water for an additional year after migrating to sea in their first year. Only 15% of the individuals with 2 summers at sea had anadromous mothers. In contrast, conspecifics sampled on the other side of Bristol Bay in the Egegik Commercial Salmon Fishery Management District started migrating at an earlier age, migrated more often, and more often had anadromous mothers. Together, these results highlight the differences in life history among Dolly Varden and indicate that freshwater rather than marine conditions influence life history patterns, at least for fish within the Nushagak District.--4.Climate-driven changes in growth and size at maturity of Gulf of Maine lobster stocks: implications for stock assessment models.Cameron T. Hodgdon, Noah S. Khalsa, Mackenzie D. Mazur and Yong Chen. Abstract-Crustacean species are socioeconomically and ecologically crucial across the world. For crustaceans, as ectotherms, anthropogenic climate change threatens to significantly alter key life history characteristics, such as size at maturity and growth rate. Because crustaceans are difficult to age, length data are used in assessments of crustacean stocks; however, climate-induced changes in maturation and growth can greatly influence the performance of size-structured stock Assessment models. We _ coupled individual-based and size-structured models for American lobster (Homarus americanus) off northeastern North America in the Gulf of Maine to conduct a novel sensitivity analysis of the effects of maturity and growth related input parameters on model outputs. For this analysis, we used a bottom-up approach (with parameters shifted independently) and a top-down approach (with parameters shifted jointly as they were predicted to be influenced by climate change). We found that our American lobster stock assessment model is resilient to relatively extreme shifts in biological input parameters. For size-structured modeling in assessments of crustacean stocks, we recommend the expansion of sensitivity analyses to include evaluation of the influence of climate-driven changes on input parameters based on time-varying life history traits.--5. Effects of incomplete sampling and standardization indices of abundance from a fishery on independent trawl survey off the Atlantic coast of the southeastern United States. Amy Zimney and Tracey Smart. Abstract-Abundance indices from fishery-independent surveys are preferred in stock assessments for their robust scientific designs that minimize uncertainty and bias. When sampling does not adhere to the design, researchers employ techniques such as imputation or standardization to improve accuracy and reduce bias. We examined 2 methods for adjusting for incomplete sampling within the coastal trawl survey (CTS) of the Southeast Area Monitoring an South Atlantic for 3 species commonly encountered in survey sampling, the Atlantic croaker (Micropogonias undulatus), bluefish (Pomatomus saltatrix), and white shrimp (Litopenaeus setiferus): design-based imputation of missing data and standardization through the delta-generalized-linear-model approach. Additionally, we determined the effect of modifying the seasonal component of the survey design through retrospective simulation. For all 3 species, standardization improved precision in annual abundance estimates relative to values estimated with the design-based method. When a stratum missed in sampling overlapped with an area or time of high variability for a species (e.g., 2019), standardization did not improve precision over the design-based method. Results from examination of the effects of dropping entire seasons, because of funding or logistical challenges, indicate that rotating which season is dropped was the best approach to balancing characteristics of each species. Overall, we recommend the standardization approach for accounting for missing data within the CTS time series.--6.Effects of salinity and turbidity on developmen, of bamboo sole (Heteromycteris japonicus). Tu T. C. Phan Albert V. Manuel, Naoaki Tsutsuj and Takao Yoshimatsy. Abstract-Heavy rain can decrease salinity and increase turbidity of the water in coastal areas, negatively affecting the development of organiams, particularly during their early life stages. In thia study, the effecta of salinity and turbidity on embryos of the bamboo sole (Heteromycteris japonicus) were evaluated to improve understanding of its tolerance to global climate change.

Three experiments were carried out over a 7-d penod. In the first experiment, embryos of bamboo sole were exposed for 3 h to 1 of 6 sal 1 els (14-34). Low salinity levels (14 an 18 ulted in significantly shorter to f newly hatched larvae in co nth larval sizes in treatments uth ghr salinities, but no significant differences were observed in hatching rate and larval survival rate among treatments. In the second experiment, embryos were exposed to turbidities of 0, 100, 300, 500, and 700 nephelometric turbidity units for 3 h. Turbidity significantly decreased hatching rate, survival rate, and total length and increased onset hatching time and percentage of abnormality. In the third experiment, embryos were exposed to different combinations of salinity and turbidity. The interaction effect of salinity and turbidity on total length of newly hatched larvae was significant. These findings indicate that embryo development of bamboo sole was more affected by changes in turbidity than by changes in salinity.