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Observations of fish behavior can provide insights into habitat preferences and use. Black sea bass, Centropristis striata, are a territorial temperate reef finfish species known for their high commercial and recreational value and association with structured habitat. We used underwater action cameras to record video of black sea bass to assess territorial (agonistic, ambush, displacement) and occupancy (station-keeping) behaviors on shelf and bag style oyster aquaculture cages at a shellfish farm, and on boulders at a natural rock reef near Milford, Connecticut in Long Island Sound, Northwest Atlantic. Black sea bass at a variety of life stages were highly associated with cages, including young-of-the-year, and age 1+ fish. The high abundance of black sea bass observed on cages relative to boulders suggests this species has an affinity for the vertical structure created by aquaculture gear. When behaviors were normalized to the total fish sightings, black sea bass showed no significant difference in frequency of behaviors between habitats, indicating that per-fish rates of behavior were similar on cages and boulders. Demonstration of territorial and occupancy behaviors by black sea bass on, and around cages suggests that aquaculture gear provides structured habitat and ecosystem services for this species similar to natural reefs. These results suggest that essential fish habitat descriptions of manmade structures used by black sea bass could be broadened to include aquaculture gear. Our study provides novel information on behavioral interactions of black sea bass with oyster cages that may support aquaculture permitting and consultation processes. [ABSTRACT FROM AUTHOR]

Observations of fish behavior can provide insights into habitat preferences and use. Black sea bass, Centropristis striata, are a territorial temperate reef finfish species known for their high commercial and recreational value and association with structured habitat. We used underwater action cameras to record video of black sea bass to assess territorial (agonistic, ambush, displacement) and occupancy (station-keeping) behaviors on shelf and bag style oyster aquaculture cages at a shellfish farm, and on boulders at a natural rock reef near Milford, Connecticut in Long Island Sound, Northwest Atlantic. Black sea bass at a variety of life stages were highly associated with cages, including young-of-the-year, and age 1+ fish. The high abundance of black sea bass observed on cages relative to boulders suggests this species has an affinity for the vertical structure created by aquaculture gear. When behaviors were normalized to the total fish sightings, black sea bass showed no significant difference in frequency of behaviors between habitats, indicating that per-fish rates of behavior were similar on cages and boulders. Demonstration of territorial and occupancy behaviors by black sea bass on, and around cages suggests that aquaculture gear provides structured habitat and ecosystem services for this species similar to natural reefs.These results suggest that essential fish habitat descriptions of manmade structures used by black sea bass could be broadened to include aquaculture gear. Our study provides novel information on behavioral interactions of black sea bass with oyster cages that may support aquaculture permitting and consultation processes.

Abstract A reliable and cost‐effective source of fingerlings is essential for the successful commercial aquaculture of black sea bass. This study aimed to determine the effects of nursery tank stocking densities on the growth performance, feed efficiency, survival, tolerance to shipping, and biochemical quality of juvenile black sea bass. In two experiments, different stocking densities were compared for black sea bass at different stages of development. In Experiment 1, intermediate stage juveniles (1.27 g mean wt) were stocked at densities of 4.5 and 6.5 fish per liter of tank volume. Growth performance and biochemical quality were similar between the two density treatments. In Experiment 2, early post‐metamorphic stage juveniles (mean wt. = 0.524 g) were compared using the same stocking densities. While the fish reared at 4.5 fish/L were slightly larger, there were no significant differences in growth performance or biochemical quality between the density treatments. After both experiments, the fingerlings from each density treatment showed high survival rates under acute crowding and simulated shipping conditions. The study demonstrates that high NT densities of 4.5 and 6.5 fish/L did not negatively impact the growth performance and quality of black sea bass fingerlings, providing transport‐ready fingerlings in a relatively short period.

A reliable and cost‐effective source of fingerlings is essential for the successful commercial aquaculture of black sea bass. This study aimed to determine the effects of nursery tank stocking densities on the growth performance, feed efficiency, survival, tolerance to shipping, and biochemical quality of juvenile black sea bass. In two experiments, different stocking densities were compared for black sea bass at different stages of development. In Experiment 1, intermediate stage juveniles (1.27 g mean wt) were stocked at densities of 4.5 and 6.5 fish per liter of tank volume. Growth performance and biochemical quality were similar between the two density treatments. In Experiment 2, early post‐metamorphic stage juveniles (mean wt. = 0.524 g) were compared using the same stocking densities. While the fish reared at 4.5 fish/L were slightly larger, there were no significant differences in growth performance or biochemical quality between the density treatments. After both experiments, the fingerlings from each density treatment showed high survival rates under acute crowding and simulated shipping conditions. The study demonstrates that high NT densities of 4.5 and 6.5 fish/L did not negatively impact the growth performance and quality of black sea bass fingerlings, providing transport‐ready fingerlings in a relatively short period. [ABSTRACT FROM AUTHOR]

Abstract The objective of this study was to optimize nursery diets for post‐metamorphic stage black sea bass by evaluating growth performance, whole‐body proximate and fatty acid composition, and utilization of University of North Carolina Wilmington (UNCW)‐formulated and commercial diets under laboratory conditions. A feeding trial was conducted to compare two UNCW‐formulated diets (D1 and D2) for black sea bass (54% crude protein = CP and 14% crude lipid = CL) and two premium, commercial marine finfish fry diets, Otohime (Reed Mariculture Inc., Campbell, CA, CP = 48% and CL = 14%, CD3) and Gemma Diamond (Skretting, Nutreco, Canada, CP = 57%, CL = 15%, CD4). The UNCW‐formulated diet 1 (D1) contained high fish meal (FM, 40% of diet), whereas UNCW‐formulated diet 2 (D2) replaced 50% FM protein by high‐quality poultry by‐product meal (PBM) protein. Post‐metamorphic stage black sea bass (~0.60 g, d40ph) were stocked in each of sixteen 75‐L tanks at a density of 1 fish per L (75 per tank), with four replicate aquaria per treatment. Fish were fed four times per day (0800, 1100, 1400, and 1600 h) to apparent satiation for 30 days. Final body weight (5.70–5.74), specific growth rate (7.40–7.45%/d), and percent body weight gain (834–848%) of fish fed the UNCW‐formulated D1 (FM‐based) and D2 (FM + PBM‐based) were higher (p

The objective of this study was to optimize nursery diets for post‐metamorphic stage black sea bass by evaluating growth performance, whole‐body proximate and fatty acid composition, and utilization of University of North Carolina Wilmington (UNCW)‐formulated and commercial diets under laboratory conditions. A feeding trial was conducted to compare two UNCW‐formulated diets (D1 and D2) for black sea bass (54% crude protein = CP and 14% crude lipid = CL) and two premium, commercial marine finfish fry diets, Otohime (Reed Mariculture Inc., Campbell, CA, CP = 48% and CL = 14%, CD3) and Gemma Diamond (Skretting, Nutreco, Canada, CP = 57%, CL = 15%, CD4). The UNCW‐formulated diet 1 (D1) contained high fish meal (FM, 40% of diet), whereas UNCW‐formulated diet 2 (D2) replaced 50% FM protein by high‐quality poultry by‐product meal (PBM) protein. Post‐metamorphic stage black sea bass (~0.60 g, d40ph) were stocked in each of sixteen 75‐L tanks at a density of 1 fish per L (75 per tank), with four replicate aquaria per treatment. Fish were fed four times per day (0800, 1100, 1400, and 1600 h) to apparent satiation for 30 days. Final body weight (5.70–5.74), specific growth rate (7.40–7.45%/d), and percent body weight gain (834–848%) of fish fed the UNCW‐formulated D1 (FM‐based) and D2 (FM + PBM‐based) were higher (p <.05) than in fish fed the commercial diets CD3 and CD4 (4.66–5.21 g, 6.80–7.15%/d, and 668–756%, respectively). Feed intake (% body weight/d was significantly lower for fish fed commercial diet (CD4) (3.94) compared with fish fed CD3 (4.20), but feed intake for CD3 was not significantly different compared with the UNCW‐formulated diets D1 and D2 (4.10–4.12). Feed conversion ratios (0.76–0.82) were significantly higher for fish fed CD3 (0.82) than for fish fed D1 and CD4 (0.76). Survival was high (99–100%) in all diet treatments. Final whole‐body crude protein content (15.2 to 15.9% wet basis), moisture (68.9–69.6%), and ash (4.31–4.77%) showed no significant differences; however, whole‐body crude lipid was lower in fish fed CD3 (9.67%) than in fish fed the other diets (9.96–10.22%). Final whole‐body fatty acid composition reflected the diet composition. Higher feed consumption and growth of fish fed the UNCW‐formulated diets were attributed to a more optimal combination of marine (fish, squid, and krill meals), terrestrial plant (soybean meal) protein sources, and the addition of chemo‐attractants, which provided both higher nutritional quality and palatability. The study suggests that the species‐specific starter diets may improve growth performance and fingerling quality and may therefore lower production costs under intensive nursery conditions. [ABSTRACT FROM AUTHOR]

Globally, climate change is inducing range shifts and expansions for numerous species. For commercially exploited species, such as those in directed fisheries, this can cause numerous issues with management and jurisdictions as the species shift and expand into areas at levels previously unseen. The black sea bass (Centropristis striata) fishery has rapidly expanded in the northern Atlantic. Over the past decade commercial landings have more than doubled in the New England and Mid-Atlantic regions. This increase is related to a northward shift in the species’ center of biomass and range expansion. There is a crucial need for increased data in this species’ northern range. Oftentimes, large-scale fisheries data collection is limited by available resources and the difficulty of collecting data at-sea. Citizen science, such as fishing industry-based Research Fleets, represent a cost-effective option to help overcome these limitations and allow for the rapid collection of large amounts of data. The Commercial Fisheries Research Foundation and Rhode Island Department of Environmental Management established the Black Sea Bass Research Fleet in 2016. The Research Fleet is composed of fishers representing a variety of gear types who collect fishery-dependent data on black sea bass at-sea on a custom tablet application. In five years, 20 captains participated in the Research Fleet and collected length, visually-identified sex, and disposition data on 40,939 individual black sea bass throughout southern New England and into the Mid-Atlantic Bight. Catch, effort, and basic environmental data from 2,288 sampling sessions have been collected alongside this biological data. We apply the collaborative Research Fleet approach to a finfish for the first time and evaluate its performance over the first five years of sampling through participant engagement, magnitude of data collection, and interest in collected data. Further, we introduce the next steps being undertaken to incorporate the collected data into the management framework. This project illustrates that a science-industry research collaboration such as the Black Sea Bass Research Fleet can consistently collect large amounts of fishery-dependent data on black sea bass, and highlights a mutual interest among fishers, scientists, and managers to expand the collection of reliable data on this important species.

Abstract Statistical models built using different data sources and methods can exhibit conflicting patterns. We used the northern stock of black sea bass (Centropristis striata) as a case study to assess the impacts of using different fisheries data sources and laboratory‐derived physiological metrics in the development of thermal habitat models for marine fishes. We constructed thermal habitat models using generalized additive models (GAMs) based on various fisheries datasets as input, including the NOAA Northeast Fisheries Science Center (NEFSC) bottom trawl surveys, various inshore fisheries‐independent trawl surveys (state waters), NEFSC fisheries‐dependent observer data, and laboratory‐based physiological metrics. We compared each model's GAM response curve and coupled them to historical ocean conditions in the U.S. Northeast Shelf using bias‐corrected ocean temperature output from a regional ocean model. Thermal habitat models based on shelf‐wide data (NEFSC fisheries‐dependent observer data and fisheries‐independent spring and fall surveys) explained the most variation in black sea bass presence/absence data at ~15% deviance explained. Models based on a narrower range of sampled thermal habitat from inshore survey data in the Northeast Area Monitoring and Assessment Program (NEAMAP) and the geographically isolated Long Island Sound data performed poorly. All models had similar lower thermal limits around 8.5℃, but thermal optima, when present, ranged from 16.7 to 24.8℃. The GAMs could reliably predict habitat from years excluded from model training, but due to strong seasonal temperature fluctuations in the region, could not be used to predict habitat in seasons excluded from training. We conclude that survey data source can greatly impact development and interpretation of thermal habitat models for marine fishes. We suggest that model development be based on data sources that sample the widest range of ocean temperature and physical habitat throughout multiple seasons when possible, and encourage thorough consideration of how data gaps may influence model uncertainty.

Statistical models built using different data sources and methods can exhibit conflicting patterns. We used the northern stock of black sea bass (Centropristis striata) as a case study to assess the impacts of using different fisheries data sources and laboratory‐derived physiological metrics in the development of thermal habitat models for marine fishes. We constructed thermal habitat models using generalized additive models (GAMs) based on various fisheries datasets as input, including the NOAA Northeast Fisheries Science Center (NEFSC) bottom trawl surveys, various inshore fisheries‐independent trawl surveys (state waters), NEFSC fisheries‐dependent observer data, and laboratory‐based physiological metrics. We compared each model's GAM response curve and coupled them to historical ocean conditions in the U.S. Northeast Shelf using bias‐corrected ocean temperature output from a regional ocean model. Thermal habitat models based on shelf‐wide data (NEFSC fisheries‐dependent observer data and fisheries‐independent spring and fall surveys) explained the most variation in black sea bass presence/absence data at ~15% deviance explained. Models based on a narrower range of sampled thermal habitat from inshore survey data in the Northeast Area Monitoring and Assessment Program (NEAMAP) and the geographically isolated Long Island Sound data performed poorly. All models had similar lower thermal limits around 8.5℃, but thermal optima, when present, ranged from 16.7 to 24.8℃. The GAMs could reliably predict habitat from years excluded from model training, but due to strong seasonal temperature fluctuations in the region, could not be used to predict habitat in seasons excluded from training. We conclude that survey data source can greatly impact development and interpretation of thermal habitat models for marine fishes. We suggest that model development be based on data sources that sample the widest range of ocean temperature and physical habitat throughout multiple seasons when possible, and encourage thorough consideration of how data gaps may influence model uncertainty. [ABSTRACT FROM AUTHOR]

Abstract Fishes commonly exhibit diel rhythms in movements with consequences to feeding, reproduction, predator evasion, and resting. Such behaviors are conceived as plastic, persisting for phases (days to weeks), and then becoming disrupted, masked, and altered by changed environmental or ecological conditions. In telemetered black sea bass Centropristis striata (family Serranidae), we documented a remarkable 4‐month record of persistent diurnal vertical movements. Within the U.S. Mid‐Atlantic Bight June–October 2019 setting, biotelemetry data of 31 fish were examined through time series analysis and generalized additive modeling. Sun altitude played a dominant role throughout the series, where movements were diurnal. Thermal conditions were uniform until a September hurricane caused a 10°C rise in inhabited waters within the span of six hours, the result of water column mixing. This and other storms caused short‐term disruptions (

Fishes commonly exhibit diel rhythms in movements with consequences to feeding, reproduction, predator evasion, and resting. Such behaviors are conceived as plastic, persisting for phases (days to weeks), and then becoming disrupted, masked, and altered by changed environmental or ecological conditions. In telemetered black sea bass Centropristis striata (family Serranidae), we documented a remarkable 4‐month record of persistent diurnal vertical movements. Within the U.S. Mid‐Atlantic Bight June–October 2019 setting, biotelemetry data of 31 fish were examined through time series analysis and generalized additive modeling. Sun altitude played a dominant role throughout the series, where movements were diurnal. Thermal conditions were uniform until a September hurricane caused a 10°C rise in inhabited waters within the span of six hours, the result of water column mixing. This and other storms caused short‐term disruptions (<2 d) to diel rhythmicity. Daytime vessel traffic, but not dolphin presence, caused ≤1 h refuge‐seeking excursions. The discovery of pelagic behaviors (up to 15 m off the seabed) requires revision to the species' natural history, which was previously conceived as exclusively demersal. Spring‐autumn movement functions included reef recruitment and evacuation, courtship and spawning, and seasonal changes in feeding ecology and predator fields. Throughout these phases, the cycle of daytime movement and nighttime inactivity persisted. We hypothesize that during the nocturnal period these visual specialists become immobile and thus evade predation and mobilize energy toward growth, reproduction, and storage. Because this function does not change from spring through autumn, we speculate that nocturnal quiescence serves as the proximate control for the diurnal activity cycle. [ABSTRACT FROM AUTHOR]

The warming of the world’s oceans has resulted in the redistribution of many marine species globally. As species undergo range shifts, the expanding edge of the population often experiences novel environmental and demographic conditions that may result in the emergence of variation in life-history strategies. The northern stock of black sea bass, Centropristis striata, has recently expanded its distribution poleward, into the Gulf of Maine. Management has struggled to keep pace with this rapid range shift, in part, because very little is known about the expanding population. We compared life-history traits of black sea bass collected from 2013 to 2016 from the northern most point of the historic range of the northern stock (southern Massachusetts) to those from two areas in the newly expanded range (northern Massachusetts and Maine). We found significant differences in size, diet, condition, maturity and sex ratio between black sea bass from southern Massachusetts and the Gulf of Maine. Overall, sea bass in the newly expanded range consumed a less diverse diet and their condition was lower, but they reached maturity at a younger age. We also found greater length- and age-at-maturity estimates from all regions combined compared to the most recent black sea bass stock assessment which includes data from Cape Hatteras, NC to southern Massachusetts. This study represents initial observations of life-history traits of sea bass in its newly expanded range in the Gulf of Maine, and suggests that these sea bass exhibit life-history strategies that differ from their southern counterparts within their historic range. Given these findings, the stock assessment for the Northeast U.S. Continental Shelf black sea bass stock may not be adequate for sea bass in the Gulf of Maine. Studies investigating the expanding edge of economically valuable fishery species are needed to aid in ongoing and future efforts to assess and manage their stocks.

The goal of this research was to characterize the shelter preferences, home ranges, site fidelity and movement patterns of spiny lobsters in the Point Loma kelp beds in San Diego. Biologists examined changes in these behaviors for lobsters placed in shelters with and without conspecifics (other lobsters). They also compared movement patterns for lobsters living in areas with relatively low and high risk of predation by large fishes such as sheephead, black sea bass and kelp bass.

Abstract Distribution shifts poleward are a widespread response to climate change and can result in altered community composition and interactions among species that previously were geographically isolated. The novel communities and species interactions that may arise during range shifts provide an opportunity to study fundamental ecological processes, while also addressing potential conservation issues. Black sea bass (Centropristis striata) historically ranged from the Gulf of Mexico to Cape Cod, but recently have expanded north into the Gulf of Maine. Very little is known about the impact of this range expansion on benthic community structure throughout the coastal waters of the Gulf of Maine. To investigate the effects of sea bass on the behavior of juvenile American lobsters (Homarus americanus), we manipulated the presence of sea bass olfactory cues and quantified shelter use and foraging behavior of lobsters from three regions in the Gulf of Maine with different potential contact histories with sea bass. Sea bass presence increased shelter usage and reduced foraging in lobsters, but contact history influenced the strength of these behavioral responses. Lobsters with no previous contact with sea bass did not significantly increase shelter usage or decrease movement in their presence but did reduce their foraging rate on mussels. This observed reduction in consumption indicates that naïve lobsters recognize novel predators, but the ineffective anti‐predator responses exhibited support the naive prey hypothesis. Meanwhile, lobsters with the longest potential contact history with sea bass significantly increased shelter usage when sea bass were present; however, they exhibited limited movement and foraging behavior in both the absence and presence of sea bass. Finally, lobsters with a short potential contact history with sea bass exhibited increased shelter usage, reduced movement, and reduced mussel consumption in the presence of sea bass, revealing that juvenile lobsters quickly adapt anti‐predator defenses to avoid this novel threat. Overall, these results suggest that prey contact history with novel predators mediates the strength of their nonconsumptive effects, and consequently can influence geographic patterns in predator–prey dynamics.

Autogenic engineers (i.e., biogenic structure) add to habitat complexity by altering the environment by their own physical structures. The presence of autogenic engineers is correlated with increases in species abundance and biodiversity. Biogenic structural communities off the coast of Delaware, Maryland, and Virginia (Delmarva) are comprised of multiple species including boring sponge Cliona celata, various hydroids (i.e., Tubularia sp., Obelia sp., Campanular sp.), northern stone coral Astrangia poculata, sea whips Leptogorgia virgulata, and blue mussels Mytilus edulis. Sea whips are soft corals that provide the majority of vertical height to benthic structure off the coast of the Delmarva peninsula. The mid-Atlantic bight is inhabited by several economically valuable fishes; however, data regarding habitat composition, habitat quality, and fish abundance are scarce. We collected quadrat and sea whip images from 12 artificial reef sites (i.e., shipwrecks) ranging from 10 to 24 m depth to determine proportional coverage of biogenic structures and to assess habitat health, respectively. Underwater video surveys were used to estimate fish abundances on the 12 study sites and determine if fish abundance was related to biogenic coverage and habitat health. Our results showed that higher fish abundance was significantly correlated with higher proportional sea whip coral coverage, but showed no significant relationship to other biogenic structure. Assessment of sea whip condition (as a damage index) showed that sea whip corals on artificial reefs off the Delmarva coast exhibited minor signs of degradation that did not differ significantly among study sites.

Autogenic engineers (i.e., biogenic structure) add to habitat complexity by altering the environment by their own physical structures. The presence of autogenic engineers is correlated with increases in species abundance and biodiversity. Biogenic structural communities off the coast of Delaware, Maryland, and Virginia (Delmarva) are comprised of multiple species including boring sponge Cliona celata, various hydroids (i.e., Tubularia sp., Obelia sp., Campanular sp.), northern stone coral Astrangia poculata, sea whips Leptogorgia virgulata, and blue mussels Mytilus edulis. Sea whips are soft corals that provide the majority of vertical height to benthic structure off the coast of the Delmarva peninsula. The mid-Atlantic bight is inhabited by several economically valuable fishes; however, data regarding habitat composition, habitat quality, and fish abundance are scarce. We collected quadrat and sea whip images from 12 artificial reef sites (i.e., shipwrecks) ranging from 10 to 24 m depth to determine proportional coverage of biogenic structures and to assess habitat health, respectively. Underwater video surveys were used to estimate fish abundances on the 12 study sites and determine if fish abundance was related to biogenic coverage and habitat health. Our results showed that higher fish abundance was significantly correlated with higher proportional sea whip coral coverage, but showed no significant relationship to other biogenic structure. Assessment of sea whip condition (as a damage index) showed that sea whip corals on artificial reefs off the Delmarva coast exhibited minor signs of degradation that did not differ significantly among study sites. [ABSTRACT FROM AUTHOR]

Alteration and degradation of benthic structure by fishing gear can impede efforts to manage fish stock sustainably. Although the impacts of mobile gear are well known, effects of passive gear (e.g. fish traps) upon structure have been little studied. We modified commercial traps for American lobster Homarus americanus and black sea bass Centropristis striata by attaching GoPro®cameras to ascertain the degree and nature of impacts to seafloor habitats. Customized traps were included within a line of 20 traps, deployed and retrieved according to standard commercial fishing practice. Less than 5% of traps landed directly on bedforms when deployed. However, during retrieval traps dragged along the ocean floor, increasing trap–habitat contact rate to 50%, and causing traps to collide with corals, bryozoans, and other epifauna. Drag time of traps depended on the position in the trap line. Experimentally extending the trap line reduced drag time during retrieval for traps near the distal end of the line. Our results show that impacts of commercial trap fishing can be substantial during trap retrieval, and that the impact depends on their location on a trap line. Fishing practices should be developed that minimize effects of trap retrieval on structural benthic habitat. [ABSTRACT FROM AUTHOR]

Failure to account for time‐varying detection ranges when inferring space use of marine species from passive acoustic telemetry data can bias estimates and result in erroneous biological conclusions. This potential source of bias is widely acknowledged but often ignored in practice due to a lack of available statistical methods.Here, we describe and apply a spatial point process model for estimating individual centres of activity (COAs) from acoustic telemetry data that can be modified to account for both receiver‐ and time‐specific detection probabilities. We use simulation testing to evaluate the suitability of the proposed models for estimating COAs and compare their performance to that of the popular mean‐weighted COA method for a variety of scenarios. We illustrate how the approach can be applied to correct for variable detection ranges by integrating data from moored test tags and demonstrate how accounting for time‐varying detection probabilities can impact space use estimates by fitting the model to data collected from a black sea bass (Centropristis striata) on a receiver array off the east coast of the United States.The proposed model reduced bias in COA estimates, particularly when tagged individuals occurred along the periphery of the receiver array. The test tag‐integrated model largely corrected the bias associated with receiver‐ and time‐specific detection probabilities. When applied to the black sea bass detection data, the model revealed fine‐scale movements not apparent when detection ranges were assumed constant.Spatial management practices for coastal marine species are often based on trends in space use inferred from passive acoustic telemetry data, which can be misinterpreted when factors influencing detection ranges are not accounted for. Our approach provides a general framework for estimating individual COAs that can be modified on a study‐specific basis to ensure resulting patterns of space use reflect a species' movements and behaviour, rather than variation in receiver detection ranges. [ABSTRACT FROM AUTHOR]

Sex change has been widely documented in many commercially and recreationally important fish species, yet the implications of this life history trait are not considered in most stock assessments. This omission can lead to poor estimates of parameters vital to understanding the health of sequentially hermaphroditic stocks. Here, we present a game theoretic approach to model the sex changing behaviour of a stock of protogynous (female first) hermaphroditic fish and produce estimates of maximum sustainable yield (MSY), equilibrium biomass at MSY (BMSY) and sex ratio, then compare these reference points to those from an otherwise identical gonochoristic (non-sex changing) stock. We tested each stock at varying levels of exploitation and with a range of assumptions about how sex ratio impacts fertilization rate. We show that a protogynous hermaphroditic stock with flexible timing of sex change produces similar MSY and slightly higher BMSY than a gonochoristic stock with otherwise identical vital rates. Sex changing stocks were also able to maintain a higher proportion of males in the population than did non-sex changing stocks as exploitation increased. Although sex changing stocks were able to maintain their sex ratio, the age at which females changed sex decreased with increased exploitation, suggesting smaller body size, and presumably lower fecundity, for females in heavily exploited sex changing stocks. Our game theoretic approach to evaluating hermaphroditic stocks can accommodate a wide variety of sex changing cues and behaviours and allows a flexible model for understanding the effects of exploitation on hermaphroditic stocks. [ABSTRACT FROM AUTHOR]

A tagging study was conducted off the New Jersey coast to study sex change in Black Sea Bass Centropristis striata as a function of size, age, and spawning season. Throughout 2011–2013, 3,670 fish were measured and 1,498 were tagged from research, charter, and commercial fishing vessels. Of the tagged fish, 437 were recaptured. Size at 50% probability of sex change was 355 mm TL; the proportion of female fish in sexual transition increased with body size from 0.5% at 175–225 mm to 15.7% at 375–425 mm and increased with age from 0.6% at 3 years old to 18.2% at 6 years old. Relatively few females (8 of 107) changed sex during the spawning season, but a larger proportion (8 of 22 females) transitioned between spawning seasons. The proportion of females with transitional gonads was lowest at the start of the spawning season in June (0.2%), slowly increased over the summer, and sharply peaked just after the spawning season in October (9.5%). In addition, a high proportion of young mature fish were male (40% at age 2), which may indicate the presence of primary males. This is the first tagging study to estimate sex change as a function of size, age, and season in a protogynous hermaphroditic fish species. Use of tagging avoids potential problems that are associated with inferring sex change rates from sex ratios based on catch data. [ABSTRACT FROM AUTHOR]

Fish species that are protogynous hermaphrodites generally have sex ratios skewed toward males at large sizes. These skewed sex ratios at length can make a stock more vulnerable to overexploitation, particularly in fisheries where minimum size is regulated, resulting in the removal of reproductively active males. We developed a length-based population model to test the vulnerability to exploitation of a population with an atypical protogynous life history, in particular the northern stock of black sea bass (Centropristis striata). Black sea bass north of Cape Hatteras, North Carolina, are unusual for protogynous species in that they may undergo prematurational transformation, remain female at large sizes, involve secondary males in spawning, and undertake seasonal migrations. The model was developed to examine the impact of participation by secondary males in population productivity, the influence of size at sex transformation, and the subsequent robustness of the population under exploitation, in comparison with equivalent gonochoristic and typical protogynous populations. Although the model does not capture all the dynamics of a population, such as density-dependent regulation of sex transformation, our results indicate that the northern stock of black sea bass may be more resilient in response to exploitation than would be expected if they were typical protogynous hermaphrodites. [ABSTRACT FROM AUTHOR]

Black sea bass (Centropristis striata) migrations are believed to play a role in overwinter survival and connectivity between juvenile and adult populations. This study investigated oceanographic drivers of winter habitat choice and regional differences between populations of juvenile and adult black sea bass. Trends in cohort strength, as a result of juvenile survival, were also identified. Oceanographic and fisheries survey data were analyzed using generalized additive models. Among the oceanographic variables investigated, salinity was the main driver in habitat selection with an optimal range of 33–35 practical salinity units (PSU) for both juveniles and adults. Preferred temperature ranges varied between juveniles and adults, but held a similar minimum preference of >8°C. Salinity and temperature ranges also differed by regions north and south of Hudson Canyon. Shelf water volume had less of an effect than temperature or salinity, but showed an overall negative relationship with survey catch. The effect of winter conditions on juvenile abundance was also observed across state and federal survey index trends. A lack of correlation observed among surveys in the fall paired with a strong correlation in the spring identifies the winter period as a factor determining year-class strength of new recruits to the population. A rank order analysis of spring indices identified three of the largest year classes occurring during years with reduced shelf water volumes, warmer winter shelf waters, and a 34 PSU isohaline aligned farther inshore. While greater catches of black sea bass in the northwest Atlantic Ocean remain south of Hudson Canyon, the species’ range has expanded north in recent years. [ABSTRACT FROM AUTHOR]

Traps are among the most common gears used to capture fish and crustaceans. When traps are deployed in surveys, the data gathered are often used to develop an index of abundance. However, trap catches are known to saturate over time for various reasons, such as space limitation of the gear or intraspecific interactions, and these features can dissociate the catch from local abundance. In this study, we develop a hierarchical state-space model of trap dynamics that is fit to data in a Bayesian framework. The model links trap catch to estimated local abundance, and additionally provides direct estimates of capture probability. For demonstration, we apply the model to data on black sea bass (Centropristis striata), which were collected using chevron traps combined with video cameras to give continuous-time observations of trap entries and exits. Results are consistent with the hypothesis that trap catch is generally proportional to local abundance. The model has potential application to surveys where animals not only enter a trap, but also may exit, such that the apparent trap saturation occurs because the system approaches equilibrium. [ABSTRACT FROM AUTHOR]

Climate change and fishing can have major impacts on the distribution of natural marine resources. Climate change alters the distribution of suitable habitat, forcing organisms to shift their range or attempt to survive under suboptimal conditions. Fishing reduces the abundance of marine populations and truncates their age structure leading to range contractions or shifts. Along the east coast of the United States, there have been major changes in fish populations due to the impacts of fishing and subsequent regulations, as well as changes in the climate. Black sea bass, scup, summer flounder, and winter flounder are important commercial and recreational species, which utilize inshore and offshore waters on the northeast shelf. We examined the distributions of the four species with the Northeast Fisheries Science Center trawl surveys to determine if the along-shelf centres of biomass had changed over time and if the changes were attributed to changes in temperature or fishing pressure through changes in abundance and length structure. Black sea bass, scup, and summer flounder exhibited significant poleward shifts in distributions in at least one season while the Southern New England/Mid-Atlantic Bight stock of winter flounder did not shift. Generalized additive modelling indicated that the changes in the centres of biomass for black sea bass and scup in spring were related to climate, while the change in the distribution of summer flounder was largely attributed to a decrease in fishing pressure and an expansion of the length-age structure. While the changes in ocean temperatures will have major impacts on the distribution of marine taxa, the effects of fishing can be of equivalent magnitude and on a more immediate time scale. It is important for management to take all factors into consideration when developing regulations for natural marine resources. [ABSTRACT FROM AUTHOR]

Black Sea Bass (Centropristis striata) in the mid-Atlantic Bight undertake seasonal cross-shelf movements to occupy inshore rocky reefs and hardbottom habitats between spring and fall. Shelf-wide migrations of this stock are well documented, but movements and home ranges of fish during their inshore residency period have not been described. We tagged 122 Black Sea Bass with acoustic transmitters at a mid-Atlantic reef to estimate home-range size and factors that influence movements (>400 m) at a 46.1-km2 study site between May and November 2003. Activity of Black Sea Bass was greatest and most consistent during summer but declined rapidly in September as water temperatures at the bottom of the seafloor increased on the inner shelf. Black Sea Bass maintained relatively large home ranges that were fish-size invariant but highly variable (13.7-736.4 ha), underscoring the importance of large sample sizes in examination of population-level characteristics of mobile species with complex social interactions. On the basis of observed variations in movement patterns and the size of home ranges, we postulate the existence of groups of conspecifics that exhibit similar space-use behaviors. The group of males released earlier in the tagging period used larger home ranges than the group of males released later in our study. In addition, mean activity levels and the probability of movement among acoustic stations varied among groups of fish in a complex manner that depended on sex. These differences in movement behaviors may increase the vulnerability of male fish to passive fishing gears, further exacerbating variation in exploitation rates for this species among reefs. [ABSTRACT FROM AUTHOR]

Direct observations were made in June 2009 and 2010 of newly recruited young-of-year (YOY) Sphyraena barracuda (Great Barracuda; 50-80 mm total length) occuring on "live bottom" sub-tropical reefs off the southeast US at depths of 18-25 m. Counts of YOY fish from roving diver surveys along multiple reefs with under-cut ledges ranged from 0-122 individuals, indicating patchy distributions at the scale of individual reefs. Individual fish occured in groups of 2-20+, primarily along the undercut side of ledges, where dense schools of Haemulon aurolineatum (Tomtate), Decapterus punctatus (Round Scad), Decapterus macarellus (Mackeral Scad), Stenotomus chrysops (Scup), and Atherinid sp. (silverside) were concentrated. Groups of YOY Great Barracuda attacked, captured and consumed YOY Tomtate and Silverside that occured in schools in the water column adjacent to (just above the sediment-water interface) and directly above the undercut edge of the reefs. Prey reacted during attacks by reducing nearest neighbor distances and retreating to the reef edge, where they were subsequently attacked by the demersal piscivores Centropristis striata (Black Sea Bass), Centropristis ocyurus (Bank Sea Bass), and Mycteroperca phenax (Scamp Grouper). That groups of YOY piscivores, at sizes close to settlement, can assume such a functional role in regards to driving such species interactions suggests greater attention should be given to the roles played by the wider diversity of YOY piscivores recruiting to reef communities. [ABSTRACT FROM AUTHOR]

This study investigated the influence of fiber size on the distribution of nuclei and fiber growth patterns in white muscle of black sea bass, Centropristis striata, ranging in body mass from 0.45 to 4840g. Nuclei were counted in 1 urn optical sections using confocal microscopy of DAPI- and Acridine-Orange-stained muscle fibers. Mean fiber diameter increased from 36±0.87μm in the 0.45g fish to 280±5.47μm in the 1885g fish. Growth beyond 2000g triggered the recruitment of smaller fibers, thus significantly reducing mean fiber diameter. Nuclei in the smaller fibers were exclusively subsarcolemmal (SS), whereas in larger fibers nuclei were more numerous and included intermyofibrillar (IM) nuclei. There was a significant effect of body mass on nuclear domain size (F=118.71, d.f.=3, P<0.0001), which increased to a maximum in fish of medium size (282-1885g) and then decreased in large fish (>2000g). Although an increase in the number of nuclei during fiber growth can help preserve the myonuclear domain, the appearance of lM nuclei during hypertrophic growth seems to be aimed at maintaining short effective diffusion distances for nuclear substrates and products. If only SS nuclei were present throughout growth, the diffusion distance would increase in proportion to the radius of the fibers. These observations are consistent with the hypothesis that changes in nuclear distribution and fiber growth patterns are mechanisms for avoiding diffusion limitation during animal growth. [ABSTRACT FROM AUTHOR]

The article presents a study which examined the diets of four demersal fish species, namely black sea bass Centropristis striata, scup Stenotomus chrysops, Northern searobin Prionotus carolinus and striped searobin Prionotus evolans, in the U.S. Northeast Shelf Large Marine Ecosystem. Their aim was to evaluate the major determinants of diet composition by examining food habits data across size class, season, 5 year time block and geographic region. The researchers found that the scup and 2 searobin species are primarily benthivorous, while black sea bass shifts towards piscivory with ontogeny.

This study was undertaken to re-assess the level of scup (Stenotomus chrysops) discards by weight and to evaluate the effect of various codend mesh sizes on the level of scup discards in the winter-trawl scup fishery. Scup discards were high in directed scup tows regardless of codend mesh -- typically one to five times the weight of landings. The weight of scup discards in the present study did not differ significantly from that recorded in scup-targeted tows in the NMFS observer database. Most discards were required as such by the 22.86 cm TL (total length) fish-size limit for catches. Mesh sizes ≤12.7 cm, including the current legal mesh size (11.43 cm) did not adequately filter out scup smaller than 22.86 cm. The median length of scup discards was about 19.83 cm TL. Lowering the legal size for scup from 22.86 to 19.83 cm TL would greatly reduce discard mortality. Scup discards were a small fraction (0.4%) of black sea bass (Centropristis striata) landings in black-sea-bass--targeted tows. The black sea bass fishery is currently regulated under the small-mesh fishery gear-restricted area plan in which fishing is prohibited in some areas to reduce scup mortality. Our study found no evidence to support the efficacy of this management approach. The expectations that discarding would increase disproportionately as the trip limit (limit [in kilograms] on catch for a species) was reached towards the end of the trip and that discards would increase when the trip limit was reduced from 4536 kg to 454 kg at the end of the directed fishing season were not supported. Trip limits did not significantly affect discard mortality. [ABSTRACT FROM AUTHOR]

Microplastics are ubiquitous in marine and estuarine ecosystems, and thus there is increasing concern regarding exposure and potential effects in commercial species. To address this knowledge gap, we investigated the effects of microplastics on larval and early juvenile life stages of the Black Sea Bass (Centropristis striata), a North American fishery. Larvae (13–14 days post hatch, dph) were exposed to 1.0 × 104, 1.0 × 105, and 1.0 × 106 particles L−1 of low-density polyethylene (LDPE) microspheres (10–20 μm) directly in seawater and via trophic transfer from microzooplankton prey (tintinnid ciliates, Favella spp.). We also compared the ingestion of virgin and chemically-treated microspheres incubated with either phenanthrene, a polycyclic aromatic hydrocarbon, or 2,4-di-tert-butylphenol (2,4-DTBP), a plastic additive. Larval fish did not discriminate between virgin or chemically-treated microspheres. However, larvae did ingest higher numbers of microspheres through ingestion of microzooplankton prey than directly from the seawater. Early juveniles (50–60 dph) were directly exposed to the virgin and chemically-treated LDPE microspheres, as well as virgin LDPE microfibers for 96 h to determine physiological effects (i.e., oxygen consumption and immune response). There was a significant positive relationship between oxygen consumption and increasing microfiber concentration, as well as a significant negative relationship between immune response and increasing virgin microsphere concentration. This first assessment of microplastic pollution effects in the early life stages of a commercial finfish species demonstrates that trophic transfer from microzooplankton can be a significant route of microplastic exposure to larval stages of C. striata , and that multi-day exposure to some microplastics in early juveniles can result in physiological stress. [Display omitted] • Larval sea bass ingest more microplastics from ciliate prey than from the water. • Exposure to fibers causes increased oxygen consumption in juvenile sea bass. • Exposure to virgin microspheres decreased immune response in juvenile sea bass. • Presence of phenanthrene or di-tert butyl phenol did not influence ingestion. • Presence of associated chemicals did not affect respiration or immune response. [ABSTRACT FROM AUTHOR]

Focuses on model calculations to assess the photoreceptor quantum catches of the Centropristis striata (black sea bass), Hemitripterus americanus (sea raven), and the Pseudopleuronectes americanus (winter flounder). Performance of calculations under disparate irradiance conditions; Comparison of each receptor type quantum catches in various water types and depths; Use of quantum catch ratios as possible criteria in the selection of pigment peaks.

Harvest restrictions (e.g. size, sex or species limitations) that are implemented to maintain sustainable fisheries often result in by-catch, e.g. unwanted non-target catch. By-catch is frequently discarded back into the ocean and assumed to survive. However, discarded fishes can succumb to delayed mortality resulting from accumulated stress from fishing activity, and such mortality can impede sustainability efforts. Quantifying reflex and behavioural impairments is a quick and cost-effective method to predict discard-related mortality in some species. We developed and evaluated the effectiveness of a release condition index, based on a reflex-action mortality prediction (RAMP) model, for predicting delayed mortality of black sea bass ( Centropristis striata ) caught and discarded by the commercial trap fishery in the Mid-Atlantic Bight. Accumulation of impairments, and therefore release condition index, was strongly correlated with delayed mortality of black sea bass discarded and held in sea cages. This is the first release condition index validation study to predict mortality in black sea bass and could be a useful approach for predicting delayed mortality in the commercial fishery., (© The Author(s) 2020. Published by Oxford University Press and the Society for Experimental Biology.)

Distribution shifts poleward are a widespread response to climate change and can result in altered community composition and interactions among species that previously were geographically isolated. The novel communities and species interactions that may arise during range shifts provide an opportunity to study fundamental ecological processes, while also addressing potential conservation issues. Black sea bass (Centropristis striata) historically ranged from the Gulf of Mexico to Cape Cod, but recently have expanded north into the Gulf of Maine. Very little is known about the impact of this range expansion on benthic community structure throughout the coastal waters of the Gulf of Maine. To investigate the effects of sea bass on the behavior of juvenile American lobsters (Homarus americanus), we manipulated the presence of sea bass olfactory cues and quantified shelter use and foraging behavior of lobsters from three regions in the Gulf of Maine with different potential contact histories with sea bass. Sea bass presence increased shelter usage and reduced foraging in lobsters, but contact history influenced the strength of these behavioral responses. Lobsters with no previous contact with sea bass did not significantly increase shelter usage or decrease movement in their presence but did reduce their foraging rate on mussels. This observed reduction in consumption indicates that naïve lobsters recognize novel predators, but the ineffective anti‐predator responses exhibited support the naive prey hypothesis. Meanwhile, lobsters with the longest potential contact history with sea bass significantly increased shelter usage when sea bass were present; however, they exhibited limited movement and foraging behavior in both the absence and presence of sea bass. Finally, lobsters with a short potential contact history with sea bass exhibited increased shelter usage, reduced movement, and reduced mussel consumption in the presence of sea bass, revealing that juvenile lobsters quickly adapt anti‐predator defenses to avoid this novel threat. Overall, these results suggest that prey contact history with novel predators mediates the strength of their nonconsumptive effects, and consequently can influence geographic patterns in predator–prey dynamics. [ABSTRACT FROM AUTHOR]