Performance of a fine-scale acoustic positioning system for monitoring temperate fish behavior in relation to offshore marine developments

Animal Biotelemetry · 2024-12-04 · 2 citations

Rapid global expansion of offshore wind farms, tidal, and wave technologies signifies a new era of renewable energy development. While a promising means to combat the impacts of climate change, such developments necessitate fine-scale monitoring of biological communities to determine impacts associated with construction, operation, and eventual decommission. Here, we evaluate the performance of a gridded, Innovasea Systems, Inc. fine-scale acoustic telemetry positioning system (FSPS, n = 20 acoustic receivers) for tracking behaviors of diverse, temperate fish assemblages in relation to a subsea cable route supporting the Ørsted offshore wind development in coastal New York. We examined array performance through positioning error derived from receiver reference transmitters and tracked animals (n = 260) comprising 17 species of teleost and elasmobranch. We evaluated the effects of environmental variables (temperature, tilt, noise, and depth), transmitter power, individual movement rates, and receiver loss on horizontal positioning error (HPE) and route mean squared error (RMSE). Across a 16-month deployment period, many positions were derived for Atlantic sturgeon (n = 2,612), black sea bass (n = 9,175), clearnose skate (n = 10,306), summer flounder (n = 13,304), and little skate (n = 15,186), suggesting that these species may serve as sentinel candidates for assessing behavioral changes following construction, operation, and decommission. We found that receivers placed at the boundary of the grid exhibited higher HPE and RMSE, however these errors did not significantly change despite large receiver losses (25%). Generalized Linear Models revealed that temperature, noise, tilt, and depth were often significant predictors of HPE and RMSE, however, a substantial amount of variance was not explained by the models (~ 70%). Average movement rates ranged from 1.1 m s−1 (common thresher shark) to 0.03 m s−1 (little skate and summer flounder) but had minimal effects on positioning error. Finally, we observed that higher transmitter powers (158 dB) may lead to higher and more variable HPE values. Overall, these findings provide new insight into the drivers of FSPS array performance and illustrate their broad utility for monitoring fish behavior associated with offshore marine developments.

Reef fish biodiversity and occurrence of endangered sharks within a small marine protected area off Sint Maarten, Dutch Caribbean

Environmental Biology of Fishes · 2024-09-17 · 2 citations

Abstract Marine protected areas (MPAs) are common conservation tools supporting the protection of threatened marine fishes, such as sharks. However, the creation of shark MPAs has been less common in the Greater Caribbean region despite a growing need and opportunity. In this study, we evaluated the occurrence of shark and reef fish biodiversity off Sint Maarten, Dutch Caribbean, with a particular emphasis on endangered shark presence within the Man of War Shoal Marine Protected Area (MPA). We utilized baited remote underwater video systems (BRUVs) to gather non-invasive data on the abundance and diversity of reef fish and shark species inside and outside the local MPA. Generalized linear models (GLMs) revealed no significant effect of protection status on the presence of the endangered Caribbean reef shark ( Carcharhinus perezi ). However, we found a significant influence of depth on shark occurrence, as well as an effect of habitat type on shark and reef fish biodiversity, with reef habitats showing the greatest significance. These results suggest that the effect of small coastal MPAs on bolstering local endangered species conservation in the Dutch Caribbean is likely to vary according to habitat features and how those species utilize those habitats across various life stages. These findings have implications for adaptive MPA management, which should be informed by the ecology and habitat preferences of target species to achieve maximum benefits for biodiversity conservation.

Celebrating recent innovations in the application of stable isotopes to fish biology

Journal of Fish Biology · 2024-07-24

It is over 50 years since the distribution of carbon and nitrogen stable isotopes (δ13C and δ15N) was first described in animal tissues (DeNiro & Epstein, 1978, 1981; Fry et al., 1978; Parker, 1964; Schroeder, 1983; Schoeninger & DeNiro, 1984). For fishes, this catalyzed a rich history of studies assessing trophic relationships, movement and migration, and physiological status across freshwater, brackish, and marine environments (Boecklen et al., 2011; Hansson et al., 1997; Shipley & Matich, 2020). As technological advancements continue to improve analytical capabilities, isotopic techniques will continue to transform the field of fish biology. This special issue celebrates some of these recent innovations with a focus on four broad themes: (1) constraining patterns of isotopic discrimination, (2) determining drivers of energy distribution across diverse fish communities, (3) assessing the impacts of human alteration on foraging and fitness, and (4) nontraditional stable isotope systems. The goal of this collection is to showcase state-of-the-art approaches that can improve our understanding of fish ecology and physiology in a changing world. Accurate interpretation of stable isotope values requires detailed knowledge of isotopic discrimination, defined as changes in the relative abundances of isotopes (e.g., 13/12C or 14/15N) due to some ecological (i.e., diet or habitat shift) or physiological (i.e., tissue anabolism/catabolism) process. Despite the need for ecological studies to effectively constrain discrimination (Canseco et al., 2022; Stephens et al., 2023), many aspects remain poorly examined. In elasmobranch fishes (sharks, skates, and rays) that exhibit diverse reproductive modes, it has long been proposed that the isotopic composition of neonate and YOY tissues may be influenced by isotopic discrimination associated with maternal provisioning. Therefore, neonate and YOY tissues may reflect maternal foraging (with some discrimination) rather than ambient environmental conditions experienced directly following birth. Because patterns of mother–embryo isotope discrimination have only been described for a handful of species, it remains uncertain whether correction factors can fully resolve estimates of neonate and YOY foraging and habitat use. Raoult et al. (2024) explore this issue through measuring δ13C and δ15N values in female sparsely spotted stingarees (Urolophus paucimaculatus), banded stingarees (Urolophus viridis), and Tasmanian numbfish (Narcine tasmaniensis) and their offspring sampled from Southeast Australia. They observed highly variable patterns of mother–embryo isotope discrimination that differed by individual and between species. This suggests that unique patterns of isotopic discrimination exist between each embryo and its mother, confounding the use of general correction factors. Assessing patterns of isotopic discrimination between tissues from the same individual can also help to resolve important ecological information. Due to the rising conservation concern of many species and ethical limitations to sampling, assessing patterns of discrimination between lethal (e.g., liver, muscle, and vertebrae) and non-lethally sampled tissues (e.g., fin, scales, and mucus) has become increasingly encouraged. This approach can challenge interpretation, however, because inter-tissue isotope discrimination is driven by the molecular composition of tissues and the rate at which they integrate isotopic information from the environment. To tackle this issue, Taulbee and Walther (2024) assess relationships between δ13C and δ15N values of scale exteriors and muscle tissue in estuarine red drum (Sciaenops ocellatus). They find strong, positive relationships for both isotopes, suggesting that scale exteriors offer a viable non-lethal alternative to muscle. Roberts et al. (2022) apply a similar approach in freshwater species, providing δ13C and δ15N linear conversation relationships between fin and muscle tissue in northern pike (Esox Lucius L.), yellow perch (Perca flavescens), and lake whitefish (Coregonus clupeaformis) while also assessing effects of seasonality. The authors suggest that seasonal variation in ecosystem dynamics combined with variable isotopic incorporation of available tissues may require seasonally specific conversions, at least for highly seasonal ecosystems such as temperate lakes. Finally, Walther and Torrance (2024) explore the complimentary use of stable isotopes with otolith microchemistry. A systematic literature review of 56 studies identified the strong complementarity of the two techniques for assessing diverse ecological questions. However, otolith microchemistry and tissue stable isotope values are not likely to be ecologically synonymous, evidenced by a lack of relationship between Ba:Ca ratios in the outer edge of the otolith and muscle tissue δ13C values in estuarine red drum. This collection of studies offers new insight into the drivers of isotopic discrimination and provides strategies for mitigating the growing ethical considerations associated with lethal sampling for stable isotope analysis. The distribution of energy within food webs presents a core component of fish community dynamics, yet it is unclear how this may be influenced by environmental characteristics such as seasonality and habitat type. Two papers in this collection aim to assess how environmental characteristics modulate energetic assembly in diverse fish communities. Cobain et al. (2024) assess the temporal stability of benthic-pelagic coupling across a diverse estuarine fish community sampled at a monthly resolution. Sulfur isotope values (δ34S) suggested remarkable consistency in benthic-pelagic coupling by benthic and benthopelagic fishes throughout the year, with larger individuals utilizing greater amounts of benthic energy. Monthly δ13C and δ15N values tracked seasonal pulses in productivity and nutrient dynamics associated with the onset and end of the spring bloom. Hayden et al. (2024) examine how energetic assembly across 15 species of reef fishes is governed by the use of cryptobenthic, epibenthic sand, epibenthic rock, and hyperbenthic microhabitats in Adriatic fish communities. They observed high niche segregation between species within each microhabitat, suggesting that microhabitat complexity may promote functional diversity within reef fish communities. Combined, these studies illustrate the utility of stable isotopes for inferring the drivers of energetic assembly in structurally complex ecosystems, such as temperate estuaries and reefs. Human activities and global climate change have been altering ecological communities for decades. Yet, the associated effects of environmental disturbance on the functional roles of fishes and their fitness remain poorly described for many species. Three articles in this issue address this topic through quantifying the implications of anthropogenically driven environmental disturbance on diet, habitat use, and fitness in both freshwater and marine fishes. Ripku et al. (2024) tackle concerns associated with silver nanoparticle pollution (AgNP) on benthic-pelagic coupling by yellow perch and northern pike in freshwater lakes. AgNPs are common antibacterial and anti-odor agents used in many textiles that enter aquatic ecosystems through wastewater effluent and elicit negative impacts on the productivity of benthic periphyton. Implementing Bayesian mixing models, the authors observe a 32% (P. flavescens) and 40% (E. lucius) decline in the contribution of benthic energy following AgNP introduction, illustrating how anthropogenic pollutants can drastically impact benthic-pelagic coupling facilitated by lake fishes. Two papers examine direct links between environmental variation, foraging, and fitness through integrating stable isotopes with body condition measurements. Scharnweber et al. (2024) employ hydrogen stable isotopes (δ2H) to assess the implications of iron oxide pollution associated with historical lignite mines on relative use of aquatic versus terrestrial insects by common bleak (Alburnus alburnus). Bleak residing in river areas associated with high iron oxide pollution exhibited greater reliance on terrestrial insects, which resulted in lower body condition. Feeney et al. (2024) compared body condition of Atlantic salmon (Salmo salar) with δ13C and δ15N values of scales that reflect the last season of growth prior to returning to natal rivers. Higher δ13C and lower δ15N values were associated with better body condition, suggesting that temperature and foraging variation may impact body condition, and potentially reproductive fitness and survival. Given the high dispersal capabilities of Atlantic salmon, these findings suggest that spatially proximate natal populations could elicit varied responses to ocean warming dictated by their previous foraging location and associated temperature regimes. Combined, these studies illustrate how environmental variation and human activity can impact the foraging dynamics of fishes and their associated functional roles with direct implications for fitness. The continued advancement in analytical technology and mass resolving power has increased the accessibility of non-traditional isotope systems to fish biologists, such as Calcium (Martin et al., 2015) and Zinc (δ66Zn; McCormack et al., 2022). Assemat et al. (2024) expand the application of calcium stable isotope analysis to modern shark tooth enamel, revealing distinct δ44/42Ca values of shortfin mako sharks (Isurus oxyrinchus), bluntnose sixgill sharks (Hexanchus griseus), and white sharks (Carcharodon carcharias), indicative of ontogenetic dietary preference and spatial variation in foraging. Given that tooth enamel can be extremely well preserved in the geologic record, continued application of δ44/42Ca holds great promise for uncovering the functional roles of many ancient fish lineages. The sustained evolution of isotopic tools offers an exciting future for fish biologists. Given the broad utility of isotopic approaches, we predict that studies will continue to exponentially increase and diversify in their applications. This will continue to expand ecological and physiological insights imperative for the management and conservation of global fish populations. Studies of global relevance are now supported by the development of new centralized repositories, such as IsoBank (www.isobank.org), thereby expanding collaborative efforts and the diversity of questions that can be pursued.

Design, development, and implementation of IsoBank: A centralized repository for isotopic data

PLoS ONE · 2024-09-06 · 14 citations

Stable isotope data have made pivotal contributions to nearly every discipline of the physical and natural sciences. As the generation and application of stable isotope data continues to grow exponentially, so does the need for a unifying data repository to improve accessibility and promote collaborative engagement. This paper provides an overview of the design, development, and implementation of IsoBank (www.isobank.org), a community-driven initiative to create an open-access repository for stable isotope data implemented online in 2021. A central goal of IsoBank is to provide a web-accessible database supporting interdisciplinary stable isotope research and educational opportunities. To achieve this goal, we convened a multi-disciplinary group of over 40 analytical experts, stable isotope researchers, database managers, and web developers to collaboratively design the database. This paper outlines the main features of IsoBank and provides a focused description of the core metadata structure. We present plans for future database and tool development and engagement across the scientific community. These efforts will help facilitate interdisciplinary collaboration among the many users of stable isotopic data while also offering useful data resources and standardization of metadata reporting across eco-geoinformatics landscapes.

Depth Range Extension for the Misty Grouper Hyporthodus mystacinus Documented via Deep-Sea Landers throughout the Greater Caribbean

Fishes · 2024-03-22 · 7 citations

Misty Groupers (Hyporthodus mystacinus) are one of the largest and most geographically widespread grouper species and one of the few grouper species known to occur at depths greater than 200 m. However, aspects of their basic biology, behavior, and ecology remain poorly understood, leaving significant gaps in our ability to evaluate their functional role throughout the vertical water column, as well as our understanding of their conservation needs in a changing ocean. Through in-situ video observation obtained using deep-sea landers in both The Bahamas and Cayman Islands over multiple years, we documented Misty Grouper occurrence up to 470 m depth in the mesopelagic zone. These observations provide a new depth range extension for the species and illuminate the potential importance of deep-water habitats for large grouper species in the wider Caribbean.

Accumulation of Per- and Polyfluoroalkyl Substances (PFAS) in Coastal Sharks from Contrasting Marine Environments: The New York Bight and The Bahamas

Environmental Science & Technology · 2024-07-12 · 24 citations

Per- and polyfluoroalkyl substances (PFAS) enter the marine food web, accumulate in organisms, and potentially have adverse effects on predators and consumers of seafood. However, evaluations of PFAS in meso-to-apex predators, like sharks, are scarce. This study investigated PFAS occurrence in five shark species from two marine ecosystems with contrasting relative human population densities, the New York Bight (NYB) and the coastal waters of The Bahamas archipelago. The total detected PFAS (∑PFAS) concentrations in muscle tissue ranged from 1.10 to 58.5 ng g–1 wet weight, and perfluorocarboxylic acids (PFCAs) were dominant. Fewer PFAS were detected in Caribbean reef sharks (Carcharhinus perezi) from The Bahamas, and concentrations of those detected were, on average, ∼79% lower than in the NYB sharks. In the NYB, ∑PFAS concentrations followed: common thresher (Alopias vulpinus) > shortfin mako (Isurus oxyrinchus) > sandbar (Carcharhinus plumbeus) > smooth dogfish (Mustelus canis). PFAS precursors/intermediates, such as 2H,2H,3H,3H-perfluorodecanoic acid and perfluorooctanesulfonamide, were only detected in the NYB sharks, suggesting higher ambient concentrations and diversity of PFAS sources in this region. Ultralong-chain PFAS (C ≥ 10) were positively correlated with nitrogen isotope values (δ15N) and total mercury in some species. Our results provide some of the first baseline information on PFAS concentrations in shark species from the northwest Atlantic Ocean, and correlations between PFAS, stable isotopes, and mercury further contextualize the drivers of PFAS occurrence.

Absence of a functional gut microbiome impairs host amino acid metabolism in the Pacific spiny dogfish (<i>Squalus suckleyi</i>)

Journal of Experimental Biology · 2024-08-02 · 5 citations

Nitrogen recycling and amino acid synthesis are two notable ways in which the gut microbiome can contribute to host metabolism, and these processes are especially important in nitrogen-limited animals. Marine elasmobranchs are nitrogen limited as they require substantial amounts of this element to support urea-based osmoregulation. However, following antibiotic-induced depletion of the gut microbiome, elasmobranchs are known to experience a significant decline in circulating urea and employ compensatory nitrogen conservation strategies such as reduced urea and ammonia excretion. We hypothesized that the elasmobranch gut microbiome transforms dietary and recycled nutrients into amino acids, supporting host carbon and nitrogen balance. Here, using stable isotope analyses, we found that depleting the gut microbiome of Pacific spiny dogfish (Squalus suckleyi) resulted in a significant reduction to the incorporation of supplemented dietary 15N into plasma amino acids, notably those linked to nitrogen handling and energy metabolism, but had no effect on gut amino acid transport. These results demonstrate the importance of gut microbes to host amino acid pools and the unique nitrogen handling strategy of marine elasmobranchs. More broadly, these results elucidate how the gut microbiome contributes to organismal homeostasis, which is likely a ubiquitous phenomenon across animal populations.

Carbon and nitrogen isotopes of lizardfish provide insight into regional patterns of ocean biogeochemistry across the eastern continental United States

Marine Biology · 2024-06-19

An integrated multi-source dataset of elasmobranchs in the Red Sea following the Red Sea Decade Expedition

Scientific Data · 2024-12-23 · 3 citations

Red Sea elasmobranch populations are facing alarming declines. Effective conservation efforts require management strategies informed by extensive datasets and by developing an understanding of distribution patterns within the basin, which is currently lacking. This study introduces CERSE (Central and Eastern Red Sea Elasmobranchs), a comprehensive compilation of elasmobranch observations in the central and eastern Red Sea basin following the route of the Red Sea Decade Expedition. The data set was curated from surveys conducted during two scientific cruises, a time-series survey within Red Sea Global project areas (Tabuk province), and observations extracted from peer-reviewed literature. Through the use of diverse methodologies, we provide a holistic view of elasmobranchs distribution in the region, for a total of 2,847 sightings recorded. By consolidating dispersed information from across the region, this dataset forms a comprehensive foundation for future research and monitoring endeavors focused on elasmobranch fauna, and will serve as a cornerstone for informing targeted conservation initiatives aimed at safeguarding endangered elasmobranch species in this region.

A new species of deep-sea Booralana Bruce, 1986 (Crustacea: Isopoda: Cirolanidae) from The Bahamas, Western North Atlantic

Zootaxa · 2024-01-11 · 2 citations

Booralana nickorum sp. nov. is described from the deep-water slope of the Exuma Sound, The Bahamas, from depths of 540 to 560 metres. It is the fourth species to be assigned to the genus and the second species described from the Western North Atlantic. The species can be distinguished from Booralana tricarinata Camp and Heard, 1988 and the other species by the sub-triangular pleotelson and the uropodal exopod of mature males being far longer than endopod, with both rami extending well beyond the posterior margin of the pleotelson. Additionally, pleopods 3 and 4 lack a prominent angle at midpoint of ramus.