Stenodus Leucichthys Research Articles

Archaeozoology Supports a Holistic View on Fish Assessments in Large Rivers—A Case Study from the Volga River: From Quantitative Data and Ancient DNA to Biodiversity Analysis

Knowledge of the historical and present dynamics of populations of migratory fish can promote our understanding of factors affecting their recruitment and abundance. Taxonomic identification of 23,802 bone remains and 13,539 scales of fish from 30 archaeological sites along Volga River revealed that they belonged to 41 different fish species. These data allow for retrospective comparisons and highlight the potential of archaeozoology in conservation biology. Sturgeons and salmonids are vulnerable to the impacts of fishery and climatic change. The sharp decline in the numbers of Starry sturgeon (Acipenser stellatus), Caspian trout (Salmo caspius), and Caspian Inconnu (Stenodus leucichthys) from the Volga in the 17th and 18th centuries was likely related to a cooling period (“Little Ice Age”). At present, the population numbers of all anadromous sturgeons and salmonids of the Volga River are critically low. In the Volga basin over the past two millennia, the sterlet (Acipenser ruthenus) has had a very large population number, high genetic (haplogroups and haplotypes) diversity, and large body sizes. Genetic analysis (aDNA and eDNA) have great potential to expand the knowledge of fish populations along large rivers and to improve long-term biomonitoring. Therefore, analyses of historical data, conventional surveys, as well as the inclusion of genetic approaches complement each other in the development of effective conservation strategies.

Investigation of ice particle formation points during fish sperm cryopreservation

This study was conducted in order to investigate of the points of formation of ice particles during cooling of fish sperm. The object of the study was spermatozoa of the Russian sturgeon (Acipenser gueldenstaedtii Brandt, 1833), hybrid Acipenser ruthenus × Huso huso, the spiny-tailed sturgeon Acipenser nudiventris Lovetsky, 1828, and the inconnu Stenodus leucichthys Güldenstädt, 1772. The growth of ice microparticles is formed at the perturbation temperature of the corresponding aqueous suspension, with the concentration of dissolved substances increasing in the non-freezing phase. The process of ice formation and the increase concentration of the remaining liquid continues as it cools to form amorphous (glassy) ice. It is interesting to bring the mass of ice with a further decrease in temperature to (-196) ° C. Cooling causes compression of the formed ice crystals.

A Rapid and Simple Procedure for the Isolation of Embryonic Cells from Fish Eggs.

Fertilized teleost fish eggs are a complex formation, in which dividing cells are located in a small point in the entire volume of eggs. Isolating embryonic cells can be considered a necessary step in the research of developmental peculiarities of fish cells at the earliest stages of embryogenesis before embryo formation. The main advantages of the offered protocol are rapid isolation, no enzymes, and overall low cost compared to other protocols. The protocol is suitable for the isolation of embryonic cells from medium-sized eggs at the stages of blastula or gastrula, for studies in a variety of applications (e.g., microscopy, flow cytometry, and other methods). Fertilized nelma eggs (Stenodus leucichthys nelma) are used in the protocol as a model. Key features • Fast and cheap isolation of cells from fish eggs at early stages (blastula or gastrula). • Applicable for most of the methods for cell study (any staining, microscopy, flow cytometry, etc.). • Can be applied to other teleost fish eggs with medium egg diameter of 3-4 mm. Graphical overview.

Обзор данных по биологии нельмы Stenodus leucichthys nelma (Pallas, 1773)

Nelma (Stenodus leucichthys nelma (Pallas, 1773)) is one of the biggest predators and a prominent representative of the whitefish family. It is a poorly studied valuable commercial species. The rate of growth and sexual maturation of this fish is very high compared to other whitefishes. Within the vast range of white salmon populations living in different geographical zones there can be found variability in meristic and size-weight characteristics. There are also differences in the time of sexual maturity of species in different rivers. Some negative limiting factors impact the nelma populations: pollution of water bodies, poaching, and transformation of the flows of large rivers (building the hydroelectric power stations, reservoirs, etc.). There have been presented the review of the published literature on nelma biology and the data of the proper research. Comparative analysis of the meristic, size-weight and physiological characteristics of nelma populations from different rivers within the geographical range has been made. From the review of available literary sources it follows that today the populations of nelma are characterized by a radical decline and rejuvenation of the spawning stock in almost all rivers of its habitat. There is found reducing the spawning areas of the species due to the regulation of the flows of large rivers. Studying biology and ecology of nelma as a valuable and endangered species is important today.

Распространение и миграционный цикл нельмы Stenodus leucichthys nelma (Pallas, 1773)

The article considers the natural habitat and migrations of nelma Stenodus leucichthys nelma (Pallas, 1773) on the basis of literary sources. This fish is a subspecies of white salmon. It belongs to the genus of nelma of the whitefish family and is of great interest for researchers, as nelma is one of the most valuable commercial objects. According to the result of analysis and data systematization, nelma is found to migrate to all major rivers flowing into the Arctic Ocean. In the rivers and lakes under consideration it is represented by the semi-anadromous species, as well as non-migratory river and lake species. The hydrological description of the reservoir has a huge influence on nelma’s migrations and biotopes. Data on the anthropogenic factor influence on the migration of this subspecies are also given. It has been stated that the construction of hydroelectric power stations, building the reservoirs and regulation of river flows negatively affect this biological complex phenomenon. After blocking some large rivers by hydroelectric dams many populations of the Ob and Yenisei nelma were deprived of their natural habitat, the duration and extent of migrations were reduced, and non-migratory (residential) stocks developed in the upper reaches of the Ob, the Yenisei and the reservoirs. Due to the human intervention in the natural processes of fish development and reproduction, the stocks of valuable commercial species have been greatly reduced. Thus, this factor has brought in the significant changes in the life cycle of nelma. In general, it can be inferred that nelma migrations in individual water bodies have not been studied enough and require detailed consideration in order to protect and preserve this rare subspecies of the whitefish family.

The Fate of the Yolk Syncytial Layer during Postembryonic Development of Stenodus leucichthys nelma

The yolk syncytial layer (YSL) is a multifunctional transient structure of teleost embryos and larvae. The YSL performs nutritional, morphogenetic and immune functions. However, the data on the YSL structure in different teleost species is fragmented. We aimed to characterize YSL of the postembryonic inconnu (Stenodus leucichthys nelma) along with the depletion of maternal reserves by analyzing serial histological sections. At hatching, the yolk complex was located anterior to the liver and contained a large oil globule (OG) in the front region, 1–2 additional OG, and the yolk itself. The YSL region around the OG was striated, the region surrounding the yolk was regionalized in an apico-basal direction. The yolk syncytial nuclei (YSN) were large and complex-shaped. The yolk was exhausted by approximately the 17th day post hatching (dph). One–two large OG remained in the yolk complex until the programmed death of the YSL at 31 dph. The organization of the larval yolk complex of the inconnu was typical for Coregonidae. The abundance of comet-shaped YSN was its peculiarity.

INVASION OF FISH BY LARVAE OF THE FAMILY DIPHYLLOBOTHRIIDAE IN THE KHANTY-MANSI AUTONOMOUS OKRUG – YUGRA

Two epidemiologically significant species of the tapeworm (D. latum и D. dendriticum) circulate in of the Ob-Irtysh basin within the Khanty-Mansi Autonomous Okrug. They have an unequal effect on the human body. The purpose of the science work is to determine the invasion of fish by larvae of tapeworms D.latum and D.dendriticum (Perch Perca fluviatilis, Ruff Gymnocephalus cernuus, Pike Esox lucius, Syrok Coregonus peled, Muksun Coregonus muksun, Nelma Stenodus leucichthys nelma) from waterbodies of the Ob River and its tributaries from 2013 to 2019 year. The study aim is to identify the main factors of transmission of the invasion (diphyllobothriasis) to population. The fish for parasitological research and species identification was caught in the Ob River and its tributary, the Vakh River, as well as Torm-Emtor Lake. The studies were carried out in the parasitological laboratory of the Center for Hygiene and Epidemiology in the Khanty-Mansi Autonomous Okrug – Yugra, Nizhnevartovsk, the Nizhnevartovsk District, in Megione and Raduzhny by the method of incomplete helminthological study of fish. The study results found in general a very high level of plerocercoid invasion of fish from the Ob and Vakh Rivers. It was noted that the pike had a significantly high percentage of infection with D. latum, 71.64%. The highest intensity of invasion and localization of larvae (the family Diphyllobothriidae) was on the abdominal wall of the fish, and then on walls and in the thickness of walls of esophagus and stomach, in eggs, and very few in muscle tissues.

Genetic Assessment of Inconnu (Stenodus leucichthys) in Great Slave Lake, Northwest Territories, Canada

Inconnu (Stenodus leucichthys) is a large freshwater migratory coregonid species that is commercially fished in some parts of its range. In Great Slave Lake, NT, Inconnu are one species that is caught in a mixed species gillnet fishery that is subject to restrictive management because four of the seven known stocks are declining or have been extirpated. The seven known Inconnu stocks have been identified based on the river systems that support or once supported a spawning population. To help identify key geographic areas for harvest control and other management approaches, we estimated the genetic diversity and population genetic structure of Inconnu in this area with 17 microsatellite loci. Temporal and spatial genetic structure was examined in four river systems, lower and upper Mackenzie River, Buffalo River, Slave River and Marian River/Lake and within Great Slave Lake. Analyses suggested that genetic diversity was greater in lower/upper Mackenzie River populations compared to populations in Great Slave Lake. Genetic structure was temporally stable at all locations except one, and spatial structure was found with significant isolation by distance detected among locations. Bayesian clustering analysis suggested five genetic groups of Inconnu, one in the lower and upper Mackenzie River and four within Great Slave Lake. The substructuring within Great Slave Lake included a genetic group representing fish collected in the lake itself. In addition, three genetic groups corresponded to river systems (Buffalo River, Marian River/Lake, Slave River), indicating that each river has genetically distinct Inconnu populations. These results suggest that the sustainability of Inconnu in and around Great Slave Lake depends upon maintaining stocks associated with river systems, especially those that are geographically disparate.

Aннотированный список рыбообразных и рыб водоемов и водотоков бассейна верхнего Иртыша Восточного Казахстана с комментариями по их таксономии и зоогеографии

Приводится список рыбообразных и рыб, обитающих в водоемах и водотоках бассейна Верхнего Иртыша. Список содержит 43 вида, относящихся к 7 отрядам, 10 семействам и 30 родам. Включены все зарегистрированные на настоящий момент виды, валидность которых была пересмотрена в соответствующих систематических ревизиях. Три вида таймень Hucho taimen Pallas, 1773, нельма Stenodus leucichtys nelma Pallas, 1773, сибирский осетр Acipenser baerii Brandt, 1869 внесены в Красную Книгу Республики Казахстан. В бассейне Верхнего Иртыша к редким ценным видам, нуждающимся в сохранении генофонда из-за возможности его утраты, кроме уже внесенных в Красную Книгу Республики Казахстан можно отнести еще ряд видов: минога тихоокеанская Lethenteron camtschaticum Tilesius, 1811, стерлядь Acipenser ruthenus Linnaeus, 1758 маркакольский ленок Brachymystax savinovi Mitrofanov 1959.

Contributions to the Life History of Kuskokwim River Inconnu

AbstractA radiotelemetry study conducted during 2007–2016 in the Kuskokwim River drainage in Alaska expands our understanding of the life history strategies of Inconnu Stenodus leucichthys. The Inconnu like other whitefish species has specific spawning habitat requirements and consequently spawn in very few areas. Documenting specific spawning, feeding, and overwintering areas is the necessary first step to ensure their habitats are protected. Four spawning areas in the upper Kuskokwim River were identified from radio‐tracking and verified with on‐site sampling. Inconnu arrived at their spawning areas during late July through mid‐September and spawned during late September through early October. Postspawning outmigration occurred during 1–1.5 weeks in mid‐October. Most radio‐tagged Inconnu made extensive postspawning downriver migrations and overwintered in the lower Kuskokwim River and in the brackish waters of the upper Kuskokwim Bay; however, some Inconnu made only short postspawning migrations and spent the winter in the middle and upper Kuskokwim River. After spring ice out, many fish that overwintered in the lower river swam upriver and spent summers feeding at the mouths of major tributaries. A high degree of site fidelity among years was observed for spawning, feeding, and overwintering areas. Habitat characteristics of spawning areas were similar with respect to spawning substrate, temperature, pH, conductivity, dissolved oxygen, and turbidity. Information gathered from this study can be used by to identify a reliable index stock for the spawning population that can be enumerated periodically to ensure the long‐term sustainability of the population.

ПРИМЕНЕНИЕ ГЛИЦЕРИНА ДЛЯ КРИОКОНСЕРВАЦИИ СПЕРМЫ БЕЛОРЫБИЦЫ

The article studies the possibility to use glycerol as cryoprotectant, instead of dimethylsulfoxide for cryopreservation of sperm of inconnu ( Stenodus leucichthys Gueldenstaedtii, 1772). Investigations were carried out from 2015 to 2016 in the laboratory of the Southern Scientific Center, Russian Academy of Sciences, on the basis of the Astrakhan State Technical University. The material collected on the Alexander sturgeon hatcheries (the Astrakhan region) in the spawning period. Native sperm of 6 male inconnu species was used as a control means. The semen quality was determined in terms of moving activity (life time) of sperm after its activation by water. As the cryoprotectant there were used: base solution - 80%, sucrose - 1.71 g/l, mannite - 0.98 g/l, yolk - 10%, dimethylsulfoxide - 10% and base solution - 87%, sucrose - 1.71% g/l, mannite - 0.98 g/l, yolk - 10%, glycerol - 3 variants: 3; 5 and 10%. In order to provide the most complete penetration of cryoprotectants into the cells there were used electrostimulation of cell membranes. Equilibration time was 5 and 15 minutes. Thawing semen was performed in a water bath at a temperature of 38-40°C. For removing protectors from cells there was chosen a saline solution (0.7% NaCl) as isotonic solution. In tests using dimethylsulfoxide life activity of sex cells was 2 times lower than in tests with glycerol: 78 and 186.2 s at the end of equilibration and 52.3 and 128.9 s after thawing. Sperm showed maximum activity under 5% glycerol concentration during equilibration - 15 min. Concentration of 3% was insufficient, concentration of 10% was excessive, as it suppressed activity of sperm. Egg yolk which coagulated together with glycerol, making difficulty for observing, had to be excluded from the composition of cryoprotectant.

Variation in bioaccumulation of persistent organic pollutants based on octanol–air partitioning: Influence of respiratory elimination in marine species

Risk assessments of persistent organic pollutants (POPs) are often based on octanol–water (KOW) partitioning dynamics and may not adequately reflect bioaccumulation in air-breathing organisms. It has been suggested that compounds with low KOW and high octanol–air partitioning (KOA) coefficients have the potential to bioaccumulate in air-breathing organisms, including marine mammals. Here we evaluate differences in concentrations of POPs for two trophically matched Arctic species, spotted seal (Phoca largha) and sheefish (Stenodus leucichthys). We compared concentrations of 108 POPs in matched tissues (liver and muscle) across three ranges of KOW. We found a significant positive correlation between POP concentration and log KOA in spotted seal tissues for low log KOW compounds (log KOW <5.5, p<0.05). This provides further evidence for empirical models and observed bioaccumulation patterns in air-breathing organisms, and highlights the potential for bioaccumulation of these compounds in Arctic marine mammals.

Seasonal Movement Patterns of Inconnu in an Arctic Estuary Delta Complex

AbstractInconnu Stenodus leucichthys are a large, long‐lived, piscivorous whitefish harvested in subsistence and sport fisheries in Alaska. In the Kotzebue region of northwestern Alaska, Inconnu are one of the most important food fishes, with 20,000+ fish being harvested each year. This study was conducted to describe the summer and winter distribution of Inconnu from the Hotham Inlet–Selawik Lake delta complex, Alaska, between 2010 and 2012. Data collection methods consisted of surgically implanting acoustic telemetry tags in 80 fish from both the Selawik and Kobuk rivers in 2010 and 2011 (n = 320 total) and deploying a fixed array of 20 acoustic receiving stations throughout Selawik Lake and Hotham Inlet. Tagged Inconnu detections revealed that individuals from the Selawik and Kobuk rivers displayed a high degree of spatial and temporal overlap while colocated in the Hotham Inlet–Selawik Lake complex during both sampling years. During the winter period, tagged fish from both rivers predominately occupied the northern end of Hotham Inlet. In the summer period, fish moved between the northern end of Hotham Inlet to Selawik Lake and the southern end of Hotham Inlet. Average daily displacements for Selawik and Kobuk River Inconnu ranged from 2,000–10,000 m/d. As well as providing a more complete account of Inconnu life history, these results provide useful data that can be used for developing future management strategies, such as the appropriateness of stock‐specific harvest guidelines and spatial and temporal regulations.Received January 12, 2015; accepted May 6, 2015

Mixed-stock Inconnu Stenodus leucichthys habitat use in an Arctic estuarine delta complex

Inconnu Stenodus leucichthys is a large, long-lived piscivorous whitefish found in the Arctic and subarctic waters of Alaska. In the Kotzebue region of northwestern Alaska, Inconnu is one of the most important fishes harvested for subsistence purposes. With ongoing climate change, it is important to understand how a changing environment will affect Inconnu habitat use. This study described the habitat use of Inconnu in the Hotham Inlet/Selawik Lake complex from 2010 to 2012. Data collection consisted of surgically implanting acoustic telemetry tags in 80 fish from both rivers in 2010 and 2011 (n = 320), and deploying a fixed array of 20 Vemco VR2W acoustic receiving stations affixed with archival tags throughout the study area. Inconnu were detected at water temperatures and salinities ranging from −1.39 to 23.51 °C and 0 to 31.3 psu, respectively, and there was no detection of stock-specific or temporal trends in habitat use. Fish occupied colder water temperatures (−0.5 to 0.5 °C) during winter and primarily occupied the upper (15 °C) and lower (0 °C) ends of the temperature spectrum during summer. Although Inconnu occupied the entire range of salinities available during summer and winter months, they generally occupied waters of 5 to 20 psu. By providing a more thorough account of Inconnu habitat use, our results contribute baseline data for future comparisons to evaluate effects from climate-induced changes to Inconnu sustainability.

English

The authors investigated the growth of straminipilous organisms on the eggs of inconnu (Stenodus leucichthys) and nelma (Stenodus nelma) in water from three different eutrophication levels. Thirty (30) straminipilous species were found growing on the investigated eggs (of both fish species) used as baits. The majority of species has been found on the eggs of inconnu (20) in comparison with those found on the eggs of nelma (15). The highest number of infected eggs of both investigated species has been observed also in the water from Biała river (27.3% of the inconnu and 21.6% of the nelma; the most eutrophication), the smallest in water from Supraśl River (6.3 and 8.8% respectively; the less eutrophication). These differences for both species were statistically significant. Amino acid, carbohydrate and urease tests were used. &nbsp; Key words: Inconnu, Stenodus leucichthys, nelma, Stenodus nelma, fish eggs, straminipilous organisms, eutrophication.

Long-Distance Migrations by Inconnu (&lt;i&gt;Stenodus leucichthys&lt;/i&gt;) in the Mackenzie River Syste

Inconnu (Stenodus leucichthys) stocks of the Mackenzie River drainage exhibit complex life histories. In a single stock, some fish may make occasional or regular movements between freshwater and marine environments while others lead a completely freshwater existence. Many inconnu migrate between the Mackenzie River system and the Beaufort Sea, but during spawning migrations, most are believed to move only as far south as the Rampart Rapids near the community of Fort Good Hope. However, an inconnu tagged in the Liard River in northern British Columbia in 2001 was recaptured near Inuvik (Northwest Territories) in 2002, and a second inconnu tagged in the Liard River in 2002 was recaptured near Tuktoyaktuk (Northwest Territories) in 2003. These two fish exhibited some of the longest freshwater migrations by a species from Canadian waters other than Pacific salmon. Otolith strontium distributions of these two fish confirmed migrations of close to 1800 km between fresh and marine waters and indicated different life histories. Additional inconnu tagged in the Liard River in 2002 were recaptured in or near Great Slave Lake in 2002 and 2003. The movements of all these fish suggest that the management of inconnu stocks will be far more complicated than previously thought: they point out the need for management plans and protection that incorporate large geographic areas.

Species composition of fish from archeological site Ust’-Haita (Belaya River – tributary of Angara River)

Baikal has passed through different climatic epochs in its evolution. This is reflected in the structure of its ichthyofauna, which includes species of different faunistic complexes. Of significant interest is the comparison of ichthyofaunas in the northern rivers and especially between the Angara River and Lake Baikal, which have been connected for a long time. Studies of fish bone remains from the archeological sites with Mesolithic layers (6–8 Ky) at the upper parts of the Angara River (the Belaya River, Verholenskaya Mountain) has been carried out in most detail by Tzepkin (1976), based on large specimens of: Acipeser baeri, Hucho taimen, Esox lucius, Lota lota, and also Perca fluviatilis and Cyprinidae. At lower parts of the river (Pashino Settlement) Aciperser ruthenus and Stenodus leucichthys nelma were also studied. Coregonus lavaretus are observed in the upper reaches of the river, but Tzepkin’s review (1995) does not include them, or Thymallus arcticus, among the ancient commercial ichthyofauna of the Angara River. In 1996, N.A. Savel’ev and E.S. Igumnova found a great deal of archeological material (Savel’ev et al., 2001) at Ust’-Haita site (high flood-lands on the right bank of the Haita River, a tributary of the Belaya River) near Mishelevka Settlement. Scales of one fish species predominated in fish remains in layers 5a and 6; in layers 7 and 8 skeleton fragments were chiefly of large fish heads. The material included fragments of Cyprinidae skeletons and perch, Perca fluviatilis only rarely. In total, ten fish species and a Cyprinidae group were identified, among which Thymallus arcticus, Coregonus lavaretus, Esox lucius, Lota lota and Hucho taimen predominated. Good preservation of the material allowed the authors to define fish age and their catching terms. Quantitative ratios of scales to skeletons (more than 95%) at the archeological sites on the Belaya River, as well as in all archeological sites on territory of the former USSR, were demonstrated for the first time.

Age determination of a long-lived coregonid from the Canadian North: comparison of otoliths, fin rays and scales in inconnu (Stenodus leucichthys)

We examined otoliths, pelvic fin rays and scales of inconnu to determine precision of age estimates within and between readers, and to compare relative accuracy of estimates from different structures. Our main objective was to determine if readability and estimates from fin rays and scales, which can be non-lethally removed, were similar to those of otoliths, which are generally considered the most reliable ageing structure. Among- and within-reader variation was low for both fin rays and otoliths, but higher for scales. Variation tended to increase with fish length for all structures. Scales were most difficult to read and had age estimates that were significantly lower than the other structures at ages of ten years and greater. Age estimates and readability of fin rays and otoliths were similar.

Abundance, Length Composition, and Migration of Spawning Inconnu in the Selawik River, Alaska

Abstract Inconnus Stenodus leucichthys in the Selawik River, Alaska, were sampled during spawning migrations in the years 1993–1996. Modified Petersen estimates of spawning inconnu were 5,190 (95% confidence interval = 3,690–7,272) for 1995 and 5,157 (3,038–12,983) for 1996. Fork lengths of migrating fish ranged from 52 to 120 cm. Minor differences in length-frequency distributions were observed among the 3 years sampled. Migrating inconnu reached holding areas 25 km below the spawning area in the first week of July and resided there for up to 1 month. Further upstream movement in late August was associated with precipitation. A short reach of river, approximately 12 km long, was identified as the spawning area by use of radiotelemetry. Postspawning migrations occurred as early as September 27 and were completed by October 19. Dispersal during the winter, as measured by tag returns, showed mixing with Kobuk River inconnu within the Selawik Lake–Hotham Inlet complex. Lack of observed interdrainage migratio...

Elemental distribution within polymorphic inconnu (Stenodus leucichthys) otoliths is affected by crystal structure

The chemistry and crystal structure of sagittal otoliths from inconnu (Stenodus leucichthys) were examined optically, with an electron microprobe, a scanning electron microscope, and with X-ray diffraction techniques. The distributions of strontium (Sr), sodium (Na), potassium (K), and calcium (Ca) were determined with line scans and area maps of thin, transverse otolith sections. Regions depleted in Sr, Na, and K were found to be discordant with optical annuli and were optically distinct from other regions of the otoliths. These patterns of trace element depletion cannot be explained by models of otolith growth that are based on ionic composition of endolymph fluids as the sole control of otolith composition. Electron micrographs showed the depleted regions of the otoliths to be of a different crystal structure than other regions of the otoliths. X-ray diffraction analyses revealed the presence of vaterite in otoliths with depleted regions, while otoliths without depleted regions showed no evidence of vaterite. The depleted areas may be composed of vaterite, and the crystal structure of vaterite may prevent certain trace elements from incorporating in the otolith. Scientists using fish otolith chemistry to infer environmental conditions or life history should be aware that elemental abundance within otoliths may be affected by other processes as well.