Fish Transport Research Articles

Effectivness of giving clove oil as an anaesthetic for survival rate and number of leucocytes in cantang grouper (Epinephelus sp.) in the closed transportation

Cantang groupers is one of fish commodities that have high economic value. Live fish transport has several problems for fish and one of the problem is stress in fish. Many stressors can cause mortality of fish if the fish body can not tolerate it. One way that can be used to reduce stress on fish which can increase the value of survival and decrease leucocytess during the transport is giving clove oil as an anaesthetic. This study aim to determine the effect of clove oil as an anesthetic substance on the survival rate (SR) and number of leucocytes in cantang grouper (Ephinephelus sp.) in the closed transport. The method is an experimental method with a completely randomized design (CRD), with five treatments and three replications. The main parameters observed were survival rate and leucocytes of cantang groupers. The data obtained will be analyzed using ANOVA followed by Duncan’s Multiple Range Test. The results showed that administration of clove oil as an anesthetic may improve the survival rate and lower the number of leucocytes of cantang grouper, after the closed transport for 10 hours. The highest survival rate is 86,67% and the Leucocytes is 2,35×104 cell/mm3 with 10ppm of clove oil dosage.

Fish in the desert: Identifying fish trade routes and the role of Red Sea parrotfish (Scaridae) during the Byzantine and Early Islamic periods

Recent archaeological excavations in the Negev desert of the southern Levant have yielded a surprising and unprecedented amount of fish remains, found in the landfills at Byzantine (4th–7th century CE) and Early Islamic (7th–9th century CE) sites. The significant economic and dietary role of Red Sea fish, especially parrotfish (Scaridae), in addition to fish originating from freshwater habitats, including the Nile, as well as from the Mediterranean Sea, attest to the importance of fish in sophisticated trade networks, which facilitated the transport of fish from different aquatic habitats to the distant provinces. The discovery of Red Sea parrotfish at all three studied sites is of particular interest. Analysis of the Scaridae remains revealed their role as a flagship species of the Red Sea coral-reef fishery and as an essential commodity in the Byzantine and Early Islamic economic systems; as well as the presence of more than one Scaridae species. The study of skeletal element representation indicated that complete fish, larger than 23 cm in length (SL), were transported to the sites. The bone fragmentation patterns reflected typical traditional butchering during the desiccation processes. The fish remains recovered from the desert provide new insights into the infrastructure of commercial networks that enabled the transport of fish over long distances during periods of high demand for fish products.

Fish Availability and Market Channel in Rajbari, Bangladesh: A Case Study in Sadar Sub-District Markets

The study of fisheries marketing channel and market margins is a useful tool for market management and a crucial system for creating an effective and well-planned marketing strategy. The aim of the research is to know about the fish marketing channel, marketing margins, fish availability and difficulties related fish marketing system in three fish markets of Rajbari, Bangladesh from June to December 2019. Here, data were collected through questionnaire surveys, focus group discussions and field visits. A total of 109 species of fish and shellfish were available in the fish market. Perciformes (28.97% of total fishes) were the most dominant followed by Cypriniformes (23.37%), Siluriformes (19.63%), Clupeiformes (7.48%) and Decapoda (7.48%). A total of 19 species of processed fish were available including dried (77.77% of total processed fishes), salted (16.67%) and fermented (5.56%) that arrived from Dhaka and Chattogram. The price of fish and processed fish depends on consumer demand, availability, season, storage facilities and marketing channel. The length of marketing channel of freshwater fishes was comparatively shorter such: fisherman or farmer – auctioneer – wholesaler – retailer – consumer. Marine fishes arrived from other places like Khulna, Chattogram and Cox’s Bazar, Jashore, Barishal, Chandpur, Bhola where supplier purchased those fishes through auctioneer and supply to other cities where retailer bought fishes through wholesaler and delivery to consumer. The market channel of processed fishes was the longest. However, the market margin of marine fishes is comparatively higher than freshwater fishes. The unplanned market location (P.I = 0.80) was major constraints followed by insufficient drainage system, low supply of fish for Covid-19 pandemic, high transportation cost, and traditional fish transportation system. This research, therefore, would suggest that modern equipped fish market with high quality cold storage and ice factories could help to maintain the better quality of fish and reduce economic losses.

Analysis of training needs of fish farmers in Ikorodu Local Government Area of Lagos state, Nigeria

In this study the level of knowledge, skill and training needs of fish farmers in Ikorodu Local Government Area of Lagos State were investigated. Eighty out of 150 fish farmers currently operating in the Fish Farm Estate, Ikorodu were randomly selected. Data were collected from the farmers with structured interview schedule and were summarised with frequency counts, percentages, mean and correlation coefficient. Result showed that the following practices were carried out by farmers: pond/vats/fibre glass/tank cleaning, water quality maintenance and management, pond fertilisation, brood stock production, spawning, fingerlings sourcing/production, disease prevention, control and management, feed formulation and production/sourcing, record keeping, fish feeding, fish processing, fish storage, fish sorting, pest and predator control, fry care, transfer and feeding, siphoning, and fish transportation. The mean age of the fish farmers were 45±13.0 years with 63.8% being males.Majority (78.8%) weremarried withmean family size of 4±2 .Majority (82.5%) of the farmers had more than twelve years of formal education. The mean farming experience was 8±3 yearswith averagemean income of 1.4million naira.58.8% and 47.5% had high level of knowledge and skill respectively. Training was needed in seven out of the seventeen practices. The major constraints to fish production are high cost of feed and lack of capital. Also, a positive and significant relationship exist between level of knowledge of the farmers and farmers' gender, marital status, membership of cooperative society and fish farming association and primary occupation while age of the farmers had a negative but significant relationshipwith it. It is recommended that training by extension agents should focus the area of training needs and that credit and cost of fish feeds be subsidized

Potential benefit of I-Tiao-Gung (Glycine tomentella) extract to enhance ornamental fish welfare during live transport

Multiple stressors associated with live fish transport, such as shaking, packing, hyper‑oxygenation, and cold stress, present a growing concern for fish welfare. The current study was designed to evaluate the fish welfare promoting effects of I-Tiao-Gung extract (Glycine tomentella, GTE), an extract derived from a Chinese herb, during live transport of blood parrot cichlid (Amphilophus citrinellus x Cichlasoma synspilum) and koi (Cyprinus carpio). The study analyzed plasma electrolytes, glucose, lactate, and cortisol levels from blood of both fishes during simulated transport. Results showed that adding GTE in water significantly decreased cortisol levels in blood parrot cichlid after 2–6 h and in koi after 4–6 h of simulated transport, respectively. Levels of glucose, lactate, and K+ in blood parrot cichlid began to elevate significantly between 2 and 6 h under stress. While levels of blood Na+, Ca2+ and lactate of koi significantly increased after simulated transport. Interestingly, Cl− levels were depressed significantly upon stress in both fishes. An indirect approach using ventilation frequency (VF) to gauge metabolism was taken to assess the physiological effects. VF was significantly slower in blood parrot cichlid after GTE addition comparing to that of the control group, but the effect was not significant in koi. Therefore, addition of GTE mitigated transport stress responses in both ornamental fishes through down-regulation of cortisol; thereby, promoting fish welfare during live transport.

Examination of ionoregulatory characteristics of South American cichlids

We examined ionoregulatory traits of four cichlid species from South America, oscars (Astronotus ocellatus), Tapajos cichlids (Geophagus sp.), Macmaster's dwarf cichlids (Apistogramma macmasteri), and keyhole cichlids (Cleithracara maronii), all inhabitants of ion-poor waters. Km values for Na+ transport in fish held in 100 μmol L−1 Na+ water ranged from 49 to 143 μmol L−1, and Jmax values spanned 450 to 1205 nmol g−1 h−1. After one month in 1000 μmol L−1 Na+ water, kinetic parameters for Na+ uptake in three of the four species acclimated, but only oscars displayed the “typical” pattern of higher Km and lower Jmax values. Low pH water inhibited Na+ uptake (JinNa) in all, and stimulated Na+ efflux (JoutNa) 2.5 to 3.5-fold in three of the four species. Oscars alone had had a measurable JinNa at pH 3.5 and no stimulation of JoutNa. We measured JinNa in oscars and keyhole cichlids during exposure to 100 μmol L−1 Ethoxzolemide (EZ), an inhibitor of carbonic anhydrase, and 1 mmol L−1 NH4Cl (HEA). EZ inhibited JinNa by about 50% and HEA reduced JinNa by 80–90%. These results suggest that Na+ uptake involves H+ extrusion. Acute exposure to 1 μmol L−1 CuSO4 and 60 nmol L−1 AgNO3 inhibited JinNa in both species by 30–85%. Exposure of oscars to 5-fold higher concentrations of both metals did not further inhibit JinNa, but it did stimulate JoutNa 50–150%. The response to metals of both species are similar to other species that have been examined.

Molecular mechanisms of Cl- transport in fishes: New insights and their evolutionary context.

With remarkably few exceptions, aquatic vertebrates maintain internal Cl- homeostasis despite strong and sometimes fluctuating Cl- concentration gradients between extracellular fluids and external environments. In this "Perspective," we discuss recent advances in the understanding of epithelial Cl- transport at the molecular level within key osmoregulatory organs in fishes. New insights into mechanisms for epithelial Cl- transport in basal lineages are highlighted to provide an evolutionary context. We describe Cl- transport processes that employ: cystic fibrosis transmembrane conductance regulator, cation-chloride cotransporters, voltage-gated chloride channels, and chloride-anion exchangers. As the collective understanding of Cl- transport processes continues to expand, investigators are equipped to more precisely characterize how endocrine factors promote hydromineral balance. We, therefore, conclude our discussion by paying special attention to recently defined roles for prolactin and corticosteroids in the regulation of Cl- transport in basal and derived clades.

A novel approach to ornamental fish transportation for the aquarium hobbyist

A novel approach to ornamental fish transportation for the aquarium hobbyist

Study on fish marketing system of some fish species in Hobiganj District, Bangladesh

The study was conducted on fish marketing system of Hobiganj sadar upazila to look out the existing marketing channels of some fresh fish species and to explore marketing cost and income of wholesalers and retailers in the study areas. The present investigation was carried out for a period of July 2019 to November 2019 mainly in three different markets of Hobiganj sadar town of Bangladesh. A total of 60 fish traders were selected randomly and data were collected through direct interview utilizing a well-structured questionnaire. The study pointed that in supply chain about only 5% customers received fish from fish farmers directly and rest 95% fishes arrived to the consumer levels through intermediaries. About 60% fish species were come locally and 40% came from different portions of the country. Fish of most priceable and high consumer preference were Air and Ilish due to its good taste on the other hand Tilapia and Pungas were the less priceable and low consumer preference fish in the surveyed areas because of their bad odour and low taste. The net margin of piker, wholesaler and retailer were 690 Tk. ($8.14), 350 Tk. ($4.13), 830 Tk. ($9.79) quintal-1 whereas gross margin was 900 Tk ($10.62), 500 Tk. ($5.90) and 1000 Tk. ($11.80) quintal-1, respectively and these were satisfactory for their daily livelihood. Traders faced numerous problems such as poor drainage, security, electricity, icing, personal expense, unhygienic environment and transportation etc. To develop the facilities of fish marketing is crucial by improving fish transport facilities, establish ice factory and to introduce fish quality monitoring unit.

Monitoring water quality changes and ornamental fish behaviour during commercial transport

Live transport of fishes is recognised as a major source of stress leading to poor welfare and mortality within the ornamental fish industry. While previous studies have aimed to simulate the stressors experienced by fishes during transport in the laboratory, there is little documented evidence of the actual conditions experienced by fishes under commercial conditions. The aim of this study was to monitor water quality and fish health (physiology and behaviour) through a commercial supply chain for three popular freshwater ornamentals (neon tetra, oranda, variatus platy). Water samples were collected at nine stages of the supply chain beginning at arrival of the fishes at a UK wholesaler from Singapore through their recovery at the wholesaler, to subsequent shipment to and recovery at retail stores. Water chemistry was recorded at various points in the transport chain and the water tested for common fish pathogens. Fish health parameters measured included mortality, injuries, waterborne cortisol and behavioural changes. Most water parameters were found to change significantly through the transport chain, including pH, carbonate hardness (KH), chloride (Cl−), nitrate (NO3−), sodium (Na+), magnesium (Mg2+), potassium (K+) and calcium (Ca2+). Pathogens were detected in the water at each stage of transport, but no disease outbreaks were observed. Mortality was low and was not affected by transport stage. Behaviour was found to change the most between different stages of transport. Neon tetras and orandas showed some behavioural changes during transport but the behaviour of variatus platys was more affected by transport stage. The findings of this study highlight the changes in water quality experienced by fishes during commercial transport that are often over-looked in simulated studies and confirm the need for species-specific indicators of welfare during commercial transport.

Glutamate and glutamine transporter genes in grass carp (Ctenopharyngodon idellus): Molecular cloning, characterization and expression in response to different stocking densities

Active transporters play a central role in the uptake and efflux of glutamate by cells and organelles. We aimed to assess the effects of crowding stress on the efficiency of active glutamate and glutamine transport in fish. We cloned intestinal-related transporters and investigated their transcriptional changes in grass carp Ctenopharyngodon idellus exposed to different stocking densities. The full-length cDNA sequences of slc1a1, slc1a3 and slc7a6 cloned by rapid amplification of cDNA ends were 2,869, 2,508 and 2,141 base pairs respectively. Based on homology modelling, we derived three-dimensional models of SLC1A1, SLC1A3, SLC7A6 and SLC7A7 and noted their transmembrane domains. The expression profiles of slc1a1, slc1a3 and slc7a7 demonstrated tissue specificity, with section-dependent expression patterns along the intestine. Moreover, segmental mRNA expression patterns of slc1a3, slc7a6 and slc7a7 were affected by stocking density. Crowding stress notably altered the segment-specific mRNA expression of slc7a6. The results of this study showed that increased stocking density increased mRNA expression levels of glutamine transporters (slc7a6 and slc7a7) but decreased mRNA expression of the glutamate transporter (slc1a3). These results furthered our understanding of the relationship between crowding stress and intestinal glutamate/glutamine transport in fish.

İnci Kefalinde (Chalcalburnus tarichi, Pallas 1811) Listeria Türlerinin Varlığı ve Yaygınlığı

Lake Van is not a very convenient environment for life of both sea and freshwater fish due to its high alkaline (pH 9.8) and salty (0.21%) water and only pearl mullet (Chalcalburnus tarichi, Pallas 1811) are present in the lake. In this study, the presence and prevalence of Listeria species in samples of the pearl mullet (Chalcalburnus tarichi, Pallas 1811) living as an endemic species in Lake Van and taken a total of 160 times for 12 months were examined. The method recommended by the United States Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) was used for the isolation and identification of Listeria species. Among the pearl mullet samples examined, Listeria spp. were isolated in 20 (12.50%) and of them L. innocua in 10 (6.25%) and L. welshimeri in 8 (5.00%) and L. ivanovii in 2 (1.25%) were identified. In this study, the presence of Listeria species in pearl mullet samples examined according to the seasons was revealed for the first time. Failure to identification of L. monocytogenes in any of the samples that is an important pathogen for humans, was assessed as an indicator that these fish did not constitute a public health risk in terms of listeriosis. As a result, Listeria spp. and other pathogenic microorganisms not to pose a risk to public health and in order to prevent the deterioration of fishes and reduce the economic losses, the transportation, storage and marketing of the caught fishes should be done under hygienic and cold conditions.

Traditional knowledge of the fishermen community of Indian Sundarbans: An assessment of rationality and effectiveness

The present paper describes various Indigenous Technical Knowledge (ITK) of the fishermen community of Indian Sundarbans in West Bengal documented during the period from 2013 to 2015. A total of eleven ITKs were documented including therapeutic value of fish with special reference to small indigenous fishes (SIF) and were categorised based on their uses. Effectiveness and rationality were assessed based on the view of the experts as well as that of fishers. The study indicated that seven ITKs documented were rational and effective. Those valid ITKs include four types of unique fishing methods; fish as special energy booster; methods to support natural fish breeding and fish marketing. Remaining four ITKs, like use of fishes to address unique human health issues, method to reduce mortality during prawn seed transport and behaviour of fish for forecasting extreme climatic events, although appeared as irrational and less effective as per the view of experts, fishers are practicing them and hence demand special attention for proper validation, improvement and popularisation in the context of changing regional resource structure and stakeholders’ needs.

PENGGUNAAN EKSTRAK AKAR TUBA (Derris elliptica) DENGAN DOSIS YANG BERBEDA DALAM PENGANGKUTAN IKAN PATIN SISTEM TERTUTUP

The transportation process can lead to stress which increases mortality in fish. Efforts to reduce mortality in the process of fish transportation can be conducted by minimizing the metabolic activities of fish during transportation. One of the natural substances that is used for fish transportation is tuba roots. The aim of this study is to determine the effect of different dosages of tuba root extract on the transport of catfish seeds with a closed transport system for 12 hours. This research was conducted at the Aquaculture Laboratory, Aquaculture Study Program, Faculty of Agriculture, Sriwijaya University. The research was conducted in April 2019. This study used a completely randomized design (CRD) method with four different dosage treatments (T) and three replications. The dosages of tuba root extract were: 0 ml.L-1 (T0), 0.05 ml.L-1 (T1), 0.10 ml.L-1 (T2), 0.15 ml.L-1 (T3). The parameters observed were blood glucose levels, water quality, survival of catfish after transportation and maintenance for 7 days. The results showed that T1 (0,05 ml.L-1) was gave the highest survival rate of 91.66±2.88%, with the lowest stress level indicated by blood glucose values 89±30.63. In addition, there was no further effect from the administration of tubal root extracts to protect the life of the fish after transportation and maintenance.Keywords : Tuba root, catfish, transportation

Survival and serum biochemical responses of spotted sea bassLateolabrax maculatusduring simulated waterless live transportation

Waterless live fish transportation is an alternative and promising transport strategy, which may reduce shipping costs, increase stocking density and improve survival of some species. Spotted sea bass is one of the most economically important marine fish in China. However, waterless transportation has not yet been studied on spotted sea bass. To explore the possibility of waterless transportation of spotted sea bass and its sublethal stress responses, the survival rate and dynamics of blood biochemical parameters were evaluated in the present study by preserving it under no water, less water and water (control) conditions for 9 hr. The serum biochemical parameters including total protein, cortisol, glucose, lactate, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total carbon dioxide (TCO2), creatinine, blood urea nitrogen (BUN), ammonia, superoxide dismutase (SOD) activity and malonaldehyde (MDA) were investigated. Results showed that the survival rates of fish in all groups gradually declined with time increasing. At the end of transportation, the survival rates in the control group, less-water group and no-water group decreased to 49.11%, 15.60% and 23.96% respectively. Significant changes were observed in several selected serum biochemical parameters, including glucose, lactate, ALT, TCO2, BUN and ammonia during simulated waterless transportation, which might negatively affect the physiological homeostasis of fish, leading to the high mortality in present study. In general, waterless transportation of spotted sea bass was possible, but it might be rather suitable for short time than long time.

Application of the consortia of nitrifying archaea and bacteria for fish transportation may be beneficial for fish trading and aquaculture

The growing popularity of the aquarium trade is greatly increasing the demand for many ornamental fish. While shipping technology has made the worldwide transportation of ornamental fish possible, a significant portion of the fish caught for the aquarium trade perish in transport before being sold to hobbyists. One of the major causes of fish death in transport is ammonia building up to toxic levels in the shipping bags. In order to solve this problem, we investigated the effectiveness of using nitrifying consortia in reducing the ammonia build-up in marine fish bags during transport. A pre-activated nitrifying consortium was effective in safely maintaining low ammonia levels during a three-day experiment. We found that both ammonium chloride and urea can activate nitrifying consortia. Activation of nitrifiers by urea is not only novel but also beneficial due to being less harmful to fish in comparison with ammonia. We also discovered that unexpectedly one nitrifying consortium examined mainly contained ammonia-oxidizing archaea. The confirmation of the concept of the use of activated nitrifying consortia and the usefulness of nitrifying archaea for fish transportation may be beneficial for the fish trading and aquaculture.

Efektivitas Infusum Daun Durian (Durio zibethinus) Sebagai Anestesi Alami Ikan Lele (Clarias gariepinus)

Bahan anestesi buatan atau alami sangat dibutuhkan dalam transportasi ikan hidup, karena ikan secara fisiologi harus tetap hidup dan sehat sampai tempat tujuan. Daun durian adalah merupakan salah satu bahan alami yang dapat digunakan sebagai anetesi dalam transport karena mengandung mengandung senyawa metabolit sekunder seperti saponin, tanin dan flavonoid. Tujuan dari penelitian ini yaitu untuk mengetahui konsentrasi efektif infusum daun durian sebagai anestesi ikan lele terhadap waktu induksi dan sedatif, profil glukosa darah dan sintasan. Ikan dengan berat rataan 185,62 ± 9,06 g dalam 3 L air dengan konsentrasi bahan anestesi daun durian yang berbeda digunakan untuk mengetahui status pingsan ikan. Rancangan acak lengkap dengan empat perlakuan (konsentrasi infusum daun durian 5%, 15%, 25%, dan 35%.) dan tiga ulangan digunakan dalam penelitian ini. Hasil dari penelitian ini menunjukkan bahwa konsentrasi terbaik yang diperoleh adalah 35%, dengan waktu induktif 9 menit-19 detik dan waktu sedatif 1 menit-42 detik. Sintasan ikan lele pada perlakuan terbaik sebesar 88.89%, dengan kadar glukosa darah sebesar 63,23 mg/dL.

The Evolutionary Development of Transit Transport of Temperature-Sensitive Goods

The presented study identifies modern organizational and institutional trends in the evolutionary development of transit transport of temperature-sensitive goods.Aim. The study aims to determine the place and role of transit transport of temperature-sensitive goods across Russia and within the Eurasian space via global communication lines as an efficient direction for the development of transit economy, an innovative method of transport, and a highly profitable form of export for transport services.Tasks. The authors examine, systematize, and analyze the organizational and institutional directions for the evolutionary development of transit transport of temperature-sensitive goods and formulate proposals for implementing the most efficient corporate mechanisms for the development of transit economy in Russia and formation of a global Eurasia.Methods. This study uses the methods of evolutionary-institutional theory, systems analysis, theory of engineering and manufacturing balance, and historical approach.Results. It is determined that the development of transport of temperature-sensitive and other sensitive goods should be evolutionary. In the early 21st century, the transport of fish and seafood from the Asia-Pacific region to the European Union is becoming increasingly important for meeting the demands of retail trade and the food service industry. The benefits (competitive advantages) and shortcomings (market problems) of transit transport of temperature-sensitive goods by different modes of transport are identified. A set of organizational and institutional measures has been developed to improve the traceability of movement of Russian food products for the purpose of development, dispatch, and regular operation of a fleet of “cold express trains”.Conclusions. One of the organizational and institutional directions for the evolutionary development of transit transport of temperature-sensitive goods involves the activity of supranational political and integration entities, primarily the Eurasian Economic Union (EAEU) and the Shanghai Cooperation Organisation (SCO), and their efforts to create a unified transport space and to combine infrastructure and integration projects. The establishment of a supranational Eurasian Transit Transport Company (ETTC) should serve as a corporate framework for integration processes within the global Eurasian space in terms of linking transport and communication systems.

Good management practices course and social technologies for aquaculture farmers in Marajó, Pará, Brazil

The objective of this study was capacitate aquaculture farmers and develop social technologies for the culture of tambaqui (Colossoma macropomum) in the archipelago of Marajó (Pará - Brazil). The study was carried out in the municipality of Curralinho by the Federal Institute of Education, Science and Technology of Pará (IFPA) Campus Breves, in March 2020. Two structured questionnaires were applied to 13 course participants who participated in the training. The first was before the course, about fish farming and the adoption of Good Management Practices (BPM) adopted by aquaculture farmers in the Marajó region. The second, composed of closed questions to evaluate the training course, whose themes were: 1) water quality, 2) indicated species, 3) fish transport management, 4) fish quarantine and stock, 5) fish biometrics, 6) liming and fertilizing ponds, 7) management of fish nutrition and health, and 8) fish harvesting and slaughter, were approached in the course. At the end of the lectures / training, a workshop for the production of social technologies was conducted, among students, teachers and aquaculture farmers. Previous knowledge about fish farming and the adoption of BPM were essential for the effectuation of the course. Issues about water quality, biometrics and fish nutrition and health were the ones that called the most attention from aquaculture farmers. Secchi's disk, ichthyometer, hand net and net-tank were the social technologies built. Post-course evaluation was essential to understand the impact of the socialization of knowledge provided to the community. In conclusion, the project reinforced teaching, research and extension actions, involving the community in favor of strengthening aquaculture in the Marajó island, Pará, Brazil.

Factors affecting the fate of Pacific lamprey carcasses and resource transport to riparian and stream macrohabitats

Abstract Anadromous fish transport marine‐derived nutrients to freshwaters during spawning migrations with potential implications for stream food webs. While many studies have explored the role of marine‐derived nutrients instream ecosystems (particularly via Pacific salmonids [Oncorhynchus spp.]), relatively few have examined the spatial distribution and patchiness of non‐salmonid fish carcasses or rates of transport to the riparian zone. We radio‐tagged and released 144 mature Pacific lamprey (Entosphenus tridentatus) prior to spawning and tracked the fate of post‐spawn carcasses in two inland Columbia River basin streams to characterise spatial distribution of carcasses and marine‐derived nutrient deposition. We found that 27 and 40% of lamprey that could be assigned a fate were moved into the riparian zone adjacent to stream segments exhibiting higher velocity conditions with larger substrates. Conversely, lamprey with instream fates were associated with depositional microhabitats and woody debris dams. Estimated carcass loading rates varied by more than an order of magnitude among habitats. These patterns probably reflect a combination of processes influencing the likelihood of carcass removal (e.g. by predators or scavengers, or stranding) and factors affecting the distribution of carcasses remaining within the stream. Our results demonstrate substantial transport of lamprey carcasses across the stream‐riparian ecotone and a non‐random distribution of carcasses within streams, patterns which probably influence how resources enter stream and riparian food webs. More broadly, the results suggest local and landscape‐scale hydrogeomorphic factors, along with species‐specific traits and phenology, affect the distribution and potential roles of fish carrion in stream food webs.