1
|
Taormina B, Escobar-Lux RH, Legrand E, Parsons AE, Kutti T, Husa V, Hannisdal R, Samuelsen OB, Agnalt AL. Effects of the sea lice chemotherapeutant, emamectin benzoate, on metabolism and behaviour of the sea-pen Pennatula phosphorea. MARINE POLLUTION BULLETIN 2024; 198:115903. [PMID: 38091631 DOI: 10.1016/j.marpolbul.2023.115903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 11/30/2023] [Accepted: 12/03/2023] [Indexed: 01/05/2024]
Abstract
Chemotherapeutants used to control infestations by sea lice can be released into the marine environment surrounding aquaculture farms. Among these therapeutic agents, emamectin benzoate is extensively utilized even though its impact on non-target taxa has not been thoroughly examined. In this context, we explored the effects of emamectin benzoate on a common Norwegian habitat-forming species: the phosphorescent sea-pen Pennatula phosphorea. Specifically, we examined P. phosphorea metabolic and responses before, during and after exposure to emamectin benzoate. Results indicate that an 8-day emamectin benzoate exposure (0.8 mg/L) did not induce P. phosphorea mortality or significant behavioural or metabolic modifications. However, we highlighted the presence and persistence of emamectin benzoate in exposed P. phosphorea tissue. These results indicate that emamectin benzoate is unlikely to adversely impact P. phosphorea populations in the environment. However, persistence of emamectin benzoate in tissue constitutes a potential for bioaccumulation with repeated treatments and should be examined in further studies.
Collapse
Affiliation(s)
- Bastien Taormina
- Institute of Marine Research, Nordnesgaten 50, Bergen 5005, Norway.
| | - Rosa Helena Escobar-Lux
- Institute of Marine Research, Austevoll Research Station, Sauganeset 16, Storebø 5392, Norway
| | - Erwann Legrand
- Institute of Marine Research, Nordnesgaten 50, Bergen 5005, Norway
| | | | - Tina Kutti
- Institute of Marine Research, Nordnesgaten 50, Bergen 5005, Norway
| | - Vivian Husa
- Institute of Marine Research, Nordnesgaten 50, Bergen 5005, Norway
| | - Rita Hannisdal
- Institute of Marine Research, Nordnesgaten 50, Bergen 5005, Norway
| | - Ole B Samuelsen
- Institute of Marine Research, Nordnesgaten 50, Bergen 5005, Norway
| | | |
Collapse
|
2
|
Vollset KW, Lennox RJ, Skoglund H, Karlsen Ø, Normann ES, Wiers T, Stöger E, Barlaup BT. Direct evidence of increased natural mortality of a wild fish caused by parasite spillback from domestic conspecifics. Proc Biol Sci 2023; 290:20221752. [PMID: 36695034 PMCID: PMC9880801 DOI: 10.1098/rspb.2022.1752] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/30/2022] [Indexed: 01/26/2023] Open
Abstract
Parasite spillback from domestic animals can distort the balance between host and parasites in surrounding wildlife, with potential detrimental effects on wild populations. In aquatic environments, parasite spillback from aquaculture to wild salmon is one of the most contentious sustainability debates. In a 19 year time series of release group studies of Atlantic salmon, we demonstrated that (i) the effect of subjecting out-migrating salmon smolts to parasite treatment on marine survival has been reduced over a time, (ii) the relation between salmon lice levels in the out-migration route of the salmon and effect of treatment against the parasite is weak, but also (iii) the return rates in both treated and untreated groups of salmon are negatively correlated with salmon lice levels, and (iv) returns of wild salmon to the region are similarly negatively correlated with salmon lice levels during the out-migration year. Our study suggests that salmon lice can have a large effect on wild salmon populations that is not revealed with randomized control trials using antiparasitic drugs. This should be better accounted for when considering the impacts of farms on wild salmon populations.
Collapse
Affiliation(s)
- Knut Wiik Vollset
- Climate and Environment, NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries, Nygårdsgaten 112, 5008 Bergen, Norway
| | - Robert J Lennox
- Norwegian Institute for Nature Research, Høgskoleringen 9, 7034 Trondheim, Norway
| | - Helge Skoglund
- Climate and Environment, NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries, Nygårdsgaten 112, 5008 Bergen, Norway
| | - Ørjan Karlsen
- Institute of Marine Research, Nordnesgaten 50, 5005 Bergen, Norway
| | - Eirik Straume Normann
- Climate and Environment, NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries, Nygårdsgaten 112, 5008 Bergen, Norway
| | - Tore Wiers
- Climate and Environment, NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries, Nygårdsgaten 112, 5008 Bergen, Norway
| | - Elisabeth Stöger
- Institute of Marine Research, Nordnesgaten 50, 5005 Bergen, Norway
| | - Bjørn T Barlaup
- Climate and Environment, NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries, Nygårdsgaten 112, 5008 Bergen, Norway
| |
Collapse
|
3
|
Abstract
AbstractThe negative effects of parasitism on host population dynamics may be mediated by plastic compensatory life-history changes in hosts. Theory predicts that hosts should shift their life-history towards early reproduction in response to virulent pathogens to maximize reproduction before death. However, for sublethal infections that affect growth, hosts whose fecundity is correlated with body size are predicted to shift towards delayed reproduction associated with larger body size and higher fecundity. This has been observed in Atlantic salmon and parasitic sea lice, via mark-recapture studies that recover mature fish from paired groups of control and parasiticide-treated smolts. We investigated whether such louse-induced changes to age at maturity can offset some of the negative effect of mortality on population growth rate in salmon using a structured population matrix model. Model results show that delayed maturity can partially compensate for reduced survival. However, this only occurs when marine survival is moderate to poor and growth conditions at sea are good. Also, the impact of delayed maturity on population growth when parameterizing the model with empirical data is negligible compared with effects of direct mortality. Our model thus suggests that management that works on minimizing the effect of sea lice from fish farms on wild salmon should focus mainly on correctly quantifying the effect of parasite-induced mortality during the smolt stage if the goal is to maximize population growth rate.
Collapse
|
4
|
Dalvin S, Are Hamre L, Skern-Mauritzen R, Vågseth T, Stien L, Oppedal F, Bui S. The effect of temperature on ability of Lepeophtheirus salmonis to infect and persist on Atlantic salmon. JOURNAL OF FISH DISEASES 2020; 43:1519-1529. [PMID: 32882750 DOI: 10.1111/jfd.13253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
The salmon louse (Lepeophtheirus salmonis) is an ecologically and economically important parasite of salmonid fish. Temperature is a strong influencer of biological processes in salmon lice, with development rate increased at higher temperatures. The successful attachment of lice onto a host is also predicted to be influenced by temperature; however, the correlation of temperature with parasite survival is unknown. This study describes the effects of temperature on infection success, and survival on the host during development to the adult stage. To accurately describe infection dynamics with varying temperatures, infection success was recorded on Atlantic salmon (Salmo salar) between 2 and 10°C. Infection success ranged from 20% to 50% and was strongly correlated with temperature, with the highest success at 10°C. Parasite loss was monitored during development at eight temperatures with high loss of lice at 3 and 24°C, whilst no loss was recorded in the temperature range from 6 to 21°C. Sea temperatures thus have large effects on the outcome of salmon louse infections and should be taken into account in the management and risk assessment of this parasite. Improving understanding of the infection dynamics of salmon lice will facilitate epidemiological modelling efforts and efficiency of pest management strategies.
Collapse
Affiliation(s)
- Sussie Dalvin
- SLRC - Sea Lice Research Centre, Institute of Marine Research, Bergen, Norway
- Department of Biological Sciences, SLRC - Sea Lice Research Centre, University of Bergen, Bergen, Norway
| | - Lars Are Hamre
- Department of Biological Sciences, SLRC - Sea Lice Research Centre, University of Bergen, Bergen, Norway
| | | | | | - Lars Stien
- Institute of Marine Research, Matredal, Norway
| | | | | |
Collapse
|
5
|
Lennox RJ, Salvanes AGV, Barlaup BT, Stöger E, Madhun A, Helle TM, Vollset KW. Negative impacts of the sea lice prophylactic emamectin benzoate on the survival of hatchery released salmon smolts in rivers. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2020; 224:105519. [PMID: 32502848 DOI: 10.1016/j.aquatox.2020.105519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/07/2020] [Accepted: 05/10/2020] [Indexed: 06/11/2023]
Abstract
Emamectin benzoate (EB) is a prophylactic pharmaceutical used to protect Atlantic salmon (Salmo salar) smolts migrating out of rivers and into the ocean against sea lice parasites. Randomized control trials comparing the marine survival of smolts treated with EB to a control group is used to calculate the fraction of marine mortality attributable to sea lice parasitism. However, it is assumed that there is no baseline difference in survival induced by the application of EB treatment. We used a combined laboratory and field study approach to investigate the potential impacts of EB treatment on behaviour and survival of hatchery-reared Atlantic salmon in western Norway. In aquaria experiments, EB-treated salmon smolts did not differ significantly in exploratory behaviour. Fish from treated groups responded similarly to simulated predator attack with spontaneous escape and elevated gill beat rate. Three rivers in the Osterfjord system of western Norway were selected for field experiments, Dale, Vosso, and Modalen. Dale River smolts were treated with intraperitoneal EB injections and had lower probability of detection in a wolf trap downstream of the release site than control smolts. Salmon smolts raised in the Vosso River hatchery were treated with EB delivered in their food and were detected on PIT antennas at the rivermouth of Vosso and Modalen at lower rates than control fish, but only when released at downstream sites. Calculation of risk ratios suggested that the bias in mortality caused by treatment with EB decreased the estimated survival of treated fish from an expected 18%to 46%, reducing the observable negative impact of sea lice on Atlantic salmon smolts in randomized control trials. The results suggest that estimates of the fraction of mortality attributable to sea lice may be underestimated due to lower baseline survival of treated fish caused by treatment and bring urgent attention towards a potential systematic underestimation of the impacts of sea lice on wild salmon.
Collapse
Affiliation(s)
- Robert J Lennox
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries (LFI), Nygårdsporten 112, 5008 Bergen, Norway.
| | | | - Bjørn T Barlaup
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries (LFI), Nygårdsporten 112, 5008 Bergen, Norway
| | - Elisabeth Stöger
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries (LFI), Nygårdsporten 112, 5008 Bergen, Norway
| | | | - Turid M Helle
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries (LFI), Nygårdsporten 112, 5008 Bergen, Norway
| | - Knut Wiik Vollset
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries (LFI), Nygårdsporten 112, 5008 Bergen, Norway
| |
Collapse
|
6
|
Bøhn T, Gjelland KØ, Serra‐Llinares RM, Finstad B, Primicerio R, Nilsen R, Karlsen Ø, Sandvik AD, Skilbrei OT, Elvik KMS, Skaala Ø, Bjørn PA. Timing is everything: Survival of Atlantic salmon
Salmo salar
postsmolts during events of high salmon lice densities. J Appl Ecol 2020. [DOI: 10.1111/1365-2664.13612] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | - Bengt Finstad
- Norwegian Institute for Nature Research (NINA) Trondheim Norway
- Department of Biology NTNU Center of Fisheries and Aquaculture Trondheim Norway
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Vollset KW. Parasite induced mortality is context dependent in Atlantic salmon: insights from an individual-based model. Sci Rep 2019; 9:17377. [PMID: 31758025 PMCID: PMC6874588 DOI: 10.1038/s41598-019-53871-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 11/04/2019] [Indexed: 11/09/2022] Open
Abstract
An individual-based model was parameterized to explore the impact of a crustacean ectoparasite (sea louse, Lepeophtheirus salmonis & Caligus spp.) on migrating Atlantic salmon smolt. The model explores how environmental and intrinsic factors can modulate the effect of sea lice on survival, growth and maturation of Atlantic salmon at sea. Relative to other effects, the parasite infestation pressure from fish farms and the encounter process emerge as the most important parameters. Although small variations in parasite-induced mortality may be masked by variable environmental effects, episodes of high infestation pressure from fish farms should be observable in wild populations of Atlantic salmon if laboratory studies accurately reflect the physiological effects of sea lice. Increases in temperature in the model negatively influenced fish survival by affecting the development time of the parasite at a rate that was not compensated for by the growth of the host. Discharge from rivers was parameterized to increase migration speed and influenced parasite induced mortality by decreasing time spent in areas with increased infestation pressure. Initial size and growth of the host was inversely related to the impact of the parasite because of size-dependent parasite-induced mortality in the early phase of migration. Overall, the model illustrates how environmental factors modulate effects on the host population by impacting either the parasite load or the relative effect of the parasite. The results suggest that linking population-level effects to parasite infestation pressure across climatic and environmental gradients may be challenging without correctly accounting for these effects.
Collapse
Affiliation(s)
- Knut Wiik Vollset
- NORCE Norwegian Research Centre, Laboratory for Freshwater ecology and Inland fisheries, Nygårdsporten 112, 5006, Bergen, Norway.
| |
Collapse
|
8
|
Halttunen E, Gjelland KØ, Hamel S, Serra-Llinares RM, Nilsen R, Arechavala-Lopez P, Skarðhamar J, Johnsen IA, Asplin L, Karlsen Ø, Bjørn PA, Finstad B. Sea trout adapt their migratory behaviour in response to high salmon lice concentrations. JOURNAL OF FISH DISEASES 2018; 41:953-967. [PMID: 29159923 DOI: 10.1111/jfd.12749] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/21/2017] [Accepted: 09/24/2017] [Indexed: 05/25/2023]
Abstract
Sea trout face growth-mortality trade-offs when entering the sea to feed. Salmon lice epizootics resulting from aquaculture have shifted these trade-offs, as salmon lice might both increase mortality and reduce growth of sea trout. We studied mortality and behavioural adaptations of wild sea trout in a large-scale experiment with acoustic telemetry in an aquaculture intensive area that was fallowed (emptied of fish) synchronically biannually, creating large variations in salmon lice concentrations. We tagged 310 wild sea trout during 3 years, and gave half of the individuals a prophylaxis against further salmon lice infestation. There was no difference in survival among years or between treatments. In years of high infestation pressure, however, sea trout remained closer to the river outlet, used freshwater (FW) habitats for longer periods and returned earlier to the river than in the low infestation year. This indicates that sea trout adapt their migratory behaviour by actively choosing FW refuges from salmon lice to escape from immediate mortality risk. Nevertheless, simulations show that these adaptations can lead to lost growth opportunities. Reduced growth can increase long-term mortality of sea trout due to prolonged exposure to size-dependent predation risk, lead to lower fecundity and, ultimately, reduce the likelihood of sea migration.
Collapse
Affiliation(s)
- E Halttunen
- Institute of Marine Research (IMR), Tromsø, Norway
| | - K-Ø Gjelland
- Norwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - S Hamel
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, The Arctic University of Norway, Tromsø, Norway
| | | | - R Nilsen
- Institute of Marine Research (IMR), Tromsø, Norway
| | - P Arechavala-Lopez
- Department of Marine Sciences and Applied Biology, University of Alicante, Alicante, Spain
- Department of Ecology of Marine Resources, Mediterranean Institute for Advanced Studies, Esporles, Mallorca, Spain
| | - J Skarðhamar
- Institute of Marine Research (IMR), Tromsø, Norway
| | - I A Johnsen
- Institute of Marine Research (IMR), Bergen, Norway
| | - L Asplin
- Institute of Marine Research (IMR), Bergen, Norway
| | - Ø Karlsen
- Institute of Marine Research (IMR), Bergen, Norway
| | - P-A Bjørn
- Institute of Marine Research (IMR), Tromsø, Norway
| | - B Finstad
- Norwegian Institute for Nature Research (NINA), Trondheim, Norway
| |
Collapse
|
9
|
Johannesen A, Joensen NE, Magnussen E. Shelters can negatively affect growth and welfare in lumpfish if feed is delivered continuously. PeerJ 2018; 6:e4837. [PMID: 29844984 PMCID: PMC5971831 DOI: 10.7717/peerj.4837] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 05/04/2018] [Indexed: 11/20/2022] Open
Abstract
Due to the socioeconomic importance of salmon farming in the North Atlantic and the economic impact of sea lice in this industry, there is high demand for novel pest control methods. One such method is the use of cleaner fish to remove the lice from the salmon. A cleaner fish that has recently gained in popularity due to its ability to work in cold water, is the lumpfish (Cyclopterus lumpus). This fish varies in efficiency, but when mortality is low and cleaning optimal, the fish are successful in keeping parasite burdens low. However, there is some concern for the welfare of lumpfish in the industry, because mortality is often high. This is sometimes attributed to inadequate feeding and shelter. Here we compare growth, body condition, and fin health of fish reared for four weeks in a crossed treatment design crossing shelter availability (shelter vs none) and feed delivery method (manual meal time feeds and continuous automated feeding). In terms of weight gain, shelter availability interacted with feeding method, with fish that had access to shelters and were fed using automated feeders gaining less weight than other fish. Fin health was not affected, but body condition was lowered both by access to shelter and being fed continuously. The results indicate a need to carefully consider how feeding method and shelter use is combined, both in cages and during rearing on land.
Collapse
Affiliation(s)
- Asa Johannesen
- Nesvik Marine Centre, Fiskaaling, Hvalvik, Faroe Islands
| | - Nakita E Joensen
- Department of Science and Technology, University of the Faroe Islands, Tórshavn, Faroe Islands
| | - Eyðfinn Magnussen
- Department of Science and Technology, University of the Faroe Islands, Tórshavn, Faroe Islands
| |
Collapse
|
10
|
Bui S, Dalvin S, Dempster T, Skulstad OF, Edvardsen RB, Wargelius A, Oppedal F. Susceptibility, behaviour, and retention of the parasitic salmon louse (Lepeophtheirus salmonis) differ with Atlantic salmon population origin. JOURNAL OF FISH DISEASES 2018; 41:431-442. [PMID: 28921589 DOI: 10.1111/jfd.12707] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 07/18/2017] [Accepted: 07/25/2017] [Indexed: 06/07/2023]
Abstract
Atlantic salmon populations across the world have diverse ecological and evolutionary histories, from wild anadromous or landlocked, to domestication and genetic modification. The natural host behaviours confer protection from infestation by ectoparasitic salmon lice Lepeophtheirus salmonis, yet whether genetic origin results in different behaviours and thus susceptibility to infestation is unknown. In common garden experiments, we tested antiparasite behaviours, susceptibility and retention of salmon lice in wild anadromous, wild landlocked, domesticated and genetically modified domesticated strains. Within domesticated strains, we tested two infestation histories (previously infested and naïve) and a new phenotype (albino colouring). Farmed stocks initially acquired 24%-44% higher levels of parasite density than the wild and landlocked strains. Burst swimming and displacement behaviours were higher in the domesticated groups, and jumping was more prevalent in the domesticated strains. At 34 days post-infestation, domesticated strains and the wild anadromous strain did not differ significantly from each other; however, landlocked salmon had increased infestation levels considerably. Domesticated strains lost ~20% (±9.9%-16.5%; 95% CI) of their initial parasite load, while parasite load increased by 5.5% (±30.1%) for wild salmon and 20.1% (±28.5%) in landlocked salmon. This study provides early evidence for diverged host-parasite interactions associated with domestication in this system.
Collapse
Affiliation(s)
- S Bui
- Sustainable Aquaculture Laboratory - Temperate and Tropical (SALTT), School of BioSciences, University of Melbourne, Parkville, Vic, Australia
- Institute of Marine Research, Bergen, Norway
| | - S Dalvin
- Institute of Marine Research, Bergen, Norway
| | - T Dempster
- Sustainable Aquaculture Laboratory - Temperate and Tropical (SALTT), School of BioSciences, University of Melbourne, Parkville, Vic, Australia
- Institute of Marine Research, Bergen, Norway
| | | | | | - A Wargelius
- Institute of Marine Research, Bergen, Norway
| | - F Oppedal
- Institute of Marine Research, Bergen, Norway
| |
Collapse
|
11
|
Kristoffersen AB, Qviller L, Helgesen KO, Vollset KW, Viljugrein H, Jansen PA. Quantitative risk assessment of salmon louse-induced mortality of seaward-migrating post-smolt Atlantic salmon. Epidemics 2017; 23:19-33. [PMID: 29233546 DOI: 10.1016/j.epidem.2017.11.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/26/2017] [Accepted: 11/29/2017] [Indexed: 10/18/2022] Open
Abstract
The Norwegian government recently implemented a new management system to regulate salmon farming in Norway, aiming to promote environmentally sustainable growth in the aquaculture industry. The Norwegian coast has been divided into 13 production zones and the volume of salmonid production in the zones will be regulated based on salmon lice effects on wild salmonids. Here we present a model for assessing salmon louse-induced mortality of seaward-migrating post-smolts of Atlantic salmon. The model quantifies expected salmon lice infestations and louse-induced mortality of migrating post-smolt salmon from 401 salmon rivers draining into Norwegian coastal waters. It is assumed that migrating post-smolts follow the shortest path from river outlets to the high seas, at constant progression rates. During this migration, fish are infested by salmon lice of farm origin according to an empirical infestation model. Furthermore, louse-induced mortality is estimated from the estimated louse infestations. Rivers draining into production zones on the West Coast of Norway were at the highest risk of adverse lice effects. In comparison, rivers draining into northerly production zones, along with the southernmost production zone, were at lower risk. After adjusting for standing stock biomass, estimates of louse-egg output varied by factors of up to 8 between production zones. Correlation between biomass adjusted output of louse infestation and densities of farmed salmon in the production zones suggests that a large-scale density-dependent host-parasite effect is a major driver of louse infestation rates and parasite-induced mortality. The estimates are sensitive to many of the processes in the chain of events in the model. Nevertheless, we argue that the model is suited to assess spatial and temporal risks associated with farm-origin salmon lice.
Collapse
Affiliation(s)
| | - Lars Qviller
- The Norwegian Veterinary Institute, PB. 750 Sentrum, N-0106 Oslo, Norway
| | - Kari Olli Helgesen
- The Norwegian Veterinary Institute, PB. 750 Sentrum, N-0106 Oslo, Norway
| | - Knut Wiik Vollset
- Uni Research Environment, LFI-Freshwater Biology, Nygårdsporten 112, N-5006 Bergen, Norway
| | | | | |
Collapse
|
12
|
The Caligus rogercresseyi miRNome: Discovery and transcriptome profiling during the sea lice ontogeny. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.aggene.2017.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
13
|
Sauterleute JF, Hedger RD, Hauer C, Pulg U, Skoglund H, Sundt-Hansen LE, Bakken TH, Ugedal O. Modelling the effects of stranding on the Atlantic salmon population in the Dale River, Norway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 573:574-584. [PMID: 27580469 DOI: 10.1016/j.scitotenv.2016.08.080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 07/23/2016] [Accepted: 08/12/2016] [Indexed: 06/06/2023]
Abstract
Rapid dewatering in rivers as a consequence of hydropower operations may cause stranding of juvenile fish and have a negative impact on fish populations. We implemented stranding into an Atlantic salmon population model in order to evaluate long-term effects on the population in the Dale River, Western Norway. Furthermore, we assessed the sensitivity of the stranding model to dewatered area in comparison to biological parameters, and compared different methods for calculating wetted area, the main abiotic input parameter to the population model. Five scenarios were simulated dependent on fish life-stage, season and light level. Our simulation results showed largest negative effect on the population abundance for hydropeaking during winter daylight. Salmon smolt production had highest sensitivity to the stranding mortality of older juvenile fish, suggesting that stranding of fish at these life-stages is likely to have greater population impacts than that of earlier life-stages. Downstream retention effects on the ramping velocity were found to be negligible in the stranding model, but are suggested to be important in the context of mitigation measure design.
Collapse
Affiliation(s)
- Julian F Sauterleute
- SINTEF Energy Research, P.O. Box 4761, Sluppen, NO 7465 Trondheim, Norway; Sweco Norway, Professor Brochs gate 2, NO 7030 Trondheim, Norway.
| | - Richard D Hedger
- Norwegian Institute for Nature Research, P.O. Box 5685, Sluppen, NO 7485 Trondheim, Norway
| | - Christoph Hauer
- Institute for Water Management, Hydrology and Hydraulic Engineering, University of Natural Resources and Life Sciences, Muthgasse 107, 1190 Vienna, Austria
| | - Ulrich Pulg
- Uni Research Environment, P.O. Box 7810, NO 5020 Bergen, Norway
| | - Helge Skoglund
- Uni Research Environment, P.O. Box 7810, NO 5020 Bergen, Norway
| | - Line E Sundt-Hansen
- Norwegian Institute for Nature Research, P.O. Box 5685, Sluppen, NO 7485 Trondheim, Norway
| | - Tor Haakon Bakken
- SINTEF Energy Research, P.O. Box 4761, Sluppen, NO 7465 Trondheim, Norway
| | - Ola Ugedal
- Norwegian Institute for Nature Research, P.O. Box 5685, Sluppen, NO 7485 Trondheim, Norway
| |
Collapse
|
14
|
Aaen SM, Hamre LA, Horsberg TE. A screening of medicinal compounds for their effect on egg strings and nauplii of the salmon louse Lepeophtheirus salmonis (Krøyer). JOURNAL OF FISH DISEASES 2016; 39:1201-1212. [PMID: 27038351 DOI: 10.1111/jfd.12462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/07/2016] [Accepted: 01/07/2016] [Indexed: 06/05/2023]
Abstract
Egg strings and nauplii of the salmon louse Lepeophtheirus salmonis were exposed to a variety of medicinal compounds at 50 mg L(-1) for 30 min in two experiment series. This medicine concentration was selected as a starting point for a screening series. Hatching of egg strings and development to copepodid larvae were monitored in one experiment, and the survival and development of nauplii were monitored in the other. Two compounds, emamectin benzoate and cypermethrin, inhibited hatching effectively. Several compounds affected nauplii, either directly or through inhibiting development to the infective stage. A total of 50 mg L(-1) of azamethiphos, cypermethrin, emamectin benzoate and propoxur was lethal to >70% of the larvae. Diflubenzuron, fenoxycarb, pymetrozine, pyriprole and tebufenozide diminished the ability of nauplii developing to copepodids.
Collapse
Affiliation(s)
- S M Aaen
- NMBU School of Veterinary Science, Sea Lice Research Centre, Oslo, Norway
| | - L A Hamre
- University of Bergen, Sea Lice Research Centre, Bergen, Norway
| | - T E Horsberg
- NMBU School of Veterinary Science, Sea Lice Research Centre, Oslo, Norway
| |
Collapse
|
15
|
Eiras JDC. Parasites of marine, freshwater and farmed fishes of Portugal: a review. REVISTA BRASILEIRA DE PARASITOLOGIA VETERINARIA 2016; 25:259-78. [DOI: 10.1590/s1984-29612016057] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/20/2016] [Indexed: 11/22/2022]
Abstract
Abstract An extensive literature review is made of the parasites in marine and freshwater fish in mainland Portugal, the Portuguese archipelagos of the Azores and Madeira, as well as in farmed fish. The host(s) of each parasite species, its location in the host, site of capture of the host, whenever possible, and all the available bibliographic references are described. The economic importance of some parasites and the zoonotic relevance of some parasitic forms are discussed. A general overview of the data is provided, and some research lines are suggested in order to increase and complement the current body of knowledge about the parasites of fish from Portugal.
Collapse
|
16
|
Jonsson B, Jonsson N, Albretsen J. Environmental change influences the life history of salmon Salmo salar in the North Atlantic Ocean. JOURNAL OF FISH BIOLOGY 2016; 88:618-637. [PMID: 26725985 DOI: 10.1111/jfb.12854] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 11/04/2015] [Indexed: 06/05/2023]
Abstract
Annual mean total length (LT) of wild one-sea-winter (1SW) Atlantic salmon Salmo salar of the Norwegian River Imsa decreased from 63 to 54 cm with a corresponding decrease in condition factor (K) for cohorts migrating to sea from 1976 to 2010. The reduction in LT is associated with a 40% decline in mean individual mass, from 2 to 1·2 kg. Hatchery fish reared from parental fish of the same population exhibited similar changes from 1981 onwards. The decrease in LT correlated negatively with near-surface temperatures in the eastern Norwegian Sea, thought to be the main feeding area of the present stock. Furthermore, S. salar exhibited significant variations in the proportion of cohorts attaining maturity after only one winter in the ocean. The proportion of S. salar spawning as 1SW fish was lower both in the 1970s and after 2000 than in the 1980s and 1990s associated with a gradual decline in post-smolt growth and smaller amounts of reserve energy in the fish. In wild S. salar, there was a positive association between post-smolt growth and the sea survival back to the River Imsa for spawning. In addition, among smolt year-classes, there were significant positive correlations between wild and hatchery S. salar in LT, K and age at maturity. The present changes may be caused by ecosystem changes following the collapse and rebuilding of the pelagic fish abundance in the North Atlantic Ocean, a gradual decrease in zooplankton abundance and climate change with increasing surface temperature in the Norwegian Sea. Thus, the observed variation in the life-history traits of S. salar appears primarily associated with major changes in the pelagic food web in the ocean.
Collapse
Affiliation(s)
- B Jonsson
- Norwegian Institute for Nature Research, Landscape Ecology Department, Gaustadalléen 21, 0349 Oslo, Norway
| | - N Jonsson
- Norwegian Institute for Nature Research, Landscape Ecology Department, Gaustadalléen 21, 0349 Oslo, Norway
| | - J Albretsen
- Institute of Marine Research, Flødevigen Research Station, Nye Flødevigveien 20, 4817 His, Norway
| |
Collapse
|
17
|
Skilbrei OT, Espedal PG, Nilsen F, Garcia EP, Glover KA. Evaluation of emamectin benzoate and substance EX against salmon lice in sea-ranched Atlantic salmon smolts. DISEASES OF AQUATIC ORGANISMS 2015; 113:187-194. [PMID: 25850396 DOI: 10.3354/dao02832] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Experimental releases of Atlantic salmon smolts treated with emamectin benzoate (EB) against salmon lice have previously been used to estimate the significance of salmon lice on the survival of migrating smolts. In recent years, the salmon louse has developed reduced sensitivity to EB, which may influence the results of such release experiments. We therefore tested the use of 2 anti-lice drugs: EB was administered to salmon smolts in high doses by intra-peritoneal injection and the prophylactic substance EX (SubEX) was administered by bathing. A third, untreated control group was also established. Salmon were challenged with copepodids of 2 strains of salmon lice (1 EB-sensitive strain and 1 with reduced EB-sensitivity) in mixed-group experimental tanks. At 31 d post-challenge, the numbers of pre-adult lice on treated fish were around 20% compared with the control fish, with minor or no differences between the 2 treatments and lice strains. Both treatments therefore appeared to give the smolts a high degree of protection against infestation of copepodids of salmon lice. However, significantly lower growth of the EB-treatment group indicates that bathing the fish in SubEX is less stressful for smolts than intra-peritoneal injection of EB.
Collapse
|
18
|
Aaen SM, Helgesen KO, Bakke MJ, Kaur K, Horsberg TE. Drug resistance in sea lice: a threat to salmonid aquaculture. Trends Parasitol 2015; 31:72-81. [DOI: 10.1016/j.pt.2014.12.006] [Citation(s) in RCA: 271] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/04/2014] [Accepted: 12/15/2014] [Indexed: 01/22/2023]
|
19
|
Gallardo-Escárate C, Valenzuela-Muñoz V, Nuñez-Acuña G. RNA-Seq analysis using de novo transcriptome assembly as a reference for the salmon louse Caligus rogercresseyi. PLoS One 2014; 9:e92239. [PMID: 24691066 PMCID: PMC3972170 DOI: 10.1371/journal.pone.0092239] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 02/19/2014] [Indexed: 11/22/2022] Open
Abstract
Despite the economic and environmental impacts that sea lice infestations have on salmon farming worldwide, genomic data generated by high-throughput transcriptome sequencing for different developmental stages, sexes, and strains of sea lice is still limited or unknown. In this study, RNA-seq analysis was performed using de novo transcriptome assembly as a reference for evidenced transcriptional changes from six developmental stages of the salmon louse Caligus rogercresseyi. EST-datasets were generated from the nauplius I, nauplius II, copepodid and chalimus stages and from female and male adults using MiSeq Illumina sequencing. A total of 151,788,682 transcripts were yielded, which were assembled into 83,444 high quality contigs and subsequently annotated into roughly 24,000 genes based on known proteins. To identify differential transcription patterns among salmon louse stages, cluster analyses were performed using normalized gene expression values. Herein, four clusters were differentially expressed between nauplius I–II and copepodid stages (604 transcripts), five clusters between copepodid and chalimus stages (2,426 transcripts), and six clusters between female and male adults (2,478 transcripts). Gene ontology analysis revealed that the nauplius I–II, copepodid and chalimus stages are mainly annotated to aminoacid transfer/repair/breakdown, metabolism, molting cycle, and nervous system development. Additionally, genes showing differential transcription in female and male adults were highly related to cytoskeletal and contractile elements, reproduction, cell development, morphogenesis, and transcription-translation processes. The data presented in this study provides the most comprehensive transcriptome resource available for C. rogercresseyi, which should be used for future genomic studies linked to host-parasite interactions.
Collapse
Affiliation(s)
- Cristian Gallardo-Escárate
- Laboratory of Biotechnology and Aquatic Genomics, Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile
| | - Valentina Valenzuela-Muñoz
- Laboratory of Biotechnology and Aquatic Genomics, Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile
| | - Gustavo Nuñez-Acuña
- Laboratory of Biotechnology and Aquatic Genomics, Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile
| |
Collapse
|
20
|
Jackson D, Cotter D, Newell J, O'Donohoe P, Kane F, McDermott T, Kelly S, Drumm A. Response to M Krkošek, C W Revie, B Finstad and C D Todd's comment on Jackson et al. 'Impact of Lepeophtheirus salmonis infestations on migrating Atlantic salmon, Salmo salar L., smolts at eight locations in Ireland with an analysis of lice-induced marine mortality'. JOURNAL OF FISH DISEASES 2014; 37:419-421. [PMID: 24611448 PMCID: PMC4314703 DOI: 10.1111/jfd.12239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- D Jackson
- Marine Environment and Food Safety Services, Marine InstituteGalway, Ireland
| | - D Cotter
- Marine Environment and Food Safety Services, Marine InstituteGalway, Ireland
| | - J Newell
- School of Mathematics, Statistics and Applied Mathematics, National University of IrelandGalway, Ireland
| | - P O'Donohoe
- Marine Environment and Food Safety Services, Marine InstituteGalway, Ireland
| | - F Kane
- Marine Environment and Food Safety Services, Marine InstituteGalway, Ireland
| | - T McDermott
- Marine Environment and Food Safety Services, Marine InstituteGalway, Ireland
| | - S Kelly
- Marine Environment and Food Safety Services, Marine InstituteGalway, Ireland
| | - A Drumm
- Marine Environment and Food Safety Services, Marine InstituteGalway, Ireland
| |
Collapse
|
21
|
Gallardo-Escárate C, Valenzuela-Muñoz V, Nuñez-Acuña G, Chávez-Mardones J, Maldonado-Aguayo W. Transcriptome analysis of the couch potato (CPO) protein reveals an expression pattern associated with early development in the salmon louse Caligus rogercresseyi. Gene 2014; 536:1-8. [DOI: 10.1016/j.gene.2013.11.100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 11/20/2013] [Accepted: 11/23/2013] [Indexed: 11/28/2022]
|
22
|
Vollset KW, Barlaup BT, Skoglund H, Normann ES, Skilbrei OT. Salmon lice increase the age of returning Atlantic salmon. Biol Lett 2014; 10:20130896. [PMID: 24478199 DOI: 10.1098/rsbl.2013.0896] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The global increase in the production of domestic farmed fish in open net pens has created concerns about the resilience of wild populations owing to shifts in host-parasite systems in coastal ecosystems. However, little is known about the effects of increased parasite abundance on life-history traits in wild fish populations. Here, we report the results of two separate studies in which 379 779 hatchery-reared Atlantic salmon smolts were treated (or not) against salmon lice, marked and released. Adults were later recaptured, and we specifically tested whether the age distribution of the returning spawners was affected by the treatment. The estimates of parasite-induced mortality were 31.9% and 0.6% in the River Vosso and River Dale stock experiments, respectively. Age of returning salmon was on average higher in untreated [corrected] versus untreated fish. The percentages of fish returning after one winter at sea were 37.5% and 29.9% for the treated and untreated groups, respectively. We conclude that salmon lice increase the age of returning salmon, either by affecting their age at maturity or by disproportionately increasing mortality in fish that mature early.
Collapse
Affiliation(s)
- Knut Wiik Vollset
- LFI, Uni Environment, Uni Research, , Thormøhlensgt. 49 B, Bergen 5006, Norway
| | | | | | | | | |
Collapse
|
23
|
Space-time modelling of the spread of salmon lice between and within Norwegian marine salmon farms. PLoS One 2013; 8:e64039. [PMID: 23700455 PMCID: PMC3659056 DOI: 10.1371/journal.pone.0064039] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 04/10/2013] [Indexed: 11/19/2022] Open
Abstract
Parasitic salmon lice are potentially harmful to salmonid hosts and farm produced lice pose a threat to wild salmonids. To control salmon lice infections in Norwegian salmonid farming, numbers of lice are regularly counted and lice abundance is reported from all salmonid farms every month. We have developed a stochastic space-time model where monthly lice abundance is modelled simultaneously for all farms. The set of farms is regarded as a network where the degree of contact between farms depends on their seaway distance. The expected lice abundance at each farm is modelled as a function of i) lice abundance in previous months at the same farm, ii) at neighbourhood farms, and iii) other, unspecified sources. In addition, the model includes explanatory variables such as seawater temperature and farm-numbers of fish. The model gives insight into factors that affect salmon lice abundance and contributing sources of infection. New findings in this study were that 66% of the expected salmon lice abundance was attributed to infection within farms, 28% was attributed to infection from neighbourhood farms and 6% to non-specified sources of infection. Furthermore, we present the relative risk of infection between neighbourhood farms as a function of seaway distance, which can be viewed as a between farm transmission kernel for salmon lice. The present modelling framework lays the foundation for development of future scenario simulation tools for examining the spread and abundance of salmon lice on farmed salmonids under different control regimes.
Collapse
|
24
|
Torrissen O, Jones S, Asche F, Guttormsen A, Skilbrei OT, Nilsen F, Horsberg TE, Jackson D. Salmon lice--impact on wild salmonids and salmon aquaculture. JOURNAL OF FISH DISEASES 2013; 36:171-94. [PMID: 23311858 PMCID: PMC3675643 DOI: 10.1111/jfd.12061] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 10/15/2012] [Accepted: 10/17/2012] [Indexed: 05/04/2023]
Abstract
Salmon lice, Lepeophtheirus salmonis, are naturally occurring parasites of salmon in sea water. Intensive salmon farming provides better conditions for parasite growth and transmission compared with natural conditions, creating problems for both the salmon farming industry and, under certain conditions, wild salmonids. Salmon lice originating from farms negatively impact wild stocks of salmonids, although the extent of the impact is a matter of debate. Estimates from Ireland and Norway indicate an odds ratio of 1.1:1-1.2:1 for sea lice treated Atlantic salmon smolt to survive sea migration compared to untreated smolts. This is considered to have a moderate population regulatory effect. The development of resistance against drugs most commonly used to treat salmon lice is a serious concern for both wild and farmed fish. Several large initiatives have been taken to encourage the development of new strategies, such as vaccines and novel drugs, for the treatment or removal of salmon lice from farmed fish. The newly sequenced salmon louse genome will be an important tool in this work. The use of cleaner fish has emerged as a robust method for controlling salmon lice, and aquaculture production of wrasse is important towards this aim. Salmon lice have large economic consequences for the salmon industry, both as direct costs for the prevention and treatment, but also indirectly through negative public opinion.
Collapse
Affiliation(s)
- O Torrissen
- Institute of Marine Research, Nordnes, Bergen, Norway.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Jackson D, McDermott T, Kane F, O’Donohoe P, Kelly S. Evaluation of the impacts of aquaculture and freshwater habitat on the status of Atlantic salmon stocks in Ireland. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/as.2013.46a010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|