1. Adult coho salmon Oncorhynchus kisutch return each autumn to freshwater spawning habitats throughout western North America. The migration coincides with increasing seasonal rainfall, which in turn ...increases storm water run-off, particularly in urban watersheds with extensive impervious land cover. Previous field assessments in urban stream networks have shown that adult coho are dying prematurely at high rates (> 50%). Despite significant management concerns for the long-term conservation of threatened wild coho populations, a causal role for toxic run-off in the mortality syndrome has not been demonstrated. 2. We exposed otherwise healthy coho spawners to: (i) artificial storm water containing mixtures of metals and petroleum hydrocarbons, at or above concentrations previously measured in urban run-off; (ii) undiluted storm water collected from a high traffic volume urban arterial road (i.e. highway run-off); and (iii) highway run-off that was first pre-treated via bioinfiltration through experimental soil columns to remove pollutants. 3. We find that mixtures of metals and petroleum hydrocarbons - conventional toxic constituents in urban storm water - are not sufficient to cause the spawner mortality syndrome. By contrast, untreated highway run-off collected during nine distinct storm events was universally lethal to adult coho relative to unexposed controls. Lastly, the mortality syndrome was prevented when highway run-off was pretreated by soil infiltration, a conventional green storm water infrastructure technology. 4. Our results are the first direct evidence that: (i) toxic run-off is killing adult coho in urban watersheds, and (ii) inexpensive mitigation measures can improve water quality and promote salmon survival. 5. Synthesis and applications. Coho salmon, an iconic species with exceptional economic and cultural significance, are an ecological sentinel for the harmful effects of untreated urban runoff. Wild coho populations cannot withstand the high rates of mortality that are now regularly occurring in urban spawning habitats. Green storm water infrastructure or similar pollution prevention methods should be incorporated to the maximal extent practicable, at the watershed scale, for all future development and redevelopment projects, particularly those involving transportation infrastructure.
► Crude oils from distinct geological sources produce an overlapping cardiotoxicity syndrome in developing zebrafish embryos. ► The patterns of AHR activation in cardiac tissue depended on the degree ...of weathering of the oils. ► Mechanisms of cardiotoxicity of petrogenic PAH mixtures likely shift with changes in mixture composition due to weathering. ► Data collected on intensively studied crude oils such as ANSCO can help predict the impacts of other oil spills.
Crude oils from different geological formations vary in composition, yet most crude oils contain a polycyclic aromatic hydrocarbon (PAH) fraction that would be expected to produce cardiotoxic effects in developing fish. To determine whether different crude oils or PAH compositions produce common or distinct effects, we used zebrafish embryos to directly compare two crude oils at different states of weathering. Iranian heavy crude oil (IHCO) spilled in the Yellow Sea following the 2007 Hebei Spirit accident was compared to the intensively studied Alaska North Slope crude oil (ANSCO) using two different exposure methods, water-accommodated fractions containing dispersed oil microdroplets and oiled gravel effluent. Overall, both crude oils produced a largely overlapping suite of defects, marked by the well-known effects of PAH exposure on cardiac function. Specific cardiotoxicity phenotypes were nearly identical between the two oils, including impacts on ventricular contractility and looping of the cardiac chambers. However, with increased weathering, tissue-specific patterns of aryl hydrocarbon receptor (AHR) activation in the heart changed, with myocardial AHR activation evident when alkyl-PAHs dominated the mixture. Our findings suggest that mechanisms of cardiotoxicity may shift from a predominantly AHR-independent mode during early weathering to a multiple pathway or synergistic mode with prolonged weathering and increased proportions of dissolved alkyl-PAHs. Despite continued need for comparisons of crude oils from different sources, the results here indicate that the body of knowledge already acquired from studies of ANSCO is directly relevant to understanding the impacts of other crude oil spills on the early life history stages of fish.
In November 2007, the container ship Cosco Busan released 54,000 gallons of bunker fuel oil into San Francisco Bay. The accident oiled shoreline near spawning habitats for the largest population of ...Pacific herring on the west coast of the continental United States. We assessed the health and viability of herring embryos from oiled and unoiled locations that were either deposited by natural spawning or incubated in subtidal cages. Three months after the spill, caged embryos at oiled sites showed sublethal cardiac toxicity, as expected from exposure to oil-derived polycyclic aromatic compounds (PACs). By contrast, embryos from the adjacent and shallower intertidal zone showed unexpectedly high rates of tissue necrosis and lethality unrelated to cardiotoxicity. No toxicity was observed in embryos from unoiled sites. Patterns of PACs at oiled sites were consistent with oil exposure against a background of urban sources, although tissue concentrations were lower than expected to cause lethality. Embryos sampled 2 y later from oiled sites showed modest sublethal cardiotoxicity but no elevated necrosis or mortality. Bunker oil contains the chemically uncharacterized remains of crude oil refinement, and one or more of these unidentified chemicals likely interacted with natural sunlight in the intertidal zone to kill herring embryos. This reveals an important discrepancy between the resolving power of current forensic analytical chemistry and biological responses of keystone ecological species in oiled habitats. Nevertheless, we successfully delineated the biological impacts of an oil spill in an urbanized coastal estuary with an overlapping backdrop of atmospheric, vessel, and land-based sources of PAC pollution.
Pacific herring embryos (Clupea pallasi) spawned three months following the Cosco Busan bunker oil spill in San Francisco Bay showed high rates of late embryonic mortality in the intertidal zone at ...oiled sites. Dead embryos developed to the hatching stage (e.g. fully pigmented eyes) before suffering extensive tissue deterioration. In contrast, embryos incubated subtidally at oiled sites showed evidence of sublethal oil exposure (petroleum-induced cardiac toxicity) with very low rates of mortality. These field findings suggested an enhancement of oil toxicity through an interaction between oil and another environmental stressor in the intertidal zone, such as higher levels of sunlight-derived ultraviolet (UV) radiation. We tested this hypothesis by exposing herring embryos to both trace levels of weathered Cosco Busan bunker oil and sunlight, with and without protection from UV radiation. Cosco Busan oil and UV co-exposure were both necessary and sufficient to induce an acutely lethal necrotic syndrome in hatching stage embryos that closely mimicked the condition of dead embryos sampled from oiled sites. Tissue levels of known phototoxic polycyclic aromatic compounds were too low to explain the observed degree of phototoxicity, indicating the presence of other unidentified or unmeasured phototoxic compounds derived from bunker oil. These findings provide a parsimonious explanation for the unexpectedly high losses of intertidal herring spawn following the Cosco Busan spill. The chemical composition and associated toxicity of bunker oils should be more thoroughly evaluated to better understand and anticipate the ecological impacts of vessel-derived spills associated with an expanding global transportation network.
Adult coho salmon Oncorhynchus kisutch return each autumn to freshwater spawning habitats throughout western North America. The migration coincides with increasing seasonal rainfall, which in turn ...increases storm water run‐off, particularly in urban watersheds with extensive impervious land cover. Previous field assessments in urban stream networks have shown that adult coho are dying prematurely at high rates (>50%). Despite significant management concerns for the long‐term conservation of threatened wild coho populations, a causal role for toxic run‐off in the mortality syndrome has not been demonstrated. We exposed otherwise healthy coho spawners to: (i) artificial storm water containing mixtures of metals and petroleum hydrocarbons, at or above concentrations previously measured in urban run‐off; (ii) undiluted storm water collected from a high traffic volume urban arterial road (i.e. highway run‐off); and (iii) highway run‐off that was first pre‐treated via bioinfiltration through experimental soil columns to remove pollutants. We find that mixtures of metals and petroleum hydrocarbons – conventional toxic constituents in urban storm water – are not sufficient to cause the spawner mortality syndrome. By contrast, untreated highway run‐off collected during nine distinct storm events was universally lethal to adult coho relative to unexposed controls. Lastly, the mortality syndrome was prevented when highway run‐off was pretreated by soil infiltration, a conventional green storm water infrastructure technology. Our results are the first direct evidence that: (i) toxic run‐off is killing adult coho in urban watersheds, and (ii) inexpensive mitigation measures can improve water quality and promote salmon survival. Synthesis and applications. Coho salmon, an iconic species with exceptional economic and cultural significance, are an ecological sentinel for the harmful effects of untreated urban run‐off. Wild coho populations cannot withstand the high rates of mortality that are now regularly occurring in urban spawning habitats. Green storm water infrastructure or similar pollution prevention methods should be incorporated to the maximal extent practicable, at the watershed scale, for all future development and redevelopment projects, particularly those involving transportation infrastructure.
•Persistent organic pollutants were measured in fish prey of rhinoceros auklets.•PCB and PBDE levels were generally highest in fish from the inland water colony.•Contaminant profiles differed between ...inland water and outer coast locations.•PCB and PBDE burdens for pre-fledging auklet chicks are considerable.
Organochlorine contaminants in upper trophic-level consumers inhabiting Puget Sound are consistently higher than in those species inhabiting other west coast locations. We analyzed persistent organic pollutants (POPs) in the six most common fish prey of rhinoceros auklets breeding on Protection Island (Puget Sound), Tatoosh Island (WA coast), and Destruction Island (WA coast). Wet-weight concentrations of POPs ranged widely (PCBs: 1.6–25.0ng/g; DDTs: 0.2–56.0ng/g; PBDEs:<LOQ-49.0ng/g), but overall patterns showed fish from Puget Sound were 2–4 times more contaminated and had similar contaminant profiles compared to fish from the outer coast. Unexpectedly elevated PCB and PBDE concentrations in Chinook salmon from the outer coast likely reflected Columbia River. Calculating contaminant loads for auklet nestlings magnified differences observed between inland and outer coast fish prey. Monitoring of breeding auklets, their prey and other resident marine birds is needed to assess biomagnification impacts in the Puget Sound marine ecosystem.
Aluminum smelter-derived polycyclic aromatic hydrocarbons (PAHs) in outmigrant juvenile Chinook salmon were evaluated in Kitimat Arm, British Columbia, Canada from 2000 to 2004, and in 2015. Decades ...of continual smelter operations by Rio Tinto resulted in PAH contamination of marine sediments at levels associated with adverse effects in juvenile salmon. Recently, smelter operations have undergone process changes to reduce PAH input to the environment. The PAH concentrations in juvenile Chinook salmon observed in 2000 to 2004, at sites nearest the smelter were comparable to salmon in other urban areas where reduced disease resistance was observed; the levels were lower in 2015 than 2000–2004 suggesting that the recent process changes were effective. Further, these data establish a benchmark for assessing any future changes affecting PAH input and the potential risks to the receiving environment.
•Temporal trends of aluminum smelter derived-PAHs in juvenile Chinook salmon were assessed•PAH levels were highest in fish from sites closest to the smelter, and PAHs were similar to those produced by the smelter•Highest PAH levels were in the range where health effects occur•Following process changes at the smelter, PAH exposure tended to decline in fish from sites closest to the smelter•These data provide important benchmarks for PAH exposure in this area
Documentation of exposure of threatened and endangered sea turtles to petroleum and dispersant released into the northern Gulf of Mexico (GoM) during the Deepwater Horizon(DWH) oil spill was a ...critical component of the Natural Resource Damage Assessment (NRDA) process. Substances collected from the skin of oiled and suspected oiled turtles were analyzed for petroleum hydrocarbons to determine oiling status and oil sources. Tissue, gastroenteric and bile samples from a subset of visibly oiled and unoiled turtles that died during the spill in 2010 and in 2011 were analyzed for evidence of internal exposure and absorption of polycyclic aromatic hydrocarbons (PAHs) and the dispersant component dioctyl sodium sulfosuccinate (DOSS). The volume of external oil collected from sea turtles was sufficient to confirm the presence of petroleum on 61% of turtles, and oil from the DWH spill was identified as the source in 97% of those turtles in which conclusive comparison was possible. Visibly oiled turtles had higher concentrations of tissue PAH or biliary fluorescent PAH metabolites compared to those determined in unoiled animals. Findings in most of the unoiled turtles were suggestive of low-level PAH exposure from various sources that may represent background values for sea turtles from the northern GoM. DOSS levels were below the limit of quantitation in all samples analyzed except in an esophagus sample of a heavily oiled sea turtle. Overall, the results for petroleum or petroleum-derived compounds of both external and internal samples of sea turtles supported visual observations of oiling.
Status of sablefish, Anoplopoma fimbria, aquaculture Goetz, Frederick William; Anulacion, Bernadita F.; Arkoosh, Mary R. ...
Journal of the World Aquaculture Society,
June 2021, 2021-06-00, 20210601, Letnik:
52, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Sablefish, Anoplopoma fimbria (also called black cod), is a long‐lived marine species with wide distribution extending from Baja California to Alaska, the Bering Sea, and through to the eastern coast ...of Japan. The landed weight of sablefish in the U.S. commercial fisheries is not large compared with other species; however, the exceptional value of sablefish has ranked it high compared with other species such as pollock, sockeye salmon, and Pacific cod. Sablefish are high in omega‐3 fatty acids and have white firm flesh with superior quality and taste. Current population levels are lower relative to historic ones and harvests have decreased within the last decade. The exceptional value of sablefish and decreases in wild populations have stimulated the development of methods to commercially aquaculture this species. Over the last 20 years, significant progress has been made in addressing the production of sablefish, and while there is still research that needs to be completed, sablefish have been commercially aquacultured by a small number of Canadian companies. In the Pacific Northwest, it is relatively easy to collect sablefish broodstocks from the wild and to transition them to land‐based rearing facilities. However, they must be maintained at cold temperatures to successfully reproduce. Captive broodstocks for genetic selection are not commercially available, though producers have begun their own development. Incubation conditions for yolk‐sac larvae have been developed and currently require long incubation periods at low temperatures, elevated salinity, and light exclusion. Although incubation times are long, they do not require very much attention during this phase. Exogenously feeding larvae currently require a regimen of rotifers and Artemia prior to dry feed habituation. However, tank characteristics, water turbidity, temperature, and illumination, as well as live feed enrichments have been studied. With the research that has been accomplished so far, survival rates of 10–40% have been routinely obtained at the larval stage. Despite a scarcity of species‐specific nutritional studies, researchers have shown that sablefish can be successfully cultured from the juvenile to the adult stage on commercial salmon feeds. Off‐the‐shelf salmon feeds have been used successfully in net‐pen grow‐out trials and are used by commercial producers. In addition, sablefish have proven to be a good cold‐water marine model for alternative feeds research. Still, research is needed to optimize nutritional requirements for all life stages of sablefish, develop practical feeds with these nutrient profiles, optimize feeding schedules, and produce life‐stage specific diets since the growth of sablefish differs according to size—most likely reflective of their complex life history. Sexually dimorphic growth in sablefish occurs during the typical grow‐out period, affecting time to harvest, the proportion of undersized (male) fish, and thus overall economic return to the producer. Production of all‐female monosex offspring at semi‐commercial scale using F‐1 progeny of neomales (XX males) generated through dietary treatment with 17α‐methyltestosterone is now possible. Results of long‐term feeding trials suggest that time to harvest at 2.5 kg from stocking at 75 g may be reduced by almost 3 months when monosex stocks are used. Econometric models reveal that internal rates of return are 11–15% higher for monosex relative to mix‐sex stocks over a 10‐year period under typical cage culture conditions. Sablefish are susceptible to diseases (furunculosis and vibriosis) brought on by atypical Aeromonas salmonicida and Vibrio anguillarum. Vaccination of sablefish using commercial vaccines to A. salmonicida (typical and atypical) has demonstrated that fish can be protected against a subsequent challenge by A. salmonicida, but this has only been effective by injection of the vaccine (not immersion) and how long the protection lasts has not been studied. More research is required to develop more effective vaccines, methods for vaccine delivery, and to understand conditions (ontogenetic and environmental) that may promote or enhance pathogenesis.
From 2000-2004 a monitoring study was conducted to evaluate the impacts of aluminum smelter-derived polycyclic aromatic hydrocarbons (PAHs) on the health of fish in the marine waters of Kitimat, ...British Columbia, Canada. These waters are part of the historical fishing grounds of the Haisla First Nation, and since the 1950s the Alcan Primary Metal Company has operated an aluminum smelter at the head of the Kitimat Arm embayment. As a result, adjacent marine and estuarine sediments have been severely contaminated with a mixture of smelter-associated PAHs in the range of 10,000-100,000 ng/g dry wt. These concentrations are above those shown to cause adverse effects in fish exposed to PAHs in urban estuaries, but it was uncertain whether comparable effects would be seen at the Kitimat site due to limited bioavailability of smelter-derived PAHs. Over the 5-year study we conducted biennial collections of adult English sole (Parophrys vetulus) and sediment samples at the corresponding capture sites. Various tissue samples (e.g. liver, kidney, gonad, stomach contents) and bile were taken from each animal to determine levels of exposure and biological effects, and compare the uptake and toxicity of smelter-derived PAHs with urban mixtures of PAHs. Results showed significant intersite differences in concentrations of PAHs. Sole collected at sites nearest the smelter showed increased PAH exposure, as well as significantly higher prevalences of PAH-associated liver disease, compared to sites within Kitimat Arm that were more distant from the smelter. However, measures of PAH exposure (e.g., bile metabolites) were surprisingly high in sole from the reference sites outside of Kitimat Arm, though sediment and dietary PAHs at these sites were low, and fish from the areas showed no biological injury. PAH uptake, exposure, and biological effects in Kitimat English sole were relatively lower when compared to English sole collected from urban sites contaminated with PAH mixtures from other sources. These findings indicate that while smelter-associated PAHs in Kitimat Arm appear to be causing some injury to marine resources, they likely have reduced bioavailability, and thus reduced biological toxicity, compared to other environmental PAH mixtures.
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