scholarly journals Physiological resilience of pink salmon to naturally occurring ocean acidification

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Andrea Y Frommel ◽  
Justin Carless ◽  
Brian P V Hunt ◽  
Colin J Brauner

Abstract Pacific salmon stocks are in decline with climate change named as a contributing factor. The North Pacific coast of British Columbia is characterized by strong temporal and spatial heterogeneity in ocean conditions with upwelling events elevating CO2 levels up to 10-fold those of pre-industrial global averages. Early life stages of pink salmon have been shown to be affected by these CO2 levels, and juveniles naturally migrate through regions of high CO2 during the energetically costly phase of smoltification. To investigate the physiological response of out-migrating wild juvenile pink salmon to these naturally occurring elevated CO2 levels, we captured fish in Georgia Strait, British Columbia and transported them to a marine lab (Hakai Institute, Quadra Island) where fish were exposed to one of three CO2 levels (850, 1500 and 2000 μatm CO2) for 2 weeks. At ½, 1 and 2 weeks of exposure, we measured their weight and length to calculate condition factor (Fulton’s K), as well as haematocrit and plasma [Cl−]. At each of these times, two additional stressors were imposed (hypoxia and temperature) to provide further insight into their physiological condition. Juvenile pink salmon were largely robust to elevated CO2 concentrations up to 2000 μatm CO2, with no mortality or change in condition factor over the 2-week exposure duration. After 1 week of exposure, temperature and hypoxia tolerance were significantly reduced in high CO2, an effect that did not persist to 2 weeks of exposure. Haematocrit was increased by 20% after 2 weeks in the CO2 treatments relative to the initial measurements, while plasma [Cl−] was not significantly different. Taken together, these data indicate that juvenile pink salmon are quite resilient to naturally occurring high CO2 levels during their ocean outmigration.

2017 ◽  
Vol 130 (4) ◽  
pp. 336 ◽  
Author(s):  
Eric A Parkinson ◽  
Chris J Perrin ◽  
Daniel Ramos-Espinoza ◽  
Eric B Taylor

The Coho Salmon, Oncorhynchus kisutch, is one of seven species of Pacific salmon and trout native to northeastern Pacific Ocean watersheds. The species is typically anadromous; adults reproduce in fresh water where juveniles reside for 1–2 years before seaward migration after which the majority of growth occurs in the ocean before maturation at 2–4 years old when adults return to fresh water to spawn. Here, we report maturation of Coho Salmon in two freshwater lakes on the north coast of British Columbia apparently without their being to sea. A total of 15 mature fish (11 males and four females) were collected in two lakes across two years. The mature fish were all at least 29 cm in total length and ranged in age from three to five years old. The occurrence of Coho Salmon that have matured in fresh water without first going to sea is exceedingly rare in their natural range, especially for females. Such mature Coho Salmon may represent residual and distinct breeding populations from those in adjacent streams. Alternatively, they may result from the ephemeral restriction in the opportunity to migrate seaward owing to low water levels in the spring when Coho Salmon typically migrate to sea after 1–2 years in fresh water. Regardless of their origin, the ability to mature in fresh water without seaward migration may represent important adaptive life history plasticity in response to variable environments.


2011 ◽  
Vol 68 (6) ◽  
pp. 1122-1130 ◽  
Author(s):  
James R. Irvine ◽  
Masa-aki Fukuwaka

Abstract Irvine, J. R., and Fukuwaka, M. 2011. Pacific salmon abundance trends and climate change. – ICES Journal of Marine Science, 68: 1122–1130. Understanding reasons for historical patterns in salmon abundance could help anticipate future climate-related changes. Recent salmon abundance in the northern North Pacific Ocean, as indexed by commercial catches, has been among the highest on record, with no indication of decline; the 2009 catch was the highest to date. Although the North Pacific Ocean continues to produce large quantities of Pacific salmon, temporal abundance patterns vary among species and areas. Currently, pink and chum salmon are very abundant overall and Chinook and coho salmon are less abundant than they were previously, whereas sockeye salmon abundance varies among areas. Analyses confirm climate-related shifts in abundance, associated with reported ecosystem regime shifts in approximately 1947, 1977, and 1989. We found little evidence to support a major shift after 1989. From 1990, generally favourable climate-related marine conditions in the western North Pacific Ocean, as well as expanding hatchery operations and improving hatchery technologies, are increasing abundances of chum and pink salmon. In the eastern North Pacific Ocean, climate-related changes are apparently playing a role in increasing chum and pink salmon abundances and declining numbers of coho and Chinook salmon.


2016 ◽  
Vol 74 (4) ◽  
pp. 1051-1061 ◽  
Author(s):  
Christopher S. Murray ◽  
Lee A. Fuiman ◽  
Hannes Baumann

Ocean acidification may impact the fitness of marine fish, however, studies reporting neutral to moderate effects have mostly performed short-term exposures to elevated CO2, whereas longer-term studies across life stages are still scarce. We performed a CO2 exposure experiment, in which a large number (n > 2200) of Atlantic silverside Menidia menidia offspring from wild spawners were reared for 135 days through their embryonic, larval, and juvenile stages under control (500 µatm) and high CO2 conditions (2300 µatm). Although survival was high across treatments, subtle but significant differences in length, weight, condition factor and fatty acid (FA) composition were observed. On average, fish from the acidified treatment were 4% shorter and weighed 6% less, but expressed a higher condition factor than control juveniles. In addition, the metrics of length and weight distributions differed significantly, with juveniles from the high CO2 treatment occupying more extreme size classes and the length distribution shifting to a positive kurtosis. Six of twenty-seven FAs differed significantly between treatments. Our results suggest that high CO2 conditions alter long-term growth in M. menidia, particularly in the absence of excess food. It remains to be shown whether and how these differences will impact fish populations in the wild facing size-selective predation and seasonally varying prey abundance.


2020 ◽  
Vol 77 (6) ◽  
pp. 943-949 ◽  
Author(s):  
Brendan Connors ◽  
Michael J. Malick ◽  
Gregory T. Ruggerone ◽  
Pete Rand ◽  
Milo Adkison ◽  
...  

Pacific salmon productivity is influenced by ocean conditions and interspecific interactions, yet their combined effects are poorly understood. Using data from 47 North American sockeye salmon (Oncorhynchus nerka) populations, we present evidence that the magnitude and direction of climate and competition effects vary over large spatial scales. In the south, a warm ocean and abundant salmon competitors combined to strongly reduce sockeye productivity, whereas in the north, a warm ocean substantially increased productivity and offset the negative effects of competition at sea. From 2005 to 2015, the approximately 82 million adult pink salmon (Oncorhynchus gorbuscha) produced annually from hatcheries were estimated to have reduced the productivity of southern sockeye salmon by ∼15%, on average. In contrast, for sockeye at the northwestern end of their range, the same level of hatchery production was predicted to have reduced the positive effects of a warming ocean by ∼50% (from a ∼10% to a ∼5% increase in productivity, on average). These findings reveal spatially dependent effects of climate and competition on sockeye productivity and highlight the need for international discussions about large-scale hatchery production.


1994 ◽  
Vol 21 (3) ◽  
pp. 281 ◽  
Author(s):  
S Seneweera ◽  
P Milham ◽  
J Conroy

The growth and development of a short-duration rice cultivar (Oryza sativa L. cv. Jarrah), grown in flooded soil with a range of phosphorus (P) levels and exposed to atmospheric CO2 concentrations of either 350 or 700 μL L-1 was followed for 146 days after planting (DAP). Development (estimated by rate of tiller production and time to flowering) was faster with higher soil P levels and CO2 enrichment, the effect being more pronounced with CO2 enrichment. During the early vegetative phase (up to 35 DAP), when rates of tiller production were low, shoot growth and rates of leaf expansion were faster at elevated CO2 concentrations and high soil P levels. Rates of tiller production were greater with these treatments during the 35-56 DAP period, when tillering was at a maximum. Shoot elongation was reduced at elevated CO2 levels and at high soil P levels during this period. By 146 DAP leaf weight was greater at high P levels, but CO2 enrichment accelerated tiller production to such an extent that final leaf weight was lower at high CO2, probably because there were fewer, and smaller, leaves on each tiller. Despite this, grain yield was increased by up to 58% by CO2 enrichment, with increases occurring even at low soil P levels. This was due mainly to an increase in grain number per panicle, although panicle number also increased. Higher soil P levels also increased grain number and yield. The P concentration in the foliage was unaffected by the CO2 treatments and the concentration required to produce maximum yield was 0.18% (dry wt basis) at both CO2 levels. Greater starch accumulation in the stems of high-CO2-grown plants may have accounted for the higher number of grains in each panicle.


1936 ◽  
Vol 2 (5) ◽  
pp. 439-455 ◽  
Author(s):  
Neal M. Carter

The proximate compositions and calculated calorific values of individual and composite samples of canned sockeye (Oncorhynchus nerka) and pink (O. gorbuscha) salmon from fish caught in several localities on the British Columbia coast are compared. The resulting data are also presented in such a way as to allow comparison of the composition and energy content of the various constituents in the can, some of which are frequently discarded in the utilization of canned salmon. The average percentages of the total oil, protein, salt (sodium chloride)-free minerals, and Calories contributed by the different constituents in the samples were respectively: flesh—(sockeye) 62, (pink) 72; 85, 81; 55, 54; 73, 78; skin—(sockeye) 11.2, (pink) 15.3; 3.6, 4.3; 9.8, 6.7; 7.7, 9.0; free aqueous liquor—(sockeye) 0, (pink) 0; 11, 14; 5, 7; 4, 8; free oil—(oil) 26, 10; (Calories) 15, 4; bone—(salt-free minerals) 30.2, 32.6. Corresponding average percentage compositions of composite samples of entire contents were: water—(sockeye) 68.6, (pink) 71.5; oil—8.82, 6.75; protein—20.2, 19.3; salt-free minerals—1.57, 1.57. The average energy contents were (sockeye) 749, (pink) 644 Calories per pound. Comparison with published analyses of canned sockeye and pink salmon from Alaska and Washington indicated that more extensive and detailed sampling will be necessary before conclusions can be drawn regarding the comparative compositions and food values of canned British Columbia salmons, and the relation of these values to those of salmon caught to the north and south.


2006 ◽  
Vol 63 (9) ◽  
pp. 2076-2086 ◽  
Author(s):  
Morgan D Hocking ◽  
Thomas E Reimchen

Anadromous Pacific salmon (Oncorhynchus spp.) subsidize terrestrial food webs with their nutrients and carcasses, a process driven largely by selective foraging by bears (Ursus spp.). We quantify wildlife transfer of salmon carcasses to riparian zones on two watersheds in coastal British Columbia and estimate total terrestrial fly production from remnant carcasses. Large-bodied chum salmon (Oncorhynchus keta) were transferred into the forest at a greater rate than were pink salmon (Oncorhynchus gorbuscha) (chum salmon mass = 6089–11 031 kg, 16%–48% of salmon run; pink salmon mass = 2266–2808 kg, 4%–6% of salmon run). Blow flies (genus Calliphora) and other Diptera dominated colonization (>90% of salmon carcasses). Between the two watersheds, 196 and 265 g of Calliphora larvae per metre of spawning length (4 and 7 million larvae for whole watersheds) were generated from salmon carcass transfer. Stable isotope analysis of δ15N and δ13C of spring-emerging adult Calliphora revealed that >80% of individuals had salmon-based signatures. Flies are a dominant consumer and vector of salmon nutrients in terrestrial habitats and supplement the diet of at least 16 vertebrate and 22 invertebrate species. Anticipated further declines of salmon in the North Pacific can be expected to further erode the complex associations coupling marine and terrestrial ecosystems.


2020 ◽  
Vol 77 (12) ◽  
pp. 1960-1968
Author(s):  
Cole B. Brookson ◽  
Martin Krkošek ◽  
Brian P.V. Hunt ◽  
Brett T. Johnson ◽  
Luke A. Rogers ◽  
...  

Fraser River Pacific salmon have declined in recent decades, possibly from parasitism by sea lice (Caligus clemensi and Lepeophtheirus salmonis). We describe the abundance of both louse species infesting co-migrating juvenile pink (Oncorhynchus gorbuscha), chum (Oncorhynchus keta), and sockeye (Oncorhynchus nerka) salmon over 5 years in the Discovery Islands and Johnstone Strait, British Columbia. The generalist louse, C. clemensi, was 5, 7, and 39 times more abundant than the salmonid specialist, L. salmonis, on pink, chum, and sockeye salmon, respectively. Caligus clemensi abundance was higher on pink salmon (0.45, 95% CI: 0.38–0.55) and sockeye (0.39, 95% CI: 0.33–0.47) than on chum salmon. Lepeophtheirus salmonis abundance was highest on pink salmon (0.09, 95% CI = 0.06–0.15). Caligus clemensi had higher abundances in Johnstone Strait than in the Discovery Islands. These results suggest differences in host specialization and transmission dynamics between louse species. Because both lice infest farmed salmon, but only C. clemensi infests Pacific herring (Clupea pallasii), conservation science and management regarding lice and Fraser River salmon should further consider C. clemensi and transmission from farmed salmon and wild herring.


2017 ◽  
Vol 74 (7) ◽  
pp. 1077-1087 ◽  
Author(s):  
Allan J. Debertin ◽  
James R. Irvine ◽  
Carrie A. Holt ◽  
Gladys Oka ◽  
Marc Trudel

Thirty-nine years of scale growth measurements from Big Qualicum River chum salmon (Oncorhynchus keta) in southern British Columbia demonstrated that competition and climate variation affect marine growth and age-at-maturity. A longitudinal study design that accounted for correlation among individuals revealed growth at all ages was reduced when the biomass of North American chum, sockeye (Oncorhynchus nerka), and pink salmon (Oncorhynchus gorbuscha) was high. When North Pacific Gyre Oscillation (NPGO) was positive, indicating increased primary productivity, predicted growth increased. Climate variation influenced competition effects. For instance, density-dependent competition effects increased when NPGO became more positive and Pacific Decadal Oscillation became more negative (indicating cool conditions), causing the greatest range in predicted scale size. Chum salmon are likely to exhibit continued reduction in growth at age due to increased ocean temperatures driven by climate change and high aggregate salmon biomass that includes hatchery releases. If evidence of biomass and climate effects presented here are common among Pacific salmon populations, reduction of hatchery releases should be considered.


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