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Multiple stressor effects in early life stage fish

Multiple stressor effects in early life stage fish. Adria A. Elskus U.S. Geological Survey – Aquatic Toxicology Section University of Maine NOAA/Maine SeaGrant Atlantic Salmon Workshop 22-23 July 2008. Contaminant effects on salmonids as related to tissue residue levels.

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Multiple stressor effects in early life stage fish

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  1. Multiple stressor effects in early life stage fish Adria A. Elskus U.S. Geological Survey – Aquatic Toxicology Section University of Maine NOAA/Maine SeaGrant Atlantic Salmon Workshop 22-23 July 2008

  2. Contaminant effects on salmonids as related to tissue residue levels Triazines Olfaction, Endocrine disruption (ug/L)1 ppb Triazines+NP Smoltification (ug/L)6 ppb Organophosphates Olfaction, Homing (ng-ug/L)2 pptr-ppb Dioxin Visual acuity (100 pg/g egg)3 pptr Prey capture (300 pg/g egg)3 pptr Blue sac disease (30 pg/g egg)4 pptr Adult & fry survival (0.3 pg/g egg)8 pptr o,p-DDE Immunosuppression (0.5 ug/g lipid)9ppm PCBs ~ Sublethal threshold for juvenile salmonids (2.4 ug PCB/g lipid; 24-192 ng/g wet)7ppm, ppb Methyl mercury Altered feeding (4000 ng/g liver)5ppb 1Moore&Lower, 2001;2Scholz et al., 2000;3Carvalho & Tillitt, 2004; 4Cook et al., 2003;5Berntssen et al., 2003; 6Moore et al., 2003;7Meador et al., 2002;8Giesy et al. 2002;9Milston et al. 2003

  3. Poor marine survival of ATS:Compromised during early life stages? Hatchery fish ~ compromised due to conditions in the hatchery: • Contaminants in feed10 ~ very efficient bioaccumulation/biomagnification (parr broodstock)11 ~ remobilized during fasting (e.g. smoltification) to vital organs (brain, liver, kidney)12 ~ alter immune function, growth, survival, olfaction 12, 13, 14 ~ early life stage exposure alters development of these systems9,14,22 ~ additive/synergistic effects of mixtures of chemicals10 ~ levels of PCBs in GLNFH salmon (1-3 year olds)21 approaching PCB effects threshold7 • Dry food instead of live food ~ prey capture efficiency compromised? • Lack learned behaviors of wild counterparts ~ prey capture efficiency compromised? ~ poor predator avoidance? • Physical environment in hatchery ~ L/D cycles (photoperiod) inconsistent/not ambient? ~ diurnal temperature swings dampened? ~ noise (e.g. low water alarm/CBNFH) CONSEQUENCES: • MULTIPLE STRESSOR CONDITIONS EXIST IN THE HATCHERIES, • EXPOSURE/STRESS DURING EARLY LIFE STAGES CAN BE MANIFESTED AS COMPROMISED PHYSIOLOGY IN LATER LIFE STAGES 10 Maule et al 2007; 11 Isosaari et al 2004; 12 Jorgensen et al 2002; 13 Maule et al 2005; 14 Jorgensen et al 2004; 21 Millard et al 2004; 22Lerner et al 2007b

  4. ‘Wild’ fish ~ compromised due to riverine conditions: • acid, aluminum, pesticides, organochlorines, temperature interactions = multiple stressors ~ olfaction (homing, synchronized mating, detecting mating cues, alarm/predator cues) 15 ~ smolting16,23 ~ immune competence9 ~ ability to mount effective response to stress13 ~ survival of adults exposed as parr-smolts17 ~ swimming, survival, growth of smolts19 ~ early life stage exposure alters development of these systems23 • compromised prey? (abundance/timing of arrival/appropriate species composition) 15Moore & Waring 1998; 16Arsenault et al 2004; 17Brown & Fairchild 2003; 19Smith&Haines, 1995; 23Lerner et al 2007a [Data in graph: 17Jackson, 2003; 18MBPC, 2002;20Johnson & Kahl, 2005]

  5. Hypothesis, Research, Management-1 Hypothesis: Effects on early life stages are not manifested until fish reach transitional life stages (e.g., smolting, SW entry, spawning). Research Activities: Evaluate effects of early life stage rearing conditions on later life stages (fry, parr, smolts): A. Compare the effects of the parr-broodstock rearing strategy on contaminant loads and fitness of fry and smolts: i. Screen: Screen fry and smolts, reared from adult-broodstock and parr-broodstock, for tissue contaminants. Compare contaminant loads to published sublethal thresholds for salmon. ii. Screen: Screen fry and smolts reared from adult-broodstock and parr-broodstock, for fitness endpoints (e.g. immune competence, critical swimming speed, prey capture efficiency).

  6. Hypothesis, Research, Management - 2 B. Compare the effects of eliminating exposure to periodic pulses of acid and aluminum throughout early life stage development iii. Rear salmon, fertilization through smolts, at the DSF-Pleasant River hatchery with half the water buffered, and half not-buffered (study in progress) and measure fitness endpoints at several life stages. • Strength: isolates acid/Al stress from other stresses. • Drawback: combines river and hatchery stressors. iv. Temperature-mark DSF fry (from iii. above), release them in the Pleasant River, collect migrating smolts (both hatchery-reared and wild) from the Pleasant River and compare fitness. • Strength: isolates effects of hatchery conditions (e.g. parr-broodstock rearing) from acid/Al stress (since both DSF fry and wild ATS fry will experience acid/Al from fry stage to smolt). • Drawback: will there be enough wild fish for comparison? Management Activities a. Change rearing strategies? b. Change stocking strategies? c. Determine whether or not to lime the rivers?

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