Novel and emerging tools to assess the impacts of aquatic invasive species

Transcription

1 Novel and emerging tools to assess the impacts of aquatic invasive species

2 Hemimysis anomala the bloody red shrimp occupy littoral regions associated with structure diurnal migration daytime: crevices, rocky substrates night time: up in the water column omnivores algae, zooplankton consumed by a variety of fishes A. Perez-Fuentetaja, Buffalo State College J. Marty, St Lawrence River Institute 2 mm

3 Range expansion You are here native to Ponto Caspian range expansion through western Europe intentional, canals, bilge detected in N. Am. Great Lakes in 2006 ballast water

4 Great Lakes distribution Quebec City (2011) Montreal (2008) Muskegon (2006) Port Dover (2006) Oswego (2006) Finger Lakes (2009/10)

5 Spread to inland lakes? Rideau Canal 64,000 boats in 2012 Ottawa Kingston Recreational boating as vector for spread to inland lakes?

6 Spread to inland lakes? at present not in inland waters of Ontario Present Absent boater surveys distribution survey none detected in canal environmental DNA (edna) detection limit 2/L present below first lock but not above First lock

7 Prevent the spread? Decontamination guidelines Inspect, clean, drain Physiological tolerance: 1 min LC 90 = 41.3 ±0.6 C 30 min LC 90 = 44.2 ±4.6 mg/l NaOH (bleach)

8 Management Intervention Invasion Process Species in pathway General Policy & Management Options Arrival Survival Establishment Spread Ecological, human health or economic impact Prevention Early detection, rapid response & eradication Control / slow the spread Adaptation (change behaviour / bear the cost) or Restoration

9 Potential impacts of Hemimysis zooplankton & phytoplankton* fish growth & productivity* less for food for young fish but prey for larger planktivores (alewife & perch) contaminant biomagnification * Based on European studies

10 Effects on Lake Ontario food web , spring, summer & fall 4 nearshore locations gradient of Hemimysis density fish, Hemimysis, zooplankton, benthos, seston gut content & stable isotope analyses

11 Project Objectives 1. Quantify dominant trophic linkages from invertebrates to fish across a known gradient of Hemimysis density in Lake Ontario using diet analyses and stable isotopes. 2. Determine nutritional, physiological, and toxicological properties and transfer efficiencies for dominant food web linkages across the same Hemimysis density gradient.

12 Diet Analyses OMNR Lake Ontario diet analysis, examined 3,382 stomachs representing 38 species of nearshore fish 1,105 stomachs representing 24 species contained zooplankton 68 stomachs representing 10 species of fish contained Hemimysis only at sites where Hemimysis are present

13 Factors Influencing Detection Maybe fish don t like Hemimysis or fish need to adapt to the novel prey. (Fitzsimons et al. 2012) Or maybe Hemimysis are difficult to detect in stomachs?

14 Digestion Rate laboratory feeding trails (n=266) rock bass as predators four temperatures: 10, 15, 20, 25ºC range of Hemimysis size (4 mm to 9 mm) 1 to 5 Hemimysis per fish; also mixed diets no physical remains in stomach gone intact

15 Rapid Digestion in first 60 minutes Percent digestion Hemimysis mass (g) highly digested in <2 hrs more rapid for smaller body size not much effect of temperature Johnson et al. (in review) J. Great Lakes Res.

16 icanhascheezburger.com We need to find what we can t see...

17 Molecular Genetics Develop a highly specific tool to identify Hemimysis anomala remains in fish stomachs DNA fingerprint homogenise stomach content fluorescent dye + primer presence / absence snp assay useful for detection, feeding preference (frequency of occurrence, and by species) but we also need a quantitative measure of diet

18 Stable isotopes Waupoos, fall 2009 Hemimysis are at same trophic level as zooplankton but more enriched in δ 13 C similar δ 13 C as benthos but higher trophic level δ 15 N Zoop. Phyto. Top predators Hemimysis Prey fish Benthic Inverts Plants Offshore δ 13 C Nearshore Yuille et al J Great Lakes Res.

19 Hemimysis as prey higher frequency of occurrence at sites with higher Hemimysis density No Hemi High varies by species and life stage use SI mixing models to estimate diet C R SDA combine with bioenergetic models to evaluate growth U F

20 Effects on fish growth Instantaneous growth rate current range of historic growth 25% 50% 75% 100% % Hemimysis Diet scenario replace zoop. replace Amphi. seasonal change in growth must be greater than historic variability growth of omnivore (YP) declines; growth of planktivore (alewife) undetectable simple prey switching undetectable likely negative consequences for fish growth Yuille et al. (in review) Can. J. Fish. Aquat. Sci.

21 Required prey density 5000 Energy density (J/g) X = Energy availability (J m -2 ) 0 Prey density (g m -2 ) R. Dermott & K. Bowen, DFO? = Energy density (J g -1 ) planktivore: 210 to 1,062 m -2 omnivore: 170 to 642 m -2 Yuille et al. (in review) Can. J. Fish. Aquat. Sci.

22 Contaminant biomagnification 3 Cobourg nearshore log 10 Hg (ng/g) 2 1 QM CHI QM s s 366 AMP HA 366 HA Hemimysis offshore Hemimysis Hg burden reduced in nearshore food web; unlikely to increase contaminant biomagnification δ 15 N Zhang et al Environ. Pollut.

23 Management implications Hemimysis reach high abundance in the Great Lakes but largely confined to nearshore localised effects spread to inland lakes highly probable without aggressive intervention Hemimysis are centrally located in the food web fish consume Hemimysis Hemimysis is a good food* for planktivorous fish omnivorous fish will likely experience poorer growth Hemimysis can reach densities able to support good growth Hemimysis are unlikely to change contaminant bioaccumulation

24 AIS toolbox standardised sampling methods factors influencing detection Digestion rate, snp assay edna integrative measures Stable isotopes modelling Bioenergetic and contaminant models mitigation strategies Physiologic tolerances Outreach

25 Great Lakes Hemimysis meeting, Oct 2011

26 J. Marty, St Lawrence River Institute