status of aquatic non-indigenous species …...status of aquatic non-indigenous species in the...
TRANSCRIPT
STATUS OF AQUATIC NON-INDIGENOUS SPECIES IN THE DULUTH-SUPERIOR HARBOR
Anett Trebitz, Greg Peterson,Joel Hoffman,John R. Kelly, Corlis West
U.S. Environmental Protection Agency,Mid Continent Ecology Division, Duluth MN
MN–WI Invasive Species Conference St. Paul MN, Nov. 2010.
UNITED STATES
EN
VIR
ON
ME
NTAL PROTECTIO
NA
GE
NC
Y
Goal: Develop a generalized approach to early detection monitoring for aquatic non-indigenous species (NIS) in vulnerable coastal ecosystems
Technical Challenge:Finding “rare” before it becomes “common”, doing so efficiently without knowing what to look for (not targeting particular species or pathways)
Objectives of This Presentation:- Report on NIS found- Describe their abundance & distribution- Examine habitats and sampling gears they occurred in- Discuss challenges in determining invasion status
Duluth-Superior Harbor (St. Louis R. Estuary) as case study
Introduction Vectors Shipping - ballast water, tank-residue, cargo hitchhikers
Recr. boating & fishing - bilge, bait-bucket, hull & trailer fouling
Population center - sewer, aquarium dumping, transport. nexus
GL’s largest shipping port, known invasion “hotspot”
Large, open, ecotone system with substantial habitat diversity and range in anthropogenic impacts.
Extensive sampling to amass data with which to evaluate alternative strategies. Two designs for covering space: random, targeted.
Data collectionapproach
Data types and sources (sampling in 2005, 2006, 2007)
fyke netbottom trawl
ponar
Fish239 separate
samples
Benthos207 separate
samples
electrofishing
Habitat(fish & benthos stations)
depth, vegetation, substrate
water quality
geospatial context
colonization plates (littoral)
benthic sledsweep net (vegetation)
beach seine
19 benthic NIS detected - 8% of total taxa
quagga mussel*Lumholtz waterflea*Henslow’s pea clam*
hump-backed pea clam*2 oligochaete worms**Ischium sideswimmer
New Zealand mud snail
a colonial hydrozoanAsian clam
3 oligochaete worms
zebra musselEuropean valve snail
Moitessier’s pea clamtiger sideswimmer
greater European pea clamfasciatus sideswimmer
detected in 10 yrs prior to our study
present >10 yrs
newly detected
zebra mussel – most abundant benthos NIS
*new to L. Sup. ** new to G. Lks.
Joint press releases by U.S. EPA, Sea Grant, U.S. FWS, MN-DNR, WI-DNR
Example distributions for benthic NIS
adult size ~2.5 cm
USGS
Zebra mussel
Native to Eurasia.
First detected 1989.
Very abundant in lower
& middle system.
adult size 8-11 mm
USACE
Ischium sideswimmer
Native to Eurasia.
First detected 2005.
Scattered throughout system.
adult size up to 5 cm
USGS
Asian Clam
Native to Asia
first detected ~1999
Restricted, but abundant
in unique environment.
widespread, extremely abundant
spatially restricted, but abundant in unique habitat
common although not abundant
10 fish NIS detected – 24% of total taxa
tubenose goby round goby
3-spine stickleback brook silverside
white perch Eurasian ruffe
freshwater drum
rainbow smeltcommon carp
alewife
present <10 yrs
present >50 yrs
round goby & eurasian ruffe – most
abundant fish NIS present 10-20 yrs
We did not catch any NIS salmonids, which are seasonal users of DSH
Example distributions for fish NIS
adult size: 3.5 to 6.5 cm
(max 8 cm)
U.S. EPA
Threespine stickleback
Native to east and west coasts of N.
America including Lake Ontario.
First detected 1994.
Relatively rare.
adult size 10 to 15 cm
(max 23 cm)
Eurasian ruffe
Native to Eurasia.
First detected 1986.
Abundant throughout system.
localized, not abundant
widespread, very abundant
widespread, moderately abundant
adult Size: 12 to 20 cm
(max 26 cm)
White perch
Native to Atlantic slope.
First detected 1986.
Abundant throughout system.
Varied Places of Origin & Modes of Arrival
Eurasia2 dreissenid mussels
4 peaclams1 amphipod
3 oligochaetescolonial hydrozoa
European valve snail--
common carp2 gobies
eurasian ruffe
Africa/Pacific RimLumholtz waterfleaN. Zealand mudsnail
Asian clam
N. America2 oligochaetes2 amphipods
--brook silversidefreshwater drum
alewiferainbow smelt
threespine sticklebackwhite perch
Natural dispersal(range expansion, barriers removed)
Deliberate Introduction
Unintentional direct delivery
(shipping implicated)
2’dcarp?
Taxonomy & Historic Records as Challenge
Benthic surveys often not to best attainable taxonomic resolution (expensive, unnec. for biotic assessment). Can render otherwise thorough surveys uninformative w.r.t. NIS.
Ex: Extensive 1995 EMAP-type survey of DSH reported NO benthic NIS, but had IDs only to genus and only to class for oligochaetes.
Lack of historic records makes arrival date and even NIS status of some taxa unclear.
Ex: historic range of oligochaetes poorly documented; unclear if first finding of circumboreal species is range expansion or not.
Gear/habitat differs by NIS - benthos
4 oligochaetes
4 peaclams
Asian clam
NZ mudsnail
valve snail
2 dreissenids
1 oligochaete3 amphipods
bottom samples (ponars, benthic
sled)
littoral samples (sweep net, coln’z.
plates)
NIS gear/habitat pattern doesn’t necessarily match related native taxa; unwise to assume you know where to look.
* single instance of D. lumholtzi & colonial hydrozoa not enough to establish pattern
Gear/habitat differs by NIS - fish
electrofishing,
fyke nets(interm. depth)
trawling(open water,
deepest)
round goby
eurasian ruffe
common carp
3spine stickleback
brook silverside
tubenose goby
freshwater drum
rainbow smelt
white perch
beach seine(shoreline,
very shallow)Newest Eurasian invader, tubenose goby, is not vulnerable to the gear (trawls) that formed backbone of ruffe invasion monitoring.
Invasion status varies among NIS
3sp.stickleback
0 20 40 60 80 100
0
20
40
60
80
100
alewife
silverside
carpdrum
smelt
round goby
ruffe
tuben.goby
wh.perch
local rare
local dom.
widespread rare
widespread dom.
Fish
- Some life histories more likely problematic than others, but also depends on habitat match, competition/predation, etc.
- We don’t yet know path a given NIS will take when it is newly arrived - Ideally we want detection at the localized, rare stage
0 20 40 60 80 1000.001
0.01
0.1
1
10
100
oligo
hydrozoa, peaclam, daphnia
oligo
Corbicula
oligo
oligo
oligo
G.tigrinus
juv. Dreissena
zebra m.
G.fasciatus
E.ischnus
P.henslow.
P.moitessquagga m.
NZmudsnail
oligo
valvesnail
Benthos
Increasing % occurrence
Incre
asin
g r
el. a
bu
nd
ance
local rare
local dom.
widespread rare
widespread dom.
Invasion stage framework of Colautti & MacIsaac (2004)
- Whether a NIS expands over time is highly variable. - NIS not necessarily rare when first detected. - Benchmark for monitoring effectiveness should be finding rare species.
Invasion status only weakly related to time
Years since earliest record (back from 2006)
0 20 40 60 80 120
Pe
rce
nt o
ccu
rre
nce (
be
st g
ea
r)
0
20
40
60
80
alewifesilverside
carp
drum
smelt
r.gobyruffe
3sp stickleback
t.n.goby
wh.perch
Fish
0 5 10 15 20 25
0
20
40
60
80
100
daphniaoligooligo
P.henslowanum
NZ mudsnail
peaclam
quagga m.
E.ischnus
oligo
G.fasciatus
G.tigrinus
P.Moitess.
EU peaclam
zebra m.
valve snail
Corbicula
oligo
hydrozoa
oligo
Benthos
It takes substantial effort to find some species
Number of samples taken
0 20 40 600
50
100
Pro
babili
ty o
f dete
ction (
%)
zebra mussel,
pygmy peaclam
3 peaclams
an amphipod
european valve snail
1 oligochaetenew zealand
mud snail
1 amphipod
lumholtz waterflea
asian clam
Widely-distributed species are detected quickly........ rare species take many samples to detect (reliably)
Effort = cost, and can mean both in the field and in the lab (taxonomy)
Benthos - 2006 ponars
0
50
100
150
72 %
86 %
100 %
Ta
xa
accu
mu
late
d
0 20 40 60 80
Number of samples taken
Impression of “invasion” depends where you look
Exotic richness
0
1–2
3–5
Fish
↑ less riverine
↓ more riverine
- More NIS in lower system Disturbance? Vector proximity? Hydro. gradient?
- 2005 gave different impression than 2006
OligochaetesP. moldaviensis
P. vejdovskyi
both
Impression of “invasion” depends on endpoint and gear used
0
30
60
90
% N
IS b
y n
um
be
r
ponar bottom
sled
coloniz.
platessweep
net
Dreissena
other NIS
Benthos
- Richness: % NIS similar among gear despite total richness differences.- Abundance: dramatic differences in % NIS by gear
Fish
electro-
fish
fyke
nets
seine bottom
trawl
10
30
50
% N
IS b
y n
um
be
r
other NIS
ruffe
tubenose goby
round goby
Ric
hn
ess
5
15
25
35native
NIS
25-29%
NIS
0
50
100
150
Ric
hn
ess
native
NIS
6-9% NIS
Impression of “invasion” depends on impact on native species
A complete & nuanced picture takes a thorough and multi-faceted sampling strategy- Sufficient effort to reliably detect rare species- Sufficient taxonomic resolution and thoroughness- Sampling design that enforces spatial coverage- Covering multiple habitats with multiple gear types- Examining multiple endpoints (e.g., richness & abundance)
- Status of natives gives context (so sample those too)
Summary
Duluth-Superior Harbor remains invasion hotspot- 19 benthos NIS, 10 fish NIS, 8 new detection records- Plethora of NIS from Eurasia implicates shipping as vector- Degree of “invasion” varies widely among NIS
Work informs ongoing & planned efforts by partners
Acknowledgements • Trawling - Gary Czypinski and crew (U.S. FWS)• Field work - Charlie Butterworth, Tim Corry, Brian
Sederberg, Jon Van Alstine, Sam Miller, Mario Picinich. • Sampling design - Tony Olson (U.S. EPA - Corvallis) • GIS - Jesse Adams, Roger Meyer, Tatiana Nawrocki,
Matt Starry (CSC Corp). • Invertebrate sample processing - Wilson Env. Lab • Taxonomy – Mary Balcer, Kurt Schmude (UW-Superior),
Gerry Mackie (U. Guelph), Brett Nagle (U. Minn.), Igor Grigorovich, John Sandberg, Kevin Stroom (Wilson)
• Genetic analyses - John Darling (U.S. EPA - Cincinnati)
UNITED STATES
EN
VIR
ON
ME
NTAL PROTECTIO
NA
GE
NC
Y
More Info• Kelly et al. Early detection monitoring for vulnerable Great Lakes coastal ecosystems. TOMORROW 11:30.
• Trebitz et al., 2010, Status of non-indigenous benthic invertebrates in the Duluth-Superior Harbor and the role of sampling methods in their detection. JGLR, in press.
• Trebitz et al., 2009. Exploiting habitat and gear patterns for efficient detection of rare and non-native benthos and fish in Great Lakes coastal ecosystems. Aq. Inv. 4:651-67.
• Grigorovitch et al., 2008. The quagga mussel invades the Lake Superior basin. JGLR 34: 342-350.