the lionfish invasion - florida fish and wildlife ...native fish and invertebrate species recent...
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The Lionfish InvasionFlorida Fish and Wildlife Conservation Commission
Division of Marine Fisheries Management
What is an Invasive Species?▪ Animals, plants, or other organisms introduced by people in
places outside of their natural habitat that cause negative
impacts on humans and/or the native ecosystem.
▪ Rapidly reproduce and become established in new habitat
▪ Cause negative impacts like preying on native species,
physical damage to habitat, introduction of diseases, and
competition for resources
Marine Invasions
▪ 37 nonnative marine fishes in Florida, but
have not become established▪ USGS non-indigenous aquatic species database 2017
▪ Lionfish are a marine fish that has
become successfully established in
nonnative range and classified as
the worst marine invasion to date
Lionfish
(Pterois volitans & P. miles)
▪ Tropical predatory fish from Indo-Pacific region
▪ Introduced by an aquarium release in 1980’s
▪ Established in western Atlantic Ocean,
Caribbean Sea, and Gulf of Mexico
▪ Density and biomass exceed that in
their native range
Invasive Characteristics▪ Wide range of habitat use – natural and artificial, 1 – 1,000 ft.
depths, tolerate temperatures as low as 50°F
▪ Sexually mature at 1 year; spawn frequently (every 4 days); up to
30,000 eggs/spawn
▪ Consume economically & ecologically-important species; over 90
different species found in stomach; swallow prey over half body size
▪ 18 venomous spines; neuromuscular toxin; treatment: apply heat
▪ Unique coloration – native predators do not recognize as prey
▪ Economically important species
▪ Fish: groupers, snappers, baitfish
▪ Invertebrates: shrimp, crabs, lobster
Lionfish Diet
▪ Ecologically important species
▪ Cleaners: maintain health of reef fish by consuming parasites
▪ Grazers: maintain health of coral reefs by consuming algae
Lionfish Diet
Effects on Native Ecosystems
▪ Consume over 90 different species of
native fish and invertebrate species
▪ Recent documentation of lionfish
consumption of undescribed mesophotic goby (Tornabene & Baldwin 2017)
▪ Reduction in recruitment and prey
biomass:
▪ 79% reduction in juvenile fish recruitment to
new reefs observed in the Bahamas (Albins & Hixon 2008)
▪ 2.6 times reduction in recruitment compared
to a native predator (Albins 2013)
▪ 65% reduction in prey biomass (Green et al. 2012)
▪ Non-consumptive effects: Competition
for resources with other top and
mesopredators (Raymond et al. 2014)
▪ Habitat degradation
▪ Phase shift to algal-dominated reefs (Lesser
& Slattery 2011)
▪ Absence of natural, consistent control
mechanism
▪ Humans as a predator: Models
estimate 27-65% adult populations
removed monthly to achieve
substantial declines (Morris et al. 2010)
Effects on Native Ecosystems
Lionfish Landings by Gear Type
0
20000
40000
60000
80000
100000
120000
140000
2010 2011 2012 2013 2014 2015 2016 2017
Nu
mb
er
of
lio
nfi
sh
(lb
s)
Year
Trawl
Traps
Hook and
LineDiving
Conflict Wildlife – Lionfish • Agency strategic goals: Minimize human health and safety, environmental,
social, economic, and other adverse impacts
▪ Encourage removal efforts & increase
recreational and commercial harvest tracking
• Remove regulatory barriers to harvest
• Support lionfish tournaments
• Promote incentive removal programs
• Support innovative strategies for removal
▪ Increase public awareness
• Traveling “Be the Predator” outreach booth
• Workshops and school dissections
• Lionfish Removal and Awareness Day
▪ Promote consumption and commercial market
From 2014-2018 FWC has tracked the removal of over
539,300 lionfish from Florida waters!
Questions?Video and Diver: Meaghan Faletti
Goals of Dissection
▪ Provide unique information on the physiology,
biology and ecology
▪ Population structure
▪ Age and growth
▪ Reproductive biology
▪ Food web ecology
Venomous Spines
• 18 venomous spines
• 13 on dorsal fin
• 1 on each pelvic fin
• 3 on anal fin
• Spine contains grooves (not hollow) that house venomous
glandular tissue
External Anatomy
Key:
A - Dorsal spines*
B - Soft Dorsal
C - Caudal Fin
D - Pectoral Fin
E - Pelvic Fin*
F - Anal Fin*
G - Super-ocular
tentacles
H - Opercular spines
* - Contain venom
Photo credit C. Calloway; Green et al. 2012
*
*
*
External measurements
Weight
▪ Application: growth, body
condition, population size
structure
▪ Methods:
▪ Blot fish dry of excess water with a
paper towel
▪ Place weigh boat or specimen tray
on the scale and tare it
▪ Place fish into weigh boat or tray –
ensure not resting on table
▪ Record measurement in grams.
External measurementsTotal length
▪ Application: Growth, body
condition, population size
structure
▪ Methods:
▪ Place the lionfish on top of the
measuring tape
▪ The tape should run parallel to the
fish’s midline from snout to tail
▪ Measure from the tip of the snout
to the longest point on the tail
▪ Ensure mouth is closed
▪ Record measurement to the
nearest 1 mm
External measurements
Mouth gape
▪ Application: Feeding ecology
▪ Methods:
▪ Open the mouth to the fullest extent (without overextending)
▪ Using a ruler, measure to the nearest 1 mm
Gape height Gape width
Opening the Gut Cavity
A. Incision from urogenital
opening towards the base of
the pelvic fins (pelvic girdle).
B. Deeper cut will be required
to sever the pelvic girdle.
C. Cut along the rear edge of
the gill arch toward the
dorsal fin.
D. Lift the flank to expose the
gut cavity and internal
organs. Cut through any
minor connecting tissue as
needed.Green et al. 2012
Internal Anatomy
Key:A. Gill rakers and filaments
B. Swim bladder
C. Swim bladder muscles
D. Liver
E. Gonad
F. Urinary bladder
G. Interstitial fatty deposits
H. Stomach
I. Intestine
Green et al. 2012
Reproductive Organs
Immature gonadsMale testes
Female ovary
▪ Application: Reproductive physiology
▪ Methods: ▪ Remove both gonads
▪ Place in weigh boat on scale
▪ Record measurement in grams (g)
Green et al. 2012
Opening the StomachApplication: Feeding ecology
A. Sever the esophagus where it
terminates.
B. Insert scissors into the
esophageal opening of the
stomach.
C. Make a shallow cut along the
length of the stomach wall to
the intestine opening.
D. Invert the stomach and
remove all prey items; place
prey onto a clean surface for
identification. Green et al. 2012
Prey Score Digestion LevelScore Description Identification resolution
1
No degradation or digestion;
prey item appears freshly
consumed
Species
2Minor degradation to fin rays
and scale pigmentationSpecies
3
Substantial degradation to
external structures such as fin
rays and scale pigmentation
Family
4
Major degradation: parts of
body flesh missing, no
pigmentation, length
measurement not possible
Vertebrate/invertebrate
5
Prey item fully digested and
reduced to mush-like
condition
Visual identification not
possible
Green et al. 2012
Interstitial Fat Deposits
(optional)• Remove fat deposits from gut cavity
• Fill graduated cylinder to 50 mL
• Measure volume after adding fat deposits to
the graduated cylinder