Effects of altered salinity on
California Grunion embryos
during beach incubation
Karen L. Martin, Juli K. Matsumoto, and Cassadie Moravek
Pepperdine University Dept. of Biology
24255 Pacific Coast Highway, Malibu CA 900263-4321
Sandy beaches are Essential Fish
Habitat for California Grunion
Leuresthes tenuis
Photo by K. Martin/ Grunion.org
Spawning and early development are
synchronized with the tides.
Art by G. Martin/ Grunion.org
Out of water, grunion embryos may
encounter osmotic challenges:
•
•
•
•
•
dilution by rainfall or
dilution by freshwater runoff, or
tidal excursions and wave wash
hypersalinity from evaporation
hypersalinity from human activities
Desalination plants planned for coastal
California will discharge concentrated brine
This prototype was on the beach in
Long Beach in the intertidal zone
Long Beach grunion run
Photos by K. Hoang/ Grunion.org
METHODS:
aquarium water and Coralife
Scientific Grade Marine Salt
for five treatment salinities
• Control
salinity, 32 + 1
ppt (100%)
• 16 + 1 ppt (50%)
• 24 + 1 ppt (75%)
• 40 + 1 ppt (125%)
• 48 + 1 ppt (150%)
Photo by K. Martin/ Grunion.org
Eggs were collected from
1
1.
2.
3.
4.
2
3
4
Leo Carrillo State Beach (34 o 01’N, 118o56’W),
Broad Beach (34 o 01’N, 118o51’W),
Will Rogers Beach at Sunset Boulevard (34 o 02’N, 118o33’W), and
Will Rogers Beach at Chautauqua Boulevard (34 o 01’N, 118o31’W),
Grunion eggs in situ
Photo by M. Walton/ Grunion.org
• One group was fertilized in vitro at
treatment salinities.
• Another group was collected 12
hours after natural fertilization.
• For the three State Beach sites, five
replicates contained 200 eggs each
in five salinities,
– a total of 3000 embryos.
• For Broad Beach, five replicates of
20 eggs for each salinity,
– for a total of 500 embryos.
• no effect of collection site on
results
Stripping eggs
Photo by J. Matsumoto/ Grunion.org
Hatching, %
Effects of altered salinity initiated 12
hours post-fertilization: hatching %
100
90
80
70
60
50
40
30
20
10
0
a
a
Control
a
Treatment
b
c
16
24
32
40
Salinity, ppt
48
California Grunion Hatching
Assessment: Instant Fish!
Photo by R. Darken/ Grunion.org
Effects of altered salinity initiated
during fertilization: fertilization %
100%
90%
80%
70%
*
60%
50%
40%
30%
20%
10%
0%
16
32
40
48
Effects of altered salinity initiated
during fertilization: survival at 1.5 dpf
100
90
80
70
%
*
60
50
40
30
*
20
10
0
16
32
40
48
Effects of altered salinity initiated during
fertilization: hatching % of survivors
Hatching
100
90
80
*
70
*
60
%
50
40
*
30
20
10
0
16
32
40
48
Cumulative effects on survival
90
80
70
*
60
50
%
*
40
30
20
10
*
0
16
32
40
48
Total effects on survival to hatching for
in vitro fertilized eggs
• Lower fertilization % in low salinity.
• Lower survival to neurulation at low or high
salinity.
• Lower hatching % at low and high salinities.
• Cumulative effects: significant losses at lower
or higher salinities than normal.
Larval length decreased with
hypersaline incubation
Length, mm
8
a
a
b
7.5
c
7
6.5
10
20
30
40
Incubation Salinity, ppt
50
Distinct morphological deformities of
the California Grunion embryo
A
Normal
B
Enlarged spleen
Less robust
C
Malformed Tail
Altered sand salinity reduces viability
• Cumulative effects of
altered salinity on
early life history
significantly decrease
total survival to
hatching.
• Salinities below 10 ppt
and above 50 ppt are
lethal to California
Grunion embryos.
Photo by Julianne E. Steers/ Grunion.org
Effects of altered salinity include:
•
•
•
•
•
reduced fertilization,
early embryo mortality,
deformities,
lower hatching success,
smaller hatchlings,
• Result: significantly lower survival
Photos by K. Martin/ Grunion.org
Photo: S. Howard/ Grunion.org
Coastal
management
should strive to
avoid potentially
serious negative
effects of altered
salinity on the
California Grunion’s
beach nursery
grounds.
Many thanks to…
National Marine Fisheries Service-Southwest Region,
Habitat Conservation Division
California Sea Grant College
National Geographic Society
Project Partners: Grunion Greeters, Pepperdine University, Birch Aquarium at
Scripps Institution of Oceanography, Cabrillo Marine Aquarium, Surfrider Foundation,
Santa Barbara Channel Keepers, Santa Barbara Natural History Museum/Ty Warner
Sea Center, Heal The Bay/ Santa Monica Pier Aquarium, Aquarium of the Pacific in
Long Beach, Port of Oakland, Tijuana River National Estuarine Research Reserve,
Southwest Wetlands Interpretive Association, Ocean Institute at Dana Point, Audubon
Society, City of San Diego, California Department of Fish and Game, US Fish and
Wildlife Service, California State Parks, California Coastal Commission, County of
Orange, Los Angeles County Beaches and Harbors, California Coastal Coalition,
Ventura County Coastal Coalition, Orange County Coastal Coalition, East Bay
Regional Park District, Point Reyes National Seashore, Golden Gate National
Recreation Area, Lawson’s Landing, National Fish and Wildlife Foundation, and the
National Oceanic and Atmospheric Administration
REFERENCE: Matsumoto, J. K., and K. L.
M. Martin. 2008. Lethal and sublethal
effects of altered sand salinity on
embryos of beach-spawning California
Grunion. Copeia 2008: 483-490.
Available as a pdf from kmartin@pepperdine.edu
For more information please see
www.Grunion.org
www.BeachEcologyCoalition.org
or www.BeachECo.org