Potential impacts of the DWH oil spill on fishery resources: will there be reduced
recruitment of commercially important shrimp, crabs, and finfish in seagrass and marsh
nursery habitats of the north central Gulf of Mexico?
Principal Investigators:
K.L. Heck, Jr.
Just Cebrian
Rationale
Salt marshes and submerged aquatic vegetation (SAV) are highly productive habitats known
to provide critical habitat for a diverse assemblage of ecologically and economically important
fish and invertebrate species. To date, our NGI-supported sampling efforts have unequivocally
demonstrated the nursery role of the coastal marsh-SAV system within the north central Gulf of
Mexico (Grand Bay, AL), and the capacity of the system to sustain high levels of secondary
production (Table 1, Figure 1). Oil from the Deepwater Horizon (DWH) platform has not
impacted Alabama’s coastal habitats with the severity seen in Louisiana and, despite the
presence of tar balls and light sheens within our study marshes and SAV beds, significant oiling
has not occurred. As a result, no loss of marsh and SAV plants due to oil has occurred and the
structure provided by coastal marshes and SAV meadows remains intact. However, a significant
proportion of the finfish and shellfish that utilizes coastal marsh-SAV systems, particularly those
that sustain lucrative commercial and recreational fisheries, breed offshore. There eggs are
spawned, larvae and post-larvae develop and are subsequently transported to vegetated coastal
habitats where they metamorphose into rapidly growing juvenile forms.
Oil released from the Macondo well could have smothered or otherwise harmed eggs and
larvae of finfish and economically important shellfish in the offshore waters of the Gulf. In
addition, oil droplets produced by dispersants and natural biodegradation have been reported to
be incorporated into microbial and planktonic food webs, which constitute the prey base for
many fish and invertebrate larvae. Oil droplets have also been observed within the carapaces of
larval blue crabs. Thus, the DWH accident may be producing, either directly or indirectly,
detrimental impacts on eggs/larvae offshore and reduced recruitment of juveniles of
economically important finfish and shellfish in coastal nursery habitats quite distant from the
well site, such as our study sites in Grand Bay, AL.
Here we propose to continue our surveys of juvenile recruitment in a number of marsh and
SAV locations in Grand Bay AL (Figure 1). We have a baseline of data extending back as far as
2005 at some locations, and during the past year new data have been obtained with support by
NGI Phase I funds. Our data set will allow us to carry out a statistically rigorous Before-AfterControl-Impact (BACI) comparison of the potential effects of the DWH accident on the
recruitment of juvenile finfish and shellfish, owing to the fact that some of our study areas
experienced oiling while others did not. Due to the time lag between spawning and recruitment
events, there may be reduced recruitment in 2011 in comparison with pre-oil spill levels if there
have indeed been detrimental impacts on eggs and larvae offshore. We thus request funding to
continue our on-going sampling efforts from January to December 2011. The extended
monitoring period will allow us to determine if the DWH accident resulted in large-scale
perturbations in the northern Gulf through depressed finfish and shellfish recruitment in critical
nursery habitats.
Selected Results from NGI Phase I
We have made monthly nekton collections within the salt-marsh and SAV habitats of Grand
Bay, AL (Figure 1) during the summer and fall of 2010, and have identified 27 marsh-associated
species and 26 SAV-associated species of fish and invertebrates. Marsh catches were dominated
by grass shrimp, Palaemonetes pugio, and SAV catches were by the following fish species:
pinfish, Lagodon rhomboides; bay anchovy, Anchoa mitchilli; and silver perch, Bairdiella
chrysoura. A list of other species found in significant numbers in these habitats is provided in
Table 1. Following P. pugio, the economically important blue crab and penaeid shrimp species,
as well as white and spotted sea trout, accounted for the greatest number of individuals within
the marsh and SAV habitats. It is also important to note that juveniles of gray snapper, Lutjanus
griseus and red drum, Sciaenops ocellatu and gulf menhaden, Brevoortia patronas, were
collected in the SAV locations, although at lower abundances.
Expected results
Data from the extended survey period requested here will allow us to:
-- Gather evidence of economically important impacts of the DWH accident in the north central
Gulf of Mexico, if they exist, by quantitatively comparing (with BACI analysis) juvenile
recruitment of finfish and shellfish in relation to pre-accident levels.
-- Respond to additional oiling of marshes and SAV beds that might occur during the project
period (i.e., if noticeable quantities of oil arrive from offshore and persist in our study locations),
by assessing its effects on marsh and SAV plant biomass and species composition, as well as
further impacts on juvenile finfish and shellfish abundance and species composition.
Methods
We will continue to sample nekton assemblages at each of the established study sites in
Grand Bay, AL (Figure 1). The shoreline at each site is populated by Spartina alternifloradominated marsh, and the seagrass Halodule wrightii forms extensive meadows in the adjacent
subtidal areas. At each site marsh-associated nekton will be sampled by placing three 6-m wide,
tidal fyke nets along the marsh edge for a full tidal period. The nets are designed to capture
organisms as they exit the marsh during the outgoing tide. Three 5-m otter trawl swaths will be
made to sample the SAV-associated fauna at each site. Salt-marsh and SAV nekton samples will
be collected throughout 2011, first in February to detect early recruitment, and then monthly
from April to October during the main portion of the recruitment period, and finally in
December. We will spatially and temporally pair our sampling of marsh and SAV habitats so that
collections in each habitat will be separated by no more than one tidal cycle. All organisms will
be enumerated and measured following collection. In addition, we will preserve individuals of
selected economically important finfish and shellfish species for future hydrocarbon and oil ID
analysis, if that becomes desirable after the sampling has been completed.
Spartina densities will be assessed using permanently established quadrats installed at each
site in summer 2010. SAV density and biomass in the trawled meadows will be sampled through
coring. Environmental data, including water temperature, salinity and dissolved oxygen, will be
collected using a hand-held YSI unit. Subsurface irradiance (PAR) will be assessed at all SAV
meadows using LICOR sensors. Plant and environmental samples will be taken along with the
nekton samples.
Table 1. Mean Catch-per-Unit-Effort (CPUE) ± SE for selected species in the salt-marsh and
SAV habitats of Grand Bay, AL. Means represent pooled catches for fyke nets (marsh; n=3 per
site) and trawls (SAV; n=3 per site) across sites (n=3 sites) for three sampling dates (total of 27
samples). CPUE values for marsh catches correspond to the total number of individuals collected
per tidal period. CPUE values for SAV catches correspond to the number of individuals collected
during a 2-min trawl swath.
Species
Marsh
SAV
27.8 ± 4.7
9.0 ± 4.4
60.4 ± 15.4
6.6 ± 4.5
Brown Shrimp
Farfantepenaeus aztecus
4.6 ± 1.0
22.7 ± 9.1
White Trout
Cynoscion arenarius
6.7 ± 3.8
0.0
Spotted Sea Trout
Cynoscion nebulosus
0.8 ± 0.5
3.9 ± 1.0
Southern Kingfish
Mentichirrus americanus
0.0
0.4 ± 0.1
Silver Mojarra
Eucinostomus argenteus
0.0
0.5 ± 0.2
Sheepshead
Archosargus probatocephalus
0.0
0.5 ± 0.2
Blue Crab
Callinectes sapidus
White Shrimp
Litopenaeus setiferus
Figure 1. Study sites within Grand Bay, AL.
Budget: Double click on budget table below to activate Excel spreadsheet
Project Title: Potential impacts of the DWH oil spill on fishery resources:
Project Lead: Dr. K.L. Heck, Jr.
Jan 1-Dec 30, 2011
I. Salaries
$47,547
1a.1 Senior Personnel (K.L. Heck, Chief Scientist)
$0
1a.2 Senior Personnel (J. Cebrian, Senior Marine Scientist III)
$0
1b.1 Senior Personnel: (D. David, Research Associate)
25%
$42,266
$10,567
1b.2 Senior Personnel: (J. Goff, Research Technician)
25%
$35,000
$8,750
1b.3 Senior Personnel: (S. Havard, Research Technician)
25%
$28,288
$7,072
1c.1 Graduate Students
50%
$17,004
$8,502
1c.2 Graduate Students
25%
$17,004
$4,251
1c.3 Student Interns (qty 2)
25%
$33,614
$8,404
II. Fringe Benefits
$16,017
2a.1 1a. Senior Personnel
@
0.00%
$0
2a.2 1b. Senior Personnel (D. David)
@
44.11%
$4,661
2a.3 1b. Senior Personnel (J. Goff)
@
48.81%
$4,271
2a.3 1b. Senior Personnel (S. Havard)
@
55.31%
$3,912
@
15.00%
$3,173
2b 1c Students
2c Tuition, Fees, and Insurance
$0 month
$0
III. Travel
$4,575
IV. Commodities/Supplies
$5,700
V. Equipment
$0
VI. Contractuals
$0
VII. Subcontracts
Total Direct Costs
0
$0
$73,839
Budget Justification: Provide sufficient detail for a cost analysis of each applicable cost category.
1. Salaries (with description of duties)
a. Senior Personnel (name and title, annual salary (12 month basis) and % of time) Insert
additional lines in budget if necessary.
i. Just Cebrian, Jr, Senior Marine Scientist III, no charge, 5% effort
ii. Kenneth L. Heck, Jr, DISL Chief Scientist, no charge, 5% effort
iii. Dorothy Byron, Research Associate (Heck Lab), $42,266, 25%
-Lab Management, Field Team Leader, Data management and Quality
Assurance
iv. Josh Goff, Research Technician (Cebrian Lab), $35,000, 25%
-Lab Management, Field Work, Data management and Quality Assurance
v. Sharon Havard, Research Technician (Heck Lab), $28,288, 25%
-Sample collection and processing and Quality Assurance
b. Graduate Students (name and degree program, hourly rate, hours estimated)
i. One MS graduate student in Dr. Cebrian’s Lab will be funded part time (50%) by
this project
ii. One MS graduate student in Dr. Heck’s Lab will be funded part time (25%) by
this project
c. Student Interns: $8.08/intern/hour, 520 hours estimated/intern
-Sample Collection and processing.
2. Fringe Benefits (by Salary category, or employee listed, if unique rate)
Fringe is calculated on a sliding scale.
a. Senior Personnel:
i. Just Cebrian: no charge
ii. Kenneth L. Heck: no charge
iii. Dorothy Byron : 44.11%
iv. Josh Goff : 48.81%
v. Sharon Havard: 55.31%
b. Students: Includes graduate students and interns: 15%
c. Tuition, Fees and Insurance
3. Travel (destination, estimate of transportation, accommodations, per diem, etc if >$5,000)
a. We request $4575 for 27 sampling trips (3 trips per month for 9 months) using DISL
vehicles and vessels. We estimate $1200 needed for vehicle use at $0.505/mile. Each
sampling trip will travel approximately 40 miles round trip to launch in either Bayou la
Batre, AL or Bayou Heron, MS. We estimate $3375 in vessel use at $125/8hr day to visit
sites located in Grand Bay and Portersville Bay.
4. Commodities/ Supplies ( provide unit costs, if applicable)
a. We request $5700 for the purchase of expendable supplies to be used during the project.
These include basic field supplies such as pencils, markers, clipboards, all weather
paper, ziploc bags, and additional protective gear such as nitrile gloves and any
necessary protective gear (eg. waders). We have also included funds for the purchase of
3 new tidal fyke nets (including maintenance), a dissecting scope, and funds to calibrate
the sensors and purchase sensor cables needed for measuring water clarity.
5. Equipment (Lease vs. purchase analysis if >$5,000)
none
6. Contractuals
none
7. Subcontracts – submit statement of work, budget and justification for each subcontract
none
Subcontra ct Poi nt of Conta ct:
BUDGET REQUEST
Funding Request
I. Salaries
$0
Sa l a ry
1a Name, Title
$0
1b Name, Title
0
% effort
100% $
100%
II. Fringe Benefits
2a Category of employee
$0
$0
@
0.00%
$0
III. Travel
$0
IV. Commodities/Supplies
$0
V. Equipment
$0
VI. Contractuals
$0
VII. Subcontracts
$0
Total Direct Costs
$0
Indirect (F & A) Costs
$0
Total Costs
$0
8. Indirect (F&A) Costs
Indirect costs are calculated at 42.6% which is the current rate charged by the Dauphin Island
Sea Lab.