HomeMy WebLinkAboutSUP 06-10X2A; AGUA HEDIONDA OUTER LAGOON MAINTENANCE; PRE-DREDGE CAULERPA SURVEY IN SUPPORT OF THE ENCINA POWER STATION; 2017-12-19 Merkel & Associates, Inc.
5434 Ruffin Road, San Diego, CA 92123
Tel: 858/560-5465 Fax: 858/560-7779
e-mail: associates@merkelinc.com
December 19, 2017
M&A #14‐051‐06
Cabrillo Power I LLC
Attn: Sheila Henika
Encina Power Station
4600 Carlsbad Boulevard
Carlsbad, CA 92008
Re: Pre‐dredge Caulerpa survey in support of the Encina Power Station,
Agua Hedionda 2017‐2018 Dredging Project at Agua Hedionda Lagoon
(Outer Lagoon), Carlsbad, CA
Dear Sheila:
Enclosed is the report for the Caulerpa survey conducted in support of the upcoming maintenance
dredging in the Outer Lagoon. The survey was performed at the Surveillance Level per the Caulerpa
Control Protocol (Version 4.0, adopted February 25, 2008) on November 28‐29 and December 8, 2017
by certified Caulerpa Surveyors using SCUBA, a Remotely Operated Vehicle (ROV), a drop camera, and
visual observation on foot and by observing the bottom over the side of the vessel in shallow portions of
the outer lagoon over the shoals and shoreline fringe.
I am pleased to report that Caulerpa was not found within the survey area. This survey will complete
your pre‐construction survey obligations for Caulerpa surveillance. This survey is valid for construction
activities in the project area initiated within the next 90 days.
I hope your dredge program proceeds in a safe and timely manner. If you have any questions regarding
the enclosed documents or this letter, feel free to contact me at (858) 560‐5465.
Sincerely,
Keith W. Merkel
Principal Consultant
Caulerpa Survey Reporting Form
This form is required to be submitted for any surveys conducted for the invasive exotic alga Caulerpa
taxifolia that are required to be conducted under federal or state permits and authorizations issued by
the U.S. Army Corps of Engineers or Regional Water Quality Control Boards (Regions 8 & 9). The form
has been designed to assist in controlling the costs of reporting while ensuring that the required
information necessary to identify and control any potential impacts of the authorized actions on the
spread of Caulerpa. Surveys required to be conducted for this species are subject to modification
through publication of revisions to the Caulerpa survey policy. It is incumbent upon the authorized
permittee to ensure that survey work is following the latest protocols. For further information on these
protocols, please contact: Bryant Chesney, National Marine Fisheries Service (NOAA Fisheries), (562)
980‐4037, or William Paznokas, California Department of Fish & Wildlife, (858) 467‐4218).
Report Date: December 19, 2017
Name of bay, estuary,
lagoon, or harbor:
Agua Hedionda Lagoon, Carlsbad, CA
Specific Location Name:
(address or common
reference)
Outer Lagoon of Agua Hedionda Lagoon, San Diego, CA
Site Coordinates:
(UTM, Lat./Long., datum,
accuracy level, and an
electronic survey area map
or hard copy of the map
must be included)
Lat. 33.1428; Long. –117.3390
The entire 51‐acre Outer Lagoon basin was surveyed.
Survey Contact:
(name, phone, e‐mail)
Keith Merkel, Merkel & Associates, (858) 560‐5465,
kmerkel@merkelinc.com
Personnel Conducting
Survey (if other than
above): (name, phone,
e‐mail)
Daniel Kahl (certified Caulerpa Surveyor)
Chris Hughes (certified Caulerpa Surveyor)
Daniel Hartsook (vessel support)
Permit Reference:
(ACOE Permit No., RWQCB
Order or Cert. No.)
ACOE 200100328‐RRS
CCC CDP 6‐17‐0732
Is this the first or second
survey for this project?
First and only for this dredge cycle. A post‐dredge survey of the
nearshore area outside of the beach placement sites will be
conducted when dredging is complete.
Was Caulerpa
Detected?:
(if Caulerpa is found, please
immediately contact NOAA
Fisheries or CDFW
personnel identified above)
__________________Yes, Caulerpa was found at this site and
___________________has been contacted on __________ date.
________X__________No, Caulerpa was not found at this site.
Description of Permitted
Work:
(describe briefly the work
to be conducted at the site
under the permits
identified above)
Maintenance dredging of the outer lagoon basin and beach
replenishment with the dredged sand.
Depth range: Approximately +1 to ‐36 ft MLLW
Substrate type: Sand and mud bottom with riprap shorelines.
Temperature: 60 ‐ 62° F
Salinity: ~34 ppt
Dominant flora: Eelgrass (Zostera marina), Ulva sp., and Sargassum
muticum with wrack of Egregia menziesii, and
Macrocystis pryfiera
Dominant
fauna:
Round rays (Urobatis halleri), Sargo (Anisotremus
davidsonii), Bat rays (Myliobatis californica), lobster
(Panulirus interruptus), Garibaldi (Hypsypops
rubicundus), Barred sand bass (Paralabrax nebulifer)
Exotic species
encountered
(including any
other Caulerpa
species):
Sargassum muticum, Steyla clava, Musculista
senhousii, and Codium fragile
Description of Site:
(describe the physical and
biological conditions within
the survey area at the time
of the survey and provide
insight into variability, if
known. Please provide
units for all numerical
information).
Other site
description
notes:
A large sand shoal (to be dredged) occurs in the
northern portion of the basin. Shallows along the
sides of the lagoon and in the southern half of the
basin support Zostera marina. Aquaculture racks
occur in the southern portion of the basin.
Unvegetated bottom occurs within the central
portions of the basin extending along the previously
dredged central regional of the basin.
Survey date and
time period:
November 28, 2017 ‐ 07:45 ‐ 15:45
November 29, 2017 ‐ 08:30 ‐ 16:30
December 11, 2017 ‐ 07:30 ‐ 15:30
Horizontal
visibility in
water:
5 ‐ 10 feet with some brief periods of greater
horizontal visibility.
Survey type and
methods:
SCUBA diver visual surveys, surface visual
observations within intertidal and shallow water,
navigated transect search patterns with ROV and
towed video camera arrays
Description of Survey
Effort:
(please describe the
surveys conducted
including type of survey
(SCUBA, remote video, etc.)
and survey methods
employed, date of work,
and survey density
(estimated percentage of
the bottom actually
viewed). Describe any
Survey
personnel:
Daniel Kahl (certified Caulerpa Surveyor)
Chris Hughes (certified Caulerpa Surveyor)
Daniel Hartsook (vessel support)
Survey density: Method(acres covered/% total/% method effective)
Interferometric Sidescan Sonar (48.9 ac./95.9%/5%)
Low Tide Visual Inspection (17.8 ac./34.9%/90%)
SCUBA Diver (7.6 ac./14.9%/50%)
ROV/ Towed Video (28.4 ac./55.7%/30%)
Intake Area Not Surveyed (0.03 ac./0.06%)
Overall survey density within the outer lagoon is
based on the percentage of cover and the efficacy of
the survey methodology. Each survey method has
its strengths and weaknesses depending upon many
factors. By considering these factors, an estimate of
the efficacy of each method was developed and the
area covered by the method was multiplied by the
efficacy to determine the estimated percentage of
the bottom that was effectively surveyed. The
results indicate that bottom coverage was estimated
to be 62 percent overall with no weak survey areas.
limitations encountered
during the survey efforts.
Survey
limitations:
None. Water clarity was good during all survey days.
Multiple methods and multiple survey days and tide
levels allowed good access to all portions of the
lagoon basin
Other Information:
(use this space to provide
additional information or
references to attached
maps, reports, etc.)
Please see attached map (Figure 1) and survey data sheet. Agua
Hedionda Lagoon was as an infected system until eradication success
was declared in 2006. The lagoon is now considered to not be infected,
and thus subject to the 20% survey of CCP Surveillance Level. This level
was exceeded during this survey.
Caulerpa Survey Reporting Form (version 1.2, 10/31/04)
Agua Hedionda Outer LagoonPre-Dredge Caulerpa SurveyNovember/December 2017 Figure 1
M#A #14-051-06
Merkel & Associates, Inc.
µ
Surveyed by Interferometric Sidescan Sonar for Target-Identification
Surveyed by ROV and Towed Video Camera
Surveyed by SCUBA
Surveyed by Low Tide Visual Inspection
Area Around Intake Not Surveyed 0 100 20050Meters
1111
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