Channel Islands MPA Project:
Phase II - Quantitative Surveys
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The Channel Islands MPA Project is being achieved through a partnership with California Department of Fish and Game, the National Oceanic and Atmospheric Administration and The Nature Conservancy. |
Background
- Channel Island Marine Protected Areas (MPAs)
Phase
I - Exploratory Surveys
Phase II - Quantitative Surveys |
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Background
The goal of the quantitative surveys is to identify any
changes in species abundance since fishing was banned in
the Marine Protected Areas in April 2003. Our prime focus
is finfish species of commercial and recreational interest
which inhabit rocky reefs.
Following on from exploratory
surveys undertaken in 2003, a
total of 10 sites were confirmed for annual monitoring
surveys. Eight of the total of 18 candidate sites surveyed
were excluded due to lack of hard substrate. For each site
selected within a reserve an adjacent site outside the reserve
with similar rocky substrate and depth range was selected
for comparison. |
ROV
on deck in front of Santa Cruz Island |
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Survey Methods for Quantitative surveys
The following images provide an overview of how we use ROVs
to gain species abundance data. |
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| The background layer
is a sidescan map. The green lines show the transect lines
in deep water selected for survey. |
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Completed
and post-processed transect lines. Observations of Treefish
(orange), Vermillion Rockfish (red), Blue Rockfish (pale
blue), Bocaccio (blue), Lingcod (yellow), Ocean Whitefish
(green), Sebastomus complex (pink), California
Sheephead (white) and Blacksmith schools (pale blue circle)
were all noted and highlighted in the relevant positions
on the map above.
The pictures below show the two areas inside
the blue squares above in more detail. The transect line
is color coded by observed habitat type of rock (brown),
sand (yellow) and boulder (black). |
Sebastomus, Blue Rockfish, Treefish,
Vermillion Rockfish and Bocaccio were all observed. Video
link |
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Treefish, Ocean Whitefish, California Sheephead and two
Blacksmith schools were observed. Video
link |
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2006 quantitative
survey summary
Surveys were undertaken during August, September
and October 2006 from NOAA and CDFG ships. All 10 sites
were visited, and a total of 102 km were surveyed this year.
MARE has also been using the video records to locate and
identify derelict fishing gear for removal by the Seadoc
Society. In 2006, two new large derelict fishing nets were
discovered and details were passed onto Seadoc.
Once again, MARE welcomed aboard its partners and funders
for an 'Observer Day' in September to give them a first
hand look at what our ROV survey work involves. |
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2005
quantitative survey summary
Our work in 2005 is a continuation of the quantitative
monitoring started in 2004, expanding to the full set of
10 approved deepwater sites: 5 in and 5 adjacent to MPAs.
PB Swordfish surveys -
August 14 to 27, 2005
In August, we used the California Department of Fish and
Game's PB Swordfish for ROV operations for the
first time. During six days at sea, we trained two enforcement
staff in ROV operations and completed 34 km of track line.
Quantitative sampling was initiated at Anacapa Island State
Marine Reserve (SMR) and completed at Carrington Point SMR
and Rodes Reef.
R/V Shearwater surveys
- September 22 to October 12, 2005
In September and October we used the NOAA Channel Islands
National Marine Sanctuary RV Shearwater to gather
over 79 km of survey data and complete the eight remaining
target sites. |
Results
In 2005, we completed quantitative surveys at
10 sites (106km total), bringing our site total up to
18 sites surveyed. Our target of sampling enough hard
substrate for seventy-five 100m2 transects was reached
at all sites. 8km of exploratory survey was also undertaken
at two additional sites off San Miguel Island.
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2004 quantitative
survey summary
In September 2004 we completed the first quantitative surveys
of finfish abundance at five sites. These together with
the next few years of data will form a baseline dataset
for comparison against future surveys.
Analysis of substrate data from 2004 revealed
that in the five sites sampled, transects lines averaged
from 33% to 71% soft substrate. In order to increase sampling
efficiency and obtain a higher percentage of our target
hard substrate, we reviewed all sites by superimposing the
substrate data we'd collected onto the acoustic surveys
maps. This allowed us to more clearly differentiate between
hard and soft substrates, and exclude 'soft only’
areas for the 2005 surveys. |
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