Haugen, Charles

Schultz, Steven

English

Aquatic Commons

State of California - The Resources Agency
Department of Fish and Game
Marine Resources Region
Long Beach, California
CRUISE REPORT 74-KB-30 and 74-M-6 - ABALONE - LOBSTER INVESTIGATIONS
Prepared by Steven Schultz and Charles Haugen
Vessels:
Dates:
Locality:
Purpose:
R/V KELP BASS and R/V MOLLUSK
November 15-22, 1974
San Clemente Island and Santa Catalina Island
1. To retrieve green abalones, HaZiotis fuZgens, tagged
at China Cove and Northlvest Harbor San Clemente
Island, and the IstlmlUs, Santa Catalina Island
during August and November 1973.
2. To tag additional green abalones as time allowed.
3. To conduct escape-port studies for connnercial
lobster traps.
4. To recover marked lobster at Catalina Isthmus for
grm,th studies.
Procedure: 1. Divers carefully retrieved tagged abalones, measured
length and ltTidth, tag-coded each with string, and
returned them to abalones scars on rocks.
2. Twenty-six commercial lobster traps, half of which
were fitted with one 60.3 x 39.2-nnn (2 3/8 x 11~-inch)
escape port were fished three nights at San Clemente
Island and two nights at Santa Catalina Island.
Results: Abalone
The three green abalone tagging sites established at
China Cove in 1973 "Jere revisi ted. Of the 613 green
abalone tagged at area I and II in 1973, we retrieved
257 (41.9%). This retrieval rate would have been con-
siderably higher in tha t l,7e only incidentally picked
abalones from area I and we were not able to dive either
area for the period desired due to navul operations closing
the are2. Th"!:"ee hundred forty tagged abaloEe (55. 5/~)
were not accounted for, 2 (0.3%) Were lost as a result
of natural mortality, and l~ (2.3%) were mortalities
attributed to the original tagging.
During retrieval of the 257 tagz,~d green abalones we lost
an a~Jiti.c~31 ~~ due to ba~ c~~tt~_I1~ and 8 due to pr2Jators
.,hen ~h~ 2.L'31()(·2~ i.:c~r8 l.-e.tnrned tc th~~ ::..ubst:~"ate.
Results:
Four lnJ.nJr(:.d. c:Ild ~hirty·-~~.(?\'12n. ,;re'2n ;.~b8lone 'h'2ce o1:iginnl1y
tagged in area III. A to[3l of 138 (31.6%) W2re retrieved.
Again, this figure does not reflect the possible retrievable
rate due to an unexpected Navy closure. Two hundred
eighLr-three tagged abalone .(64.8%) were unaccounted for,
4 (0.9%) were attributed to natural mortality, and 12
(2.7%) ~ere mortalities attribl1ted to the original tagging.
Of the 138 retrieved, we lost an additional 11 from bar
cutting and 5 were lost to predators.
Northwest Harbor produced the highest tag return of the
trip, with 125 (52.1%) of the original 240 tagged green
abalones being retrieved. One hundred and ten (45.8%)
were not accounted for, 3 (1.3%) were attributed to natural
mortalities, and 2 (0.8%) were mortalities during original
tagging. Of the 125 retrieved at Northwest Harbor we lost
an additional 12 due to bar cutting and 1 was eaten by a
bat ray, Myliobatis californicus, when returned to the rocks.
At Catalina Island we retrieved 82 (26.4%) of the 310 that
had been tagged and transplanted to the Isthmus fro~
Northwest Harbor, San Clemente Island. This low retrieval
was probably due to the large boulder habitat and dense
algal growth, primarily Sargasswn sp. Two hundred more
tagged abalone (67.4%) were unaccounted for, 2 (0.6%) were
natural ffiortalities, 4 (1.3%) were returned by sportsmen,
and 15 (4.8%) were mortalities attributed to original
tagging. Of the 82 retrieved, we lost an additional 2
(0.6%) due to bar cutting, and 2 (0.6%) were eaten by
predators when returned to the rocks.
Growth rates for green abalones at San Clemente were
very poor at all size classes. Many lest growth by
wearing their shells against the substrate. The green
abalones transplanted from Northwest Harbor to the Isthmus
showed definite new growth bands.
Time did not allow additional tagging.
Lobster
A total of 146 lobster was captured in 77 trap sets at
San Clemente Island. Traps without escape ports caught
15 legal size lobster and 98 shorts. Those with escape
ports took 17 legal lobster and 16 shorts. Ninty-eight
lobster were taken in 52 trap sites at Catalina Island.
Catches for tra~s without ports totaled 26 legals and 22
shorts; with ports, 46 le~als and 4 shorts.
Catch per haul rates for
San Clemente
Santa Catalina
traps without
legal
0.39
1. 00
escape ports:
short
2.51
0.85
San Clemente
Santa Catalina
-3-
Catch pe'r haul rates for traps ~Tith escape ports:
legal short
0.45 0.42
1.77 0.15
Forty-four of the 94 lobsters captured at Santa Catalina
were recaptures (45%); of these 13 (13.3%) were recapturen
for the first time. All recaptures had moltedv
Personnel: M. Mazarovich, Vessel Captain, KELP BASS
D. Carvahlo, Vessel Captain, MOLLUSK
S. Schultz, Biologist-in-charge
M. Odemar, Biologist
J. Duffy, Biologist
R. McAllister, Biologist
OHB/LB/150
2-10~.75/pb


Cruise Report 74-KB-30 and 74-M-6: Abalone - Lobster Investigations

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Cruise Report 74-KB-30 and 74-M-6: Abalone - Lobster Investigations

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