Alvin dive #4503
Feb 24, 2009
Erik Cordes, port observer
Costa Rica seeps – Mound 12
Launch target: 8°55.86 N, 84°18.45 W
X = 12012 Y = 20017
Time
1355
1439
Depth X,Y
0
1005 12012, 20017
1445
1452
1454
1455
1500
1503
1506
1509
1510
1005
1007
1005
1000
992
985
977
967
964
12098 19968
12000 20017
11949 20010
11925 20010
11872 20002
11846 20003
11814 20005
11775 20012
11761 20033
1522
1525
1534
1551
1554
1559
1602
1604
1605
1609
1611
1615
1616
1621
964
964
11751 20035
11746 20033
965
11732 20043
964
11733 20045
965
972
980
985
987
11680 20058
11681 19987
11648 19949
11606 19882
11628 19882
988
988
988
11632 19891
11632 19891
11632 19891
990
11636 19886
11655 19878
11640 19883
11630 19880
11631 19881
1640
1645
1646
1656
1701
1709
1724
1725
1745
1754
1756
1807
1812
988
989
989
Activity___________________________________________________
Launch
On bottom, plain mud
headed 300° towards crest of mound
piece of wood with small fish noted
few bacterial mats, came to 270°
first dead Acharax shell
dropped target – many dead Acharax, bact mats, headed up slope
lots of Acharax, more carbonates, straight up-slope
small tubeworm aggregation, dropped target
muddy slope on eastern edge of crest
steep carbonate outcrop along eastern edge of crest, isolated tubeworms
brief tour of crest of mound – abundant carbonate, some slabs
few Acharax shells, isolated tubeworms, black coral noted
re-located coral, setting up to collect
nice coral video
Bruce wrangles the coral into the small biobox
setting up for carbonate collection
small carbonate into S1
Acharax shell into small biobox
locating top of mound, heading 300° upslope
carbonate blocks, solitary tubeworms
dropping off to the south
plain bottom, few carbonates
few more carbonates, 1-2 tubeworm aggregations, headed 225°
headed towards Skate Park waypoint, 090°
heavy carbonates, scattered tubeworm aggregations, mussel beds
tour of skate park looking for bushmaster-able tubeworms
note: right on the numbers from previous dive
note: shark (or skate) egg case on tubeworm tube
tape change
attempted box core on mussels, but hit carbonate
good yeti / tubeworm video
took triangle scoop in same spot as box core attempt
big crab video – climbing through tubeworm aggregation
square scoop in mussels
re-set LBL
firing niskins 4&5 over active tubeworm site
setting up for more mussel collections
mostly unsuccessful box core – but now closed
collected adjacent rock – 2 pieces
round scoop next to it in live clams (upon recovery got 3 live lucinids)
grabbed 2 live Acharax in same spot – into small biobox
1829
1837
1839
1840
1848
1854
1900
1902
1904
1918
1923
1927
1931
1932
1934
1935
1940
1941
1945
1946
1949
1950
1955
1956
1959
2019
2022
2029
2041
2043
2048
2059
2108
2112
993
995
11521 19867
11518 19864
995
11518 19864
996
997
995
995
995
11507 19864
11507 19862
11515 19847
11516 19853
11499 19880
995
994
994
995
11484 19946
11486 19988
11488 19988
11486 19989
11434 19996
998
11434 19977
995
11479 19957
985
988
989
11610 19881
11632 19883
11631 19870
11641 19866
990
990
990
990
992
11651 19875
11651 19878
11586 19887
11569 19878
11546 19855
headed west to scout out other sites for bushmaster collection & cores
at other “small seep” location
small gorgonians on some carbonates next to potential bushmaster
tape change
attempting bushmaster
big slip as it was coming out – aborted
another potential collection, but mostly mussels
fired niskin #3 over hot yeti crab spot
cores 1-4 in gray mat – shallow & rocky, a few short cores, target #18
headed to Yettisburg – immediately over plain mud bottom
low-lying carbonates, mussels
N then E upslope, few carbonates & mats along the way
large rockwall, entering Yettisburg
tons of mussels
very weird, large swimming polychaete
dropped target #19 near center of Yettisburg
large carbonate slabs, big mussel bed, few tubeworms
bubble stream noted
positioned over bubble stream, fired niskins 1 & 2
headed back to Skate Park to bushmaster
another bubble stream
plain mud bottom, few carbonates
back into carbonates, outcrops
back to Skate Park
located another potential bushmaster – setting up
Bruce is the master again – sample stowed
carbonate paired with bushmaster sampled into L3
attempted core under / adjacent to bushmaster, but failed
tape change
slurp in mussel bed – white canister
headed west to slurp more and core
cores 5-8 in nice white, active mat, some bubbles noted
grabbed a large piece of wood
permission to surface