Biological Communities Associated with the Indian Ocean Seamounts
Baban Ingole
National Institute of Oceanography,
Dona Paula, Goa 403 004, India
OutlineWhat we known about the
Indian Ocean seamount biology? - (available data as well as New data)
Identify the gaps Proposed national & international studies.
INDIA
Worlds second largest & second high grade manganese nodule deposit.
Over 10000 seamounts –many have potential of cobalt rich
Mid Ocean Ridge system –potential for sulphidedeposits
In last 25 years >70deep-sea expeditions.
400 seabed samples & 55000 still phto & few kms of deep tow photography for benthic studies Potential for many new spp.
But non of the study was aimed at seamount biology
CIOB
Central Indian Ocean Basin (CIOB) Somali Basin; Madagascar Basin; Arabian Sea; Central Indian Ridge (CIR); Carlsberg Ridge (CR) Rodriguez Triple Junction Andaman Back-Arc Basin (ABAB)
Area of interest
Bathymetry and morphology of the central Indian Ocean (Kodagali & Raju, 1992)
(Kodagali & Raju 1992)
BASINAL SEAMOUNTS AND SEAMOUNTS CHAINS OF THE CENTRAL INDIAN OCEAN (Mukhopadhyay et al 2002)
In facts app. 6000 seamounts of small (> 100 m), medium (>500m0 and large (>1500m) are recorded from Indian Ocean nodule field
Afanasij Nikitin Unknown Unknown Unknown Unknown
Scherbakovunknown Walters Farquhar Equator Equator Walters Shoals
Unknown
Among >10000 seamounts, biological features are known only from 16; mainly from the fishery surveys
AfanasiyAfanasiy--Nikitin Nikitin seamount in the CIOBseamount in the CIOB
Many of the rock samples have thick coating of ferromanganese oxides.
Cobalt Crust
dredging & sediment sampling indicated presence of highly diverse in benthic communities
Fish Catch statistics of Soviet/Ukrainian vessels on Southwestern Indian Ridge Seamounts (FAO 2003)
1472
60295472
21121720
152 153 34
583
36 15 10
1676 1500
26332970
3480
1570 1623
3303
2015
810
0
1000
2000
3000
4000
5000
6000
7000
8000
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
Year
Tota
l cat
ch (t
)
Highest catch (6029 t) recorded in 1980.& Lowest (10 t) in 1991. Main target species were alfonsino(Beryx splendens), two species ofrubyfish & two spp. butterfish
Alfonsino, Baryx splendens, accounted for 45% of the total average catch.
Figig. Composition of major fish species
01020304050
Beryx splendensEmmelic
hthys sppCentro
lophidae
Trachurus picturatusSelachim
orphaPolyprio
n spp.Cat
ch C
ompo
sitio
n (%
)
0
500
1000
1500
2000
2500
3000
3500
1975 1980 1985 1990 1995 2000 2005Years
Fish
Cat
ch (T
onne
s)
Baryx splendens
Seamounts (120)
Butterfish
59%
Rubyfishes
18%
Cardinalfish12%
Alfoncinos
11%Jack
mackerel
0.3%
Others0.3%
Seamounts(150)
Jack mackerel
1 3 %
O thers2 %
Cardinalfish
0 %
Rubyfishes8 3 %
A lfoncino0 %
Butterfish2 %
Trawl surveys conducted in 1980-1981 at the Southwest Indian Ridge seamounts Suggested that individual seamount may have different catch composition (Nikolaj et al., FAO 2003)
Vertical distribution of zoopl. (ind./m2) on the region of Equator Seamount (Voronina & Timonin, 1986)
0
500
1000
1500
2000
2500
3000
3500
4000
Acroca
lanus gracili
s
Neocalanu
s gracili
s
Undinulia da
rwini
Acartia
negligens
Lucicu tia fla
vicorni
s
Euchaeti
a spp
Sagitta en
flata
Oneaea m
editerra
ea
Nannoca
lanus far
rani
Oneaea ve
nusta
Clausocal
anus farra
ni
Eusalanus s
ubtenuis
Pterosag
itta drac
o
Clausocalanus m
inor
Eusalanus
a ttenuatus
Haloptilu
s longic
orn is
Heterorhab
dus pappilig
e
Oneaea
con ifer
a
Rhinca lanus c
ornutus
Eucalanu
s crassus
Calanoids ca
rinatu
s
Abu
ndan
ce (n
o. m
-2) bacground slope seamount
21 major Zoopl. species; highest abundance was on the summit & slope
Vertical distribution of zooplankton (ind./m2) on the region of Fred Seamount(1986)
0200400600800
100012001400160018002000
Oncaea venu st
Acar tia ne gligen
Un dinula da rwin
Sagit ta en flata
Sagitta serra
to dentat
Sagitta regular i
Eupha usiacea ju
P te rosagitta drac
Lu cicutia f la
vicorni
Euca lanus subc ra ssu
Eupha usia tene r
Euca lanus a ttenu atu
S ty loch eiron carina tu
Sagit ta m inima
Neo calan us gracili
A car tia tonsa
Sagitta he xap te r
Na nnocalan us min
Oncaea conifer
Euca lanus subten ui
Oncaea med iter rane
Rh inca la nus corn utu
Ha loptilus lo
ngicorn i
Euca lanus c ra ssuA
bund
ance
(No.
m-2
)
bacground seamount
24 major species; highest abundance was in the back ground samples
Biological diversity of the seamount habitat in the Indian Ocean
0102030405060708090
100
Equ
ator
, Fre
d an
d Fa
rquh
ar
Wal
ters
Sho
als
Unkn
own
(260
)
Unk
now
n(33
6)
Unkn
own(
6631
)
Unkn
own
(549
)
Equa
tor
(01°
07'-0
1°02
' N56
°23'
-56°
43' E
)
Fred
(6.2
3 S
54.3
8 E)
Equa
tor (
0°26
' N 5
6°04
' E)
Erro
r,Equ
ator
,Fre
d,Fa
rquh
ar&
off n
orth
wes
tern
Mad
agas
car Fa
rquh
ar
Wal
ters
Sea
mou
nt
Sout
hwes
tern
Indi
an R
idge
seam
ount
s M
id-In
dian
ridg
e an
dBr
oken
ridge
sea
mou
nts
Afan
asiy
Nik
itin
Unkn
own
Seamounts
No.
of s
peci
es ProtozoansZooplanktonFishMegabenthicMacrobenthicMeiobenthicNo.of Endemic spp.
Parameiropsis sp.
Parameiropsis sp.Prionospio sp.
Hesionidae
Nematode
0
10
20
30
40
50
60
Hes
ione
sp
Prio
nosp
iosp
.
Para
done
is s
p
Nem
atod
e
Isop
oda
Tana
idac
ea
Para
mei
rops
is
Den
sity
(no.
m-2
)
Macrofaunal density & (no.m-2) diversity at unknown seamount in CIOB
Meiobenthic composition at CIOB Seamount
Nematodes 66%
Harpacticoids11%
Polychaetes6%
Nauplii6%
Halacaroidea11%
Vertical distribution of meiofauna (no.10cm-2)
0 1 2 3 4 5 6
0-0.50.5-11-1.51.5-2
2.0-4.04.0-6.06.0-8.0
8.0-10-12.0
12.0-Sedi
men
t dep
th (c
m)
Density (no.10cm-2)
Nematodes
Harpacticoids
PolychaetesNauplii
Halacaroidea
Fauna recovered in top 12 cm although core obtained up to 25 cm sed.depths.
Nematodes dominated (66%)
Desmoscolex
Sabatieria
Spiliphera
Araeolaimus
Halalaimus
Nematode genera (13) from unknown Seamount
in CIOBHalalaiusEumorpholaimusAraeolaimusLinhysteraDiplopeltulaRhabditisParaethmolaimusSabatieriaOdentophoraAxonolaimusSpilipheraUnidentified-1Unidentified-2
24%
14%0%
62%
Selective deposit feeders Non-selective deposit feeder
Epistrate feeder Predatory Omnivores
# Selective deposit feeders 62%.# No Predatory omnivores.
# High abundance and diversity in the 2-4cm depth.
# Rhabditis and Paraethmolaimus recorded only from seamount region.
Rhabditis (Head)
Rhabditis (Tail)
Octocorallia
Hexatinellidae
Pennatulacea? Station No. Phylum Class Subclass Order Family CC-2/DR-32 Porifera HexactinellidaCC-2/DR-12 Porifera HexactinellidaCC-2/ADR-33 Porifera HexactinellidaCC-1/DR-2 Arthropoda Crustacea Cirripedia Thoracica ScalpellidaeCC-1/DR-24A Cnidaria Anthozoa Zoantharia Antipatharia AntipathidaeCC-2/DR-25 Cnidaria Anthozoa Zoantharia Antipatharia AntipathidaeCC-2/DR-13 Cnidaria Anthozoa Zoantharia Antipatharia AntipathidaeCC-2/AR-11 Cnidaria AnthozoaCC-1/DR-23 Echinodermata CrinoideaCC-1/DR-23A Echinodermata CrinoideaCC-2/AR-11 Echinodermata OphiuroideaCC-2/AR-11 Cnidaria Anthozoa Octocorallia Pennatulacea?CC-1/DR-2 Unidentified
Megafauna of the Afanasiy
Nikitin seamount
Hydroid
Serpent star Ophiura sp.?Ophiura sp.?
Hyalonema spHyalonema spShrimp
Environmental Impact of deep-sea mining
Indian nodule area150,000 sq.km•2700 km away
Objectives
to assess the potential impact of nodule mining on marine ecosystem
to provide scientific inputs for design and operation of deep-sea mining system
International commitment
SCHEMATIC OF SAMPLINGIN DISTURBANCE AREA
Sedimentcores
Sediment traps
CTD & watersamples
Disturbancearea
Parameters Analysed Biology•Surface productivity•Microbiology•Biochemistry• Meiofauna• Macrofauna•Megafauna
Physics• Currents• Temperature• Conductivity• Meteorology
Chemistry• Metals
• Nutrients
• DOC
• POC
Geology•Seafloor features•Sediment thickness•Topography•Sediment sizes•Pore water and sediment chemistry•Geotechnical props.•Stratigraphy
Baseline conditionsBaseline conditionsAv. Nodule size : ~ 4 cm
Av. abundance : 1-5 kg/sq.m.
Sediment type : Clayey silt
Water content : High (300-600 %)
Sediment type : Clayey silt
Sediment flux : 7-16 g/m2/y.
Biogeochemistry : Nutrient rich
Microbial biomass : High (109g-)
Meiofauna : 07 taxa
Macrofauna : 11 taxa
Sledge mark of the disturber &sediment lumps on the side
Pre-dist. Post-dist. Mon-I Mon-II Mon-III(Jun 97) (Aug 97) (Apr 01) (Jun 02) (Apr 03)
Abund.(no.10 cm-2) 46 23 11 6 11
Groups 11 4 9 6 10Some recovery seen…..natural conditions taking over
Faint trace of disturber track with a holothurian
Holothurians were the major constituents of the megafauna (15 spp. during all three INDEX phases. A majority of the sea cucumber species are deposit feeders, can react rapidly to the fall of fresh phytodetritus arriving at the seafloorn & may recolonize the disturbed area faster compared to other spp.
DISTRIBUTION OF HARPACTICOIDA
18 genera identified; possibility of 03 new spp.
Abyssal fauna (NEW DATA)
Lat (S)
Long.(E)
DISTRIBUTION OF POLYCHAETA
20 species belonging to ten families
Lat (S)
Long.(E)
73.5 74 74.5 75 75.5 76 76.5 77
73.5 74 74.5 75 75.5 76 76.5 77
-15.5
-15
-14.5
-14
-13.5
-13
-12.5
-12
-11.5
-11
-10.5
-10
-15.5
-15
-14.5
-14
-13.5
-13
-12.5
-12
-11.5
-11
-10.5
-10
Xyalidae
Trileptium sp.Adoncholaimus sp. Cervonema sp.
Enchelidiidae Enoplid sp.
Greefilla sp.Halalaimus sp.Leptostomum sp.
Linhystera sp.
Phanodermatidae
Quadricoma sp.Spiliphara sp.
Viscosia sp.
DISTRIBUTION OF NEMATODES IN CIOB
28 genera identified; possibilities of 06 new spp.
Lat (S)
Statement of environmental impact assessment
Baseline data in proposed mining area
Criteria for selection of test and reference sites
Results of simulated impact experiment
Expected environmental impact due to mining
Parameters for monitoring impacts
Phases and milestones of the projectPhases and milestones of the project
Activity Period Remarks
• Baseline data collection 1996 - 1997 Completed • Selection of T & R sites 1997 Completed• Benthic Disturbance and 1997-2001 Completedimpact assessment
• First monitoring studies 2001-2002 Completed• Second monitoring studies 2002-2003 Completed• Third monitoring 2003-2004 Completed• Environmental variability study 2003-2005 Ongoing• Modeling of sediment plume 2003-2006 Ongoing• Creation of database 2002-2007 Ongoing_________________________________________________________
Creation of environmental databaseCreation of environmental databaseFeatures• Interactive data retrieval and comparison
• Multi-disciplinary data set
Water ColumnBenthicPhoto/Video
Applications• Ecological models
• Mining design
Proposed seamount studyBased on the detailed bathymetry, geology and geomorphology of some of the seamounts in the equatorial Indian Ocean & CIOB region as well as Arabian Sea, a multidisciplinary oceanographic survey have been proposed by NIO Goa for aiming at four EEZ (Raman, Panikkar, Wadia & Sagarkanya); few open ocean (such as Afanasiy Nikitin) seamounts in the Indian Ocean
Seamounts in the Arabian Sea
Raman
Wadia
Panikkar
The Deep Sea Drilling Project sites are located in the vicinity
Sagarkanya seamount
Some of us present here are working for a joint proposal for Indian Ocean seamount study
Acknowledgements
Thanks to all my oceanographic colleagues for their help in sample collection and processing.
COML, DARWIN (UK) CeDAMar projects for taxonomic identification & training.
ISA- for providing platform to present out data & possible int. collaboration.