Table 1 Excavations into crustal subseafloor hydrothermal vents at Fava Flow Suburbs at 9°50’N EPR region in 2023

From: Animal life in the shallow subseafloor crust at deep-sea hydrothermal vents

ROV recovery dive #

S0552

S0554

S0556

S0557

S0558

S0560

Fig. 2c

#1

#2

#3

#4

#5

#6

Fig. 3

a,b

c,d

e,f

g,h

i,j

k,l

Date

13.07.23

15.07.23

17.07.23

18.07.23

19.07.23

21.07.23

Longitude

9.840237

9.840121

9.840075

9.840133

9.840238

9.840108

Latitude

−104.291860

−104.291818

−104.291812

−104.291874

−104.292038

−104.291805

Depth (m)

2515

2515

2515

2515

2512

2515

Ambient T (°C)

1.9

1.9

1.9

2.0

2.0

2.1

Ambient salinity

34.7

34.7

34.7

34.7

34.7

34.7

Ambient oxygen (∑mol·L−1)

107

106

105

106

105

N/A

Surface max. T (°C)

19.7

10.4

22.7

2.1

9.5

9.1

Subseafloor max. T (°C)

24.9

24.0

24.9

11.6

7.0

10.0

Subs. salinity

33.8

34.0

33.3

34.0

34.4

33.8

Subs. pH

6.4

5.7

5.5

6.5

6.5

6.2

Subs. min. H2S (∑mol·L−1)a

N/A

197

401

14

20

25

Subs. max. oxygen (∑mol·L−1)

N/A

N/A

50

91

115

47

~ Lava shelf thickness (cm)

10

12

11

15

10

12

~ Lava plate surface (m2)

0.13

0.21

0.24

0.08

0.07

0.06

~ Cavity height (cm)

10

10

10

10

5

10

Animals at vent surfaceb

      

 Oasisia alvinae

5

4

3

1

0

0

 Riftia pachyptila

6

5

7

6

0

0

 Bathymodiolus thermophilus

0

3

5

2

4

22

Animals in lava crackb

      

 Oasisia alvinae

0

N/Ad

N/Ad

1

0

10

 Oasisia tubes

30

N/Ad

N/Ad

N/Ad

0

40

 Riftia pachyptila

6

5

N/Ad

N/Ad

0

0

 Lepetodrilus spp.

2

1

0

0

0

0

 Nereis sandersi

1

0

0

1

0

1

 Paralvinella spp.

0

0

1

0

0

0

Animals in subseafloor cavitiesc

     

 Oasisia alvinae

0

0.8

0.7

2

0

5.3

 Oasisia tubes

12.3

15.2

53.3

200

0

16

 Riftia pachyptila

0

0

3.3

2

0

0

 Archinome rosacaea

0

0.8

0

0

0

0

 Branchinotogluma spp.

0

0.8

0.7

0

0

2.7

 Lepetodrilus spp.

0

1.5

0.7

0

0

0

 Lepidonotopodium williamsae

0

0

0.7

0

0

2.7

 Neomphalus fretterae

0

0

0

0

0

10.7

 Nereis sandersi

0

2.3

0

0

0

2.7

 Nicomache arwidssoni

1.2

0

0

0

0

5.3

 Paralvinella spp.

0

0

33.3

0

0

0

  1. Abiotic and biotic characteristics of subseafloor (subs.) and surface habitats.
  2. asum of all forms of dissolved sulfide; short sulfide.
  3. b custom-made aluminum frame (0.16 m2) placed on the surface over a crack in the lava shelves, animals on the surface and in the crack were counted.
  4. c total numbers of counted animals in subseafloor cavities beneath lava shelves estimated to 0.16 m−2.
  5. d present but not counted.