Helgoland Marine Research

, Volume 69, Issue 1, pp 13–23 | Cite as

The fish fauna of Ampère Seamount (NE Atlantic) and the adjacent abyssal plain

  • Bernd Christiansen
  • Rui P. Vieira
  • Sabine Christiansen
  • Anneke Denda
  • Frederico Oliveira
  • Jorge M. S. Gonçalves
Original Article

Abstract

An inventory of benthic and benthopelagic fishes is presented as a result of two exploratory surveys around Ampère Seamount, between Madeira and the Portuguese mainland, covering water depths from 60 to 4,400 m. A total of 239 fishes were collected using different types of sampling gear. Three chondrichthyan species and 31 teleosts in 21 families were identified. The collections showed a vertical zonation with little overlap, but indications for an affinity of species to certain water masses were only vague. Although most of the species present new records for Ampère Seamount, all of them have been known for the NE Atlantic; endemic species were not found. The comparison with fish communities at other NE Atlantic seamounts indicates that despite a high ichthyofaunal similarity, which supports the “stepping stone” hypothesis of species dispersal, some differences can be attributed to the local features of the seamounts.

Keywords

Deep sea Fish distribution Ichthyofauna Seamounts Zoogeography 

Introduction

Due to their vertical range and habitat diversity, seamounts often support high fish diversity, as compared to the surrounding ocean, and some are known as hotspots of endemic species (e.g. Shank 2010; Stocks et al. 2012). Seamounts are considered to act as “stepping stones” for species dispersal (Almada et al. 2001; Ávila and Malaquias 2003; Santos et al. 1995; Shank 2010; Xavier and van Soest 2007), bridging large oceanic areas in particular for shelf and slope dwelling species. Recently, studies of seamount ecosystems have received a great deal of attention by the scientific community, due to their role as habitat providers for benthopelagic fishes and important spots for great pelagics (e.g. Clark et al. 2010; Morato et al. 2010). There is an ongoing concern that seamount stocks are overfished, and fishing is impairing the benthic communities (e.g. Clark 2001; 2010; Clark and Koslow 2007; Clark and Rowden 2009; Clark et al. 2006; Norse et al. 2012).

Little has been known about the ichthyofauna at most NE Atlantic seamounts, in particular in the deeper regions. Although commercial fisheries have targeted many banks and seamounts, detailed scientific studies of the demersal and benthopelagic fish fauna are available only for a few of them. In particular, extensive sampling programmes were conducted at Great Meteor Bank and other seamounts south of the Azores (Ehrich 1977; Kukuev 2004; Maul 1976 and literature cited therein), and at Seine and Sedlo Seamounts (Christiansen et al. 2009; Menezes et al. 2009, 2012). Knowledge of the fish communities at Ampère Seamount is currently based on visual observations by Russian researchers covering the upper and middle slopes, but there is also anecdotal evidence that Ampère Seamount is a fishing ground for commercially valuable species, such as the black scabbardfish Aphanopus carbo (Bordalo-Machado et al. 2009) and the silver scabbardfish Lepidopus caudatus (personal observation).

The fish survey at Ampère Seamount reported here was part of a comprehensive, multidisciplinary sampling programme, which also included hydrography, phyto- and zooplankton, benthos, biogeochemistry and sedimentology. The studies aimed at an advanced understanding of the seamount ecology, in comparison with other seamounts in the NE Atlantic and the Eastern Mediterranean, and addressed, for example, the relationships between flow field and plankton distribution, fluxes of organic matter, the trophic structure and the biodiversity of benthic and pelagic seamount communities. First results show that the oligotrophic nature of the sea area around Ampère is reflected in low zooplankton standing stocks, with no indications of an enhanced biomass at the seamount as compared to the surrounding ocean (Denda and Christiansen 2013). The major aim of the fish studies conducted on the P384 cruise of R.V. Poseidon and the M83/2 cruise of R.V. Meteor was to characterize the benthopelagic fish community at different depths, using various fishing gears and considering several locations at and around Ampère Seamount, including the summit, the slopes and an abyssal reference station. The results are compared to fish assemblages found at other NE Atlantic seamounts.

Materials and methods

Study area

Ampère Seamount is part of the Horseshoe Seamounts Chain and located at 35°N, 13°W between the island of Madeira and the Portuguese southern coast, to the west of the Exclusive Economic Zone of Morocco (Fig. 1). Ampère rises from a base depth of ca. 4,500 to 55 m below the surface. It is separated from the neighbouring Coral Patch Seamount by a deep valley of 3,400 m depth. The seamount has a conical shape with an elongated base and a small, rough summit plateau at 110–200 m, with a single narrow peak reaching to 55 m (Fig. 2). The slopes are steep and rocky with canyon-like structures particularly at the northern, eastern and southern sides (Halbach et al. 1993; Hatzky 2005; Kuhn et al. 1996), but sediment-covered flat areas exist as well. For comparison, a reference station on a flat, sedimentary abyssal plain in 4,400 m depth, located ca. 70 nm south of Ampère Seamount at 33°56′N, 013°16′W, was also sampled (Fig. 1).
Fig. 1

The Horseshoe seamount chain. The location of the reference station south of Ampère Seamount is marked by a triangle. Depth contour interval 500 m. Bathymetric data source: GEBCO (IOC et al. 2003)

Fig. 2

Central area of Ampère Seamount with locations of stationary fishing gear and beam trawl tracks during cruise M83/2. Credit bathymetric data: J. Hatzky, AWI

Sampling

The inventory of demersal fishes on Ampère Seamount was derived from sampling during the P384 cruise of R.V. Poseidon in May 2009 and the M83/2 cruise of R.V. Meteor in November/December 2010, using hooks-and-line, longlines, baited traps, beam trawl and otter trawl. The variety of sampling methods aimed at broadening the collection of fishes caught to several feeding types. However, the rough and steep terrain of the seamount made benthopelagic trawling in the upper 2,000 m extremely risky and led to the damage of the beam trawl during all tows and to the complete loss of one beam trawl. The otter trawl was deployed only below 2,000 m. Stationary fishing gears (longlines, hook-and-line and traps) were used down to a maximum depth of 1,200 m, except for small traps which were exposed in connection with lander deployments at 1,700–2,200 m.

During the P384 cruise, hook-and-line fishing was performed opportunistically in the vicinity of the summit area at depths between 70 and 213 m (Fig. 2). Different hooks and various types of bait were used, including commercial fish lures, aluminium foil and pieces of sardines. Fish traps (“Madeira type”, Fig. 3; Biscoito 1993) were baited with sardines and deployed for several hours, also in the summit area. A 2-m beam trawl with 6-mm mesh (see Christiansen et al. 2009 for details) was towed twice at 123–133 m depth on the summit plateau (Fig. 2); bottom time was 10–15 min each.
Fig. 3

Trap types used during cruises P322 and M83/2. Upper left “Madeira type” (Biscoito 1993); upper right “Apollo” eel trap; lower left crab trap; lower right flatfish trap

During the M83/2 cruise, a total of 12 demersal longline sets were deployed between 60 m and 1,200 m depth on the summit and on the upper slopes of the seamount (Fig. 2; Table 1). The basic design of the longline sets is shown in Fig. 4. From the third deployment on, a drift anchor was used instead of the weight at the end of the longline. In haul 7, a different design using 30 m long branch lines with 10 snoods each was employed, similar to the longline “Type B” used by Menezes et al. (2009). In hauls 8–12, small buoys and weights were alternately attached to the main rope every 10 hooks. A total of 48–83 hooks of different size (straight # 3 and # 6; twisted # 6/0 and # 8/0) per set were baited with mackerels and sardines, and up to 8 traps of different design (Madeira-type fish trap, eel trap, crab trap and flatfish trap; Fig. 3) were attached either to the anchor weight or to the end of the main rope. Soak time was usually 5–6 h. Of the 12 longline/trap deployments, one longline was completely entangled and did not fish, and two longlines were lost. The total number of recovered hooks was ca. 500. Small traps made from 1.5-l plastic bottles were also attached to a lander system in four deployments at depths from 1,700 to 2,172 m.
Table 1

Features of the longline deployments during cruise M83/2

Depl. no

Station no

Depth (m)

Position

No hooks

No traps

Observations

LL1

1,094

314

Upper slope SE

52

5

 

LL2

1,095

444

Upper slope S

52

 

Entangled, not fishing

LL3

1,111

160

Rim NW

48

8

 

LL4

1,112

490

Upper slope NW

49

8

 

LL5

1,183

60

Peak

52

7

36 Hooks recovered. traps lost

LL6

1,184

330

Upper slope S

  

Rope snapped

LL7

1,195

127

Summit plateau

60

2

 

LL8

1,216

938

Middle slope S

83

2

42 Hooks recovered

LL9

1,228

991

Middle slope NW

55

5

 

LL10

1,257

416

Upper slope W

60

3

 

LL11

1,271

981

Middle slope W

  

Lost

LL12

1,288

1,200

Middle slope S

55

2

 
Fig. 4

Basic design of the longline used during cruise M83/2

A 15-m semiballoon otter trawl was towed on a single warp at 2–3 knots on the western lower slope of the seamount (approximately 2,000–2,100 m depth, bottom time approximately 30 min) and on the abyssal plain at the reference station south of Ampère Seamount (two hauls, both at 4,415 m depth, bottom time approximately 180 and 120 min, respectively). The estimated horizontal net opening of the trawl was 8.6 m; the mesh size was 44 mm in the front part and 37 mm in the intermediate and rear parts, with a 13-mm inner liner in the cod end.

Immediately after recovery of the catch, specimens were identified to the lowest taxonomic level possible using the keys in Whitehead et al. (1986). Total and standard lengths and weights of all specimens were measured and, where possible, stomachs were dissected and tissue samples taken for later analysis of DNA and isotopic ratios. Fishes from cruise P384 could not be landed due to lack of freezing facilities during transport, whereas all fishes from M83/2 were frozen at −20 °C to be transported to the University of Hamburg. Here, the on-board identifications were checked using a variety of taxonomic keys and descriptions (Franco et al. 2009; Froese and Pauly 2013; Nielsen et al. 1999; Sulak 1977; Sulak and Shcherbachev 1997; Whitehead et al. 1986). Less common species are being finally deposited at the Zoological Museum, Hamburg.

Results

The list of fishes (Table 2) collected at Ampère Seamount includes a total of 239 specimens (pelagic bycatch in the otter trawl not included). Thirty-four species belonging to 23 families were identified. Three species were Chondrichthyes, and 31 were Actinopterygii. Perciformes (seven species), Anguilliformes and Gadiformes (five species each) were the most speciose orders in the collections.
Table 2

Fishes collected at and around Ampère Seamount, arranged according to depth of occurrence

Species

Order

Family

N

Gear

Min depth (m)

Max depth (m)

Size (mm)

Muraena helena

Anguilliformes

Muraenidae

7

LL,T

60

164

940–1,100 TL

Lepidopus caudatus

Perciformes

Trichiuridae

13

LL,HL

73

180

790–1,380 SL

Serranus atricauda

Perciformes

Serranidae

6

LL,HL

75

213

210–375 SL

Trachurus picturatus

Perciformes

Carangidae

16

LL,HL

106

489

275–375 SL

Coris julis

Perciformes

Labridae

2

T

127

127

125–145 SL

Scomber scombrus

Perciformes

Scombridae

10

LL

127

164

335–415 SL

Scomber colias

Perciformes

Scombridae

11

LL,HL

127

180

310–480 SL

Callanthias ruber

Perciformes

Callanthiidae

2

BT

134

177

60–70 SL

Capros aper

Zeiformes

Caproidae

2

BT

134

177

90–110 SL

Pontinus kuhlii

Scorpaeniformes

Scorpaenidae

9

LL,HL,BT,T

164

170

150–330 SL

Conger conger

Anguilliformes

Congridae

3

LL, T

164

314

735–1,305 TL

Helicolenus dactylopterus

Scorpaeniformes

Sebastidae

5

LL,T

314

489

125–275 SL

Malacocephalus laevis

Gadiformes

Macrouridae

1

LL

420

420

250 TL

Dipturus batisa

Rajiformes

Rajidae

1

LL

420

420

580 TL

Zenopsis conchifer

Zeiformes

Zeidae

1

LL

489

489

705 SL

Aphanopus carbo

Perciformes

Trichiuridae

2

LL

938

938

1,000–1,080 SL

Deania calcea

Squaliformes

Centrophoridae

5

LL

938

992

570–890 TL

Mora moro

Gadiformes

Moridae

37

LL,T

938

1,200

300–585 TL

Etmopterus pusillus

Squaliformes

Etmopteridae

2

LL

992

992

395–430 TL

Synaphobranchus kaupii

Anguilliformes

Synaphobranchidae

30

LL,OT,T

992

2,050

335–730 TL

Simenchelys parasitica

Anguilliformes

Synaphobranchidae

6

T

1,700

1,700

n.a.

Bathypterois grallator

Aulopiformes

Ipnopidae

1

OT

2,050

2,050

295 SL

Halosauropsis macrochir

Notacanthiformes

Halosauridae

3

OT

2,050

2,050

550–640 TL

Cataetyx laticeps

Ophidiiformes

Bythitidae

1

OT

2,050

2,050

645 SL

Bajacalifornia megalops

Osmeriformes

Alepocephalidae

1

OT

2,050

2,050

480 SL

Conocara salmoneum

Osmeriformes

Alepocephalidae

7

OT

2,050

4,416

250–720 SL

Histiobranchus bathybius

Anguilliformes

Synaphobranchidae

1

OT

4,416

4,416

1,210 SL

Bathypterois sp.

Aulopiformes

Ipnopidae

1

OT

4,416

4,416

125 TL

Holcomycteronus squamosus

Ophidiiformes

Ophidiidae

1

OT

4,416

4,416

375 SL

Bathymicrops regis

Aulopiformes

Ipnopidae

6

OT

4,416

4,419

90–110 SL

Bathypterois longipes

Aulopiformes

Ipnopidae

15

OT

4,416

4,419

65–195 SL

Coryphaenoides armatus

Gadiformes

Macrouridae

15

OT

4,416

4,419

660–860 TL

Coryphaenoides profundicolus

Gadiformes

Macrouridae

7

OT

4,416

4,419

270–410 TL

Coryphaenoides sp.

Gadiformes

Macrouridae

2

OT

4,416

4,419

540–665 TL

Echinomacrurus mollis

Gadiformes

Macrouridae

2

OT

4,416

4,419

50–205 TL

Rinoctes nasutus

Osmeriformes

Alepocephalidae

5

OT

4,416

4,419

125–195 SL

Gear abbreviations: HL hook-and-line, LL longline, T trap, BT beam trawl, OT otter trawl. Size abbreviations: SL standard length, TL total length

aThe taxonomic status of D. batis is currently under discussion. D. batis may actually consist of two nominal species, D. cf. flossada and D. cf. intermedia (Iglésias et al. 2010)

The collections showed a vertical zonation with little overlap. The upper depth guild, which included longline, hook-and-line, trap and beam trawl catches from 60 to 300 m, was the most diverse and comprised a total of 11 species belonging to 10 families. The most frequently caught species were the pelagic or benthopelagic horse mackerel Trachurus picturatus with 16 specimens, silver scabbard fish Lepidopus caudatus with 13 species, and the two mackerel species, Scomber colias and Scomber scombrus with 11 and 10 specimens, respectively. The scorpionfish Pontinus kuhlii (9 specimens), the Mediterranean moray Muraena helena (7) and the blacktailed comber Serranus atricauda (6) were also relatively abundant in the catches, whereas the other species were rare with only two or three specimens each.

The next depth guild from 300 to 500 m was covered by longline and traps. A total of five species were captured in this depth range including Trachurus picturatus, which was also caught above 300 m. Apart from the blackbelly rosefish Helicolenus dactylopterus with five specimens, only single fishes were caught from each family.

Longlines and traps were also employed between 900 and 1,200 m. The predominant species in this depth layer was the common mora Mora moro with 37 specimens. Further, a few specimens of the black scabbardfish Aphanopus carbo, Kaup’s arrowhead Synaphobranchus kaupii, and two shark species, the birdbeak dogfish Deania calcea and the smooth lanternshark Etmopterus pusillus, were captured.

Synaphobrancus. kaupii, was also caught on the lower slope of the seamount at about 2,000 m, where it was the predominant species in the otter trawl catch with 30 individuals, corresponding to nearly 75 % of all specimens. Other families included Alepocephalidae, Bythitidae, Ipnopidae, Ophidiidae and Halosauridae with one species and 1–3 specimens each. The small traps attached to the lander system at 1,700 m in two deployments captured six specimens of the Synaphobranchidae Simenchelys parasitica.

A total of 11 species were collected in the otter trawl on the abyssal plain at a depth of ca. 4,400 m. The most abundant families were Macrouridae with 26 specimens (3 species), Ipnopidae with 22 specimens (3 species) and Alepocephalidae with 12 specimens (2 species). The families Synaphobranchidae and Ophidiidae were caught with one species and one specimen each. The most common species were the abyssal grenadier Coryphaenoides armatus and the abyssal spiderfish Bathypterois longipes, with 15 specimens each. One species was found in the otter trawl collections from both 2,400 and 4,400 m, the salmon smooth-head Conocara salmoneum.

In addition to the benthopelagic species, the otter trawl also collected pelagic species. Only a few particularly rare pelagic species have been analysed in detail so far, such as the first record in the North Atlantic of the cetomimid Cetichthys indagator (Vieira et al. 2012) and two large females of the anglerfish Gigantactis vanhoeffeni, and one unidentified Gigantactis female, which represent, to our best knowledge, the first records of adult Gigantactis females in the region (Bertelsen 1986; Santos et al. 1997; Swinney 1995).

Discussion

Contrary to the relatively well-known fish fauna of seamounts and islands around the Azores and Madeira (Arkhipov et al. 2004; Christiansen et al. 2009; Ehrich 1977; Kukuev 2004; Maul 1976; Menezes et al. 2006, 2009, 2012; Pakhorukov 2008; Santos et al. 1997; Shcherbachev et al. 1985), the ichthyofauna of the Horseshoe Seamount Chain (Fig. 1) and in particular of Ampère Seamount has been little studied until now. Visual observations were conducted on the summit area of Gorringe Bank (Abecasis et al. 2009; Gonçalves et al. 2004) and on the upper and middle slopes at Ampère Seamount and Josephine Bank; the latter was also trawled (Pakhorukov 2008). Recently, Wienberg et al. (2013) reported some fish species at Coral Patch Seamount from ROV observations above the middle slope.

The results presented here increase the number of fish species described from Ampère seamount substantially. Most of the 34 species collected at and around the seamount in this study are widely distributed in the Atlantic and in the Mediterranean (e.g. Froese and Pauly 2013; Haedrich and Merrett 1988; Menezes et al. 2006, 2009, 2012; Merrett 1992; Merrett and Marshall 1981; Pakhorukov 2008). Endemic species were not found. Except for the abyssal fishes Conocara salmoneum, Bathymicrops regis, Coryphaenoides profundiculus and Echinomacrurus mollis, all species have also been reported from waters around the Azores (Menezes et al. 2006, 2012; Santos et al. 1997). Of all species listed here, Conocara salmoneum is reported explicitly in Portuguese waters for the first time, but data from Merrett (1992) already suggest its presence in the Madeiran EEZ.

In the 1980s, Soviet investigators surveyed Ampère Seamount together with Josephine Bank and most of the seamounts south of the Azores down to 1,200 m depth by a submersible, the so-called underwater inhabited device (UID), and partly also with bottom trawls (Pakhorukov 2008). Table 3 lists all fish species at Ampère Seamount reported from Pakhorukov (2008) and the present study. Species are organized according to the main depth of catch/observation in these studies and include occurrence and depth range at other NE Atlantic seamounts. The resulting inventory comprises a total of 52 identified species of benthic and benthopelagic fishes. From the visual observations at Ampère, Pakhorukov (2008) reports of 24 fish species, complemented by observations of their behaviour and the type of habitat. Only 6 of these species were recovered in this study, but on the other hand, an additional 14 species were found between summit and middle slope at 1,200 m. On the lower slope and surrounding abyssal plain at 1,700, 2,050 and 4,400 m depth, a further 14 species add to the ichthyocoenoses of Ampère Seamount. The little overlap between Pakhorukov’s (2008) and the results from this study in the upper layers points to the importance of applying a wide variety of methods in order to assess the ichthyofauna as completely as possible.
Table 3

Inventory of fish species recorded at Ampère Seamount from the present study (C) and from Pakhorukov (2008, P), and comparative occurrences and depth ranges at NE Atlantic seamounts

This study; Abecasis et al. (2009), Christiansen et al. (2009), Ehrich (1977), Menezes et al. (2009), Pakhorukov (2008), Shcherbachev et al. (1985)

JB Josephine Bank, GB Gorringe Bank, SS Seine Seamount, SSAz seamounts south of the Azores

aSee remark in Table 2

The results from this study suggest a clear vertical zonation of the fishes at Ampère; however, part of this can probably be attributed to the rather small sample size and the few discrete sampling depths in our study, particularly in the upper 1,200 m. Information which includes depth ranges at other NE Atlantic seamounts shows that many of the same species occur along a wide depth range (Table 3), thus, making the allocation of single species to vertically discrete assemblages difficult.

Menezes et al. (Menezes et al. 2006, 2009 and literature quoted therein) identified vertically structured fish assemblages around the Azores archipelago and at Seine Seamount and related them to the water mass properties in the areas. During the Meteor cruise in December 2010 (Christiansen et al. 2012), Eastern North Atlantic Central water (ENACW; 10–20 °C, 35.2–36.7 °C) characterized the upper 500 m below a 50–80 m thick, warm mixed layer. Between 600 and 1,300 m depth Mediterranean Outflow Water (MOW; 13 °C, 38.4 PSU) was found, and underneath a mixing zone from 1,400 to 2,000 m, North Atlantic Deep water (NADW; 1.5–4 °C, 34.8–35 PSU) and probably Antarctic Bottom water (ANBW) formed the water layers in the lower bathyal and abyssal zones (Fig. 5).
Fig. 5

Profiles of temperature, salinity and oxygen concentration at the southern slope of Ampère Seamount

Both the summit and upper slope regions of Ampère Seamount down to about 600 m are under influence of the Eastern Atlantic Central Water/Azores current. The benthic and benthopelagic fish communities in this depth stratum comprise 35 species (Table 3). Among this shallow fish community, 21 fish species seem to occur exclusively in this depth range, with four species being confined to the summit area down to 200 m. The remaining 14 species, including commercially exploited fish like alfonsino Beryx splendens Lowe, silver scabbardfish Lepidopus caudatus and silver roughy Hoplostethus mediterraneus, have also been found deeper in the Mediterranean Outflow water between 600 and 1,300 m. Only two species, Ruvettus pretiosus and Alepocephalus bairdii, seem to be restricted to this water mass of Mediterranean origin; however, this is based on only a small number of observations and should be judged with some caution. Generally, indications for an affinity of species to certain water masses are vague. Most of the fishes on the upper and middle slope of Ampère Seamount occur in a wide range of temperatures, salinities and oxygen concentrations.

The majority of the shallower species at Ampère were found in common with Gorringe Bank on the northern arc of the Horseshoes seamounts: Conger conger, Muraena helena, Capros aper, Coris julis and Serranus atricauda. However, Pontinus kuhlii (also observed at Seine and Great Meteor, Christiansen et al. 2009; Ehrich 1977; Menezes et al. 2009) and the widely distributed Lepidopus caudatus, which has been known from other NE Atlantic seamounts like the neighbouring Seine and Josephine and the more southern Great Meteor, Atlantis, Flamingo and Hyères (Ehrich 1977; Menezes et al. 2009; Pakhorukov 2008), were not observed at Gorringe (Abecasis et al. 2009), see Table 3. On the other hand, several species common at Gorringe were not found at Ampère, most of them being littoral fishes like Blenniidae or Labridae. However, the survey at Gorringe employed visual observations from divers and covered only the peaks at depths from 29 to 50 m, so the different methodologies involved do not allow for a comprehensive comparison of the fish communities between these seamounts, and Lepidopus caudatus, for example, has been known from commercial catches in the Gorringe area.

The upper and mid-slope collections included species that are usually found at the continental and island slopes, and, with the exception of the blue skate Dipturus batis (taxonomic status of this species is under discussion, see Iglésias et al. 2010), have been reported also from other seamounts in the NE Atlantic (Table 3). In particular, Helicolenus dactylopterus, Aphanopus carbo, Mora moro and Deania calcea have been observed at several seamounts in the Horseshoe region and to the north and south of the Azores (Abecasis et al. 2009; Menezes et al. 2009; Pakhorukov 2008). Synaphobranchus kaupii were also observed at Seine and Sedlo Seamounts (Menezes et al. 2009), but not at other Horseshoe seamounts or at seamounts south of the Azores, which is probably due to the limited depth range of the samples there, since Almeida and Biscoito (2007) reported their presence at the Lucky Strike vent field on the mid-Atlantic Ridge south of the Azores.

Due to the depth limitation to 1,200 m in the observations of Pakhorukov (2008), the ichthyocoenoses found in this study on the lower slope of Ampère (1,700 and ∼2,000 m depth) and on the adjacent deep-sea abyssal plain (4,400 m) supplement the species described from the regional seamounts substantially. With the exception of Cataetyx laticeps, which is restricted to the Atlantic and Mediterranean, all of the fishes caught on the lower slope are species with a circumglobal distribution (Froese and Pauly 2013). They are usually found at bathyal depths, often with a wide depth range. However, no overlap was observed with the upper/mid-slope species, except for the predominating species on the lower slope of Ampère, Synaphobranchus kaupii, which has been reported, for example, from Porcupine Seabight at depths from 230 to 2,420 m (Merrett et al. 1991).

The Alepocephalidae Conocara salmoneum was the only species present on both the lower slope and the abyssal plain adjacent to Ampère Seamount. The fishes found here are typical abyssal species belonging to the northern and intermediate deep-sea fish assemblages as proposed for the NE Atlantic by Merrett (1992). Only the Ophidiidae Holcomycteronus squamosus was not included in those assemblages, but it is a particularly rare species known from a few scattered locations in the North Atlantic, with a certainly incomplete distribution record.

Despite the general similarities of the ichthyofaunal assemblages of the Northeast Atlantic seamounts, the comparisons also show some differences. These can partly be attributed to differing methodologies, as already indicated above, and to sampling effort. For example, the higher number of species collected with longlines by Menezes et al. (2009) at Seine Seamount is most probably due to the much higher fishing effort (>14,000 hooks at Seine Seamount, as compared to ca. 500 recovered hooks at Ampère), and to the deeper-reaching sets (max. 2,000 vs. 1,200 m). On the other hand, despite the differences in sampling effort, seven of the 20 species captured down to 1,200 m at Ampère Seamount in this study had not been collected at Seine (all gears considered). Apart from possible dissimilarities in gear selectivity, true differences between the two seamounts like summit depth, topography, substrate or coral cover may play a role. For example, most of the species missing at Seine, including Muraena helena, Serranus atricauda, Coris julis and Capros aper, were captured at depths shallower than the Seine summit plateau. Furthermore, the much more rugged topography with basaltic outcrops of the Ampère summit area, as compared to the flat, sedimentary summit plateau of Seine, may provide suitable habitat for species, such as the moray eel M. helena, which depend on or prefer richly structured, rocky substrate (e.g. Bauchot 1986).

The relatively similar inventory of shelf and slope fish species in the summit and upper slope regions of the seamounts of the Horseshoe Chain and of the seamounts around the Azores supports the hypothesis of these topographic features being “stepping stones” for species dispersal within the larger NE Atlantic region, possibly powered by the large-scale current system (Azores Current, Canary Current) and westward propagating meddies. This may also apply to the benthopelagic deep-water fishes found at the seamount slopes, which are also dependent on suitable substrate at appropriate depths. However, a higher sampling effort and the use of genetic tools will be necessary to evaluate the biogeographic significance of Ampère Seamount and to assess the biogeographic links between the NE Atlantic seamounts.

This effort will also be important for designing conservation and management measures in order to mitigate eventually unsustainable impacts of fishing activities on the commercially targeted species such as several species found at Ampère, which are important in the southern Portuguese longline fisheries (Borges 2007), like Lepidopus caudatus, Aphanopus carbo, Mora moro, Helicolenus dactylopterus and Pontinus kuhlii, and, usually restricted to coastal areas, Conger conger and Muraena helena.

In conclusion, the data show, despite the comparatively low sampling effort, that Ampère Seamount hosts a rich and diverse fish community. Generally, the seamounts in the subtropical NE Atlantic appear to be very similar with respect to their ichthyofauna. However, the differences, for example between the adjacent and relatively well-sampled Ampère and Seine Seamounts, point to the role of properties like substrate type and habitat complexity in shaping the final expression of community composition.

Notes

Acknowledgments

We would like to thank the crews of RVs Meteor and Poseidon for their skilful support on the cruises. Shiptime and financial support were provided by the Deutsche Forschungsgemeinschaft and the Universität Hamburg. R. P. V. would like to thank DAAD—Deutscher Akademischer Austauschdienst (German Academic Exchange Service) in support of short-term scholarship for research in the IHF—Universität Hamburg (Germany) and CCMAR for the financial support. R. P. V. is currently supported by a doctoral grant from the Portuguese Science Foundation (SFRH/BD/84030/2012).

References

  1. Abecasis D, Cardigos F, Almada F, Gonçalves JMS (2009) New records on the ichthyofauna of the Gorringe seamount (Northeastern Atlantic). Mar Biol Res 5(6):605–611. doi:10.1080/17451000902729696 CrossRefGoogle Scholar
  2. Almada VC, Gonçalves EJ, Oliveira RF, Almeida AJ, Santos RS, Wirtz P (2001) Patterns of diversity of the north-eastern Atlantic Blenniid fish fauna (Pisces: Blenniidae). Glob Ecol Biogeog 10(4):411–422CrossRefGoogle Scholar
  3. Almeida AJ, Biscoito M (2007) New records of Synaphobranchus (Anguilliformes, Synaphobranchidae) from the Azores, (eastern Atlantic Ocean). Cybium 31(3):391–392Google Scholar
  4. Arkhipov AG, Kozlov DA, Sirota AA, Shnar VN (2004) Structure of waters and distribution of fish at different ontogenetic stages around seamounts of the Central-Eastern Atlantic Ocean. Arch Fish Mar Res 51(1–3):201–214Google Scholar
  5. Ávila SP, Malaquias MAE (2003) Biogeographical relationships of the molluscan fauna of the Ormonde Seamount (Gorringe Bank, Northeast Atlantic Ocean). J Mollusc Stud 69:145–150CrossRefGoogle Scholar
  6. Bauchot M-L (1986) Muraenidae. In: Whitehead PJP, Bauchot M-L, Hureau J-C, Nielsen J, Tortonese E (eds) Fishes of the North-eastern Atlantic and the Mediterranean, vol II. UNESCO Press, Paris, pp 537–544Google Scholar
  7. Bertelsen E (1986) Gigantactinidae. In: Whitehead PJP, Bauchot M-L, Hureau J-C, Nielsen J, Tortonese E (eds) Fishes of the North-eastern Atlantic and the Mediterranean, vol III. UNESCO Press, Paris, pp 1406–1407Google Scholar
  8. Biscoito M (1993) An account on the shrimps of the family Pandalidae (Crustacea, Decapoda, Caridea) in Madeiran waters. In Proceedings of the 5th Symposium “Fauna and Flora of the Cape Verde Islands”, Leiden, 4-7 October, 1989. Courier Forschungsinstitut Senckenberg 159:321–325Google Scholar
  9. Bordalo-Machado P, Fernandes AC, Figueiredo I, Moura O, Reis S, Pestana G, Gordo LS (2009) The black scabbardfish (Aphanopus carbo Lowe, 1839) fisheries from the Portuguese mainland and Madeira Island. Sci Mar 73S2:63–76. doi:10.3989/scimar.2009.73s2063
  10. Borges TC (ed) (2007) Biodiversity in fisheries off South Coast of Portugal (Algarve). MARE Research Programme, Impriluz, LisbonGoogle Scholar
  11. Christiansen B, Martin B, Hirch S (2009) The benthopelagic fish fauna of Seine Seamount, NE Atlantic: composition, population structure and diets. Deep-Sea Res II 56(25):2705–2712. doi:10.1016/j.dsr2.2008.12.032 CrossRefGoogle Scholar
  12. Christiansen B, Albers L, Brand T, Chivers A, Christiansen H, Christiansen S, Denda A, Diniz T, George K-H, Irion I, Janßen T, Kaufmann M, Kullmann B, Lamont P, Molodtsova T, Montgomery J, Peine F, Schneehorst A, Schuster A, Springer B, Stahl H, Stefanowitsch B, Turner G, Turnewitsch R, Vieira R, Vogel S, Wehrmann H (2012) Biodiversity and biological production at a shallow NE Atlantic seamount (Ampère Seamount), 2010, METEOR-Berichte, Cruise No. M83/2. DFG-Senatskommission für Ozeanographie. doi:10.2312/cr_m83_2
  13. Clark M (2001) Are deepwater fisheries sustainable? The example of orange roughy (Hoplostetus atlanticus) in New Zealand. Fish Res 51:123–135CrossRefGoogle Scholar
  14. Clark MR (2010) Effects of trawling on seamounts. Oceanogr 23:132–133CrossRefGoogle Scholar
  15. Clark MR, Koslow JA (2007) Impacts of fisheries in seamounts (chapter 19). In: Pitcher TJ, Morato T, Hart PJB, Clark MR, Haggan N, Santos RS (eds) Seamounts: ecology, fisheries and conservation. Blackwell Publishing, Oxford, pp 413–441CrossRefGoogle Scholar
  16. Clark MR, Rowden AA (2009) Effect of deepwater trawling on the macro-invertebrate assemblages of seamounts on the Chatham Rise, New Zealand. Deep-Sea Res I 56(9):1540–1554. doi:10.1016/j.dsr.2009.04.015 CrossRefGoogle Scholar
  17. Clark MR, Tittensor D, Rogers AD, Brewin P, Schlacher T, Rowden A, Stocks K, Consalvey M (2006) Seamounts, deep-sea corals and fisheries: vulnerability of deep-sea corals to fishing on seamounts beyond areas of national jurisdiction. UNEP regional seas report and studies no 183. UNEP-WCMC biodiversity series no 25. UNEP-WCMC, CambridgeGoogle Scholar
  18. Clark MR, Rowden AA, Schlacher T, Williams A, Consalvey M, Stocks KI, Rogers AD, O’Hara TD, White M, Shank TM, Hall-Spencer JM (2010) The ecology of seamounts: structure, function, and human impacts. Ann Rev Mar Sci 2(1):253–278. doi:10.1146/annurev-marine-120308-081109 CrossRefPubMedGoogle Scholar
  19. Denda A, Christiansen B (2013) Zooplankton distribution patterns at two seamounts in the subtropical and tropical NE Atlantic. Mar Ecol. doi:10.1111/maec.12065 Google Scholar
  20. Ehrich S (1977) Die Fischfauna der Großen Meteorbank. Meteor Forsch Ergebn (D) 25:1–23Google Scholar
  21. Franco MAL, Braga AC, Nunan GWA, Costa PAS (2009) Fishes of the family Ipnopidae (Teleostei: Aulopiformes) collected on the Brazilian continental slope between 11° and 23° S. J Fish Biol 75:797–815. doi:10.1111/j.1095-8649.2009.02324.x CrossRefPubMedGoogle Scholar
  22. Froese R, Pauly D (2013) FishBase. World Wide Web electronic publication. Version (06/2013)Google Scholar
  23. Gonçalves JMS, Bispo J, Silva JA (2004) Underwater survey of ichthyofauna of eastern Atlantic seamounts: gettysburg and Ormond (Gorringe Bank). Arch Fish Mar Res 51(1–3):233–240Google Scholar
  24. Haedrich RL, Merrett NR (1988) Summary atlas of deep-living demersal fishes in the North Atlantic Basin. J Nat Hist 22:1325–1362CrossRefGoogle Scholar
  25. Halbach P, Maggiulli M, Plieske B, Kuhn T (1993) Technical cruise report of RV Sonne cruise 83—Marflux 4. Freie Universität BerlinGoogle Scholar
  26. Hatzky J (2005) Ampère Seamount. In: Wille PC (ed) Sound images of the ocean in research and monitoring. Springer, Berlin, pp 131–132Google Scholar
  27. Iglésias SP, Toulhoat L, Sellos DY (2010) Taxonomic confusion and market mislabelling of threatened skates: important consequences for their conservation status. Aquatic Cons 20(3):319–333. doi:10.1002/aqc.1083 CrossRefGoogle Scholar
  28. IOC, IHO, BODC (2003) Centenary edition of the GEBCO digital atlas, published on CD-ROM on behalf of the Intergovernmental Oceanographic Commission and the International Hydrographic Organization as part of the General Bathymetric Chart of the Oceans. British Oceanographic Data Centre. Available via British Oceanographic Data CentreGoogle Scholar
  29. Kuhn T, Halbach P, Maggiulli M (1996) Formation of ferromanganese microcrusts in relation to glacial/interglacial stages in Pleistocene sediments from Ampere Seamount (Subtropical NE Atlantic). Chem Geol 130:217–232CrossRefGoogle Scholar
  30. Kukuev EI (2004) 20 years of ichthyofauna research on seamounts of the North-Atlantic Ridge and adjacant areas. A review. Arch Fish Mar Res 51(1–3):215–232Google Scholar
  31. Maul GE (1976) The fishes taken in bottom trawls by R.V. “Meteor” during the 1967 seamounts cruises in the Northeast Atlantic. Meteor Forsch Ergebn (D) 22:1–69Google Scholar
  32. Menezes G, Sigler MF, Silva HM, Pinho MR (2006) Structure and zonation of demersal fish assemblages off the Azores Archipelago (mid-Atlantic). Mar Ecol Prog Ser 324:241–260CrossRefGoogle Scholar
  33. Menezes GM, Rosa A, Melo O, Pinho MR (2009) Demersal fish assemblages off the Seine and Sedlo Seamounts (Northeast Atlantic). Deep Sea Res II 56(25):2683–2704. doi:10.1016/j.dsr2.2008.12.028 CrossRefGoogle Scholar
  34. Menezes GM, Rosa A, Melo O, Porteiro F (2012) Annotated list of demersal fishes occurring at Sedlo Seamount, Azores north-east central Atlantic Ocean. J Fish Biol 81:1003–1018. doi:10.1111/j.1095-8649.2012.03355.x CrossRefPubMedGoogle Scholar
  35. Merrett NR (1992) Demersal ichthyofaunal distribution in the abyssal eastern North Atlantic, with special reference to Coryphaenoides (Nematonurus) armatus (Macrouridae). J Mar Biol Ass UK 72:5–24CrossRefGoogle Scholar
  36. Merrett NR, Marshall NB (1981) Observations on the ecology of deep-sea bottom-living fishes collected off northwest Africa (08°–27°N). Prog Oceanog 9:185–244CrossRefGoogle Scholar
  37. Merrett NR, Gordon JD, Stehmann M, Haedrich RL (1991) Deep demersal fish assemblage structure in the Porcupine Seabight (eastern North Atlantic): slope sampling by three different trawls compared. J Mar Biol Ass UK 71:329–358CrossRefGoogle Scholar
  38. Morato T, Hoyle SD, Allain V, Nicol SJ (2010) Seamounts are hotspots of pelagic biodiversity in the open ocean. PNAS. doi:10.1073/pnas.0910290107 PubMedCentralPubMedGoogle Scholar
  39. Nielsen JG, Cohen DM, Markle DF, Robins CR (1999) FAO species catalogue. Volume 18. Ophidiiform fishes of the world (Order Ophidiiformes). An annotated and illustrated catalogue of pearlfishes, cusk-eels, brotulas and other ophidiiform fishes known to date. FAO Fish Synop 125(18):178Google Scholar
  40. Norse EA, Brooke S, Cheung WWL, Clark MR, Ekeland I, Froese R, Gjerde KM, Haedrich RL, Heppell SS, Morato T, Morgan LE, Pauly D, Sumaila R, Watson R (2012) Sustainability of deep-sea fisheries. Mar Pol 36(2):307–320. doi:10.1016/j.marpol.2011.06.008 CrossRefGoogle Scholar
  41. Pakhorukov NP (2008) Visual observations of fish from seamounts of the Southern Azores region (the Atlantic Ocean). J Ichthyol 48(1):114–123. doi:10.1134/S0032945208010104 CrossRefGoogle Scholar
  42. Santos RS, Hawkins S, Monteiro LR, Alves M, Isidro EJ (1995) Marine research, resources and conservation in the Azores. Aquatic Cons 5(4):311–354CrossRefGoogle Scholar
  43. Santos RS, Porteiro FM, Barreiros JP (1997) Marine fishes of the Azores. Annotated checklist and bibliography. A catalogue of the Azorean marine ichthyodiversity. Arquipel Suppl 1:1–242Google Scholar
  44. Shank TM (2010) Seamounts: deep-ocean laboratories of faunal connectivity, evolution, and endemism. Oceanogr 23(1):108–122CrossRefGoogle Scholar
  45. Shcherbachev YN, Kukuev EI, Shlibanov VI (1985) Composition of the benthic and demersal ichthyocenoses of the submarine mountains in the southern part of the North Atlantic range. J Ichthyol 25:110–125Google Scholar
  46. Stocks KI, Clark MR, Rowden AA, Consalvey M, Schlacher TA (2012) CenSeam, an international program on seamounts within the census of marine life: achievements and lessons learned. PLoS ONE 7(2):e32031. doi:10.1371/journal.pone.0032031 CrossRefPubMedCentralPubMedGoogle Scholar
  47. Sulak KJ (1977) The systematics and biology of Bathypterois (Pisces, Chlorophthalmidae), with a revised classification of benthic myctophiform fishes. In: Wolff T (ed) Galathea report. Scientific Results of The Danish Deep-Sea Expedition Round the World 1950–1952, vol 14. Copenhagen, pp 49–108Google Scholar
  48. Sulak KJ, Shcherbachev YN (1997) Zoogeography and systematics of six deep-living genera of synaphobranchid eels, with a key to taxa and description of two new species of Ilyophis. Bull Mar Sci 60(3):1158–1194Google Scholar
  49. Swinney GN (1995) Ceratioid anglerfish of the families Gigantactinidae and Linophrynidae (Lophiiformes, Ceratioidea) collected off Madeira, including two species new to the north-eastern Atlantic. J Fish Biol 47:39–49CrossRefGoogle Scholar
  50. Vieira RP, Christiansen B, Christiansen S, Gonçalves JMS (2012) First record of the deep-water whalefish Cetichthys indagator (Rofen, 1959) (Actinopterygii: Cetomimidae) in the North Atlantic. J Fish Biol 81:1133–1137. doi:10.1111/j.1095-8649.2012.03378 CrossRefPubMedGoogle Scholar
  51. Whitehead PJP, Bauchot M-L, Hureau J-C, Nielsen J, Tortonese E (eds) (1986) Fishes of the North-eastern Atlantic and the Mediterranean 1-3. UNESCO Press, ParisGoogle Scholar
  52. Wienberg C, Wintersteller P, Beuck L, Hebbeln D (2013) Coral Patch seamount (NE Atlantic)—a sedimentological and megafaunal reconnaissance based on video and hydroacoustic surveys. Biogeoscience 10(5):3421–3443. doi:10.5194/bg-10-3421-2013 CrossRefGoogle Scholar
  53. Xavier J, van Soest R (2007) Demosponge fauna of Ormonde and Gettysburg Seamounts (Gorringe Bank, north-east Atlantic): diversity and zoogeographical affinities. J Mar Biol Ass UK 87(06):1643–1653. doi:10.1017/S0025315407058584 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg and AWI 2014

Authors and Affiliations

  • Bernd Christiansen
    • 1
  • Rui P. Vieira
    • 2
    • 3
    • 4
  • Sabine Christiansen
    • 5
  • Anneke Denda
    • 1
  • Frederico Oliveira
    • 2
  • Jorge M. S. Gonçalves
    • 2
  1. 1.Institut für Hydrobiologie und FischereiwissenschaftUniversität HamburgHamburgGermany
  2. 2.CCMAR, Centre of Marine SciencesUniversity of AlgarveFaroPortugal
  3. 3.Departamento de Biologia and CESAMUniversidade de AveiroAveiroPortugal
  4. 4.Ocean and Earth ScienceNational Oceanography CentreSouthamptonUK
  5. 5.HamburgGermany

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