Vertical zonation and functional diversity of fish assemblages revealed by ROV videos at oil platforms in The Gulf

Abstract

An assessment of vertical distribution, diel migration, taxonomic and functional diversity of fishes was carried out at offshore platforms in The (Arabian-Iranian-Persian) Gulf. Video footage was recorded at the Al Shaheen oil field between 2007 and 2014 using a remotely operated vehicle (ROV). A total of 12 822 individual fishes, from 83 taxonomic groups were recorded around the platforms. All the species identified are considered native to The Gulf, although Cyclichthys orbicularis and Lutjanus indicus were recorded for the first time in Qatari waters. Several trends were uncovered in the vertical distribution of the fish community; most species were observed between 20 and 50 m depth and fish abundance decreased towards the bottom, with the highest abundances recorded in the upper layers, i.e. down to 40 m depth. Vertical variation in fish diversity, however, was generally not accompanied by differences in vertical movements. Carnivores and invertivores were the dominant trophic groups, being found at each depth range from surface to seabed. The functional indices showed no significant differences between water depths or diel cycles. The study demonstrates that oil platforms represent a hotspot of fish diversity and interesting sites for studying fish communities, abundance and behaviour.

Using vertebrate environmental DNA from seawater in biomonitoring of marine habitats

“…This is not unexpected given the proximity (approximately 500 m) of these sand bottom sites to oil platforms, which provide attachment for corals and attract a large diversity of fish species (Torquato et al. ). However, some reef species (e.g., Chaetodontids) observed in abundance at the platforms were missing in the water samples, suggesting a relatively limited influence from the artificial reefs.…”

“…At the 3 offshore sand bottom sites in the Al Shaheen oil field (SB.OUT_NE_2, SB.OUT_NE_3, SB.OUT_NE_4), additional 3 × 1‐L samples were collected from a depth of approximately 30 m with a 1.7‐L Ruttner water sampler (model number 11.002) because fish abundance at the platforms appears to peak at around 21–30 m depth (Torquato et al. ). All sites were sampled twice, summer 2016 and spring 2017, to obtain a greater coverage of biodiversity, especially of species with seasonal migrations.…”

An Indo-Pacific damselfish (Neopomacentrus cyanomos) in the Gulf of Mexico: origin and mode of introduction

“…Offshore petro-platforms have been shown to support an abundance of reef- fishes belonging to a broad variety of taxa, in the Gulf of Mexico ( Hastings, Ogren & Mabry, 1976 ; Topolski & Szedlmayer, 2004 ; Ajemian et al, 2015 ), Brazil ( Ferreira, Gonçalves & Coutinho, 2006 ), California ( Claisse et al, 2014 ; Martin & Lowe, 2010 ), the Mediterranean ( Consoli et al, 2013 ), west Africa ( Friedlander et al, 2014 ), Australia ( Pradella et al, 2014 ), the Canary Islands ( Pajuelo et al, 2016 ), and the Persian Gulf ( Torquato et al, 2017 ). In the SwGoMx, we have observed N. cyanomos living on two such platforms, including in superabundance on a relatively lightly-fouled platform near Cayo Arcas, in the southwest corner of Campeche Bank (up to ∼100 individuals m −2 ; Simoes & Robertson, 2016 ).…”

Peer Review #2 of "An Indo-Pacific damselfish (Neopomacentrus cyanomos) in the Gulf of Mexico: origin and mode of introduction (v0.1)"

“…Manuscript to be reviewed fishes belonging to a broad variety of taxa, in the Gulf of Mexico (Hastings, Ogren & Mabry, 1976;Topolski & Szedlmayer, 2004;Ajemian et al, 2015), Brazil (Ferreira, Goncalves & Coutinho, 2006), California (Claisse et al, 2014Martin & Lowe, 2010), the Mediterranean (Consoli et al, 2013), west Africa (Friedlander et al, 2015), Australia (Pradella et al, 2014), the Canary Islands (Pajuelo et al, 2016), and the Persian Gulf (Torquato et al, 2017). In the SwGoMx, we have observed N. cyanomos living on two such platforms, including in superabundance on a relatively lightly-fouled platform near Cayo Arcas, in the southwest corner of Campeche Bank (up to ~100 individuals m -2 ;…”