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Citation: Bravo, G.; Kaminsky, J.;
Bagur, M.; Alonso, C.P.; Rodríguez,
M.; Fraysse, C.; Lovrich, G.; Bigatti, G.
Roving Diver Survey as a Rapid and
Cost-Effective Methodology to
Register Species Richness in
Sub-Antarctic Kelp Forests. Diversity
2023,15, 354. https://doi.org/
10.3390/d15030354
Academic Editors: Thomas J. Trott
and Michael Wink
Received: 3 February 2023
Revised: 23 February 2023
Accepted: 26 February 2023
Published: 1 March 2023
Copyright: © 2023 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
diversity
Article
Roving Diver Survey as a Rapid and Cost-Effective
Methodology to Register Species Richness in Sub-Antarctic
Kelp Forests
Gonzalo Bravo 1, 2, *,† , Julieta Kaminsky 3 ,*, †, María Bagur 3,*,† , Cecilia Paula Alonso 4, Mariano Rodríguez 4,
Cintia Fraysse 3, Gustavo Lovrich 3and Gregorio Bigatti 1,2,5
1Instituto de Biología de Organismos Marinos (IBIOMAR-CCTCONICET-CENPAT), Bvd. Brown 2825,
Puerto Madryn U9120ACF, Argentina
2Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB),
Bvd. Brown 3051, Puerto Madryn U9120ACE, Argentina
3Centro Austral de Investigaciones Científicas (CADIC-CONICET), Bernardo Houssay 200,
Ushuaia V9410CAB, Argentina
4Instituto de Ciencias Polares, Ambiente y Recursos Naturales, Universidad Nacional de Tierra del
Fuego (ICPA-UNTDF), Fuegia Basket 251, Ushuaia V9410BXE, Argentina
5Escuela de Ciencias Ambientales, Universidad de Especialidades Espíritu Santo, Av. Samborondón,
Guayaquil 09230, Ecuador
*Correspondence: gonzalobravoargentina@gmail.com (G.B.); kaminsky.julieta@gmail.com (J.K.);
mariabagur@conicet.gov.ar (M.B.)
† These authors contributed equally to this work.
Abstract:
Underwater sampling needs to strike a balance between time-efficient and standardized
data that allow comparison with different areas and times. The roving diver survey involves divers
meandering and actively searching for species and has been useful for producing fish species lists but
has seldom been implemented for benthic taxa. In this study, we used this non-destructive technique
to register species associated with kelp forests at the sub-Antarctic Bécasses Island (Beagle Channel,
Argentina), detecting numerous species while providing the first multi-taxa inventory for the area,
including macroalgae, invertebrates, and fish, with supporting photographs of each observation
hosted on the citizen science platform iNaturalist. This research established a timely and cost-effective
methodology for surveys with scuba diving in cold waters, promoting the obtention of new records,
data sharing, and transparency of the taxonomic curation. Overall, 160 taxa were found, including 41
not reported previously for this area and three records of southernmost distribution. Other studies in
nearby areas with extensive sampling efforts arrived at similar richness estimations. Our findings
reveal that the roving diver survey using photographs is a good approach for creating inventories of
marine species, which will serve for a better understanding of underwater biodiversity and future
long-term monitoring to assess the health of kelp environments.
Keywords:
benthic species; scuba diving; Bécasses Islands; iNaturalist; Patagonia; underwater
photography; biodiversity; rocky reefs
1. Introduction
Making reliable and effective biodiversity surveys is crucial to evaluate the status of
the marine environment and for conservation planning. Species richness is a key parameter
used as basic information for community ecology and is considered among the biological
and ecological essential ocean variables (EOVs, [
1
]). Monitoring the presence of marine
species in space and time at local and global scales is necessary to reduce the knowledge
gap in biodiversity, particularly in subtidal habitats. Furthermore, global platforms with
open accessibility for uploading species occurrences, such as the Ocean Biogeographic
Information System (OBIS) or the Global Biodiversity Information Facility (GBIF), provide
Diversity 2023,15, 354. https://doi.org/10.3390/d15030354 https://www.mdpi.com/journal/diversity
Diversity 2023,15, 354 2 of 18
databases to test ecological and biogeographic hypotheses. Recently, websites like iNatu-
ralist.org enable shortcuts for adding observations to GBIF, and researchers have started
integrating iNaturalist data in their studies [2–5].
Although there is an increase in underwater biodiversity studies, there are still gaps
in the knowledge of benthic communities in the Southwest Atlantic [
6
,
7
], especially at
shallow (<30 m) rocky shores in Atlantic Patagonia, Argentina. The Beagle Channel and
the sub-Antarctic region, recognized as a conservation priority site for coastal biodiversity,
houses the most southern Macrocystis pyrifera kelp forests globally [
8
]. These structurally
complex and highly productive giant kelp forests provide habitat and food for marine
mammals, seabirds, invertebrates, fish, and macroalgae, e.g., [9–13].
Previous studies in nearby areas have examined M. pyrifera kelp forest communities by
using traditional underwater samplings such as transects, in situ quadrats, photoquadrats,
or extractive samples, e.g., [14–22], that are difficult to perform due to weather conditions
in these cold environments. Notwithstanding, many areas in this spatial and temporally
heterogeneous region remain to be explored. With this in mind, we performed an active
search photographic survey with the roving diver technique to investigate species richness
associated with kelp forests at Bécasses Island. The roving diver survey involves divers
meandering and actively searching for species [
23
] and has been useful for producing fish
species lists in tropical seas, e.g., [
24
,
25
], but only seldom implemented for benthic taxa,
e.g., [
26
,
27
]. This study constitutes a good example to establish a timely and cost-effective
methodology for surveys with scuba diving in this area, characterized by strong winds
and low water temperatures (average 6.8
◦
C [
28
]), especially during winter (minimum
5.1
◦
C, [
28
]). We created a species list and field photographic record of invertebrates,
macroalgae, and fishes that occurred in kelp forests (2–30 m depth) at Bécasses Island,
Beagle Channel, that will serve as a baseline of biodiversity and future monitoring to
determine the health of sub-Antarctic kelp forests. Then, we discuss and compare our
results to other approaches developed to study kelp forest communities in nearby areas.
2. Materials and Methods
2.1. Study Site
The Bécasses Islands are located at the eastern end of the Beagle Channel (Figure 1).
They constitute a group of two main islands and a few islets, the larger one “Bécasses
Island”, also known as Septentrional Island, is approximately 750 m in length from north to
south (Figure 1). Geomorphology in the Beagle Channel has been modeled during the Last
Glacial Maximum previous to ca. 11,000 Ka [
29
], whereas the present fluvial and marine
processes mainly have modeled coastal landscapes, e.g., cliffs, capes, and bays [
30
–
32
].
This natural Channel connects the Pacific and Atlantic Oceans with sub-Antarctic waters,
particularly the Cape Horn Current, determining its hydrodynamics [
33
]. Oceanographic
and meteorological conditions present a seasonal pattern in water and air temperatures and
light and nutrient availability [
28
,
34
]. The Beagle Channel has subpolar wet weather, strong
exposure to prevailing southwest winds, and a mixed semidiurnal tide regime with an
average amplitude of 1.15 m [
35
,
36
]. During warmer months, freshwater inputs from glacial
melting and river runoff reduce surface salinities, driving water column stratification and
reducing light availability in the water column [
33
,
37
]. The Bécasses Islands are a nesting
site for seabirds (Phalacrocorax atriceps and P. magellanicus, [
38
]) and marine mammals
(Otaria flavescens, [39]).
Diversity 2023,15, 354 3 of 18
Diversity2023,14,xFORPEERREVIEW3of17
Figure1.BécassesIslandlocationintheBeagleChannel,TierradelFuego,Argentina.(a)Amapof
thestudyarea,thesurveyedzonesareindicatedwithgridlines(SW=SouthwestandNE=North‐
east).(b)BécassesIsland,photoacquiredbyadrone,surveyzonesmarkedwithletters(SWand
NE);andthesailboat“Kostat”isobservedintheNEbay.
2.2.SurveyMethod
BécassesIslandwasexploredduringaresearchcruiseconductedinAugust2021
(winterintheSouthernHemisphere)onboardthesailboat“Kostat.”Anunderwaterrov‐
ingdiversurvey[23]wasconductedontheNEandSWsubtidalareasofBécassesIsland
(Figure1)tocreateabenthicspeciesinventory.TheSWareaisexposedtothedominant
SWwindsinthearea.Inbothsamplingareas,threetofourdiveswereperformedby4–5
diversswimmingfreelyfor~45minandtakingphotosofeachspeciestheyencountered,
coveringintotalmorethan700minofdivingand~20,000m
2
.Thedivingrangewas2–33
mindepth,andineachdive,morethan100linealmeterswerecovered.Two‐nightdives
wereperformedtorecordspecieswithnocturnalbehavior.Specialattentionwaspaidto
takinggood‐qualityphotosofeachspecimen.Highlymobileandsmall‐sizedspecies(<1
cm)werenotphotographed.Alldiversparticipatinginthesurveyshadmarinebiology
backgroundsandknowledgeoflocalspecies,whichwasrelevantforfindingrareorcryp‐
ticspecies.ThecamerasusedforthesurveywereOlympusTG6(Olympuscorporation,
Vietnam),CannonSL1(Canon,Taiwan,RepublicofChina),SonyAlpha7S2(SonyCor‐
poration,Thailand),andNikonCoolpixW300(NikonCorporation,Indonesia)withexter‐
nallightsorflashes.Onlysomeindividualsofspecificgroups(somemacroalgaeandsea
stars)werecollectedbyhandinordertoconfirmthespeciesidentificationunderastere‐
oscopicmicroscope.
2.3.DataPreparationandQualityControl
Allthephotos(n=672)wereuploadedtoaniNaturalistproject
[40]
thatonlyincludes
observationsofdiversinthisexpedition.TheopenplatformiNaturalist(launchedin2008)
allowsuserstosubmitspeciesobservationsalongwithimagesandGPScoordinates.Once
submitted,theobservationswereidentifiedbythecommunityandvettedbyspecialists
(curators).Inourcase,werequestlocaltaxonomiststoreviewtheobservationsofthis
projectinordertoimprovethetaxonomicresolution(seeAcknowledgments).Highertax‐
onomiclevelsasgenusorfamilywereonlyusedwhenthephotographwasnotclear
enough,orthespecimendidnotshowthetaxonomicfeaturesneededforspecificidenti‐
fication.Alltheseobservationsidentifiedtospecieslevelandacceptedbytwoormore
Figure 1.
Bécasses Island location in the Beagle Channel, Tierra del Fuego, Argentina. (
a
) A map of the
study area, the surveyed zones are indicated with grid lines (SW = Southwest and NE = Northeast).
(
b
) Bécasses Island, photo acquired by a drone, survey zones marked with letters (SW and NE); and
the sailboat “Kostat” is observed in the NE bay.
2.2. Survey Method
Bécasses Island was explored during a research cruise conducted in August 2021
(winter in the Southern Hemisphere) on board the sailboat “Kostat.” An underwater roving
diver survey [
23
] was conducted on the NE and SW subtidal areas of Bécasses Island
(Figure 1) to create a benthic species inventory. The SW area is exposed to the dominant SW
winds in the area. In both sampling areas, three to four dives were performed by 4–5 divers
swimming freely for ~45 min and taking photos of each species they encountered, covering
in total more than 700 min of diving and ~20,000 m
2
. The diving range was 2–33 m in
depth, and in each dive, more than 100 lineal meters were covered. Two-night dives were
performed to record species with nocturnal behavior. Special attention was paid to taking
good-quality photos of each specimen. Highly mobile and small-sized species (<1 cm) were
not photographed. All divers participating in the surveys had marine biology backgrounds
and knowledge of local species, which was relevant for finding rare or cryptic species. The
cameras used for the survey were Olympus TG6 (Olympus corporation, Vietnam), Cannon
SL1 (Canon, Taiwan, Republic of China), Sony Alpha 7S2 (Sony Corporation, Thailand),
and Nikon Coolpix W300 (Nikon Corporation, Indonesia) with external lights or flashes.
Only some individuals of specific groups (some macroalgae and sea stars) were collected
by hand in order to confirm the species identification under a stereoscopic microscope.
2.3. Data Preparation and Quality Control
All the photos (n = 672) were uploaded to an iNaturalist project [
40
] that only includes
observations of divers in this expedition. The open platform iNaturalist (launched in 2008)
allows users to submit species observations along with images and GPS coordinates. Once
submitted, the observations were identified by the community and vetted by specialists (cu-
rators). In our case, we request local taxonomists to review the observations of this project
in order to improve the taxonomic resolution (see Acknowledgments). Higher taxonomic
levels as genus or family were only used when the photograph was not clear enough, or
the specimen did not show the taxonomic features needed for specific identification. All
these observations identified to species level and accepted by two or more iNaturalist users
(“Research Grade”) were automatically uploaded to GBIF by the platform.
Diversity 2023,15, 354 4 of 18
Our sampling method was compared with previous studies involving diving surveys
and reporting marine species in the nearby areas (50
◦
S to 56
◦
S) with similar subtidal
environments, hence we created a list combining all species (Supplementary Material
Table S1). Only studies involving communities sampled through transects or quadrats
were selected instead of detailed extractive samplings, e.g., analysis of the macrofauna
inhabiting kelp holdfasts [
10
,
22
] was not selected because of species sizes and sampling
effort differences. All the taxonomic names recovered by this list were verified using the
Taxon Match tool [
41
] of the World Register of Marine Species (WoRMS) in December 2022,
to prevent the inflation of taxa richness by synonyms, unaccepted or non-updated names.
The websites AlgaeBase [
42
] and FishBase [
43
] were also used to check the accepted names
of macroalgae and fishes, respectively. Due to some invalid taxonomic names that drive
inconsistencies (e.g., Porifera sp. 1, Porifera sp. 2, Porifera sp. 3, etc.), the total number of
species reported by each study was calculated using this list instead of using the numbers
presented in the original articles. In order to compare the richness variation among the
different studies and for each group of taxa, the coefficient of variation (CV = standard
deviation divided by the mean) was calculated. Additionally, a presence–absence table was
constructed to find “unique” species in each of the studies, i.e., species only present in one
of the studies and absent in all others (Supplementary Material Table S2).
3. Results
3.1. Environment
Kelps widely colonized subtidal environments in Bécasses Island where the water
temperature was 7 ◦C during the samplings. In the upper subtidal, down to 2 m of depth,
kelp forests were mainly dominated by Lessonia flavicans, whereas Macrocystis pyrifera
and Lessonia searlesiana formed dense, mixed forests between 2 and 20 m depth. Lessonia
searlesiana was also found down to 30 m depth. The underwater landscape presented visual
differences between NE and SW coasts: the former, the windward side, with a stepped
topography with flat bedrock reaching more than 30 m deep, whereas the SW coast was
shallower (13 m maximum deep) and presented bedrock with boulders surrounded by
sand patches.
3.2. Bécasses Checklist
A total of 160 taxa were recorded by the roving diver survey at the two zones sampled
(see Figure 1) at Bécasses Island, including 121 invertebrates, 7 fishes, and 32 macroalgae
(Table 1). Invertebrates were dominated by Mollusca (40 taxa), followed by Echinodermata
(27), Cnidaria (14), Arthropoda (13), Tunicata (10), Annelida (7), Bryozoa (5), and Porifera
(4). Most species of fish belonged to the Nototheniidae family. Regarding macroalgae, 19
Rhodophyta, 10 Ochrophyta, and 3 Chlorophyta species were found. All observations are
publicly available at iNaturalist (see Section 2).
3.3. Comparison with Other Studies
In order to compare the species richness obtained with our photographic survey
method with traditional methods performed in nearby areas (such as transects and photo-
quadrats), seven articles were selected (Table 2). One paper studies only the understory
macroalgae community in nearby kelp forests [
9
], another studies only the fishes commu-
nity [
11
], and the rest investigate the invertebrate community only [
18
,
20
], or together with
fish [
17
,
19
,
21
]. Careful data control was taken to avoid species name artifacts (see Section 2
and Supplementary Material Table S1) as inputs for Tables 1and 2.
Diversity 2023,15, 354 5 of 18
Table 1.
List of marine species found during this study with indication of the number of observations (N) with associated photograph and those taxa recorded by
other studies in the region (*). Bold letter indicates “unique” records (family, genus, or species) found in our study. N for taxa higher than species corresponds to
specimens not possible to be determined to specific level.
Phylum Class Order Family Genus Species N (this study) Beaton et al. 2020
[18]
Cárdenas and
Montiel 2015 [20]
Friedlander et al.
2018 [17]
Friedlander et al.
2020 [19]
Friedlander et al.
2021 [21]
Santelices and
Ojeda 1984 [9]
Vanellaet al. 2007
[11]
Porifera Calcarea Leucosolenida Syconidae Sycon 2 * * *
Demospongiae 2
Haplosclerida Chalinidae Haliclona 1 * * * *
Poecilosclerida Hymedesmiidae Phorbas Phorbas ferrugineus 9 * *
Cnidaria Anthozoa Actiniaria 2 * *
Actiniidae Bunodactis Bunodactis
octoradiata
1 * * * * *
Actinostolidae Actinostola 3
Actinostolidae Antholoba Antholobaachates 4 * * *
Halcuriidae Halcurias 4
Isanthidae Isoparactis Isoparactisfionae 1
Metridiidae Metridium Metridium senile 24 * *
Preactiniidae Dactylanthus Dactylanthus
antarcticus
4
Alcyonacea Alcyoniidae Alcyonium Alcyonium
haddoni
6
Clavulariidae Incrustatus 1
Primnoidae Primnoella 4
Primnoidae Primnoella Primnoella chilensis 1 * *
Hydrozoa Leptothecata Campanulariidae Obelia Obelia geniculata 2 * * *
Staurozoa Stauromedusae Haliclystidae Haliclystus Haliclystus
antarcticus
1 *
Annelida Polychaeta Chaetopteridae Chaetopterus 1
Chaetopteridae Chaetopterus Chaetopterus
variopedatus
1 * * * * *
Phyllodocida Nereididae 1
Phyllodocidae Eulalia 1 *
Phyllodocidae 3
Polynoidae 1
Terebellida Cirratulidae 1
Mollusca Bivalvia Mytilida Mytilidae Aulacomya Aulacomya atra 3 * *
Pectinida Pectinidae Austrochlamys Austrochlamys
natans
2
Cephalopoda Myopsida Loliginidae Doryteuthis Doryteuthis gahi 10
Octopoda Enteroctopodidae Enteroctopus Enteroctopus
megalocyathus
4
Gastropoda Limapontiidae Placida Placida
sudamericana
1
Nacellidae Nacella 2 *
Nacellidae Nacella Nacella deaurata 2
Nacellidae Nacella Nacella mytilina 3 * * * *
Plakobranchidae Elysia Elysia patagonica 2
Lepetellida Fissurellidae Fissurella 1 * * *
Fissurellidae Fissurella Fissurellaoriens 4 *
Fissurellidae Fissurella Fissurellapicta 1
Littorinimorpha Calyptraeidae Crepidula 1
Calyptraeidae Crepipatella Crepipatella dilatata 2 * *
Cymatiidae Fusitriton Fusitriton
magellanicus
9 * * *
Velutinidae Lamellaria 1 * *
Neogastropoda Cominellidae Pareuthria Pareuthria fuscata 1 * * * *
Muricidae 1
Muricidae Acanthina Acanthina monodon 1 * * *
Muricidae Trophon Trophon geversianus 1 * * * *
Volutidae Adelomelon Adelomelon ancilla 6 * * *
Volutidae Odontocymbiola Odontocymbiola
magellanica
6 *
Nudibranchia Chromodorididae Tyrinna Tyrinna delicata 3 * *
Diversity 2023,15, 354 6 of 18
Table 1. Cont.
Phylum Class Order Family Genus Species N (this study) Beaton et al. 2020
[18]
Cárdenas and
Montiel 2015 [20]
Friedlander et al.
2018 [17]
Friedlander et al.
2020 [19]
Friedlander et al.
2021 [21]
Santelices and
Ojeda 1984 [9]
Vanellaet al. 2007
[11]
Coryphellidae Coryphella Coryphella
falklandica
5 *
Discodorididae Diaulula Diaulula hispida 1 * * *
Discodorididae Diaulula Diaulula
punctuolata
2 * * *
Dorididae Doris Doris fontainii 3 * * *
Polyceridae Thecacera Thecacera darwini 4 * * *
Tritoniidae Tritonia Tritonia
challengeriana
10 * *
Tritoniidae Tritonia Tritonia odhneri 3
Tritoniidae Tritonia Tritonia vorax 1
Pleurobranchida Pleurobranchidae Berthella Berthella platei 4 *
Trochida 1
Calliostomatidae Calliostoma 1
Calliostomatidae Margarella Margarellaviolacea 3 * * * *
Polyplacophora Chitonida Chitonidae Tonicia 8 * *
Chitonidae Chiton Chiton magnificus 3 * * *
Chitonidae Tonicia Toniciachilensis 1 *
Chitonidae Tonicia Toniciadisjuncta 5 *
Mopaliidae Plaxiphora Plaxiphora aurata 2 * * * *
Arthropoda Hexanauplia 2 * *
Balanomorpha Balanidae Austromegabalanus Austromegabalanus
psittacus
4 * * * *
Malacostraca Amphipoda Ampithoidae 1
Gammarellidae cf. Austroregia 2
cf. Gammarellidae 2
Decapoda Campylonotidae Campylonotus Campylonotus
vagans
11 * * *
Hippolytidae Nauticaris Nauticaris
magellanica
5 * * * *
Hymenosomatidae Halicarcinus Halicarcinus
planatus
2 * * * *
Inachidae Eurypodius Eurypodius
longirostris
7
Lithodidae Paralomis Paralomis granulosa 10 * * * *
Munididae Grimothea Grimothea gregaria 7 * * *
Paguridae Pagurus Pagurus comptus 2 * * * *
Trichopeltariidae Peltarion Peltarion
spinulosum
1 * * *
Brachiopoda Rhynchonellata Terebratulida Terebratellidae Magellania Magellania venosa 3 * * * *
Bryozoa 4 * * * * *
Gymnolaemata Cheilostomatida Beaniidae Beania Beania magellanica 1 * * * *
Cellariidae Cellaria Cellaria malvinensis 2 * * * * *
Alcyonidiidae Alcyonidium Alcyonidium
australe
1 *
Stenolaemata Cyclostomatida Crisiidae Crisia 3 * *
Echinodermata Asteroidea Forcipulatida Asteriidae 1
Asteriidae Anasterias Anasterias antarctica 4 * * * *
Asteriidae Diplasterias Diplasterias
brandti
12
Heliasteridae Labidiaster Labidiaster radiosus 21 * * * *
Stichasteridae Allostichaster Allostichaster
capensis
1
Stichasteridae Cosmasterias Cosmasterias lurida 16 * * * *
Spinulosida Echinasteridae Henricia Henricia obesa 4 * * *
Valvatida 1
Asterinidae Asterina Asterina fimbriata 1 * * * *
Asterinidae Cycethra Cycethra verrucosa 8 * * * *
Asterinidae Ganeria Ganeria falklandica 9 * * *
Odontasteridae 2
Diversity 2023,15, 354 7 of 18
Table 1. Cont.
Phylum Class Order Family Genus Species N (this study) Beaton et al. 2020
[18]
Cárdenas and
Montiel 2015 [20]
Friedlander et al.
2018 [17]
Friedlander et al.
2020 [19]
Friedlander et al.
2021 [21]
Santelices and
Ojeda 1984 [9]
Vanellaet al. 2007
[11]
Odontasteridae Diplodontias Diplodontias
singularis
3 * *
Odontasteridae Odontaster Odontaster
penicillatus
4 * * * *
Poraniidae Glabraster Glabraster antarctica 25 * * *
Poraniidae Poraniopsis Poraniopsis
echinaster
6 * *
Echinoidea Arbacioida Arbaciidae Arbacia Arbacia dufresnii 23 * * * *
Camarodonta Parechinidae Loxechinus Loxechinus albus 24 * * * *
Temnopleuridae Pseudechinus Pseudechinus
magellanicus
11 * * * *
Holothuroidea Apodida Chiridotidae Chiridota Chiridota pisanii 2 * *
Dendrochirotida Cucumariidae Cladodactyla Cladodactyla crocea 4 *
Cucumariidae Trachythyone Trachythyone
lechleri
1
Psolidae Psolus Psolus patagonicus 2 *
Ophiuroidea Amphilepidida Amphiuridae Ophiophragmus Ophiophragmus
chilensis
1
Ophiactidae Ophiactis Ophiactis asperula 3 * * * *
Euryalida Gorgonocephalidae Gorgonocephalus Gorgonocephalus
chilensis
16
Ophiacanthida Ophiomyxidae Ophiomyxa Ophiomyxa vivipara 1 * * * *
Chordata Actinopterygii Perciformes Bovichtidae Cottoperca Cottoperca trigloides 2 * * *
Harpagiferidae Harpagifer Harpagifer bispinis 1 * *
Liparidae Careproctus Careproctus pallidus 1 * *
Nototheniidae Patagonotothen 9 * * *
Nototheniidae Paranotothenia Paranotothenia
magellanica
2 * * * *
Nototheniidae Patagonotothen Patagonotothen
tessellata
1 * * * *
Zoarcidae Dadyanos Dadyanos insignis 3 *
Ascidiacea 3 * *
Aplousobranchia Didemnidae 3 *
Holozoidae Sycozoa Sycozoa gaimardi 2 * * * *
Polyclinidae Aplidium 3 * * * *
Polyclinidae Aplidium Aplidium fuegiense 5 * * * *
Stolidobranchia Molgulidae Paramolgula Paramolgula
gregaria
1 *
Pyuridae Pyura Pyura legumen 3 * * * *
Styelidae Cnemidocarpa 1 * * *
Styelidae Cnemidocarpa Cnemidocarpa
verrucosa
1 * * *
Styelidae Polyzoa Polyzoa opuntia 6 * * *
Rhodophyta Florideophyceae Balliales Balliaceae Ballia Ballia callitricha 3 * *
Bonnemaisoniales Bonnemaisoniaceae Ptilonia Ptilonia magellanica 9 *
Ceramiales Delesseriaceae Paraglossum 1
Delesseriaceae Cladodonta Cladodonta lyallii 1
Delesseriaceae Hymenena Hymenena
falklandica
2
Delesseriaceae Pseudophycodrys Pseudophycodrys
phyllophora
6
Rhodomelaceae Lophurella Lophurella
hookeriana
1
Rhodomelaceae Picconiella Picconiella
pectinata
4
Wrangeliaceae Griffithsia 1 *
Corallinales 3
Corallinaceae Ellisolandia Ellisolandia
elongata
1
Gigartinales 1
Diversity 2023,15, 354 8 of 18
Table 1. Cont.
Phylum Class Order Family Genus Species N (this study) Beaton et al. 2020
[18]
Cárdenas and
Montiel 2015 [20]
Friedlander et al.
2018 [17]
Friedlander et al.
2020 [19]
Friedlander et al.
2021 [21]
Santelices and
Ojeda 1984 [9]
Vanellaet al. 2007
[11]
Gigartinaceae Sarcopeltis Sarcopeltis
skottsbergii
11 * *
Kallymeniaceae Callophyllis Callophyllis
atrosanguinea
5
Kallymeniaceae Callophyllis Callophyllis
variegata
2 *
Hildenbrandiales Hildenbrandiaceae Hildenbrandia 3
Plocamiales Plocamiaceae Plocamium Plocamium
secundatum
1 *
Rhodymeniales Rhodymeniaceae Rhodymenia Rhodymenia
coccocarpa
2
Rhodymeniaceae Rhodymenia Rhodymenia
falklandica
1 *
Ochrophyta Phaeophyceae Desmarestiales Desmarestiaceae Desmarestia 5
Dictyotales Dictyotaceae Dictyota Dictyota
falklandica
5
Ectocarpales Adenocystaceae Adenocystis Adenocystis
utricularis
1 * *
Adenocystaceae Caepidium Caepidium
antarcticum
2 *
Scytosiphonaceae Colpomenia 1
Laminariales Laminariaceae Macrocystis Macrocystis pyrifera 9******
Lessoniaceae Lessonia Lessonia flavicans 9 * *
Lessoniaceae Lessonia Lessonia
searlesiana
4
Sphacelariales Stypocaulaceae Halopteris 1
Syringodermatales Syringodermataceae Microzonia Microzonia
velutina
3
Chlorophyta Ulvophyceae Bryopsidales Bryopsidaceae Bryopsis 1
Codiaceae Codium Codium
subantarcticum
8
Ulvales Ulvaceae Ulva 4 *
Diversity 2023,15, 354 9 of 18
The number of taxa reported in this study reached similar values to previous studies
and the overall CV (31%) was low (Table 2). Comparisons of the number of taxa for each
taxonomic group revealed that our estimations had similar values to other studies for most
of the groups, except for Porifera, Bryozoa, and fishes. The highest number of taxa (n = 196)
was found by Friedlander et al. [
21
] at the Kawésqar Reserve, Chile. The closest area to our
study, Peninsula Mitre, and Isla de los Estados, was surveyed by Friedlander et al. [
19
],
where they recorded 162 taxa in a broader area. Santelices and Ojeda [
9
] for macroalgae
and Vanella et al. [
11
] for fish, using extractive sampling (no other option available for
comparison), found similar species richness estimations compared with our photo surveys
(Table 2). Bunodactis octoradiata,Chaetopterus variopedatus,Cellaria malvinensis,Macrocystis
pyrifera, and Lessonia spp. constitute common species recorded by all the studies (Table 1).
From the overall number of taxa found in this work, 41 (30 species, eight genera, and
three families) were not reported in previous studies and therefore here considered as
“unique” species (Table 1, see names in bold). This number represented the highest as
compared to other studies (between 2 and 28 species, see Supplementary Material Table S2).
Three of these “unique” species represented the southernmost record of the species (checked
in GBIF and local references): the seastar Allostichaster capensis, and the molluscs Elysia
patagonica and Placida sudamericana (Figure 2a,c,d).
Diversity2023,14,xFORPEERREVIEW8of17
Thenumberoftaxareportedinthisstudyreachedsimilarvaluestopreviousstudies
andtheoverallCV(31%)waslow(Table2).Comparisonsofthenumberoftaxaforeach
taxonomicgrouprevealedthatourestimationshadsimilarvaluestootherstudiesfor
mostofthegroups,exceptforPorifera,Bryozoa,andfishes.Thehighestnumberoftaxa
(n=196)wasfoundbyFriedlanderetal.[21]attheKawésqarReserve,Chile.Theclosest
areatoourstudy,PeninsulaMitre,andIsladelosEstados,wassurveyedbyFriedlander
etal.[19],wheretheyrecorded162taxainabroaderarea.SantelicesandOjeda[9]for
macroalgaeandVanellaetal.[11]forfish,usingextractivesampling(nootheroption
availableforcomparison),foundsimilarspeciesrichnessestimationscomparedwithour
photosurveys(Table2).Bunodactisoctoradiata,Chaetopterusvariopedatus,Cellariamalvinen‐
sis,Macrocystispyrifera,andLessoniaspp.constitutecommonspeciesrecordedbyallthe
studies(Table1).
Fromtheoverallnumberoftaxafoundinthiswork,41(30species,eightgenera,and
threefamilies)werenotreportedinpreviousstudiesandthereforehereconsideredas
“unique”species(Table1,seenamesinbold).Thisnumberrepresentedthehighestas
comparedtootherstudies(between2and28species,seeSupplementaryMaterialTable
S2).Threeofthese“unique”speciesrepresentedthesouthernmostrecordofthespecies
(checkedinGBIFandlocalreferences):theseastarAllostichastercapensis,andthemolluscs
ElysiapatagonicaandPlacidasudamericana(Figure2a,c,d).
Figure2.Fieldphotosofthosespeciesthatrepresentedfirstphotographicrecordfortheareaor
southernmostrecord:(a)Allostichastercapensis(southernmostrecord);(b)Diplasteriasbrandti(first
photorecordforBeagleChannel);(c)Elysiapatagonica(southernmostrecord),arrowindicatesspec‐
imens;(d)PlacidaSudamericana(southernmostrecord).
Figure 2.
Field photos of those species that represented first photographic record for the area
or southernmost record: (
a
)Allostichaster capensis (southernmost record); (
b
)Diplasterias brandti
(first photo record for Beagle Channel); (
c
)Elysia patagonica (southernmost record), arrow indicates
specimens; (d)Placida Sudamericana (southernmost record).
Diversity 2023,15, 354 10 of 18
Table 2.
List of studies in the nearby areas with information of the type of methodology, the depth range, and the number of taxa found by taxonomic groups. SD =
standard deviation and CV = coefficient of variation.
Study Geographic
Area Method Depth
Range (m) Porifera Cnidaria Annelida Mollusca Arthropoda Bryozoa Echinodermata Tunicates others in-
vertebrates Fish Macroalgae Total
Santelices
and Ojeda
1984 [9]
Puerto Toro,
Navarino
Island, Chile
(55◦)
Extractive
quadrat in
transects 4–10 39 39 *
Vanella
et al. 2007
[11]
Despard Island,
Beagle Channel,
Argentina (54◦)
Trammel nets
and holdfast
removal 6 11 11 *
Cárdenas
and
Montiel
2015 [20]
Santa Ana,
Magellan Strait,
Chile (53◦)
Photoquadrats
in vertical walls 0–30 5 5 3 3 2 9 2 6 1 31 67
Friedlander
et al. 2018
[17]
Francisco
Coloane
Reserve, Cape
Horn, Diego
Ramirez, Chile
(53◦–56◦)
Visual transect
survey 7–15 13 12 2 31 15 8 20 11 2 14 2 * 130
Friedlander
et al. 2020
[19]
Península Mitre
and Isla de los
Estados,
Argentina (54◦)
Visual transect
survey 3.7–17 20 14 4 33 14 10 28 14 1 21 3 * 162
Friedlander
et al. 2021
[21]
Kawésqar
Reserve, Chile
(50◦–54◦)
Visual transect
survey 3.5–10 19 20 6 43 18 13 32 19 4 19 2 * 195
Beaton et al.
2020 [18]
Malvinas
Islands,
Argentina (51◦)
Photoquadrats
along transects 5–20 19 11 8 31 9 2 21 13 2 2 * 118
This study Bécasses Island,
Argentina (54◦)Roving diver
survey 2–33 4 14 7 40 13 5 27 10 1 7 32 160
SD 7.28 4.89 2.37 14.2 5.64 3.87 10.63 4.36 1.17 5.73 4.36 44.3
CV 54.64 38.57 47.33 47.09 47.63 49.39 49.08 35.8 63.77 39.77 12.82 31.95
* Not considered for SD and CV calculation. Only those studies that sampled the overall community were taken into account.
Diversity 2023,15, 354 11 of 18
4. Discussion
The results of this study provide an updated checklist of marine taxa for Bécasses
Island, a location on the eastern Beagle Channel, including several new records for nearby
areas. We listed 160 taxa, this study being the first to compile with photographic support
invertebrates, fish, and macroalgae species for the Beagle Channel. We stored the photos
with geographic positions on the iNaturalist platform. The most powerful benefits of using
a citizen science platform as iNaturalist were: (a) the photos of the taxa remain with public
access, (b) verified observations were uploaded to GBIF, and (c) the digital collection could
serve as an identification guide for other studies, whereas some observations already had
additional scientific importance. For example, our observations of Metridium senile were
used as input on a scientific note aiming to track the movement of this invasive anemone
in the last ten years [
44
]. We also registered the southernmost occurrence of three species
(Allostichaster capensis,Elysia patagonica, and Placida sudamericana) and the first record with
an in situ field photo of the seastar Diplasterias brandti for the Beagle Channel (Figure 2b).
The latter is important since previous records were deeper or closer to the Beagle Channel’s
eastern entrance with Atlantic waters influence [45].
Most of the studies analyzed in Table 2showed similar species richness compared to
our survey, meaning the roving diver survey succeeded in characterizing the local species
richness. Compared to our study, the greater number of species recorded by Friedlander
et al. [
17
,
21
] could be related to their sampling effort and broader survey areas. However,
we also notice a high estimation of sponges, bryozoans, and some sea star species that is too
detailed for a visual survey without sample extraction and dissection. Sponges of the same
species typically vary in color and shape; therefore, identification requires the study of the
morphology and size of spicules [
46
]. This is similar for bryozoans since microscopical
analysis might be needed. Fraysse et al. [
45
] identified 22 sea star species along the
Beagle Channel, but some of them are cryptic species that can only be identified under a
stereoscopic microscope. With this in mind, we decided to be conservative in identifying
these taxa by photos, resulting in fewer species. Although Friedlander et al. [
17
,
19
,
21
]
might have overestimated these groups, we probably underestimated them.
For macroalgae, it is often necessary to collect samples and dissect them under a
microscope for proper identification. Moreover, at the Beagle Channel, macroalgae com-
munities commonly show variations in composition and biomass between seasons, spring
and summer being the seasons with higher abundances [
47
]. Notwithstanding, we could
identify by field photos (using macro lenses in many cases and collecting small samples in
a few others) as many as 32 different macroalgae. This richness is similar to that reported
by Santelices and Ojeda [
9
], see Table 2) in the nearby Puerto Toro by means of extractive
sampling. Furthermore, in a one-year seasonal extractive sampling conducted in two
different kelp forests of the Beagle Channel, we found around 60 macroalgae species [
48
],
double what we found in winter in Bécasses Island with the roving diver survey. Therefore,
we believe this kind of survey is a good method for registering macroalgae as an initial
monitoring method, which can be complemented later with extractive samplings for more
detailed information. Most of the common macroalgae can be identified through pictures
by a trained diver. However, small-sized species or specific groups still need collection and
processing in the lab. For example, Mendoza [
49
] found 17 species of Corallinales for Tierra
del Fuego, most of them impossible to identify in the field.
4.1. Limitations of the Roving Diver Survey Methodology
Because richness estimates are dependent on the sample design and sampling effort,
the comparisons with other studies found here should be considered only qualitative.
However, based on the low number of dives employed and the high number of species
reported only by this study, we suggest that the roving diver survey should be considered
a good method to complement richness estimates. The weakness of this type of survey is
that density and cover cannot be estimated, and it is well-known that this information is
important for biodiversity studies [
50
]. However, species richness data and taxa geographic
Diversity 2023,15, 354 12 of 18
distribution could serve as input for future studies, biodiversity monitoring, and species
distribution modeling [51].
Although some small-sized species could be photographed and added to the list (e.g.,
polychaetes and small crustaceans), the roving diver survey is not recommended for highly
mobile and small species (<1 cm). These kinds of organisms need extracting sampling
methods (e.g., drags, nets, etc.), with adequate processing (e.g., sieves) and conservation
depending on the taxa, in order to identify the species and count individuals. For example,
36 amphipod species have been found with extractive methods associated with the kelp
Macrocystis pyrifera at the Beagle Channel [
52
]. However, we only photographed three of
the largest species (Table 1).
4.2. Why Have We Found More “Unique” Species Than in Previous Studies?
Several reasons can explain the presence of a higher number of “unique” species when
comparing the roving diver survey with more traditional surveys. This method allows
the diver to explore a vast area and “free their eyes of other tasks” (e.g., counting and
writing down species numbers), gaining time to search for “unique” species. Particularly
the following reasons can be explained by examples from this study:
Deep species: The roving diver survey allows for freely exploring a broader area,
whereas traditional sampling methods have been conducted in shallow waters (see Table 2)
and were mostly restricted to kelp forests. Below 18 m, we found some species normally
present at depth ranges of 15–900 m. Examples are the gorgonian-feeding anemone Dacty-
lanthus antarcticus (Figure 3b), the orange deep-water anemone Actinostola sp. (Figure 3c),
the basket star Gorgonocephalus chilensis (Figure 3d) and the nudibranchs Tritonia vorax
(Figure 3f) and Tritonia odhneri (Figure 3e) [53].
Small/cryptic species: Small-sized (2–4 cm) and cryptic species are frequently not
included (intentionally or not) in traditional samplings such as bottom transects or quadrats.
The roving diver survey allows including these kinds of species, by using macro lenses
in cameras (to obtain quality pictures of small species) and fundamentally by carefully
exploring different types of habitats, which are normally restricted in traditional samplings
(e.g., vertical or overhanging surfaces, crevices, species under rocks, biological habitats
such as algae, sponges, or shells). The “good eye” and local biodiversity knowledge of
biodiversity by the survey divers are also important factors. In this survey, we can mention
as this type of “unique” species some polychaetes and small crustaceans (mainly amphipods
and isopods), the octopus Enteroctopus megalocyathus (Figure 3g), the heterobranch sea slugs
Elysia patagonica (Figure 2c), and Placida sudamericana (Figure 2d). The octopus was hiding
in a crevice and the sea slugs were associated with the green algae Codium subantarcticum.
These sea slugs were 10–20 mm in size and the same color as the algae (see Figure 2c,d);
therefore, a careful look was fundamental to find them. On the other hand, small highly
mobile species are still very difficult to detect with the roving diver survey and should not be
considered when estimating richness. We could easily photograph small sea slugs because
they are slow, but highly mobile species such as shrimps are too difficult to photograph,
and not because they are necessarily cryptic but because of their exhaust speed.
Rare species: Infrequent species (because of their low density or infrequent presence in
one particular environment) could be challenging to detect with traditional methods such
as transects or quadrats. As the roving diver survey commonly explores a broader area, the
chances to find rare species increase. The possibility of freely exploring different habitats
and not being restricted to swimming following a line increases the chances even more.
For example, only a few individuals of the sea stars Allostichaster capensis and Diplasterias
brandti (see Figure 2a,b) were photographed during the roving diver survey. However,
these records were scientifically important because they constitute the southernmost record
for A. capensis [
54
] and the first record with an in situ field photo of D. brandti for the
Beagle Channel.
Diversity 2023,15, 354 13 of 18
Diversity2023,14,xFORPEERREVIEW12of17
Figure3.Someinterestingspeciesrecordedinthefield.(a)Doryteuthisgahi;(b)Dactylanthusant‐
arcticus;(c)Actinostolasp.;(d)Gorgonocephaluschilensis;(e)Tritoniaodhneri;(f)Tritoniavorax;(g)En‐
teroctopusmegalocyathus;(h)Dictyotafalklandica.Thescalebarscorrespondto1cm.
Rarespecies:Infrequentspecies(becauseoftheirlowdensityorinfrequentpresence
inoneparticularenvironment)couldbechallengingtodetectwithtraditionalmethods
suchastransectsorquadrats.Astherovingdiversurveycommonlyexploresabroader
area,thechancestofindrarespeciesincrease.Thepossibilityoffreelyexploringdifferent
Figure 3.
Some interesting species recorded in the field. (
a
)Doryteuthis gahi; (
b
)Dactylanthus
antarcticus; (
c
)Actinostola sp.; (
d
)Gorgonocephalus chilensis; (
e
)Tritonia odhneri; (
f
)Tritonia vorax;
(g)Enteroctopus megalocyathus; (h)Dictyota falklandica. The scale bars correspond to 1 cm.
Pelagic/nocturnal species: In contrast with traditional surveys where the focus is
generally on benthic species, the roving diver method allows also registering pelagic
species (e.g., jellyfish), occasional visitors (e.g., sea lions), and epibenthic species that can
Diversity 2023,15, 354 14 of 18
be climbing or attached to the kelp at different depths in the water column. Many of these
species can also have nocturnal behavior; therefore, it is important to conduct the survey
during the day and night. For example, we have registered the squid Doryteuthis gahi
(Figure 3a). It is common to find egg masses of this species attached to kelp stipes and
blades [55], but squids are generally difficult to see.
New species/taxonomic problematic species: Finally, and in this case not concerning
the roving diver survey, we have found more “unique” species in comparison with other
published studies, simply because new species have been discovered and described in
the last few years. Taxonomy is constantly changing, and new species may have been
confused with other known species, especially if samples of individuals were not collected
and no field pictures were available. As examples, we can mention three new species
found on Bécasses Island that were described in the last four years: the macroalgae Dictyota
falklandica (Figure 3h) [
56
], the sea anemone Isoparactis fionae [
57
], and the heterobranch
sea slug Placida sudamericana [
58
]. Species with taxonomic problems or that are difficult to
identify in the field (name in revision, sibling species, etc.) often lead to misinterpretations.
In this last category is the kelp Lessonia searlesiana, which has often been confused in the
selected studies with Lessonia vadosa or L. flavicans. The genus Lessonia is actually under
revision. Following Asensi and de Reviers [
59
], we detected differences in blades and
stipes morphology between L. searlesiana and L. flavicans. Particularly, for these species, we
collected some samples and looked for the presence/absence of lagoons in blades through
microscope view: L.flavicans presented lagoons, whereas the absence was detected in L.
searlesiana. As mentioned above, the spatial distribution also differed between these species.
Lessonia flavicans was found in the upper subtidal, whereas L. searlesiana was observed at
intermediate and deeper subtidal zones, even at 30 m.
4.3. Recommendations for Applying the Roving Diver Survey
The roving diver survey applied in this study has been useful in obtaining a complete
checklist of macroalgae, invertebrates, and fish in a fast and easy way in an extreme
subtidal environment. Divers optimize their time under the water by freely swimming to
wherever they like and searching for species in special habitats (e.g., searching for cryptic
species). This method also avoids spending time and effort in carrying and deploying extra
equipment, such as transect lines or quadrats. We recommend the roving diver survey
for checklist studies by the presence–absence of species, in places difficult to sample due
to extreme conditions, and when human resources and equipment are scarce (e.g., when
comparing many sites for a marine baseline study).
Marine biodiversity knowledge is an important factor for the roving diver survey.
Local knowledge of the diving sites and their fauna will allow scientific divers to easily
obtain data on the common species and to search for rare species in specific habitats. An
inexperienced diver could easily misidentify or lose cryptic species, while a trained diver is
less likely to do so. To avoid confusion and misinterpretations, we strongly recommend
using underwater cameras and external light to back up the species identification. A
known-species checklist could be filled while diving, but the photos must accompany the
checklist. We found it very useful to upload the photos later to the iNaturalist platform,
and we encourage researchers and other divers to do this for data validation transparency
and accessibility of the community.
In order to improve the survey, an underwater position system that allows errant
swimming of divers between kelp forests, e.g., [
60
], could be used to record the dive
trajectory and estimate the density of species with precision. Another option, which does
not require additional technology, is to use the SACFOR scale (Superabundant; Abundant;
Common; Frequent; Occasional; Rare) (see [
61
]), where species are recorded, either in terms
of percentage cover or density in six logarithmic steps. This scale is quicker, compared to
more time-consuming density estimation methods such as quadrats or transects.
In conclusion, our findings reveal that the roving diver survey using photographs
is a good approach for creating inventories of subaquatic species in a timely and cost-
Diversity 2023,15, 354 15 of 18
effective way. This method is very recommendable for kelp forests, where minimum
equipment and trajectory freedom help to avoid frequent entanglements, and optimization
of the time when diving in extreme environments such as sub-Antarctic cold waters is
especially important. We encourage scientific and recreational divers to try this non-
destructive method and enjoy the freedom of exploring in every dive. As it has been
proven in other parts of the world, the roving diver survey can be easily adapted for
citizen science programs in different environments, e.g., Reef Environmental Education
Foundation (REEF) Fish Survey Project, and has provided valuable data for scientific
research [
62
,
63
]. At the same time, unstructured citizen science data stored on iNaturalist
can increase the species richness records, especially in those areas where recreational diving
is popular [
64
]. Comparing the species richness obtained in the same site by different
sampling methods (e.g., transects vs. roving diver survey) could be a way to improve and
optimize the roving diver survey. We hope this proposed method will serve for a better
understanding of underwater biodiversity and be implemented for monitoring programs,
aiming at the conservation of marine habitats.
Supplementary Materials:
The following supporting information can be downloaded at: https:
//www.mdpi.com/article/10.3390/d15030354/s1, Table S1: overall list of species from all the studies
used for comparison; Table S2: unique species: species only present in one of the studies and absent
in all others. Videos S1: https://youtu.be/Uvi083RWEz8,https://youtu.be/ZQUlATCEfkY: sailing
and underwater images from the August 2021 Bécasses campaign.
Author Contributions:
Conceptualization, G.B. (Gonzalo Bravo), M.B., J.K. and C.P.A.; methodology,
G.B. (Gonzalo Bravo), M.R., C.P.A., J.K. and M.B.; validation, G.B. (Gonzalo Bravo), J.K., M.R., M.B.
and C.P.A.; formal analysis, G.B. (Gonzalo Bravo); investigation, G.B. (Gonzalo Bravo), M.B., J.K., C.P.A.
and M.R.; data curation, G.B. (Gonzalo Bravo), M.B., J.K., C.P.A., M.R. and C.F.; writing—original draft
preparation, G.B. (Gonzalo Bravo), M.B. and J.K.; writing—review and editing, G.B. (Gonzalo Bravo),
M.B., J.K., C.P.A., C.F., G.L. and G.B. (Gregorio Bigatti); visualization, G.B. (Gonzalo Bravo); supervision,
G.B. (Gregorio Bigatti); project administration, G.B. (Gonzalo Bravo), M.B., J.K. and C.P.A.; funding
acquisition, G.B. (Gonzalo Bravo), M.B. and G.B. (Gregorio Bigatti). All authors have read and agreed to
the published version of the manuscript.
Funding:
This research was funded by Agencia Nacional de Promoción Científica y Técnica to M.B.
(PICT 2017-2731) and G.B. (Gregorio Bigatti) (PICT 2018-0969). G.B. (Gonzalo Bravo) and J.K. are
supported by CONICET fellowships.
Institutional Review Board Statement:
Not applicable, since non-invasive research was conducted.
No vertebrate sampling was conducted and therefore no approval was required by any Animal Care
and Use Committee.
Data Availability Statement:
Publicly available datasets were analyzed in this study. This data
can be found here: https://www.inaturalist.org/projects/biodiversidad-submarina-islas-becasses,
accessed on 10 December 2022.
Acknowledgments:
We thank the following researchers for their expertise in species identification:
Alicia Boraso, María Paula Raffo, and Erasmo Macaya (macroalgae), Daniel Lauretta (Anthozoa),
Mariano Martínez (Holothuroidea), Diego Urteaga (Polyplacophora), Cristian Lagger (Tunicates),
Ignacio Chiesa (Amphipoda), Facundo Llompart, and Eloísa Giménez (fish). A special thanks
to Miguel Porco Fischer, captain of the vessel “Kostat”, for his friendship and support on this
adventure. Three anonymous reviewers improved the manuscript with their comments. Fieldwork
was conducted with permission from Tierra del Fuego Province (Secretaría de Ambiente, Ministerio
de Producción y Ambiente, Res. S.A. N
º
345) and from Prefectura Naval Argentina. This is a
contribution to the program of GrIETA.
Conflicts of Interest:
The authors declare no conflict of interest. The funders had no role in the design
of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or
in the decision to publish the results.
Diversity 2023,15, 354 16 of 18
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