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Fish diversity in the Berlengas Natural Reserve (Portugal), a marine protected area

Authors:
Nuno Vasco Rodrigues at MARE - IPLeiria
Nuno Vasco Rodrigues
  • MARE - IPLeiria
Susana Mendes at Instituto Politécnico de Leiria
Susana Mendes
Joao N Franco at Instituto Politécnico de Leiria
Joao N Franco
Maria Filipa Castanheira at Universidade do Algarve
Maria Filipa Castanheira
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Resumo Em 1981, as Berlengas, arquipélago localizado a cerca de 7 milhas da costa de Peniche (costa Oeste de Portugal), tornou-se área marinha protegida. Censos visuais subaquáticos, nomeadamente percursos aleatórios, foram usados para fazer o levantamento das espécies de peixes na área, durante duas campanhas de Verão, 2004 e 2005, contabilizando um total de 16 horas de observação em mergulho. Este estudo visou criar um inventário mais exacto e detalhado das espécies de peixes presentes no arquipélago do que um feito anteriormente, em resultado de alguns estudos prévios. Um total de 48 espécies de peixes pertencentes a 22 famílias foram observadas durantes os dois períodos de estudo. Labridae e Sparidae foram as famílias mais representadas e Diplodus vulgaris e Labrus bergylta foram as espécies mais frequentes. Abstract Since 1981, Berlengas, an archipelago located about 7 miles off Peniche (Western Coast of Portugal), became a marine protected area. Underwater visual census, namely rover diver counts, were used to assess the fish species present in the area during two summer campaigns, 2004 and 2005, comprising a total of 16 hours of scuba-diving observations. This study aimed to obtain a more accurate and detailed checklist of the fish species present in the archipelago than the one already existing in result of a few previous studies. A total of 48 fish species belonging to 22 different families were observed during the two study periods. Labridae and Sparidae were the most represented families and Diplodus vulgaris and Labrus bergylta were the most frequent species.
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Fish diversity in the Berlengas Natural Reserve
(Portugal), a marine protected area
Nuno Vasco-Rodrigues
1
, Susana Mendes
1
, João Franco
2
, Maria Castanheira
3
,
Nuno Castro
4,5
& Paulo Maranhão
1,6
1
GIRM – Marine Resources Research Group
Polytecnic Institute of Leiria, Campus 4, Santuário Nª Sª dos Remédios, 2520 - 641 Peniche - Portugal
2
IMAR - Institute of Marine Research
Department of Life Sciences - University of Coimbra - Largo Marques de Pombal - 3004-517 Coimbra -
Portugal
3
CCMAR University of Algarve, Campus de Gambelas, 8005-139 Faro - Portugal
4
CO − Centre of Oceanography, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016
Lisbon – Portugal
5
CIEMAR - The Marine Laboratory, University of Évora, Apartado 190, 7520-903 Sines - Portugal
6
CEF – Centre for Functional Ecology
Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra - Portugal
Resumo
Em 1981, as Berlengas, arquipélago localizado a cerca de 7 milhas da costa de
Peniche (costa Oeste de Portugal), tornou-se área marinha protegida. Censos
visuais subaquáticos, nomeadamente percursos aleatórios, foram usados para
fazer o levantamento das espécies de peixes na área, durante duas campanhas
de Verão, 2004 e 2005, contabilizando um total de 16 horas de observação em
mergulho. Este estudo visou criar um inventário mais exacto e detalhado das
espécies de peixes presentes no arquipélago do que um feito anteriormente, em
resultado de alguns estudos prévios. Um total de 48 espécies de peixes
pertencentes a 22 famílias foram observadas durantes os dois períodos de
estudo. Labridae e Sparidae foram as famílias mais representadas e Diplodus
vulgaris e Labrus bergylta foram as espécies mais frequentes.
Abstract
Since 1981, Berlengas, an archipelago located about 7 miles off Peniche
(Western Coast of Portugal), became a marine protected area. Underwater
visual census, namely rover diver counts, were used to assess the fish species
present in the area during two summer campaigns, 2004 and 2005, comprising
a total of 16 hours of scuba-diving observations. This study aimed to obtain a
more accurate and detailed checklist of the fish species present in the
archipelago than the one already existing in result of a few previous studies. A
total of 48 fish species belonging to 22 different families were observed during
the two study periods. Labridae and Sparidae were the most represented
families and Diplodus vulgaris and Labrus bergylta were the most frequent
species.
Key words: Berlengas Archipelago, North-eastern Atlantic, fish species,
underwater visual census
Introduction
Marine protected areas (MPAs) are a
common tool in conservation and are
widely used throughout the world to
prevent overfishing and preserve
biodiversity. While much of the literature
on MPAs has dealt with no-take areas
(e.g. Rowley 1994; Ashworth & Ormond
2005), MPAs can offer several levels of
protection and many afford only partial
protection, allowing certain types of
fishing (Denny & Babcock 2004).
There are many documented examples
where fish species have benefited from
reserve establishment, in particular
through increases in mean size and
abundance (e.g. Westera et al. 2003;
Harmelin-Vivien et al. 2008).
In situ data on reef fish assemblages can
be used to evaluate community responses
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to natural and artificial changes in the
biotope (Bythell et al. 1993).
Non-destructive techniques, such as
underwater visual observation (visual
census) have frequently been used to
characterize reef fish communities
(Bohnsack & Bannerot 1986) by
quantitatively measuring relative
abundances and community structure
(Guidetti et al. 2008).
More recent studies started to address
temperate reef fish assemblages (García-
Charton et al. 2004; Guidetti et al. 2008)
and fish communities on North Atlantic
islands like Canaries (Falcon et al. 1996),
Azores (Patzner & Santos 1993; Santos et
al. 1994); and Madeira (Ribeiro et al.
2005). In Portuguese mainland few
studies have been performed (e.g. Almada
et al. 1999; Gonçalves et al. 2002; Santos
et al. 2005; Beldade & Gonçalves 2007).
Berlenga Island and the nearby Estelas
islets were declared a Nature Reserve in
1981, to preserve a rich natural heritage
and to ensure sustainable development of
human activities there. More recently,
Berlengas Natural Reserve (BNR) was
proposed to be a Biosphere Reserve. This
denomination is attributed by UNESCO to
sites where the existence of innovate
approaches to conservation and sustainable
development is recognized. The Reserve
was enlarged in 1998 to include the
remote Farilhões islets and a much wider
marine area, now up to 9541 hectares
overall (99 ha of land area and 9 442 ha
of marine area) (Queiroga et al. 2009).
Current legislation does not allow the
following activities inside the protected
area: commercial fishing to vessels
unregistered in Peniche Port Authority
(nearest fishing harbor); trawl fishing, gill
nets, trap fishing and shellfish collecting
(Queiroga et al. 2009).
Despite its biodiversity, no marine
scientific studies were done in Berlengas
Natural Reserve (BNR) prior to its
implementation. The few scientific work
carried out to assess the species that
inhabit these waters were all performed
after Berlengas archipelago was declared
a marine reserve. In addition, the studies
concerning fish are also scarce (Henriques
1993; Rodrigues 1993; Almeida 1996;
Rodrigues 2009).
The main objective of this study was to
create an accurate inventory of the fish
species present in the BNR area, in order
to improve a previous database refering to
a restricted area of this marine reserve.
2. Material and Methods
2.1 Study area
This study was performed in the BNR, an
archipelago formed by 3 groups of small
islands (Berlenga, Estelas and Farilhões),
7 miles off Peniche (Portugal) (Fig 1). This
archipelago is located at the top of the
escarpment of the Nazaré Canyon, one of
the most worldwide important submarine
canyons in the transition zone between
the Mediterranean and European
subregions. Due to this canyon, the water
is rich in nutrients, especially throughout
the upwelling season (April–September)
(Haynes et al. 1993).
2.2. Visual census
Twelve sampling stations from the 3
groups of islands were defined in this
study (Fig 2), 6 around Berlenga Island
(B1-B6), 3 at Estelas islets (E1-E3) and 3
at Farilhões islets (f1-f3). The sea floor
consists primarily of irregular hard bottom
substrate (i.e. rocks covered with sessile
biota, including a variety of algae,
sponges, hydrozoans, anemones,
crustaceans, sea urchins and tunicates
(Rodrigues et al. 2008). Non-destructive
methods, namely visual census techniques
using SCUBA gear, were used to assess
the fish diversity of the archipelago during
two campaigns, August 2004 and July
2005. These campaigns included sampling
in the same stations, in both years.
Rover-diver counts was the most suitable
method, considering the goal of the study
was to register specific richness regardless
of abundance or mean size (Baron et al.
2004). This method consists on the diver
recording all the fish species encountered
during a 20 minutes interval. The diver
was encouraged to look wherever in an
attempt to record the maximum number
of species and to register this information
on a dive slate (Baron et al. 2004). No
abundance or size data were recorded.
The dives were performed from 5 to 30
meters deep in all type of underwater
environments found in the area (sand,
rocky areas, caves, water column) and
were conducted between 10:00 and 16:00
hours local time (GMT).
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Figure 1. Geographic location and limits of the Berlengas Natural Reserve (in red)
with its 3 groups of islands
Figure 2. Location of the sampling stations in the 3 groups of islands of the Berlengas Natural Reserve
2.3. Data analysis
2.3.1. Feeding guilds
According to Elliot et al. (2007), each
species was characterized based on its
feeding guild (invertivore, macrocarnivore,
piscivore, omnivore, zooplanktivore and
herbivore). Species were considered
‘‘invertivore” when they feed
predominantly on non-planktonic
invertebrates while zooplankton feeders
(i.e. species that feed on planktonic
crustaceans, hydroids and fish
eggs/larvae) were considered
‘‘zooplanktivore”. ‘‘Herbivore” species feed
predominantly on macroalgae,
macrophytes, phytoplankton and
microphytobenthos and ‘‘omnivore”
species feed on detritus, filamentous
algae, macrophytes, epifauna and infauna.
Species that feed on macroinvertebrates
and vertebrates (mostly fish) were
considered ‘‘macrocarnivores” and the
species that feed almost exclusively on
fish were included in the ‘‘piscivore” guild.
The attribution of the feeding guild to each
fish species was based on Henriques et al.
(2008).
2.3.2. Statistical analysis
An initial binary matrix was constructed
where species’ presence/absence in the
sampling sites was denoted as 1 or 0,
respectively.
To derive similarity patterns from the
above matrix, the Jaccard coefficient was
utilized (Legendre & Legendre 1998. The
overall multivariate spatial pattern was
obtained from the initial matrix by using
the non-metric multidimensional scaling
(nMDS) (Clarke & Green 1988; Warwick &
Clarke 1991). Based on scree-plot
inspection, a scaling solution with three
dimensions was selected, which made-up
the basis for a 2D ordination plot using the
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nMDS. All statistical analyses were done
with Canoco for Windows 4.5 (ter Braak &
Šmilauer 2002) and WinKyst 1.0 add-ons
for Canoco (Šmilauer 2002–2003).
3. Results
3.1. Descriptive analysis
A total of 48 fish species belonging to 22
different families were observed during
the two study periods (Table I).
Two families, Sparidae and Labridae, were
the most represented, with nine and six
species, respectively, followed by
Blennidae and Gobiidae with four species
each, and Carangidae, Gadidae and
Scombridae all with three species.
Fourteen families were represented by a
single species.
Diplodus vulgaris was the species with
highest frequency (100% in 2004 and
91.7% in 2005), followed by Labrus
bergylta (69.2% in 2004 and 91.7% in
2005). Twelve species were observed only
once during the study period. Sampling
station B2 was the spot where the number
of species registered was highest (23 in
2004 and 19 in 2005) and station E2 was
the spot where the number of species was
lowest (5 in 2005).
The fish community is constituted mainly
on macrocarnivores species (35%),
followed by omnivorous and invertivores
species (27%) (Table I). Herbivores and
piscivores were represented by only one
species each, Sarpa salpa and Belone
belone, respectively. Sarpa salpa was
observed in 11 sampling stations during
the study period, and Belone belone was
observed only once at station F3 during
2004.
3.2. Multivariate analysis
The multivariate analyses provided
additional information on the similarity
pattern: nMDS based on Jaccard
coefficient and performed on the total
species list for the twelve sampling sites
over the two years, revealed a clear
gradient along the axis 1 of the plot (Fig.
3).
Figure 3. Non-metric MDS ordination of Berlenga Island (B1, B2, B3, B4, B5, B6), Estelas (E1, E2, E3)
and Farilhões (f1, f2, f3) sampling stations based on the dimension coefficients (dimension 1 by
dimension 2) of species presence/absence in 2004 and 2005. Stress 0.15.
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Table 1. Occurrence frequency (%) of fish species from Berlenga Natural Reserve in 2004 and 2005 and
species feeding guild (he – herbivore; inv – invertivore; ma – macrocarnivore; om – omnivore; pi –
piscivore; zoo – zooplanktivore).
FAMILY SPECIES
Feeding
guild 2004 2005
Mugilidae Liza aurata (Risso, 1810) om 69.2 41.7
Chelon labrosus (Risso, 1827) om 38.5 25
Sparidae Sarpa salpa (Linnaeus, 1758) he 76.9 58.3
Boops boops (Linnaeus, 1758) om 53.8 50
Diplodus sargus (Linnaeus, 1758) om 76.9 75
Diplodus annularis (Linnaeus, 1758) inv 7.7 33.3
Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817) inv 100 91.7
Diplodus cervinus (Lowe, 1838) om 30.8 25
Pagrus pagrus (Linnaeus, 1758) ma 7.7 0
Spondyliosoma cantharus (Linnaeus, 1758) om 46.2 41.7
Oblada melanura (Linnaeus, 1758) om 23.1 0
Labridae Labrus bergylta Ascanius, 1767 om 69.2 91.7
Labrus mixtus (Linnaeus, 1758) ma 0 8.3
Centrolabrus exoletus (Linnaeus, 1758) inv 23.1 41.7
Ctenolabrus rupestris (Linnaeus, 1758) ma 30.8 16.7
Coris julis (Linnaeus, 1758) inv 46.2 66.7
Symphodus spp. inv 7.7 16.7
Gobiidae Gobiusculus flavescens (Fabricius, 1779) zoo 46.2 58.3
Gobius xanthocephalus Heymer & Zander, 1992 inv 15.4 8.3
Pomatochistus spp. inv 0 8.3
Thorogobius ephippiatus (Lowe, 1839) om 23.1 0
Mullidae Mullus surmuletus Linnaeus, 1758 ma 15.4 25
Moronidae Dicentrarchus labrax (Linnaeus, 1758) ma 23.1 8.3
Serranidae Serranus cabrilla (Linnaeus, 1758) ma 38.5 50
Atherinidae Atherina presbyter Cuvier, 1829 ma 7.7 8.3
Gadidae Pollachius pollachius (Linnaeus, 1758) inv 23.1 8.3
Trisopterus luscus (Linnaeus, 1758) ma 7.7 8.3
Phycis phycis (Linnaeus, 1766) inv 7.7 33.3
Belonidae Belone belone (Linnaeus, 1761) pi 7.7 0
Carangidae Seriola rivoliana Valenciennes, 1833 ma 7.7 0
Trachurus trachurus (Linnaeus, 1758) ma 23.1 33.3
Trachynotus ovatus (Linnaeus, 1758) ma 7.7 0
Ammodytidae Gymnammodytes semisquamatus (Jourdain, 1879) zoo 7.7 0
Balistidae Balistes capriscus Gmelin, 1789 inv 38.5 8.3
Blennidae Parablennius gattorugine (Linnaeus, 1758) om 0 8.3
Parablennius pilicornis (Cuvier, 1829) om 15.4 33.3
Parablennius ruber (Valenciennes, 1836) om 23.1 33.3
Lipophrys pholis (Linnaeus, 1758) om 0 8.3
Tripterygiidae
Tripterygion delaisi Cadenat & Blache, 1970 inv 46.2 33.3
Triglidae Trigloporus lastoviza (Bonnaterre, 1788) inv 7.7 8.3
Gobiesocidae Lepadogaster lepadogaster (Bonnaterre, 1788) inv 7.7 0
Syngnathidae Syngnathus acus (Linnaeus, 1758) zoo 7.7 0
Scorpaenidae Scorpaena sp. ma 30.8 16.7
Scombridae Scomber scombrus Linnaeus, 1758 ma 46.2 0
Scomber colias Gmelin 1789 ma 46.2 0
Sarda sarda (Bloch, 1793) ma 7.7 0
Muraenidae Muraena helena Linnaeus, 1758 ma 7.7 8.3
Bothidae Arnoglossus laterna (Walbaum, 1792) ma 7.7 0
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The analysis showed clear differences
between Berlengas island samples and all
the remainder sites in the
presence/absence of the 48 species. With
the exception of two samples, Berlenga
Island stations are placed in the negative
part of axis 2; all the remainder sampling
stations are grouped on the right side of
the plot and particularly E2-05 and f2-04
are placed in the most distant places (on
the upper right side) of the plot. Although
not as evident as with Berlenga Island
stations, Estelas and Farilhões islets
stations also showed differences among
them, regarding similarity pattern (Figure
3). In addition, the nMDS configuration
yielded a plot where years did not play a
major role to separate the sites and
therefore do not appear to be tightly
linked to individual sites.
4. Discussion
The first study developed in the area was
performed by Almeida (1996) and focused
on the coastal zone of Berlenga Island.
Using a visual point counts technique
adapted from Bohnsack & Bannerot
(1986) for 1200 minutes, the author
recorded 51 fish species belonging to 19
families, in a study performed between
1990 and 1992, being Gadidae, Sparidae,
Labridae, Gobiidae and Blennidae the
most abundant families, the same as in
the present study. As pointed by Almada
et al. (1999), in the north-eastern
Atlantic, the temperate reef fish
communities are characterized by the
higher abundance of species belonging to
the families Labridae, Sparidae, Gobiidae,
Blenniidae and Serranidae, though
including a number of other families with
lower abundances (e.g. Carangidae,
Syngnathidae, Mugilidae, Phycidae,
Gobiesocidae, Callionymidae,
Scorpaenidae, Soleidae, Triglidae).
Almeida (1996) also reported the species
Boops boops, Diplodus vulgaris and
Gobiusculus flavescens as the most
abundant in that period. This author
recorded a total of 17 species in his study,
that were not observed in the present one,
but, on the other hand, the present study
recorded 14 new species: Pagrus pagrus,
Oblada melanura, Gobius xanthocephalus,
Atherina presbyter, Belone belone,
Trachinotus ovatus, Gymnammodytes
semisquamatus, Parablennius ruber,
Trigloporus lastoviza, Scomber scombrus,
Scomber colias, Sarda sarda, Muraena
helena and Arnoglossus laterna. Some of
the species recorded by Almeida (1996)
and absent in the present study were,
however, registered by Rodrigues et al.
(2008): Conger conger, Gaidropsarus
mediterraneus, Zeus faber, Pseudocaranx
dentex, Sparus aurata, Gobius paganellus,
Gobius cruentatus and Zeugopterus
punctatus.
Regarding Gobius auratus observed in the
first study, it could actually be G.
xanthocephalus. G. auratus has been
confused in the past with G.
xanthocephalus that has only been
recognized as a separate and valid species
by Heymer & Zander (1992).
The reef fish community of BNR is
constituted mainly on macrocarnivores,
omnivorous and invertivores species, and
rarely herbivores (just one species, Sarpa
salpa). According to Almada et al. (1999),
the large majority of reef fishes in the
temperate north-eastern Atlantic are
benthivore and rarely herbivore or
planktonivore. The high abundance of
macrocarnivores in this study is mainly
explained by the presence of some pelagic
fish belonging to the Scombridae and
Carangidae families (3 species each).
Considering the BNR is an offshore
archipelago, the occurrence of pelagic fish
is common unlike other studied places
from the north-eastern Atlantic (Gonçalves
et al. 2002; Ribeiro et al. 2008).
The nMDS analysis showed clear
differences between Berlenga Island and
all the remainder sites, as showed on
Figure 3. In this study, 22 species
occurred only in Berlenga sampling
stations, and some of them are typically
found in coastal environments (e.g. A.
presbyter, Lepadogaster lepadogaster,
Lipophrys pholis, Syngnathus acus,
Thorogobius ephippiatus). In Estelas and
Farilhões stations we registered species
which are typically found in oceanic
environments and did not occur in
Berlenga stations (e.g. S. sarda; B.
belone). Rodrigues (2009) mentioned the
existence of a coast-to-ocean
environmental gradient when going from
Berlenga to Estelas and from Estelas to
Farilhões. The presence of the Nazaré
canyon as well as the depths around
Farilhões (Haynes et al. 1993) gives to
this farthest area of BNR oceanic
characteristics which probably enhance
this gradient.
With this study, the authors provide
additional data that can be useful to
understand the present situation about
fish diversity in BNR. This new
information, could be used in future
studies focusing on fish community’s
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structure and dynamics which contribute
to monitoring BNR fish populations and
are also crucial to understand how
effective is this Marine Protected Area.
Acknowledgements
The authors would like to thank to
Reserva Natural das Berlengas for
providing a place to stay in the island,
diving equipment and a vessel and also
Luis Dória for all the help given with
logistics and his permanent will to create a
good work atmosphere. Armando Almeida
for his help and references provided, Rui
Esteves da Silva and Nuno Tavares for
their help with the figures used in this
work and also to the reviewers for the
suggestions made, improving the quality
of this paper. This study was funded by
IMAR – Institute of Marine Research and
by Instituto Politécnico de Leiria.
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... Inside PP areas, these records were lower but with a higher increment with time: in 2011, an average abundance of 0.177 ± 0.089 fishes per m 2 and 17 taxa (16 species) was observed, and in 2012, an average abundance of 0.633 ± 0.337 fishes/m 2 and 17 taxa (16 species) was sampled (Table S1). The most observed non-cryptic taxa in CP areas were medium Boops boops ( [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] cm) and small Coris julis (<8.3 cm) in 2011, while in 2012, small Atherina sp. (<5 cm) and small B. boops (<15 cm) dominated (Table S1). ...
... In PP areas, medium C. julis ([8.3-16.7] cm) and medium Diplodus vulgaris ( [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] cm) were the most abundant in 2011 (Table S1). The year after, in the same areas, small and medium Pomastochistus flavescens (<2 cm and ([2-4 cm]) were the most detected (Table S1). ...
... The year after, in the same areas, small and medium Pomastochistus flavescens (<2 cm and ([2-4 cm]) were the most detected (Table S1). Overall, the most abundant taxa were medium D. vulgaris ( [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] cm) and small and medium P. flavescens (<2 cm and [2-4 cm]) inside PP areas. In comparison, outside those areas, small B. boops (<15 cm) and small C. julis (<8.3 cm) were the most spotted fishes (Table S1). ...
Using Fish Assemblages to Assess the Ecological Effects of Marine Protection on Rocky Habitats in a Portuguese Natural Park
Article
Full-text available
  • Feb 2023
Intensive and regular fishing occurs in the marine area of the natural park "Parque Natural do Sudoeste Alentejano e Costa Vicentina" (PNSACV; SW coast of continental Portugal). In 2011, this area became a marine park with different protection levels (total, partial, and complementary). We assessed in 2011 and 2012 if partial protection (PP) in Marine Protected Areas (MPAs) changed the taxa richness, abundance, size, and community composition of cryptic and non-cryptic fishes. We also determined if these effects were observed outside PP areas in adjacent control areas. Underwater visual censuses (UVC) of cryptic and non-cryptic fish species were conducted in rocky subtidal habitats (~10 m deep) with band transects (25 × 2 m and 25 × 4 m, respectively) to determine abundance and size classes. The northern half of the PNSACV was sampled at a scale of tens (site-two sites per area; 4-6 transects per site) and hundreds (area) of meters. Two PP and six control areas were sampled. The homogeneity and abundance of bottom habitat types were assessed at each site. Effects of protection were not detected in the community structure or univariate analyses (i.e., taxa richness and total abundance) of non-cryptic and cryptic fishes. The early phase of the MPAs may have driven the lack of significant protection effects. Replication in time within a monitoring program is recommended to assess these conservation measures' ecological effects.
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... This phenomenon is intensified by the strong northwest winds originating from the warm Portugal current that flows from North to South along the Portuguese coast (Wooster et al., 1976;Amado et al., 2007;Mil-Homens et al., 2007). The seabed is composed of granite rock bottom inhabited by algae and sessile invertebrates, flanked by long sandbanks, sheltering, and supporting the life cycles of many species (Amado et al., 2007;Vasco-Rodrigues et al., 2011). Moreover, there are submerged and partially submerged caves, acknowledged by the Habitats Directive of the Natura 2000 Network, contributing to the conservation values of this protected area (Amado et al., 2007;Vasco-Rodrigues et al., 2011). ...
... The seabed is composed of granite rock bottom inhabited by algae and sessile invertebrates, flanked by long sandbanks, sheltering, and supporting the life cycles of many species (Amado et al., 2007;Vasco-Rodrigues et al., 2011). Moreover, there are submerged and partially submerged caves, acknowledged by the Habitats Directive of the Natura 2000 Network, contributing to the conservation values of this protected area (Amado et al., 2007;Vasco-Rodrigues et al., 2011). ...
Mapping elasmobranch occurrences and overlap with human activities using local knowledge and non-invasive sampling to identify areas of potential conflict
Article
Full-text available
  • Apr 2024
Over one-third of all elasmobranch species are at risk of extinction worldwide. This study aims to contribute to their conservation worldwide through a case study that combines georeferenced data on species presence and abundance with spatial distribution of human activities, through a Spatial Conflict Risk Index (SCRI). The SCRI pinpoints possible risk areas obtained from the spatial overlap of elasmobranch species abundance and distribution with impacting human activities. Data on species presence and abundance around a Marine Protected Area, the Berlengas Natural Reserve (Portugal) were obtained through four non-invasive methods: Baited Remote Underwater Videos (BRUV), Local Ecological Knowledge (LEK), scientific observers onboard longline commercial fishing vessels and citizen science and social media reports. Human activities were mapped based on LEK. Qualitative abundance and distribution data was obtained for 22 species. SCRI highlighted some high-risk areas due to overlap of areas of frequent occurrence of elasmobranchs with potential high impact activities (e.g. longline fishery). This study highlighted the potential of multi-method approaches to estimate the distribution of rare, highly mobile species in data-limited contexts, and assess their exposure to human activities. The SCRI is a useful tool to support the implementation of effective conservation regulations.
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... The maritime area in the region extends to depths of 200 m, flanked to the north and northwest by a deep-sea area, the Nazaré canyon. The rocky substrates and the high biological productivity reefs support a great marine biodiversity (Almeida 1996, Pardal & Azeiteiro 2001, Queiroga et al. 2008, Rodrigues et al. 2011. This biodiversity seems to be reflected in the varied diet of Shags. ...
... The most consumed fish families registered in Shag diet on the archipelago are also among the most abundant in the region (Almeida 1996, Rodrigues & Maranhão 2009, Rodrigues et al. 2011. The availability of potential prey species is considered to be the main factor for Shag diet composition, and the diet of these birds can even be used as an indicator of the availability of fishery resources (Barrett 1991, Einoder 2009, Lorentsen et al. 2018. ...
Hey, That's My Fish – Overlap in Prey Composition between European Shag and Local Fisheries in Portugal
Article
Full-text available
  • Mar 2021
The European Shag Phalacrocorax aristotelis is a threatened seabird species in Portugal. Knowledge about this population is limited, and currently there is no information about dietary needs and threats posed by fisheries. We studied the diet composition of Shags in the Berlengas archipelago, the largest breeding colony in the country, through the analysis of 124 regurgitated pellets, and estimated trophic overlap with local fisheries, during the breeding and winter seasons of 2016–2017. A total of 32 fish species were identified in their diet, while their major prey consisted of sand eels (Ammodytidae) and species from the Labridae, Gadidae and Sparidae families. Diet composition varied seasonally and was more specialized during the breeding season, with sand eels comprising 70% of all prey consumed and 45% of total biomass. During winter, the consumption of heavier predatory fish increased, particularly fish from the Gadidae and Sparidae families. Shags consumed 17 species also targeted by commercial fisheries, and fish were in the same size range, highlighting the potential for resource competition. Fish species that contributed the most to prey overlap were the Pouting Trisopterus luscus, White Seabream Diplodus sargus, Common Two-banded Seabream Diplodus vulgaris, Bogue Boops boops and Black Seabream Spondyliosoma cantharus. Among different types of fishery, trophic overlap with Shags was more pronounced with polyvalent gear (longlines and gillnets), especially during winter, than with purse seine and trawling. Competition between Shags and local commercial fisheries may represent an additional pressure on foraging Shags, as well as increasing their conflict with fishing activity.
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... This population also declined in the last decades. Despite the increase in protection associated with the establishment of the Berlengas' Special Protection Area (BSPA) in 1988 (Rodrigues et al., 2011;Oliveira et al., 2016;Oro, Alvarez & Velando, 2018): for the period 2002-2019, an average reduction of 22% in the breeding population was noticed (Alonso et al., 2019). ...
What to expect from alternative management strategies to conserve seabirds? Hints from a dynamic modelling framework applied to an endangered population
Article
Full-text available
The worldwide decline of seabird populations due to the combined effects of global and regional changes is creating immense challenges for managers and conser-vationists. Predicting population responses to proposed management strategies could provide the most effective tools to prevent, halt and reverse ongoing declines. System dynamic modelling frameworks are considered particularly relevant to interrelate biological, ecological and environmental characteristics and to predict population trends. A system dynamics model was designed, compiling diverse information concerning a relict population of the European Shag located in western Iberia, to outline the most effective management options for its conservation. The simulations demonstrate that mortality caused by invasive animals and bycatch mortality were the main reasons for the current population decline. Without management interventions, a decrease of 8% was projected for the next decade, which could be mitigated by specific conservation actions. The results show the usefulness of dynamic modelling frameworks to understand local cause-effect relationships and species responses to ecosystem management under changing environmental conditions. We highlight that the framework proposed, after specific parameterization, could be easily adaptable to other species within similar socio-ecological systems.
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... Furthermore, SD models allow expert opinion to be incorporated, projecting longterm population patterns in response to ecological constrains and environmental scenarios (Bastos et al., 2012;Weller et al., 2016;Arosa et al., 2017). (Rodrigues et al., 2011;Oliveira et al., 2016). Anthropogenic and environmental factors seem to be correlated with this population trend, such as invasion by exotic species, bycatch within different fishing gears, oil spill catastrophes, tourism disturbance, climate and oceanographic change and the increasingly common extreme weather events (Velando & Freire, 2002;Munilla et al., 2011). ...
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... This species is an ecologically important macrograzer in the Medi terranean (Vergés et al. 2009), particularly when occurring in schools of several hundreds of individuals (Verlaque 1990). While common in central Portugal, this species is normally found in very low abundances in northern Portugal (Rodrigues et al. 2011, Henriques et al. 2013. Hence, although we do not have unambiguous evidence, it is likely that this species is responsible for a large part of the consumption of kelp recruits in central Portugal. ...
Herbivory drives kelp recruits into ‘hiding’ in a warm ocean climate
Article
  • Jan 2015
  • MAR ECOL-PROG SER
Assessing effects of herbivory across broad gradients of varying ocean climate conditions and over small spatial scales is crucial for understanding its influence on primary producers. Effects of herbivory on the distribution and abundance of kelp recruits were examined experimentally at two regions under contrasting ocean climate. Specifically, the abundance and survivorship of kelp recruits and the abundance of macro-herbivores were compared between a ‘cool’ and a ‘warm’ region in northern and central Portugal, respectively. In each region, the abundance of kelp recruits and the intensity of grazing were compared between habitats of different topography within reefs (open reef vs. crevices). Compared to the ‘warm’ region, the abundance of kelp recruits was 3.9 times greater in the ‘cool’ region, where 85% of recruits were found in open reef habitats. In contrast, 87% of recruits in the ‘warm’ region were restricted to crevices. The ‘warm’ region had 140 times greater abundances of sea urchins, 45 times more herbivorous fish and 4.1 times more grazing marks on kelp recruits than the ‘cool’ region. Grazing assays showed ca. 50 times higher rates of kelp biomass consumption, mainly by fishes, and zero survivorship of kelp recruits in the ‘warm’ relative to the ‘cool’ region. This study suggests both temperature and herbivores affect abundances of kelp recruits across latitudes, and demonstrates how herbivores affect their distribution at local scales, driving kelp recruits into ‘hiding’ in crevices under intense herbivory. Consequently, where net recruitment success is compromised by herbivory, the persistence of kelps will be contingent on availability of topographical refuges.
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... Anyway, non-destructive sampling techniques are more appropriate, as they minimize impacts on fish stocks and habitats (Malcolm et al., 2007;Unsworth et al., 2014). So far, Underwater Visual Census (UVC) performed by trained divers with Self Contained Underwater Breathing Apparatus (SCUBA) has been the most widely applied method for assessment of fish species sizes and densities in MPAs (Jennings et al., 1996;Rakitin & Kramer, 1996;Tupper & Rudd, 2002;Christie, 2004;Williams et al., 2009;Vasco-Rodrigues et al., 2011;Vergés et al., 2012;Henriques et al., 2013;Horta e Costa et al., 2013a). Nevertheless, UVC is known to have various biases, related to observers´ level of experience, selected methodology and changes in fish behaviour in response to the presence of divers (St. ...
Evaluation of the reserve effect in a Marine Protected Area in Sagres (PNSACV)
Thesis
Full-text available
  • Aug 2019
Marine Protected Areas (MPAs), especially when set up as marine reserves, have been found beneficial for fish communities and species worldwide. Evaluation of MPA effects needs to be done to understand whether existing protection measures are efficient or not. To detect potential protection effect, we aimed to assess differences in demersal fish and commercial invertebrate community at Ilhotes do Martinhal marine reserve. Based on a comparison between locations situated inside and outside the reserve, differences in richness, abundance, length and biomass were analysed at community and species level. The influence of physical habitat was investigated, as it could get confounded with protection effect. In addition, we wanted to validate the results from Stereo Baited Remote Underwater Video (SBRUV) by another method, being Stereo Diver Operated Video (SDOV). Comparison between methods performance and costs was held to select the more efficient monitoring tool. SBRUV results suggested that the marine reserve provided positive effects, as it sustained signicantly greater biomass of target species and target species above minimum landing size, but not below that size. The reserve was found beneficial for Diplodus sargus, a valuable commercial, and Labrus bergylta, a by-catch species. However, two species showed opposite patterns, indicating negative protection effect or influence of other habitat characteristics rather than physical complexity. Furthermore, SBRUV results for abundance were non-conclusive of differences, probably due to a delayed response. SDOV showed no signs of positive protection effects, with some results complementary while other contradictory to SBRUV’s ones. This was attributed to the differences in community sampled, reflecting diver and bait effects. As illegal fishing gear was encountered inside the reserve, legal enforcement and active management might play a key role in future reserve success. This study is especially relevant for further monitoring and revaluation of protection measures and zonation of Ilhotes do Martinhal.
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... These depletions can ultimately lead to changes on fish assemblages and a consequential cascade in ecosystem effects (Friedlander & DeMartini, 2002; Despite this relatively high number of practitioners, information on recreational fishing catch and effort is limited for most areas and fishing modes and there is no periodic monitoring of catches made for recreation, sport or subsistence (Veiga et al., 2010(Veiga et al., , 2013, and most studies are relatively recent (since 2000) and dispersed spatially (e.g., Barreiros, 2015;Diogo, 2007;Diogo & Pereira, 2013a,b, 2014Diogo, Pereira & Schmiing, 2017;Guerreiro, Veiga & Erzini, 2011;Rangel & Erzini, 2007;Veiga et al., 2010Veiga et al., , 2013. This information, albeit relatively limited, has led to the development and implementation of precautionary management measures, such as the creation of several no-take Marine Protected Areas (MPAs), where specific rules have been implemented for spearfishing (see Bertocci, Dominguez, Freitas & Sousa-Pinto, 2012;Carneiro, 2011;Vasco-Rodrigues et al., 2011;Veiga et al., 2013). Additionally, al- (Table 1). ...
Spearfishing in Portugal: A baseline study on spearfishers’ profiles, habits and perceptions towards management measures
Article
Full-text available
  • Oct 2018
Despite the relatively high number of spearfishing practitioners in Portugal, scientific information on spearfishing is limited. A web‐based survey was conducted to obtain socio‐economic information on Portuguese spearfishers, identify the most common fishing habitats, target species, fishing effort, and evaluate their perceptions towards management and conservation measures. Results suggest that spearfishing is essentially seen as promoting well‐being, escaping the daily routine and outdoor enjoyment. Favourable environmental conditions and habitat availability seem to play an important role in the fishing effort, with warmer, less exposed rocky bottoms covered with algae being the most appreciated for spearfishing. Spearfishers reported targeting mostly two species: European seabass Dicentrarchus labrax and the white seabream Diplodus sargus. The added fishing mortality caused by spearfishers should be included in stock assessment of these species. Most respondents felt that the management measures in place were inappropriate and unfair for the spearfishing activity.
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... Some species are of particular commercial fishing importance, especially small pelagic fish such as sardines (Sardina pilchardus), Atlantic mackerel (Scomber scombrus), chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus). Eleven species from the family Sparidae are present in this area.The occurrence of pelagic species is common in Berlenga and the communities of reefs are dominated by macrocarnivores, omnivorous and invertivores species(Vasco-Rodrigues et al. 2011). The ...
Incorporation of Local Ecological Knowledge (LEK) into Biodiversity Management and Climate Change Variability Scenarios for Threatened Fish Species and Fishing Communities—Communication Patterns Among BioResources Users as a Prerequisite for Co-management: A Case Study of Berlenga MNR, Portugal and Resex-Mar of Arraial do Cabo, RJ, Brazil
Chapter
Full-text available
  • Nov 2017
Under current marine environmental problems and climate change scenarios, marine reserves emerge as an alternative management tool to protect marine resources and biodiversity and local ecological knowledge (LEK) can provide a valuable base for resource management. This study approaches the current situation of artisanal fisheries in two marine protected areas (MPAs) and proposes biodiversity management scenarios, under a changing climate, using fishers’ local ecological knowledge (LEK) in two hemispheres: The Berlenga Marine Natural Reserve (Berlenga MNR), Portugal and the Marine Extractive Reserve (Resex-Mar) of Arraial do Cabo, Rio de Janeiro, Brazil. The most targeted species of artisanal fisheries in both protected areas were reviewed for habitat use, threats and conservation status. The use of LEK is a powerful tool for developing new conservation strategies namely dealing with climate change responses of biological bioresources and fishing communities’ adaptation. Participatory management by all users in a protected area is regarded as an effective means to improve decision making among stakeholders. LEK studies of taxonomy, population dynamics, ecology, habitat use, threats, and reproduction as well as the assessment of this information for artisanal fisheries are still very scarce in Europe and Brazil. The use of LEK provides important biological information and insight into the attitudes of fishermen towards biodiversity conservation in both MPAs. Other MPAs in mainland Portugal and the Madeira and Azores Autonomic Regions are also potential areas for the administration of LEK studies. Also the social network used for communication of knowledge and information related to natural resources among different professionals and resource extractors operating in a coastal seascape is critical under a scenario of biodiversity loss and climate change impacts.
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Coastal sharks and rays in the Northeastern Atlantic: From an urgent call to collect more data to the declaration of a marine corridor
Article
Full-text available
  • Aug 2022
Globally, elasmobranchs have suffered severe population declines and are, therefore, under an urgent necessity of protection, particularly along the Northeastern Atlantic realm. However, a lack of ecological (e.g., abundance) knowledge across this realm limits the implementation of adequate conservation and management actions. Here, we collected 4,873 fish visual census count data (sightings at 403 sites, from 37 published studies) of sharks, rays, and skates, from coastal areas (< 40 m depth) throughout the Northeastern Atlantic, covering a latitudinal extent of ca. 60° and 9 ecoregions. We recorded a total of 14 elasmobranch species, from a total of 341 sightings, and only 4% of the counts reported any sighting. There is a severe lack of ecological data (e.g. abundance) from most ecoregions, particularly those in the nearshore continental northern Atlantic and tropical ecoregions. Nevertheless, our results showed that species richness and total abundance of elasmobranchs was higher in the eastern Atlantic oceanic archipelagos, such as Azores, Webbnesia (Madeira, Selvagens, and the Canary Islands) and Cabo Verde, compared to the other ecoregions. Our study calls for prioritising conservation efforts in these areas, a stronghold for these vulnerable taxa, in addition to the establishment of systematic monitoring programs. Refining Marine Protected Areas (MPAs), including declaration of local 'Sharks Sanctuaries', along a marine corridor encompassing these archipelagos, seem pertinent in this sense. This proposal is backed by the evident diversity and abundance patterns in nearshore waters, strong social and economic support, and political willingness to align science and marine policy, under international (EU) governance schemes.
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Development, Persistence, and Variability of Upwelling Filaments off the Ariantic Coast of the Iberian Peninsula
Article
Full-text available
  • Dec 1993
The development, persistence, and variability of upwelling filaments off the Atlantic coast of the Iberian Peninsula are examined by means of advanced very high resolution radiometer infrared imagery observed between 1982 and 1990. These observations indicate that the regime is broadly similar to that observed in the California Current system and is closely related to the large scale wind climatology of the subtropical gyre. Upwelling generally starts in late May or early June and persists until late September or early October. In May or June, a narrow band of cold water of quite uniform width is observed along much of the west coast of the Iberian Peninsula. This band has a “fringed” appearance; that is it consists of many narrow “fingers” of cool water extending 20–30 km offshore. The major filament structures generally do not begin to form until late July or August. The filaments appear first as bulges in the upwelling front. These bulges grow offshore to form filaments that reach their maximum length (200–250 km) in September. The lengths of the filaments gradually decrease until the filaments become relatively rare in late October. Typically, five or six fully developed filaments are observed off the Iberian Peninsula late in the upwelling season. Most of these are associated with major topographic features of the region, in particular the large capes which are common to the north and south of the peninsula. It is therefore postulated that the dominant dynamical processes related to filament formation off Iberia is topographic forcing. The exceptions are two major filaments commonly observed along the more regular coastline of northern Portugal. It is hypothesized that these filaments are formed by flow instabilities resulting in meandering of the southward flowing jet. These instabilities may possibly be initiated by the large capes of northern Spain.
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Use of a temperate reef-fish community to identify priorities in the establishment of a Marine Protected Area
Conference Paper
Full-text available
  • Jan 2003
Abstract Few studies have dealt with biodiversity, composition and dynamics of temperate reef fish. The present study,area is a ,25 km ,stretch of coastline ,(53 km,) on the west ,Portuguese ,coast that has recently been assigned as a Marine Park (Marine Park of the Arrábida Nature Park), for which basic information on composition of the marine communities is very scarce. From a biogeographical perspective, mainland Portugal is in a transitional zone where,many,species of cold- and warm-water,fish reach their southern,and northern,limits of distribution respectively. This situation contributes strongly to a high level of biodiversity in the Lusitanian province, and also makes it very sensitive to climatic oscillations such as those predicted as part of global warming. This study ,analysed ,the fish community ,composition ,in the ,marine ,park ,and ,ascribed ,a hierarchical
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An interference visual census technique applied to cryptobenthic fish assemblages
Article
Full-text available
  • Mar 2007
  • VIE MILIEU
We compare the accuracy of an interference visual census technique (IVC), in which dismantling of the habitat is performed, to traditional underwater visual census (VC) and anaesthetic census. We compare the performance of these techniques applied to a temperate cryptobenthic fish assemblage using two strategies: sampling over the whole depth extent of the rocky bottom, and stratified sampling over the main microhabitats present at the study site. The number of species encountered was lower using the traditional VC. Fish density estimates were significantly higher using the interference technique compared to the traditional VC, in the transect strategy. These differences were larger for clingfishes and some gobies which occurred preferably under cobble and small rocks. No differences were found when comparing the IVC and anaesthetic census in the habitat strategy, for each microhabitat considered. We conclude tat dismantling the habitat increases the performance of the visual census technique and is therefore a valuable approach when applied to temperate cryptobenthic fish assemblages.
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Structure of and relationships within and between the littoral, rock- substrate fish communities off four islands in the Canarian Archipelago
Article
Full-text available
  • Apr 1996
A total of 577 visual surveys (each of 5 min in duration and 100 m2 in area) were conducted throughout 1990 and 1991 at 32 locations off four Canary islands (i.e., Alegranza, Fuerteventura, Gran Canaria and Tenerife) with the objects of describing the coastal fish community, comparing the differences in the fish fauna within and between these islands, and determining the biotic and abiotic factors related to the structure of the fish communities. A total of 76 species were recorded; the most common were Abudefduf luridus, Canthigaster rostrata, Chromis limbatus, Sparisoma cretense and Thalassoma pavo (94.28, 86.48, 52.34, 73.31, and 94.10% frequency of occurrence, respectively). The abundance and average size of the commercially important species was greater in those locations where there was less fishing pressure. The stepwise linear regression models were capable of explaining only a low amount of variation in the dependent variables (i.e., number of species, number of individuals, average size and species diversity) of the fish community. The independent variables recorded were date, time of day, depth, slope of the substrate, substrate type, percentage of sand, percentage of algae, algal height, number of sea urchins (Diadema antillarum) and the individual islands. An ANOVA, using the islands only as independent variables, indicated that each island contributed significantly to the variation in the four dependent variables and there were significant differences among the islands. Detrended correspondence analysis (DCA) and a two-way indicator species analysis (TWINSPAN) determined associations between species and environmental attributes of the survey locations. The patterns in the TWINSPAN analysis indicated that localities had faunal resemblances based on the island off which where they were located.
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Multi-scale spatial heterogeneity, habitat structure, and the effect of marine reserves on Western Mediterranean rocky reef fish assemblages
Article
Full-text available
  • Jan 2004
A hierarchical sampling design, spanning five orders of magnitude (from 10s of metres to 100s of kilometres) was created in order to quantify the multi-scale spatial variability of visually censused rocky reef fish assemblages in the western Mediterranean Sea. Specifically, we tested the hypotheses that species abundance and the biomass of reef fish populations is higher within than outside marine reserves, and that a north-to-south geographical gradient of these variables exists. We also explored the relationship between the fish assemblage and habitat structure, as an environmental factor likely to account for an important part of the observed variability. The mixed analyses of variance revealed that total abundance and biomass, species richness and abundance and biomass of several target species reached higher average values within marine reserves. Nevertheless, some non-protected localities (e.g. Aguilas) harboured richer and more abundant fish assemblages than some marine reserves. In addition, regional variation, attributable to differences in local carrying capacity and hydroclimatic conditions, are also shown across the studied area. Moreover, the studied assemblage is patchy at small and/or intermediate spatial scales, considering both assemblage descriptors (total abundance and biomass, species richness), and the abundance and biomass of fish species and spatial categories. Detected patterns were different depending on the species and assemblage variables analysed. Differences in habitat structure account for a significant proportion of total variability of the studied variables, and are likely to be responsible for a large part of the observed differences, especially at small-to-intermediate spatial scales. Other factors—spatial variability in larval distribution, settlement and/or post-settlement survival–are discussed in order to explain the observed differences. We concluded that causes of the observed patchiness of Mediterranean reef fish assemblages are probably multiple. Long-term, multi-scale spatial and temporal monitoring actions, as well as process-oriented manipulative experiments are urgently needed in order to ascertain the relative importance of each factor.
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Characterization of the marine fish assemblage associated with the nearshore hardbottom of Broward County, Florida, USA
Article
  • Jul 2004
Some shallow (90%) of grunts (Haemulidae). After the grunts, the wrasses (Labridae) at about 5%, and damselfish (Pomacentridae) at roughly 2% were the predominant families. It is clear from this study and others that the nearshore hardbottom of Broward County is an important juvenile fish habitat, especially for grunts. However, the nearshore hardbottom does not appear to be obligate habitat for these fishes as fishes associated with this area are, apparently, not unique to the nearshore hardbottom either in species or ontogenic stage.
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The guild approach to categorizing estuarine fish assemblages: A global review
Article
  • Sep 2007
  • FISH FISH
Many studies have recently described and interpreted the community structure and function of fishes inhabiting estuaries and other transitional waters in terms of categories or guilds. The latter describe the main features of the fishes’ biology and the way in which they use an estuary. However, the approach has been developed by different workers in different geographical areas and with differing emphasis such that there is now a need to review the guilds proposed and used worldwide. The previous wide use of the guild approach has involved increasing overlap and/or confusion between different studies, which therefore increases the need for standardization while at the same time providing the opportunity to reconsider the types and their use worldwide. Against a conceptual model of the importance of the main features of fish use in estuaries and other transitional waters, this review further develops the guild approach to community classification of fish communities inhabiting those areas. The approach increases the understanding of the use of estuaries by fishes, their interactions and connectivity with adjacent areas (the open sea, coastal zone and freshwater catchments) and the estuarine resources required by fishes. This paper gives a global perspective on this categorization by presenting new or refined definitions for the categories, lists the synonyms from the literature and illustrates the concepts using examples from geographical areas covering north and central America, north and southern Europe, central and southern Africa, Australia and the Indo-Pacific.
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Initial results of a long-term coral reef monitoring program: Impact of Hurricane Hugo at Buck Island Reef National Monument, St. Croix U.S. Virgin Islands
Article
  • Nov 1993
  • J EXP MAR BIOL ECOL
Fixed position linear transects were established in early 1989 at Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands. On September 17–18 of that year Hurricane Hugo, the most severe cyclone to impact the area in over 60 years, passed directly over the island bringing hurricane-force winds for over 12 h and maximum estimated wind speeds of 70 m · s−1 (160 mph). Despite the severity of the storm, damage to coral reefs was extremely localised and concentrated mainly on reefs open to its southeasterly direction of approach. The southeast reef front at Buck Island was razed to substrate level between the surface and 7 m depth and the reef crest behind it was smothered in a 1 m deep berm of broken coral rubble. At a site on the north backreef, however, only a slight loss of coral cover was detected which was more than compensated for during 1990–1991. At a south reef site which was in 8–10 m depth, just outside the region of severe damage, coral cover was reduced by 40–46% on three out of four transects. Shifts in community structure were detected by multi-dimensional scaling of Bray-Curtis similarity measures and by k-dominance curves, but not by the Shannon diversity statistic (H′). Coral cover had returned to approximate pre-hurricane levels by June 1991, but community composition remained distinct. One of the four transects at this south site was apparently not significantly damaged during the hurricane. Such spatial variability may affect recovery rates, since pockets of relatively undisturbed benthos may provide seed populations for recruitment into adjacent, more severely damaged areas. Hurricane Hugo did not appear to cause an immediate increase in species diversity by differential mortality of the dominant species in the community. This result is consistent with previous studies of the impact of less severe storms on St. Croix, but contrary to several reports of hurricane impact in other areas.
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