53 research outputs found
The fish family Muraenidae: an ideal group for testing at small-scale the coherency of Macaronesia as a biogeographic unit, with the first report on separate fishery statistics
: The present study was conceptualized to study the muraenid species (moray eels) occurring around the volcanic archipelagos of the Azores, Madeira, Selvagens, Canary and Cabo Verde islands (eastern-central Atlantic). The biogeographic patterns of these species were analysed and compared. We then hypothesized that this fish family is an ideal group
for testing at small-scale the coherency of Macaronesia and its direct biogeographic units: i.e. the Azores, Webbnesia and
Cabo Verde, as proposed in recent scientific literature. Additionally, this paper provides for the first time separate fishery
statistics for this group in the region that were analysed to contrast the biogeographic results.En prensa1,00
On the presence of Trachinus pellegrini (Trachinidae) in the Canary and Cape Verde Islands (north-eastern Atlantic)
Présence de Trachinus pellegrini (Trachinidae) aux îles Canaries etCanaries et aux îles du Cap-Vert (Atlantique nord-est).
Trachinus pellegrini Cadenat, 1937 est signalée pour la première fois aux îles Canaries, ce qui représente sa limite de répartition la plus septentrionale. Les différences morphologiques entre adultes
et juvéniles sont également présentées. La présence de cette espèce aux îles du Cap-Vert est aussi confirmée.Postprin
New and rare records of teleost fishes from the Cape Verde Islands (eastern-central Atlantic Ocean)
As a result of six exploratory surveys and several opportunistic catches in the Cape Verde Islands from a few metres to about 1000 m of depth, a list of 66 species of teleost fishes is given, six of which are first records from the archipelago: Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) and Lappanella fasciata (Labridae). Additionally, data on six poorly-known species is also given: Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis and Physiculus cyanostrophus (Moridae). Data includes distribution, habitat, morphometry and reproduction.Six campagnes exploratoires ainsi que quelques captures opportunistes réalisées de quelques mètres jusqu’à environ 1000 m de profondeur aux îles du Cap-Vert ont permis d’établir une liste comprenant 66 espèces de poissons téléostéens. Six espèces sont signalées pour la première fois aux îles du Cap-Vert : Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) et Lappanella fasciata (Labridae). La présence de six autres espèces mal connues est confirmée pour cet archipel : Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis et Physiculus cyanostrophus (Moridae). Les données présentées concernent la distribution, l’habitat, la morphométrie et la reproduction.Postprin
The striped soldier shrimp Plesionika edwardsii (Crustacea:Decapoda:Pandalidae) from the cape Verde Islands
This study is part of the PROACTIVA 1-2 (2009-2012) and MARPROF-CV (2010-2014) projects, in the
framework of the Canary Islands Government and UE PCT MAC 2007-2013 programmes respectively.
Research has mainly focused on the stock assessment of the striped soldier shrimp, Plesionika edwardsii
(Brandt, 1851), because it has shown moderate to high levels of fishing yield and abundances compatible
with the development of a new sustainable fishery in the Cape Verde Islands.
Cruises took place on board the R/V Prof. Ignacio Lozano. Four 15-day surveys have been conducted to
date: Cabo Verde 2010-04 (April 2010), Camar˜ao-1 (November 2011), Camar˜ao-2 (Mars 2012) and Camar
˜ao-3 (July 2012). An innovative fishing gear so-called multiple semi-floating shrimp trap (MSFST)
was used. Each fishing line was composed by 40-65 traps operating around 2.4 m above the seafloor,
using Decapterus macarellus (Carangidae) as unique bait of the traps. Fishing depth was 66-458 m, and
efective fishing time was 16-18 h. Each trap was attached to the main bottom line every 15 m, and the
maximum attraction of this bait was established to be 100 or 150 m, according to the experience gained
from the local fishery for deep-sea lobsters. So density by area was calculated assuming two different
areas of attraction of the fishing gear. Initial biomass was estimated from depletion experiments at different
abundance stations by applying the Leslie & Davis (1939) method, modified by Ricker (1975). Each
fishing operation was classified according to its yield (CPUE in g/trap/night). The potential fishing planar
area was estimated between the isobathymetric lines between 90 and 220 m. Total biomasses (Bt) were
calculated from areas (km2) and mean minimum/maximum densities (kg/km2). Maximum sustainable
yield (MSY) was estimated from Bt using the Beddington and Cooke (1983) model by entering natural
mortality (0.6), growth rate (0.53 year�1) and recruitment age (1.32 year), which are the parameters for
this target species published for the Canaries. These parameters estimate a biological exploitation rate
( ) of 0.262. Interpolations were applied to estimate MSY for insular stocks representing lesser than 5%
of the total fishing grounds for this species in the archipelago.
The MSY estimated by depletion were 30.5 tons/year for the stock of S˜ao Vicente, Santa Luzia, Ilheus
and S˜ao Nicolau, 10 tons/year for the stock of Santiago, 138.8 tons/year for the stock of Boa Vista
and Maio, and 5.6 tons/year for the stock of Sal. The small stocks estimated by interpolation were:
4.5 tons/year for the stock of Santo Ant˜ao, 1.3 tons/year for the stock of Fogo, and 1.8 tons/year for
the stock of Brava and Ilheus. In total, 192.5 tons per year was the total MSY for the striped soldier
shrimp around the islands of the Cape Verde archipelago, occupying a total area of 1,918 km2 of new
fishing grounds at between 90 and 220 m of depth. In comparison with the traditional bottom trap
used in the Canary Islands, the innovative fishing gear MSFST were proved to be more selective for
pandalid shrimps, minimizing the gear impact on the seafloor as well as the by-catch by reducing the
discards. Depletion methods are based on the assumption of a closed system, that is with minimum or
zero immigration between neighbouring areas. The straight forward decline of CPUEs obtained during
the depletion experiments seems to confirm that P. edwardsii is a low mobility species, making this
assumption valid at least during short-time periods. Because of the bathymetry profile of these islands,the depth range is from very close (few nautical miles in Santiago) to far away (10-12 n.m. in Boa Vista)
to the coastline.
Fishing effort should be controlled on the basis of quotas, number of fishing vessels and a precautionary
approach in order to ensure that catching is commensurate with sustainable levels of exploitation. MSY
estimates suggest that this new Capeverdean fishery should be carried out by specialized medium-sized
fishing vessels. During the last decades a combination of shrimp trawling and industrial trapping activity
has threatened over-exploitation in the Mediterranean fisheries targeting on P. edwardsii; currently the
shrimp collapse has conducted to the decline of these fisheries. Can the Cape Verde regulatory bodies
and all the stakeholders involved learn the lessons this teaches us about this resource management
By-catch composition of the striped soldier shrimp Plesionika edwardsii (Crustace: Decapoda: Pandalidae) experimental fishery in the Cape Verde Islands
This work focuses on the by-catch composition of Plesionika edwardsii experimental fishery in the Cape
Verde Islands. Obtaining information on abundance, composition and lifecycle of species involved in this
potential fishery is useful, in order to ensure its sustainable development under an ecosystem approach.
The first step towards this goal is the description of catches.
Four 15-day research surveys were conducted on board the R/V Prof. Ignacio Lozano: April 2010 (S˜ao
Vicente and Santa Luzia islands), November 2011 (Santiago island), March 2012 (Boa Vista island,)
and July 2012 (Sal and S˜ao Nicolau islands). The working depths were between 66 and 458 m depth.
A standardized innovative fishing gear was used, so-called multiple semi-floating shrimp traps. Each
fishing line was composed by 40-65 traps operating around 2.4 m above the seafloor, using Decapterus
macarellus (Carangidae) as unique bait of the traps.
Multiple semi-floating shrimp traps is a passive fishing system that allows catch and release sea significant
part of the unwanted catches, as in the case of Chondrichthyes or Anguilliformes, reducing the
fishing impact on non-target species.
The main by-catch was composed of 53 species belonging to three groups including Chondrichthyes
(three families and three species), Crustacea (11 families and 19 species) and Osteichthyes (15 families
and 29 species). Plesionika edwardsii, the target species of this fishery, represented 97.8% of
the catch in terms of abundance and 40.1% in biomass. By-catch represented 59.9% of total catch in
terms of biomass. Osteichthyes (87.5%) were the dominant group and was represented by the following
main families; Sparidae (33.9%), Moridae (32.5%), Muraenidae (32.5%), Scorpaenidae (9.9%) and
Tetraodontidae (9.8%). Chondrichthyes (11.6%) were composed by Centrophoridae (65.3%) and Triakidae
(34.1%). Finally, Crustacea (1.9%) were chiefly composed by Pandalidae (79.1%). However,
different families represented by specific species were found to be dominant around each island. Sparidae
were the dominant family represented by Pagellus acarne (46.2% of total by-catch) at S˜ao Vicente,
and by Dentex macrophthalmus (42.6%) at Boa Vista. Tetraodontidae with Sphoeroides pachygaster
(25.9%) and Sparidae with P. acarne (25.1%) were the co-dominant families in the by-catch around
Santa Luzia. Muraenidae were the dominant family represented by Gymnothorax polygonius (69.4%)
at Sal, and by Muraena helena (63.4%) at S˜ao Nicolau. Finally, Scorpaenidae with Pontinus kuhlii
(22.3%) and Moridae with Physiculus cyanostrophus (22.1%) were the co-dominant families of the bycatch
around Santiago.
Acknowledgements: This study is part of the PROACTIVA 1-2 (2009-2012) and MARPROF-CV
(2010-2014) projects, in the framework of the Canary Islands Government and UE PCT MAC 2007-
2013 programmes respectively
Assessing sea grass meadows condition at “El Río” Special Area of Conservation off “La Graciosa e Islotes del Norte de Lanzarote” Marine Reserve
Cymodosea nodosa meadows, known as ‘sebadales’ or ‘manchones’ at Canary Islands, represent EUNIS
habitat type code A5.5311, called Macaronesian Cymodocea beds. As it’s described at European
Union Habitats Directive (92/43/CEE) Annex 1, sea grass meadows belong to 1110 Sandbanks which
are slightly covered by seawater all the time, within Natura 2000 Network.
Several ‘sebadales’ throughout the archipelago are included in this Network as Special Areas of Conservation.
Cymodosea nodosa is regionally included within the Canary Islands Protected Species List
(Ley 4/2010), as a species ‘of interest to ecosystems of Canary Islands”, is usually found at a narrow
depth range (10 to 20 m of depth) and, on the whole, best structured meadows are settled at sheltered
bays, away from wave and current beating, flimsier at exposed areas. Deeper meadows are also sparser,
being C. nodosa replaced by green algae Caulerpa prolifera and Caulerpa racemosa, although mixed
algae-sea grass meadows are often found at different depths.
The project Assessment of marine flora (‘sebadal’, ma¨erl, ‘mujo’) of ‘La Graciosa e Islotes del Norte
de Lanzarote’ Marine Reserve, funded by ‘Viceconsejer´ıa de Pesca y Aguas de la Consejer´ıa de Agricultura,
Ganader´ıa, Pesca y Aguas’, Canary Islands Government, has had the aim of assessing sea grass
meadows condition and distribution at ‘El R´ıo’ Natura 2000 Network Special Area of Conservation, the
channel between La Graciosa and Lanzarote. ‘LA GRACIOSA 1311’ cruise was performed within the
framework of the project.
First of all previous information on sea grass shallow distribution (up to a depth of 20 m) in the study
area was reviewed. Afterwards, a tugged underwater video camera was used onboard of the Marine
Reserve Surveillance Vessel to update cartographic info performing a grid of sampling stations, covering
previously known distribution limits and verifying current presence/absence data and density.
Furthermore, population parameters were obtained in order to assess ‘sebadal’ condition. Fixed stations
were selected in regards to this process, and methodology applied on them was as follows: five radial
arranged transects were performed, identifying fragmentation (it estimates meadow continuity regarding
observed cover), density (mean value of several shoots number counts with 20 x 20 cm grids placed every
2 m), height (mean value in cm of 10 independent samples by transect) and fish and macroinvertebrate
species richness for each transect.
Graphic picture of sea grass density was made depending on two levels: low density level transects (
10 shoots/grid ( 50 shoots/m2) and medium density level transects ( 10 shoots/grid ( 50 shoots/m2).
Main study result is an estimate for the study region (‘El R´ıo’) and time of year of Cymodocea nodosa
population total distribution cover which comes to 1.640.076 m2, including a higher density ‘sebadal’ of
178.256 m2
New and rare records of teleost fishes from the Cape Verde Islands (eastern-central Atlantic Ocean)
As a result of six exploratory surveys and several opportunistic catches in the Cape Verde Islands from a few metres to about 1000 m of depth, a list of 66 species of teleost fishes is given, six of which are first records from the archipelago: Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) and Lappanella fasciata (Labridae). Additionally, data on six poorly-known species is also given: Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis and Physiculus cyanostrophus (Moridae). Data includes distribution, habitat, morphometry and reproduction.Six campagnes exploratoires ainsi que quelques captures opportunistes réalisées de quelques mètres jusqu’à environ 1000 m de profondeur aux îles du Cap-Vert ont permis d’établir une liste comprenant 66 espèces de poissons téléostéens. Six espèces sont signalées pour la première fois aux îles du Cap-Vert : Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) et Lappanella fasciata (Labridae). La présence de six autres espèces mal connues est confirmée pour cet archipel : Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis et Physiculus cyanostrophus (Moridae). Les données présentées concernent la distribution, l’habitat, la morphométrie et la reproduction.S
Effects of the anthropogenics pressures (marine litter) on the coastal ecosystems of the Marine Reserve “Isla de La Graciosa e islotes del norte de Lanzarote”
The European Marine Strategy Framework Directive (2008/56/EC) considers marine litter as one of its
environmental descriptors, requiring the development and standardization of criteria and methodologies
for its use to test the good environmental status of marine conditions. The assessment of the impact
caused by litter accumulation in the shoreline lacked specific monitoring planning and had not been
systematically performed to date in Canary Islands.
During the project ”Evaluation of the effect of the anthropogenic pressures (marine litter in beaches and
alteration of shallow seabed by boats anchoring) on the coastal ecosystems of the “Marine Reserve of Isla
de La Graciosa e islotes del norte de Lanzarote (MRLG)” developed with the financial help of the Canary
Islands Government (Council of Agriculture, Ranching, Fishing and Waters), two surveys were carried
out, ”LA GRACIOSA 1310” and “LA GRACIOSA 1311”, both developed at MRLG and its vicinities.
The aim has been to depict MRLG shoreline and to locate marine litter accumulation points the most,
contributing with some tools to assess and manage the coastal ecosystems of the marine reserve.
Total shoreline sampled at both surveys together was 38326 m, 1834 m at Alegranza, 1366 m at Monta˜na
Clara, 24656 m at La Graciosa Island, and the rest, 10470 m, at the Lanzarote’s shoreline portion bathed
by MRLG waters. Shoreline sampling was made qualitatively sorting the sampling stations, according
to litter presence and distribution, by means of a upward numerical coding related to the type of waste
or garbage found. Moreover, each station was additionally depicted according to the type of substrate as
well as to the prevailing type of waste, defining what we named “transects”.
To validate methodology to European standards, a more exhaustive experimental sampling was made
in four transects identified as high density or high concentration of marine litter, following guidelines
of a method developed for OSPAR maritime area during the first half of 2000 decade (OSPAR, 2007).
It involves evaluating the possibilities and needs of adjustment of this methodology to the particular
conditions of our region (Gonz´alez, et al., 2013 a and b).
As preliminary results, the spatial distribution of garbage coastal accumulation will be shown in a cartographic
base, expressed as relative abundance by island, according to a 4 degrees scale (no litter, low,
medium and high litter presence) and according to the dominant kind of garbage in each transect. An
example with one of the most densely occupied with trash transects is shown to illustrate a sampling
method without the requirement of trash collection. This method uses a sampling unit of 1x1 m grid,
divided in 10x10 cm subgrids. This grid is set parallel to sampling direction repeatedly. Distance between
grids is determined by a randomizing software. Sampling direction zigzags from sea border to
beach back shore, making 45° degrees angles. Subgrids occupied by trash are counted once the grid is
set. Waste is depict and identified following a guide developed for this purpose by OSPAR in 2010
By-catch composition of the striped soldier shrimp Plesionika edwardsii (Crustace: Decapoda: Pandalidae) experimental fishery in the Cape Verde Islands
This work focuses on the by-catch composition of Plesionika edwardsii experimental fishery in the Cape
Verde Islands. Obtaining information on abundance, composition and lifecycle of species involved in this
potential fishery is useful, in order to ensure its sustainable development under an ecosystem approach.
The first step towards this goal is the description of catches.
Four 15-day research surveys were conducted on board the R/V Prof. Ignacio Lozano: April 2010 (S˜ao
Vicente and Santa Luzia islands), November 2011 (Santiago island), March 2012 (Boa Vista island,)
and July 2012 (Sal and S˜ao Nicolau islands). The working depths were between 66 and 458 m depth.
A standardized innovative fishing gear was used, so-called multiple semi-floating shrimp traps. Each
fishing line was composed by 40-65 traps operating around 2.4 m above the seafloor, using Decapterus
macarellus (Carangidae) as unique bait of the traps.
Multiple semi-floating shrimp traps is a passive fishing system that allows catch and release sea significant
part of the unwanted catches, as in the case of Chondrichthyes or Anguilliformes, reducing the
fishing impact on non-target species.
The main by-catch was composed of 53 species belonging to three groups including Chondrichthyes
(three families and three species), Crustacea (11 families and 19 species) and Osteichthyes (15 families
and 29 species). Plesionika edwardsii, the target species of this fishery, represented 97.8% of
the catch in terms of abundance and 40.1% in biomass. By-catch represented 59.9% of total catch in
terms of biomass. Osteichthyes (87.5%) were the dominant group and was represented by the following
main families; Sparidae (33.9%), Moridae (32.5%), Muraenidae (32.5%), Scorpaenidae (9.9%) and
Tetraodontidae (9.8%). Chondrichthyes (11.6%) were composed by Centrophoridae (65.3%) and Triakidae
(34.1%). Finally, Crustacea (1.9%) were chiefly composed by Pandalidae (79.1%). However,
different families represented by specific species were found to be dominant around each island. Sparidae
were the dominant family represented by Pagellus acarne (46.2% of total by-catch) at S˜ao Vicente,
and by Dentex macrophthalmus (42.6%) at Boa Vista. Tetraodontidae with Sphoeroides pachygaster
(25.9%) and Sparidae with P. acarne (25.1%) were the co-dominant families in the by-catch around
Santa Luzia. Muraenidae were the dominant family represented by Gymnothorax polygonius (69.4%)
at Sal, and by Muraena helena (63.4%) at S˜ao Nicolau. Finally, Scorpaenidae with Pontinus kuhlii
(22.3%) and Moridae with Physiculus cyanostrophus (22.1%) were the co-dominant families of the bycatch
around Santiago.
Acknowledgements: This study is part of the PROACTIVA 1-2 (2009-2012) and MARPROF-CV
(2010-2014) projects, in the framework of the Canary Islands Government and UE PCT MAC 2007-
2013 programmes respectively
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