Coastal meroplanktonic larval stages of peninsula de Llevant natural reserve determined with light traps

2010·0.8 MB·

by  Tor, Ariadna

Coastal meroplanktonic larval stages of peninsula de
Llevant natural reserve determined with light traps

Ariadna TOR, Salud DEUDERO, Aina CARBONELL, Raquel GOÑI and
Ben STOBART

SHNB Tor, A., Deudero, S., Carbonell, A., Goñi, R. and Stobart, B. 2010. Coastal
meroplanktonic larval stages of peninsula de Llevant natural reserve determined with
light traps. Boll. Soc. Hist. Nat. Balears, 53: 193-202. ISSN 0212-260X. Palma de

Mallorca.

The microscale spatial distribution of coastal zooplankton was studied during the
month of June at the largest marine reserve of Mallorca: Peninsula de Llevant using
light traps. The assemblage was characterized by the most abundant taxa being
peracarida crustaceans, including isopods, cumaceans and amphipods. Decapoda
larvae, especially brachyuran megalopa larvae, were also abundant with Monodaeus

SOCIETAT D’HISTÒRIA couchii, Pinnotheres sp., Ebalia sp. and specimens from Portunidae family as the
NATURAL DE LES BALEARS
most abundant species. Analyses of crustacean abundance between light traps
indicated a vertical distribution on the water column, with lower abundance at surface
traps and higher at bottom traps. No clear horizontal pattern in total crustacean
abundance was found, except in megalopa larvae that showed a gradient in relation to
the distance to coastline. Light traps have been corroborated as a valuable tool for
sampling crustacean larvae and therefore to assess effects of protection on planktonic
stages.
Keywords: larval stages, crustaceans, distribution, light traps, marine protected
areas, Balearic Sea.

DETERMINACIÓ DELS ESTADIS LARVARIS DEL MEROPLANCTON
COSTANER DE LA RESERVA MARINA DE LA PENÍNSULA DE LLEVANT
AMB TRAMPES DE LLUM. Es va estudiar la distribució a micro-escala del
zooplancton costaner de la major reserva marina de Mallorca: la Península de Llevant
mitjançant l’ús de trampes de llum durant el mes de juny de 2009. La comunitat es
caracteritza per una gran abundància de crustacis peracàrids, incloent isòpodes,
cumacis i amfípodes. Les larves de decàpodes, especialment megalopes de braquiürs
van ser abundants, amb Monodaeus couchii, espècies dels gèneres Pinnotheres i
Ebalia, i espècies de la família dels portúnids com les més comunes. L’anàlisi
d’abundància de crustacis en funció de les trampes de llum indica un patró de
distribució vertical, amb abundàncies baixes a trampes superficials i altes a trampes
profundes. No es va tobar un clar patró horitzontal, amb excepció de les larves
megalopa que presentaven un gradient en relació a la distància de la línia de la costa.
Les trampes de llum han demostrat ser una eina valuosa pel mostreig de larves de
crustacis i per tant per avaluar els efectes de la protecció en les etapes planctòniques.
Paraules clau: estadis larvaris, crustacis, distribució, trampes de llum, àrees
marines protegides, mar Balear.

Ariadna TOR, [email protected]; Salud DEUDERO; Aina CARBONELL;
Raquel GOÑI; Centro Oceanográfico de Baleares, Instituto Español de
Oceanografía, moll de ponent s/n, 07015 Palma; Ben STOBART, Port Lincoln
Marine Science Centre, PO BOX 1511, Port Lincoln SA, 5606.

Recepció del manuscrit: 17-des-10; revisió acceptada: 30-des-10
194 Boll. Soc. Hist. Nat. Balears 53 (2010)

Introduction decreasing light intensity, away from light
in response to increasing light intensity and
Marine communities are characterized disperse at constant light intensity (Tranter
by taxa having a wide range of reproductive et al., 1981). Hence, while many larval and
patterns, ranging from species with direct juvenile stages of marine organisms are
development to species with larval stages attracted to light (Deudero, 2002), factors
spending a period of time in the plankton, such as temperature, pressure, salinity and
from days to months, and estimated larval current, can also affect vertical migration
dispersal distances ranging from less than and larval behaviour (Forward, 1990).
1m to up to 4400km (Shanks et al., 2003). Plankton nets have been largely used to
Decapod larvae constitute an important part collect larvae in studies of temporal and
of the coastal zooplankton and play an spatial patterns of crustacean larval
important role on fish larval feeding. They distribution (Abelló et al., 1999; Landeira
undergo several pelagic larval stages, which et al., 2009). Comparative studies of fishes
varies from species to species, a primary using passive collecting methods, as
zoea stages and a megalopa post-larval plankton nets, often underestimate the
stage which is the transition between the abundance of taxa and larval stages with
planktonic larval phase and the benthic strong ability to swim in comparison with
juvenile stage responsible for settlement active aggregation methods, like light traps
(Abelló et al., 1999). Unfortunately, larval (Choat el al., 1993). The traps, originally
stages and larval dispersal distances are designed by Doherty (1987) have been
known for only few species. extensively used and modified to suit in
Several studies on coastal zooplankton different ambients and studies (Meekan et
assemblages’ composition and distribution al., 2001; Hovda et al., 2003). Because
patterns have been conducted in recent light traps have the potential to trap positive
years on the Mediterranean Sea and the phototactic mobile zooplankton they can be
Atlantic Ocean (González-Gordillo et al., considered as a good device for sampling
2003). Balearic Sea has been the centre of marine invertebrates (Granek et al., 2007).
several studies on zooplankton distribution In the present study, we investigated the
(Fernández de Puelles et al., 2003, 2004) at spatial and vertical distribution of the
mesoscale levels, but there is a lack of nearshore meroplanktonic assemblages in
knowledge at small spatial scales. Because the Peninsula de Llevant Marine Natural
of the potential dispersal role of larval Reserve by applying to a passive collection
stages, vertical distribution can be of method of using light traps. Marine
particular importance to meroplanktonic protected areas (MPAs) have become a
larvae of benthic marine invertebrates. popular management tool in the
Most species with a planktonic larval phase Mediterranean Sea for preserving
in their life cycle undergo vertical biodiversity or increasing fisheries yields
migration. The phenomenon has been (Palumbi, 2003). Moreover, the design and
widely studied (Zaret et al., 1976; Hays, size of MPAs play an important role in the
2003). sustainability of protected populations,
In most cases, vertical migration is communities and ecosystems, but it
related to lunar cycles or environmental requires understanding the larval import
changes, such as light cycles, in which and export dynamics in order to improve
plankton move towards light in response to marine protected areas management.
A. Tor et al., Coastal larval stages of Peninsula de Llevant 195

Fig. 1. Location of the sampled stations in Peninsula de Llevant marine reserve, Mallorca, Balearic
Islands.
Fig. 1. Localització de les estacions de mostreig a la reserva marina de la península de Llevant,
Mallorca, Illes Balears.

Methods Field sampling
The field sampling took place from the
Study site 26th to 30th of June 2009. The area was
The fieldwork took place in and around divided into five transects perpendicular to
the MPA of Cala Rajada at Mallorca Island the coast over the 20-40m isobaths.
during summer 2009 (Fig. 1). Samples were collected during the night,
The Cala Rajada MPA is located in the using light traps at three water depths, (2m
northeast coast of Mallorca Island (Balearic from the bottom, mid water and 2m from
Archipelago), comprising a total protected the surface) forming a grid of 15 stations.
area of 11,000ha with varied topography. Light trap design was based on that used in
The western part of the reserve is Granek and Fraiser (2007) (Fig. 2). The
dominated by a uniform and extensive devices were constructed using inverted
meadow of Posidonia oceanica adjoining 20L clear plastic water containers, which
well-structured and preserved coralligenous had a PVC tube attached to the bottle
and maërl bottoms. mouth. This PVC piece was perforated and
By contrast, the substrate in the eastern covered with a mesh of 220µm. The
part is more fragmented, showing a specimens had three entry points made
combination of soft bottoms with scattered through funnel-shaped openings pierced on
patches of Posidonia oceanica, precoral- the bottle sides, leading inwards to a 1cm
ligenous and detritic shore bottoms, along diameter hole. 70 Cyalume Lightsticks ®
with expanses of sand. suspended from the top of each trap inside
the bottle were used as light source.
196 Boll. Soc. Hist. Nat. Balears, 53 (2010)

Vertical distribution was tested using depth
and position of light traps in the water
column, while horizontal distribution was
tested comparing the abundances inside the
non-take area, where fishing and scuba
diving are prohibited and outside the non-
take area, where those activities are
permitted. We also compared the western
part of the marine reserve, characterized by
a flat continental platform and Posidonia
oceanica meadows, including the stations
of Farrutx, Faralló d’Aubarca and Trinquet
des moro; with the eastern part of the
reserve, including stations of Capdepera
and Cap des Freu, characterized by an
abrupt platform and a variety of bottom,
ranging from rocky and sandy bottoms to
Posidonia oceanica meadows. For the
analysis, non-parametric tests were carried
out for two species group, crustacean taxa
as a whole and megalopa brachyura only.
Fig. 2. Light trap design modified from Granek The abundance data for each station were
and Fraiser (2007). log-transformed to reduce the weight of
Fig. 2. Disseny de la trampa de llum modificada dominant taxa and a Bray-Curtis similarity
de Granek i Fraiser (2007).
matrix was created assuming a cut-off at

90%. Subsequently, the similarity ordina-
Samples were stored frozen for ulterior tions resulting from this data were repre-
analysis. In the laboratory, the specimens sented graphically with non-parametric
were sorted, counted and identified using a multidimensional scaling (MDS) plots. In
binocular microscope. When possible all order to test differences between samples,
decapod larvae were identified to the lowest one-way analysis of similarities (ANOSIM)
taxonomic level following the descriptions was performed. In addition, diversity values
and identification keys given by Ingle of specific richness, Shannon index
(2002) and dos Santos & Gonzalez- (Shannon, 1963) and evenness values
Gordillo (2004). The samples showing very (Pielou, 1969) were determined for each
high densities were divided into subsamples marine reserve. All multivariate analyses
using a Motoda Splitting Box (Motoda, were performed using the software package
1959) and a Folsom Plankton splitter; those PRIMER© V6 (Primer-E Ltd, Plymouth,
abundances were then referred to the initial UK).
volume.

Data analysis Results
Several analyses were carried out with
the aim of detecting potential differences in Species composition
vertical and horizontal abundance patterns.
A. Tor et al., Coastal larval stages of Peninsula de Llevant 197
A total of 72855 epibenthic and and Decapoda larvae (14.34%). The
meroplanktonic organisms belonging to 35 remaining 10 taxa together represented the
taxa were captured on the water column in remaining 5.97%. Among the Decapoda
the study area (Table 1); 98’74% from the larvae fraction, brachyuran was the most
total were crustaceans, while the remaining abundant group (66.30%), megalopa larval
1.26% included organisms of ictioplankton, stages represented the 85.52 %, with
Polychaete and Gastropoda. Monodaeus couchii and specimens from the
The most abundant taxa was Isopoda, family Portunidae as the most abundant
mostly from the family Gnathiidae specimens.
(34.94%), followed by Copepoda (16.57%),
Amphipoda (16.04%), Cumacea (12.14%)

Taula 1. Taxonomic composition of organisms caught in Cala Rajada MPA during June 2009.
198 Boll. Soc. Hist. Nat. Balears, 53 (2010)

Table 1. Composició taxonòmica dels organisms presents a Cala Rajada MPA durant el juny de
2009.

Fig. 3. Mean abundance of the main taxa caught on the water column in Cala Rajada’s stations, Cap
des Freu (Upper), Capdepera (Lower). (S: near-surface trap, M: mid-water trap, P: near-bottom trap).
Vertical bars represents standard error; *, represents significant differences (p<0.001).
A. Tor et al., Coastal larval stages of Peninsula de Llevant 199

Fig. 3. Abundància mitja dels principals tàxons capturats en la columna d’aigua en les estacions de
Cala Ratjada, Cap des Freu (Superior), Capdepera (Inferior). (S:prop de la superfície, M: mitja
aigua, P: prop del fons). Les barres verticals representen l’error standard; *, indica diferències
significatives (p<0.001).

Fig. 3. Mean abundance of the main taxa caught on the water column in Cala Rajada’s stations,
Farrutx (Upper), Trinquet des Moro (Middle) and Faralló d’Aubarca (Lower). (S: near-surface trap,
M: mid-water trap, P: near-bottom trap). Vertical bars represents standard error; *, represents
significant differences (p<0.001).
200 Boll. Soc. Hist. Nat. Balears, 53 (2010)

Fig. 3. Abundància mitja dels principals tàxons capturats en la columna d’aigua en les estacions de
Farrutx (superior), Trinquet des Moro (central) and Faralló d’Aubarca (inferior). (S:prop de la
superfície, M: mitja aigua, P: prop del fons). Les barres verticals representen l’error standard; *,
indica diferències significatives (p<0.001).
Diversity values were calculated by Prior to this study, little was known
depths in each station; diversity was about the small-scale spatial distribution of
slightly higher in western stations than in crustacean larval in Western Mediterranean
eastern stations, with an average of 1.62 shallow waters. These data widen the
and 1.46 in the Shannon index. In western knowledge on crustacean distribution,
stations diversity values increased with especially decapods, in the Mediterranean
depth, with the exception of Faralló Sea, and more specifically at the largest
d’Aubarca, where diversity was higher at Mallorcan Marine Reserve, Peninsula de
30m. Eastern stations showed higher Llevant.
diversity values between 20 and 30 m. The higher number of larval decapods
captured is consistent with the spawning
Spatial variability period and larval development, which in the
The analysis of the abundance of crustacean western part of the Mediterranean Sea takes
taxa, revealed a vertical distribution pattern place in spring and early summer for most
with lower values in the near-surface traps of species. Moreover, the higher proportion
and higher values in the near-bottom traps of megalopa larval stages among the bra-
(Fig. 3a-3e). ANOSIM routine revealed that chyura group suggests this marine protected
these differences were significant (Global area could act as a retention zone. This
R=0.391, p=0.001). Brachyuran megalopa reflected the neritic distribution of these
were an exception, with higher abundance larval stages, similarly as it was described
at mid-water traps. No significant in the Catalan coast by Fusté (1989) and
differences were found when comparing the Olivar (1998). The different types, in
abundances between depths, although relation to the vertical distribution, the
higher abundances were found at 40m. higher number of epibenthic crusta-ceans,
Regarding a possible horizontal pattern, including isopods, cumaceans and
bigger abundances were found out of the amphipods captured with light traps
non-take area; moreover, the analysis explains the highest captures at near-bottom
suggested a decreasing gradient with higher traps. Decapoda larvae were an exception,
abundance at stations near the coast and with highest abundances in mid-water traps
lower at further stations, but results were as they undergo nictimeral migrations,
not significant. taking shelter near the bottom by day and
Abundances of the most common taxa entering the water column at a particular
found in the water column are shown in time of the night (Tranter et al., 1981).
Fig. 4. Surface traps showed highest Moreover, the analysis suggested a
abundances of decapods; mid-water of horizontal pattern in relation to the distance
isopods and bottom samples of cumaceans, to coastline in crustaceans but especially in
amphipods and copepods. brachyuran megalopa larval stages as
bigger abundance were found near the
Discussion coastline decreasing as we move inwards;
of bottom found outside the non-take area
and in the eastern stations, which vary from
A. Tor et al., Coastal larval stages of Peninsula de Llevant 201

soft to rocky bottoms and Posidonia mobile phototactic crustaceans, such as
oceanica meadows, could explain the cumaceans, isopods or decapods, but not
highest proportion of captures in these suitable for capturing larval fishes, as cap-
areas.
Light traps used in the present study
have proved a valuable tool for sampling

Fig. 4. Relative abundance of the main taxa caught on the water column.Vertical bars represents
standard error.
Fig. 4. Abundància relativa dels principals tàxons en la columna d’aigua. Les barres verticals
representen l’error estàndard.

of Cala Rajada and Columbretes Islands.
captures did not exceed the 0.05% from the This study was included in project
total. PESCALA, suported by the “Secretaría
This study provides an overview of General del Mar” (SGM).
crustacean larval small-scale distribution,
although further studies are needed. It will
be interesting in the future to continue study References
the larval dynamics, in order to improve the
management of the marine protected areas. Abelló, P. and Guerao, G. 1999. Temporal
variability in the vertical and mesoscale
Acknowledgements spatial distribution of crab megalopae
(Crustacea: Decapoda) in the Northwestern

Mediterranean. Estuarine, coastal and shelf
We would like to thank M. Ceglia, T.
science, 49: 129-139.
Box, C. Rodríguez and D. Díaz for their
Choat, J., Doherty, P., Kerrigan B. and Leis, J.
collaboration with sampling and P. Sarriera
1993. A comparison of towed nets, purse
with sorting. We express our sincere seine and light-aggregation devices for
gratitude to the captain and crew of the ship sampling larvae and pelagic juveniles of
R.V Odón for their cooperation and to the coral reef fishes. Fishery bulletin, 91(2):
staff member of the marine protected areas 195-209.
202 Boll. Soc. Hist. Nat. Balears, 53 (2010)

Clarke, K. and Warwick, R. 2001. Change in in Bocas del Toro, Panama. Bulletin of
marine communities: an approach to marine science, 80(3): 905-914.
statistical analysis and interpretation. 2nd Hays, G. 2003. A review of the adaptative
edition. Plymouth, UK: PRIMER-E, 172pp. significance and ecosystem consequences of
Deudero S. 2002. Unexpected large numbers of zooplankton migration. Hydrobiologia, 503:
Mullus surmuletus juveniles in open waters 163-170.
of the Mediterranean sampled with light Hovda, J.L. and Fosshagen, A. 2003. Hyper-
attraction devices. Journal of Fish Biology, benthic calanoids and Thespesiopsyllus
61(6): 1639-1642. paradoxus (Sars) collected with a light trap
Doherty, P. 1987. Light-traps: selective but in western Norway. Sarsia, 88: 89-94.
useful devices for quantifying the distribu- Ingle, R. 1992. Larval stages of northeastern
tions and abundances of larval fishes. atlantic crabs. An illustrated key. Natural
Bulletin of marine science, 41(2): 423-431. History Museum Publications. 384pp.
Dos Santos, A. and González- Gordillo, J.I. Landeira, J.M., Lozano- Soldevilla, F.,
2004. Illustrated keys for the identification Hernández- León, S. and Burton, ED. 2009.
of the Pleocyemata (Crustacea: Decapoda) Spatial variability of planktonic invertebrate
zoeal stages, from the coastal region of larvae in the Canary Islands area. Journal of
south-western Europa. J. Mar. Biol. Ass. the marine biological association of the
U.K, 84: 203-227. United Kingdom, 90: 1217-1225.
Fernández de Puelles, M.L., Grás, D. and Meekan, M., Wilson SG., Halford, A. and
Hernández-León, S. 2003. Annual cycle of Retzel, A. 2001. A comparison of catches of
zooplankton biomass, abundance and species fishes and invertebrates by two light trap
composition in the neritic area of the design, in tropical NW Australia. Marine
Balearic Sea, West Mediterranean. Marine biology, 139: 373-381.
Ecology, 24(2): 123-139. Olivar, M., Sabates, A., Abelló, P. and Garcia,
Fernández de Puelles, M.L., Valencia, J., Jansá, M. 1998. Transitory hydrographic structures
J. and Morillas, A. 2004. Hydrographical and distribution of fish larvae and neustonic
characteristics and zooplankton distribution crustaceans in the NW Mediterranean.
in the Mallorca channel (Western Oceanologca acta, 21(1): 95-104.
Mediterranean): spring 2001. Journal of Palumbi, S. 2003. Population genetics,
Marine Science, 61: 654-666. demographic connectivity, and the design of
Forward, R. 1990. Behavioural responses of marine reserve. Ecological applications,
crustacean larvae to rates of temperature 13(1): 146-158.
change. Biological bulletin, 178: 195-204. Shanks, A., Grantham, B. and Carr, M. 2003.
Fusté, X. 1989. Distribution of decapod Propagule dispersal distance and the size and
crustacean larvae in the bays of the Ebro spacing of marine reserves. Ecological
Delta. Scientia marina, 53(4): 763-770. applications, 13(1): 159-169.
González- Gordillo, J. and Rodríguez, A. 2003. Tranter, D., Bulleid, N., Campbell, R., Higgins,
Comparative seasonal and spatial H., Rowe, F., Tranter, A. and Smith, D.
distribution of decapods larvae assemblages 1981. Nocturnal movements of Phototactic
in three coastal zones off the south-western Zooplankton in Shallow waters. Marine
Iberian Peninsula. Acta Oecologica, 24: 219- Biology, 61: 317-326.
233. Zaret, T. and Suffern, J. 1976. Vertical migration
Granek, E.F. and Fraser, K. 2007. The impacts in zooplankton as a predator avoidance
of red mangrove (Rhizophora mangles) mechanisms. Limnology and oceanography,
deforestation on z ooplankton communities 21(6): 804- 813.